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Update: Lumbar discectomy

Lumbar discectomy is one of the most common spinal surgery worldwide.

The traditional midline bone-destructive procedures together with approaches requiring extreme muscular retraction are being replaced by muscle sparing, targeted, stability-preserving surgical routes. The increasing speculation on LDHs and the innovative corridors described to treat them have lead to an extensive production of papers frequently treating the same topic but adopting different terminologies and reporting contradictory results.

Through the analysis of papers by Lofrese et al. it was possible to identify ideal surgical corridors for ILDHs, ELDHs, and IELDHs, distinguishing for each approach the exposure provided and the technical advantages/disadvantages in terms of muscle trauma, biomechanical stability, and nerve root preservation. A significant disproportion was noted between studies discussing traditional midline approaches or variants of the posterolateral route and those investigating pros and cons of simple or combined alternative corridors. Although rarely discussed, these latter represent valuable strategies particularly for the challenging IELDHs, thanks to the optimal compromise between herniation exposure and bone-muscle preservation.

The integration of adequate mastery of traditional approaches together with a greater confidence through unfamiliar surgical corridors can improve the development of combined mini-invasive procedures, which seem promising for future targeted LDH excisions. 1).

Indications

Lumbar discectomy is an effective therapy for neurological decompression in patients suffering from lumbar disc herniation, which can be safely performed via minimal invasive procedures 2) 3).

History

In 1908 the first successful lumbar discectomy was initiated and performed by the German neurologist Heinrich Oppenheim (1858-1919) and the surgeon Fedor Krause (1857-1937); however, neither recognized the true pathological condition of discogenic nerve compression syndrome. With the landmark report in The New England Journal of Medicine in 1934, the two American surgeons William Jason Mixter (1880-1958) and Joseph Seaton Barr (1901-1963) finally clarified the pathomechanism of lumbar disc herniation and furthermore, propagated discectomy as the standard therapy. Since then interventions on intervertebral discs rapidly increased and the treatment options for lumbar disc surgery quickly evolved. The surgical procedures changed over time and were continuously being refined.

Microsurgery

The introduction of microsurgical techniques in 1977 and 1978 was introduced for spinal surgery by the work of the famous neurosurgeon Mahmut Gazi Yasargil 4) and Wolfhard Caspar 5) and so-called microdiscectomy was introduced and represented an important evolution in lumbar disc surgery.

see Lumbar microdiscectomy

Chemonucleolysis

Besides open discectomy other interventional techniques were developed to overcome the side effects of surgical procedures.

In 1964 the American orthopedic surgeon Lyman Smith (1912-1991) introduced chemonucleolysis, a minimally invasive technique consisting only of a cannula and the proteolytic enzyme chymopapain, which is injected into the disc compartment to dissolve the displaced disc material.

Percutaneous discectomy

see also percutaneous endoscopic lumbar discectomy.

In 1975 the Japanese orthopedic surgeon Sadahisa Hijikata described percutaneous discectomy for the first time, which was a further minimally invasive surgical technique. Further variants of minimally invasive surgical procedures, such as percutaneous laser discectomy in 1986 and percutaneous endoscopic microdiscectomy in 1997, were also introduced; however, open discectomy, especially microdiscectomy remains the therapeutic gold standard for lumbar disc herniation 6).

Discectomy surgery has evolved from wide open to microscopic and now endoscopic.

Herniotomy

Microsurgery is considered a standard procedure. However, since the herniated fragment was identified as the offending agent, it has always considered necessary to remove fragment only or the entire disc. This dogma is based on the assumption that increased rates of recurrent disc herniations would follow sequestrectomy alone. For the small subgroup of patients with a free fragment compressing the nerve root, Williams was the first to report encouraging results following minimal removal of tissue from the intervertebral disc space 7).

The frequency of herniotomy is gradually increasing in LDH treatment. Herniotomy used to be synonymous with fragmentectomy or sequestrectomy. The term ‘herniotomy’ is defined as removal of the herniated disc fragment only, and the ‘conventional discectomy’ as removal of the herniated disc and degenerative nucleus from the intervertebral disc space.

Minimally invasive discectomy

Minimally invasive discectomy (MID) may be inferior in terms of relief of leg pain, LBP and re-hospitalisation; however, differences in pain relief appeared to be small and may not be clinically important. Potential advantages of MID are lower risk of surgical site and other infections. MID may be associated with shorter hospital stay but the evidence was inconsistent. Given these potential advantages, more research is needed to define appropriate indications for MID as an alternative to standard MD/OD.

In the U.S., it has been estimated that the Medicare system spends over $300 million annually on lumbar discectomies.

Technique


In conjunction with the traditional discectomy, a laminotomy is often involved to permit access to the intervertebral disc. In this procedure, a small piece of bone (the lamina) is removed from the affected vertebra, allowing the surgeon to better see and access the area of disc herniation.

Types

Outcome

More than 10% of these patients report persistent pain after surgery.

Quality of Life (QOL), pain and disability, and psychosocial outcomes improved after primary and revision discectomy, but the improvement diminished after revision discectomy 8).


From 371 abstracts, 85 full-text articles were reviewed, of which 21 studies were included. Visual analogue scales indicated that surgery helped the majority of patients experience significantly less pain. Recovery from disc surgery mainly occurred within the short-term period and later changes of pain intensity were minor. Postsurgical back and leg pain was predominantly associated with depression and disability. Preliminary positive evidence was found for somatization and mental well-being.

Patients scheduled for lumbar disc surgery should be selected carefully and need to be treated in a multimodal setting including psychological support 9).

see Lumbar discectomy in obesity

Reoperation

retrospective study includes 53 patients who underwent reoperation after failure of lumbar disc surgery to relieve pain. All patients had leg painbefore reoperation, which was successful in 28% of cases. Most clinical features, such as persistence or mode of recurrence of pain, radicular quality of pain, positive straight leg raise, and myelographic root sleeve defects, were not helpful in predicting successful and unsuccessful reoperations. However, a significantly larger percentage of women than men had successful reoperations. Patients who had past or pending compensation claims, who had sensory loss involving more than one dermatome, or who failed to have myelographic dural sac indentations resembling those caused by a herniated disc did poorly with reoperation. A very convincing myelographic defect appears to be needed to justify reoperation at a previously unoperated location. Excision of scar alone or dorsal rhizotomy was of no avail in these cases 10).

Rehabilitation

Considerable variation was noted in the content, duration and intensity of the rehabilitation programmes included in this review, and for none of them was high- or moderate-quality evidence identified. Exercise programmes starting four to six weeks postsurgery seem to lead to a faster decrease in pain and disability than no treatment, with small to medium effect sizes, and high-intensity exercise programmes seem to lead to a slightly faster decrease in pain and disability than is seen with low-intensity programmes, but the overall quality of the evidence is only low to very low. No significant differences were noted between supervised and home exercise programmes for pain relief, disability or global perceived effect. None of the trials reported an increase in reoperation rate after first-time lumbar surgery. High-quality randomised controlled trials are strongly needed 11).

Case series

2017

Fifty patients who were scheduled for lumbar disc surgery were divided into 2 groups, namely patients who accepted the surgery at the first offer and those who wanted to think over. Educational level information was obtained and patients were asked whether they had searched their disorder and offered surgery on the Internet. Then, a questionnaire was administered and the reliability of the websites was evaluated. Correction: The first 30 websites on the first 3 pages of Google® search engine, the most commonly used search engine in Turkey, were evaluated with the DISCERN® instrument.

Of 50 patients, 33 (66%) had conducted a search for the surgery on the Internet. All university graduates, 88.2% of high school graduates, and 18.7% of primary-secondary school graduates had conducted an Internet search. The quality and reliability of the information was high (4.5 points) for 2 (7.1%) websites, moderate (2.3 points) for 6 websites (21.4%) and poor (1 point) for 20 websites (71.4%) as scored with the DISCERN® instrument. The mean DISCERN® score of was 1.1 for websites of health-related institutions or healthcare news, 2.75 for personal websites of physicians and 2.5 for personal websites of non-physicians. The mean DISCERN® score of all websites was 1.5.

Most of the patients undergoing lumbar disc surgery at our clinic had searched information about the surgical procedure on the Internet. We found that 92.9% of the websites evaluated with the DISCERN® instrument had inadequate information, suggesting low-level reliability 12).

2016

The full set of prospectively gathered Medicare insurance data (2005-2012) was retrospectively reviewed. Patients who underwent primary lumbar discectomy for lumbar disc herniations from 2009 to quarter 3 of 2012 were selected. This cohort (n = 41,655) was then divided into two subgroups: those who were diagnosed with incidental durotomy on the day of surgery (n = 2,052) and those who were not (control population). To select a more effective control population, patients of a similar age, gender, smoking status, diabetes mellitus status, chronic pulmonary disease status, and body-mass-index were chosen at random from the control population to create a control cohort. In-hospital costs, length of stay, and rates of 30-day readmission, 90-day wound complications, and 90-day serious adverse effects were compared.

An incidental durotomy rate of 4.9% was observed. Higher rates of wound infection (2.4 vs 1.3%; OR 1.88; 95% CI: 1.31 – 2.70; p < 0.001), wound dehiscence (0.9 vs 0.4%; OR 2.39; 95% CI: 1.31 – 4.37; p = 0.004), and serious adverse events related to incidental durotomy (0.9 vs 0.2%; OR 4.10; 95% CI: 2.05 – 8.19; p < 0.0001) were observed in incidental durotomy patients. In-hospital costs were increased by over $4,000 in patients with incidental durotomy (p < 0.0001).

Incidental durotomies occur in almost one in every twenty elderly patients treated with primary lumbar discectomy. Given the increased hospital costs and complication rates, this complication must be viewed as anything but benign 13).


127 patients (of 148 total) with data collected 3 months postoperatively. The patients’ average age at the time of surgery was 46 ± 1 years, and 66.9% of patients were working 3 months postoperatively. Statistical analyses demonstrated that the patients more likely to return to work were those of younger age (44.5 years vs 50.5 years, p = 0.008), males (55.3% vs 28.6%, p = 0.005), those with higher preoperative SF-36 physical function scores (44.0 vs 30.3, p = 0.002), those with lower preoperative ODI scores (43.8 vs 52.6, p = 0.01), nonsmokers (83.5% vs 66.7%, p = 0.03), and those who were working preoperatively (91.8% vs 26.2%, p < 0.0001). When controlling for patients who were working preoperatively (105 patients), only age was a statistically significant predictor of postoperative return to work (44.1 years vs 51.1 years, p = 0.049).

In this cohort of lumbar discectomy patients, preoperative working status was the strongest predictor of postoperative working status 3 months after surgery. Younger age was also a predictor. Factors not influencing return to work in the logistic regression analysis included sex, BMI, SF-36 physical function score, ODI score, presence of diabetes, smoking status, and systemic illness. Clinical trial registration no.: 01220921 ( clinicaltrials.gov ) 14).

1)

Lofrese G, Mongardi L, Cultrera F, Trapella G, De Bonis P. Surgical treatment of intraforaminal/extraforaminal lumbar disc herniations: Many approaches for few surgical routes. Acta Neurochir (Wien). 2017 Jul;159(7):1273-1281. doi: 10.1007/s00701-017-3198-9. Epub 2017 May 22. Review. PubMed PMID: 28534073.

2)

Hansson E, Hansson T. The cost-utility of lumbar disc herniation surgery. Eur Spine J. 2007;16(3):329–337.

3)

Yeung AT, Yeung CA. Minimally invasive techniques for the management of lumbar disc herniation. Orthop Clin North Am. 2007;38(3):363–372.

4)

Yasargil M. Lumbar Disc Adult Hydrocephalus. Springer; 1977. Microsurgical operation of herniated lumbar disc; p.

5)

Caspar W, Campbell B, Barbier DD, Kretschmmer R, Gotfried Y. The Caspar microsurgical discectomy and comparison with a conventional standard lumbar disc procedure. Neurosurgery. 1991;28:78–86. discussion 86-87.

6)

Gruber P, Böni T. [Sciatica : From stretch rack to microdiscectomy]. Unfallchirurg. 2015 Nov 16. [Epub ahead of print] German. PubMed PMID: 26573291.

7)

Williams RW. Microlumbar discectomy: a conservative surgical approach to the virgin herniated lumbar disc. Spine (Phila Pa 1976) 1978;3:175–182.

8)

Lubelski D, Senol N, Silverstein MP, Alvin MD, Benzel EC, Mroz TE, Schlenk R. Quality of life outcomes after revision lumbar discectomy. J Neurosurg Spine. 2015 Feb;22(2):173-8. doi: 10.3171/2014.10.SPINE14359. Epub 2014 Dec 5. PubMed PMID: 25478822.

9)

Dorow M, Löbner M, Stein J, Konnopka A, Meisel HJ, Günther L, Meixensberger J, Stengler K, König HH, Riedel-Heller SG. Risk Factors for Postoperative Pain Intensity in Patients Undergoing Lumbar Disc Surgery: A Systematic Review. PLoS One. 2017 Jan 20;12(1):e0170303. doi: 10.1371/journal.pone.0170303. PubMed PMID: 28107402.

10)

Law JD, Lehman RA, Kirsch WM. Reoperation after lumbar intervertebral disc surgery. J Neurosurg. 1978 Feb;48(2):259-63. PubMed PMID: 146731.

11)

Oosterhuis T, Costa LO, Maher CG, de Vet HC, van Tulder MW, Ostelo RW. Rehabilitation after lumbar disc surgery. Cochrane Database Syst Rev. 2014 Mar 14;3:CD003007. doi: 10.1002/14651858.CD003007.pub3. Review. PubMed PMID: 24627325.

12)

Atci IB, Yilmaz H, Kocaman U, Samanci MY. An evaluation of internet use by neurosurgery patients prior to lumbar disc surgery and of information available on internet. Clin Neurol Neurosurg. 2017 Apr 25;158:56-59. doi: 10.1016/j.clineuro.2017.04.019. [Epub ahead of print] PubMed PMID: 28460344.

13)

Puvanesarajah V, Hassanzadeh H. The True Cost of a Dural Tear: Medical and Economic Ramifications of Incidental Durotomy During Lumbar Discectomy in Elderly Medicare Beneficiaries. Spine (Phila Pa 1976). 2016 Aug 31. [Epub ahead of print] PubMed PMID: 27584677.

14)

Than KD, Curran JN, Resnick DK, Shaffrey CI, Ghogawala Z, Mummaneni PV. How to predict return to work after lumbar discectomy: answers from the NeuroPoint-SD registry. J Neurosurg Spine. 2016 Mar 18:1-6. [Epub ahead of print] PubMed PMID: 26989977.

Update: Dural ectasia

Dural ectasia is widening or ballooning of the dural sac surrounding the spinal cord. This usually occurs in the lumbosacral region, as this is where the cerebrospinal fluid pressure is greatest, but the spinal canal can be affected in any plane.

Case courtesy of Dr Franco Ruales, Radiopaedia.org. From the case rID: 16114

Most common symptoms include low back painheadaches, weaknessnumbness above and below the involved limb, leg pain, and sometimes there can be rectal and genital pain. Bowel and bladder dysfunction, urinary retention or even incontinence may occur.

The symptoms are usually exacerbated by upright posture and often but not always relieved by lying down. However, in many patients it is asymptomatic.

It is common in Marfan syndrome, occurring in 63–92% of people with the syndrome. Dural ectasia may also occur in Ehlers-Danlos Syndrome, neurofibromatosis type I, ankylosing spondylitis, and trauma.

A “classic” picture of dural ectasia in the Marfan patient may consist of low back pain, headache, proximal leg pain, weakness and numbness above and below the knee, and genital/rectal pain. Symptoms, when present, are typically moderate to severe, occur several times per week (often daily), are commonly exacerbated by upright posture, and are not always relieved by recumbency 1).

Radiographic features

Dural ectasia is dilation of the dural sac. Anteroposterior diameter of the thecal sac at the S1 level greater than that of the thecal sac at the L4 level ref required.

Plain radiograph

Posterior vertebral scalloping may be an indirect indicator 2) 3). However, this is not specific, as it is seen in a significant percentage of the normal population and is also associated with several other conditions.

MRI

Increase in the AP diameter of the dural sac, usually in the lumbar region.

Differential diagnosis

Pathology

Among 1519 patients with spinal space-occupying lesions, 66 patients demonstrated spinal dura mater pathologies. Neuroradiological and surgical features were reviewed and clinical data analyzed.

Saccular dural diverticula (type I, n = 28) caused by defects of both dural layers, dissections between dural layers (type II, n = 29) due to defects of the inner layer, and dural ectasias (type III, n = 9) related to structural changes of the dura were distinguished. For all types, symptoms consisted of local pain followed by signs of radiculopathy or myelopathy, while one patient with dural ectasia presented a low-pressure syndrome and 10 patients with dural dissections additional spinal cord herniation. Type I and type II pathologies required occlusion of their dural defects via extradural (type I) or intradural (type II) approaches. For type III pathologies of the dural sac no surgery was recommended. Favorable results were obtained in all 14 patients with type I and 13 of 15 patients with type II pathologies undergoing surgery.

The majority of dural pathologies involving nerve root sleeves remain asymptomatic, while those of the dural sac commonly lead to pain and neurological symptoms. Saccular dural diverticula (type I) and dissections between dural layers (type II) pathologies were treated with good long-term results occluding their dural defects, while dural ectasias (type III) were managed conservatively 4).

Complications

Dural ectasia is one of the likely causes of incomplete or failed spinal anaesthesia. Its association with diseases like Marfans syndrome, neurofibromatosis, osteogenesis imperfecta, vertebral fracture, postopertative adhesions, trauma etc., is often overlooked as a reason for inadequate spinal anaesthesia. Greater than normal volume of cerebrospinal fluid in the lumber theca in dural ectasia is postulated to restrict the spread of intrathecally injected Local anaesthetic 5).

1)

Foran JR, Pyeritz RE, Dietz HC, Sponseller PD. Characterization of the symptoms associated with dural ectasia in the Marfan patient. Am J Med Genet A. 2005 Apr 1;134A(1):58-65. PubMed PMID: 15690402.
2)

Habermann CR, Weiss F, Schoder V et-al. MR evaluation of dural ectasia in Marfan syndrome: reassessment of the established criteria in children, adolescents, and young adults. Radiology. 2005;234 (2): 535-41. doi:10.1148/radiol.2342031497
3)

Wakely SL. The posterior vertebral scalloping sign. Radiology. 2006;239 (2): 607-9. doi:10.1148/radiol.2392040224
4)

Klekamp J. A New Classification for Pathologies of Spinal Meninges, Part 1: Dural Cysts, Dissections, and Ectasias. Neurosurgery. 2017 Mar 17. doi: 10.1093/neuros/nyx049. [Epub ahead of print] PubMed PMID: 28327939.
5)

Gupta N, Gupta V, Kumar A, Kumar G. Dural ectasia. Indian Journal of Anaesthesia. 2014;58(2):199-201. doi:10.4103/0019-5049.130829.

Update: GH secreting pituitary adenoma

Growth hormone-secreting functioning pituitary adenoma (GHPA) is a rare, chronic, systemic disease that is associated with premature death and significant morbidity 1).

75 % are > 10 mm at time of diagnosis.

Epidemiology

An increased rate of acromegaly was reported in industrialized areas, suggesting an involvement of environmental pollutants in the pathogenesis and behavior of GH secreting pituitary adenoma2).

Etiology

The aim of a study was to evaluate the effects of some widely diffused pollutants (i.e. benzene, BZ; bis(2-ethylhexyl) phthalate, DEHP and polychlorinated biphenyls, PCB) on growth hormone secretion, the somatostatin and estrogenic pathways, viability and proliferation of rat GH-producing pituitary adenoma (GH3) cells. All the pollutants induced a statistically significant increase in GH secretion and interfered with cell signaling. They all modulated the expression of SSTR2 and ZAC1, involved in the somatostatin signaling, and the expression of the transcription factor FOXA1, involved in the estrogen receptor signaling. Moreover, all the pollutants increased the expression of the CYP1A1, suggesting AHR pathway activation. None of the pollutants impacted on cell proliferation or viability. Present data demonstrate that exposure to different pollutants, used at in vivo relevant concentrations, plays an important role in the behavior of GH3 pituitary adenoma cells, by increasing GH secretion and modulating several cellular signaling pathways. These observations support a possible influence of different pollutants in vivo on the GH-adenoma aggressiveness and biological behavior 3).

Types

Giant GH-secreting adenomas are invasive, uncontrolled by surgery, and respond poorly to medical treatment. Aggressive multimodal therapy is critical for their management, enhancing control rate and biochemical remission 4).


Co-secretion of growth hormone (GH) and prolactin (PRL) from a single pituitary adenoma is common. In fact, up to 25% of patients with acromegaly may have PRL co-secretion. The prevalence of acromegaly among patients with a newly diagnosed prolactinoma is unknown. Given the possibility of mixed GH and PRL co-secretion, the current recommendation is to obtain an insulin-like growth factor-1 (IGF-1) in patients with prolactinoma at the initial diagnosis. Long-term follow-up of IGF-1 is not routinely done 5).

Clinical Features

Excessive growth hormone (GH) is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults.

Diagnosis

It is related to high levels of growth hormone (GH) and insulin-like growth factor-I (IGF-1).

MRI

The enhancement was significantly lower in GH secreting pituitary adenoma than in non-secreting ones. 6).

T2 weighted image differentiates GH secreting pituitary adenomas into subgroups with particular behaviors. This raises the question of whether T2-weighted signal could represent a factor in the classification of acromegaly in future studies 7).

In patients with acromegalyT2 weighted image signal intensity at diagnosis correlates with histological features and predicts biochemical outcome of first-line somatostatin analogues (SA) treatment 8).

Biomarkers

Each of the biomarkers, Ki-67 and p53, along with patient’s age and mixed GH-prolactin secretion showed a kind of correlation with each of aspects of the clinical, hormonal and radiologic outcome of GH-secreting pituitary adenomas 9).

Treatment

see Growth hormone secreting pituitary adenoma treatment

Surgery is the first-line therapy.

Surgery

The resection via a transsphenoidal approach is able to induce a long-term remission of acromegaly, with low risk of recurrence and complications. Endoscopic endonasal transsphenoidal approach is more suitable than microscopic technique in macroadenomas and adenomas with suprasellar extension 10).

Medical therapy

The cost of treatment including medications and the possibility of major side effects represent important limitations of the medical therapy 11) 12).

The most widely used criteria for neurosurgical outcome assessment were combined measurements of IGF-1 and GH levels after oral glucose tolerance test (OGTT) 3 months after surgery. Ninety-eight percent of respondents stated that primary treatment with somatostatin receptor ligands (SRLs) was indicated at least sometime during the management of acromegaly patients. In nearly all centers (96%), the use of pegvisomant monotherapy was restricted to patients who had failed to achieve biochemical control with SRL therapy. The observation that most centers followed consensus statement recommendations encourages the future utility of these workshops aimed to create uniform management standards for acromegaly 13)

Current pharmacotherapy includes somatostatin analogs (SAs) and GH receptor antagonist; the former consists of lanreotide Autogel (ATG) and octreotide long-acting release (LAR), and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 4-6 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated with presurgical SA may be achieved, although controversy of such adjuvant therapy exists. Combination of SA and pegvisomant or cabergoline shows advantages in some specific cases. Thus, an individual treatment program should be established for each patient under a full evaluation of the risks and benefits 14).

Somatostatin treatment can induce extensive fibrosis in GH secreting pituitary adenoma 15).

Outcome

The standardised mortality index (the ratio of observed mortality in the acromegalic population to expected mortality in the general population) ranged from 1.2 to 3.3. If left untreated, patients with acromegaly can die approximately 10 years earlier than the healthy subjects. According to prior studies, approximately 60, 25 and 15% of the patients die from cardiovascular disease, respiratory complications and cancer, respectively 16)17).

Control of serum GH and insulin-like growth factor (IGF) 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity.

Remission rates for micro- and macroadenomas were 81.8% and 45.8%, respectively. Patients of older age, with a smaller tumor, lower Knosp grade, lower preoperative GH, and insulinlike growth factor 1 levels were more likely to achieve remission. Remission rate decreased significantly with repeat surgeries. Those patients with adenomas that stained positive for somatostatin receptor subtype 2A were less likely to experience tumor recurrence and more likely to respond to medical treatment with persistent or elevated GH hypersecretion 18).

A retrospective review of 53 patients who had follow up endocrinologic data at least 3 months post-surgery was performed among patients who were treated by EEA between 1998 and 2012. Data were analyzed for remission using GH and IGF-I levels based on 2010 consensus criteria. We also analyzed the outcomes using 2000 consensus criteria for ease in comparison to prior studies of outcomes of surgery for acromegaly. In this series of mostly large (88.2% macroadenomas), invasive (46.9% Hardy-Wilson C, D, E) adenomas, there were 27 patients (50.9%) who achieved remission after EEA only. For patients who had no remission with EEA alone, RS and/or medical therapy were used and 37 patients (69.8 %) achieved remission overall. Statistical analysis showed larger tumor size, Hardy Stages C, D, E and Knosp Scores 3, 4 to be predictive against remission for EEA only and EEA with other modalities. The volume of residual tumor after EEA was not found to be predictive of remission with additional therapies. We used stringent consensus criteria from 2010 in a series which included a high proportion of invasive GH secreting adenomas to show that EEA alone or combined with other modalities results in comparable remission rates to earlier studies which used less strict criteria, while retaining low complication rates 19).

Each of the biomarkers, Ki-67 and p53, along with patient’s age and mixed GH-prolactin secretion showed a kind of correlation with each of aspects of the clinical, hormonal and radiologic outcome of GH-secreting pituitary adenomas in the series of Alimohamadi et al. 20).

Case reports

2015

A 37-year-old woman has presented with complaints of headacheamenorrhea and acromegaly.

Her laboratory studies showed markedly elevated levels of Insulin like Growth Factor 1 (IGF-1), and low levels of follicle stimulating hormone and luteinizing hormone. Computerized tomography has revealed a pituitary tumor without extra-sellar extension. The tumor has completely excised via Endoscopic transsphenoidal approach. Histologically, the tumor has diagnosed as a pituitary adenoma with GH positive cells. The serum IGF1 levels have gradually decreased to the normal range and the patient was symptom free for three and a half years when she has returned with complaint of visual impairment. The brain MRI that time has shown a supra-sellar mass growing independently into the remaining sellar part. Subsequently, surgical operation has performed via trans-nasal endoscopic approach. Histopathological and immunohistochemistry examination have revealed a rare case of growth hormone producing pituitary adenoma with brain invasion and lymphocytic infiltration.

The aim of this publication was to present a rare case of growth hormone producing pituitary adenoma with brain invasion and lymphocytic infiltration 21).

1)

Ayuk J, Clayton RN, Holder G, Sheppard MC, Stewart PM, Bates AS. Growth hormone and pituitary radiotherapy, but not serum insulin-like growth factor-I concentrations, predict excess mortality in patients with acromegaly. J Clin Endocrinol Metab. 2004;89:1613–7.
2) , 3)

Fortunati N, Guaraldi F, Zunino V, Penner F, D’Angelo V, Zenga F, Pecori Giraldi F, Catalano MG, Arvat E. Effects of environmental pollutants on signaling pathways in rat pituitary GH3 adenoma cells. Environ Res. 2017 Jul 18;158:660-668. doi: 10.1016/j.envres.2017.07.015. [Epub ahead of print] PubMed PMID: 28732322.
4)

Shimon I, Jallad RS, Fleseriu M, Yedinak CG, Greenman Y, Bronstein MD. Giant GH-secreting pituitary adenomas: management of rare and aggressive pituitary tumors. Eur J Endocrinol. 2015 Jun;172(6):707-713. Epub 2015 Mar 19. PubMed PMID: 25792375.
5)

Manuylova E, Calvi LM, Hastings C, Vates GE, Johnson MD, Cave WT Jr, Shafiq I. Late presentation of acromegaly in medically controlled prolactinoma patients. Endocrinol Diabetes Metab Case Rep. 2016;2016. pii: 16-0069. PubMed PMID: 27855229.
6)

Lundin P, Bergström K. Gd-DTPA-enhanced MR imaging of pituitary macroadenomas. Acta Radiol. 1992 Jul;33(4):323-32. PubMed PMID: 1633042.
7)

Potorac I, Petrossians P, Daly AF, Schillo F, Ben Slama C, Nagi S, Sahnoun Fathallah M, Brue T, Girard N, Chanson P, Nasser G, Caron P, Bonneville F, Ravérot G, Lapras V, Cotton F, Delemer B, Higel B, Boulin A, Gaillard S, Luca F, Goichot B, Dietemann J, Beckers A, Bonneville J. Pituitary MRI characteristics in 297 acromegaly patients based on T2-weighted sequences. Endocr Relat Cancer. 2015 Jan 2. pii: ERC-14-0305. [Epub ahead of print] PubMed PMID: 25556181.
8)

Heck A, Ringstad G, Fougner SL, Casar-Borota O, Nome T, Ramm-Pettersen J, Bollerslev J. Intensity of pituitary adenoma on T2-weighted magnetic resonance imaging predicts the response to octreotide treatment in newly diagnosed acromegaly. Clin Endocrinol (Oxf). 2012 Jul;77(1):72-8. doi: 10.1111/j.1365-2265.2011.04286.x. PubMed PMID: 22066905.
9)

Alimohamadi M, Ownagh V, Mahouzi L, Ostovar A, Abbassioun K, Amirjmshidi A. The impact of immunohistochemical markers of Ki-67 and p53 on the long-term outcome of growth hormone-secreting pituitary adenomas: A cohort study. Asian J Neurosurg. 2014 Jul-Sep;9(3):130-6. doi: 10.4103/1793-5482.142732. PubMed PMID: 25685203; PubMed Central PMCID: PMC4323896.
10)

Lenzi J, Lapadula G, D’amico T, Delfinis CP, Iuorio R, Caporlingua F, Mecca N, Mercuri V, Bassotti G, Rillo M, Santoro F, Tamburrano G, Santoro A, Gargiulo P. Evaluation of trans-sphenoidal surgery in pituitary GH-secreting micro- and macroadenomas: a comparison between microsurgical and endoscopic approach. J Neurosurg Sci. 2015 Mar;59(1):11-8. PubMed PMID: 25658052.
11) , 16)

Chanson P, Salenave S, Kamenicky P, Cazabat L, Young J. Pituitary tumours: Acromegaly. Best Pract Res Clin Endocrinol Metab. 2009;23:555–74.
12)

Gondim JA, Ferraz T, Mota I, Studart D, Almeida JP, Gomes E, et al. Outcome of surgical intrasellar growth hormone tumor performed by a pituitary specialist surgeon in a developing country. Surg Neurol. 2009;72:15–9.
13)

Giustina A, Bronstein MD, Casanueva FF, Chanson P, Ghigo E, Ho KK, Klibanski A, Lamberts S, Trainer P, Melmed S. Current management practices for acromegaly: an international survey. Pituitary. 2011 Jun;14(2):125-33. doi: 10.1007/s11102-010-0269-9. PubMed PMID: 21063787.
14)

Wang JW, Li Y, Mao ZG, Hu B, Jiang XB, Song BB, Wang X, Zhu YH, Wang HJ. Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas. Patient Prefer Adherence. 2014 Jan 6;8:43-51. Review. PubMed PMID: 24421637.
15)

Kerschbaumer J, Pinggera D, Moser P, Hofmann A, Thomé C, Freyschlag CF. Somatostatin treatment can induce extensive fibrosis in growth hormone-producing adenoma. Acta Neurochir (Wien). 2016 Mar;158(3):441-3. doi: 10.1007/s00701-016-2714-7. Epub 2016 Jan 23. PubMed PMID: 26801514.
17)

Holdaway IM, Rajasoorya C. Epidemiology of acromegaly. Pituitary. 1999;2:29–41.
18)

Sun H, Brzana J, Yedinak CG, Gultekin SH, Delashaw JB, Fleseriu M. Factors associated with biochemical remission after microscopic transsphenoidal surgery for acromegaly. J Neurol Surg B Skull Base. 2014 Feb;75(1):47-52. doi: 10.1055/s-0033-1354578. Epub 2013 Sep 9. PubMed PMID: 24498589; PubMed Central PMCID: PMC3912146.
19)

Shin SS, Tormenti MJ, Paluzzi A, Rothfus WE, Chang YF, Zainah H, Fernandez-Miranda JC, Snyderman CH, Challinor SM, Gardner PA. Endoscopic endonasal approach for growth hormone secreting pituitary adenomas: outcomes in 53 patients using 2010 consensus criteria for remission. Pituitary. 2013 Dec;16(4):435-44. doi: 10.1007/s11102-012-0440-6. PubMed PMID: 23179961.
20)

Alimohamadi M, Ownagh V, Mahouzi L, Ostovar A, Abbassioun K, Amirjmshidi A. The impact of immunohistochemical markers of Ki-67 and p53 on the long-term outcome of growth hormone-secreting pituitary adenomas: A cohort study. Asian J Neurosurg. 2014 Jul-Sep;9(3):130-6. doi: 10.4103/1793-5482.142732. PubMed PMID: 25685203; PubMed Central PMCID: PMC4323896.
21)

Bidari-Zerehpoosh F, Sharifi G, Novin K, Mortazavi N. Invasive Growth Hormone Producing Pituitary Adenoma With Lymphocytic Infiltration: A Case Report and Literature Review. Iran J Cancer Prev. 2015 Dec;8(6):e3504. Epub 2015 Dec 23. PubMed PMID: 26855718.

Update: Subtemporal approach

It is one of the surgical routes used to reach the interpeduncular fossa, offers a good access to the medial temporal region.

The subtemporal approach avoids neocortical transgression and injury to the optic radiations. 1) 2)

Indications

The subtemporal approach is historically known as the standard approach for the treatment of tumoral, vascular and inflammatory lesions of the middle cranial fossa, the tentorium, the anterior and middle tentorial incisura, the upper-third of the clivus and the petroclival region. This approach had been recognized universally for many years as the best way to treat basilar artery (BA) apex, P1 and P2 posterior cerebral artery (PCA) and superior cerebellar artery aneurysms until the introduction of the pterional approach in 1976 by Yasargil et al. 3).

Drawbacks

Access to the posteromedial temporal region needs the retraction of the temporal lobe 4) , with a risk of vein of Labbé sacrifice.

Because of the inclination of the tentorium, temporal lobe retraction increases with a more posterior location of the lesion 5).

A more posterior-oriented supratentorial-infra- occipital variation of the subtemporal approach has been described, which is performed to effectively approach and resect epileptogenic lesions in PMT regions 6) 7).

Keyhole subtemporal approaches and zygomatic arch osteotomy have been proposed in an effort to decrease the amount of temporal lobe retraction.

A keyhole and a classic subtemporal craniotomy were executed in 4 fresh-frozen silicone-injected cadaver heads. The target was defined as the area bordered by the superior cerebellar artery, the anterior clinoid process, supraclinoid internal carotid artery, and the posterior cerebral artery. Once the target was fully visualized, Ercan et al. evaluated the amount of temporal lobe retraction by measuring the distance between the base of the middle fossa and the temporal lobe. In addition, the volume of the surgical and anatomical corridors was assessed as well as the surgical maneuverability using navigation and 3D moldings. The same evaluation was conducted after a zygomatic osteotomy was added to the two approaches.

Temporal lobe retraction was the same in the two approaches evaluated while the surgical corridor and the maneuverability were all greater in the classic subtemporal approach.

The zygomatic arch osteotomy facilitates the maneuverability and the surgical volume in both approaches, but the temporal lobe retraction benefit is confined to the lateral part of the middle fossa skull base and does not result in the retraction necessary to expose the selected target 8).


With the help of an endoscope, Sun et al exposed the internal auditory canal and cerebellopontine through a translabyrinthine approach and the inferior colliculus through a keyhole subtemporal approach. This double approach can be combined to expose the internal auditory canal and cerebellopontine angle and inferior colliculus satisfactorily in the same surgical setting. This combined approach can avoid retraction of the cerebellum and reduce serious adverse events and complications 9).

As a minimally invasive approach, this can be considered an effective method for removal of vestibular schwannoma and auditory midbrain implantation in the same surgical setting, while avoiding retraction of the cerebellum and serious adverse events and complications.

see Subtemporal medial transpetrous approach.

see Subtemporal transtentorial approach.

Subtemporal Approach for AICA Aneurysm Clipping

The subtemporal approach represents a feasible approach for retrochiasmatic craniopharyngiomas when gross total resection is not mandatory. It provides rapid access to the tumor and a caudal-to-cranial visualization that promotes minimal manipulation of critical neurovascular structures, particularly the optic apparatus 10).

Subtemporal approach for distal basilar occlusion for giant aneurysm

1) , 7)

Smith KA, Spetzler RF: Supratentorial-infraoccipital approach for posteromedial temporal lobe lesions. J Neurosurg 82:940–944, 1995
2)

Tubbs RS, Oakes WJ: Relationships of the cisternal segment of the trochlear nerve. J Neurosurg 89:1015–1019, 1998
3)

Yasargil MG, Antic J, Laciga R, Jain KK, Hodosh RM, Smith RD. Microsurgical pterional approach to aneurysms of the basilar bifurcation. Surg Neurol. 1976 Aug;6(2):83-91. PubMed PMID: 951657.
4)

Olivier A: Temporal resections in the surgical treatment of epilepsy. Epilepsy Res Suppl 5:175–188, 1992
5)

Campero A, Tróccoli G, Martins C, Fernandez-Miranda JC, Yasuda A, Rhoton AL Jr: Microsurgical approaches to the medial temporal region: an anatomical study. Neurosurgery 59 (4 Suppl 2):ONS279–ONS308, 2006
6)

Russell SM, Kelly PJ: Volumetric stereotaxy and the supra- tentorial occipitosubtemporal approach in the resection of posterior hippocampus and parahippocampal gyrus lesions. Neurosurgery 50:978–988, 2002
8)

Ercan S, Scerrati A, Wu P, Zhang J, Ammirati M. Is less always better? Keyhole and standard subtemporal approaches: evaluation of temporal lobe retraction and surgical volume with and without zygomatic osteotomy in a cadaveric model. J Neurosurg. 2017 Jul;127(1):157-164. doi: 10.3171/2016.6.JNS16663. Epub 2016 Sep 16. PubMed PMID: 27636184.
9)

Sun JQ, Han DM, Li YX, Gong SS, Zan HR, Wang T. Combined endoscope-assisted translabyrinthine subtemporal keyhole approach for vestibular Schwannoma and auditory midbrain implantation: Cadaveric study. Acta Otolaryngol. 2010 Oct;130(10):1125-9. doi: 10.3109/00016481003699674. PubMed PMID: 20367538.
10)

Wong RH, De Los Reyes K, Alikhani P, Sivaknathan S, van Gompel J, van Loveren H, Agazzi S. The Subtemporal Approach to Retroinfundibular Craniopharyngiomas: A New Look at an Old Approach. Neurosurgery. 2015 Aug 18. [Epub ahead of print] PubMed PMID: 26287553.

Update: Posttraumatic epilepsy

Traumatic brain injury (TBI) is one of the most common causes of acquired epilepsy, and posttraumatic epilepsy (PTE) results in significant somatic and psychosocial morbidity.

The incidence of early post-traumatic seizures after civilian traumatic brain injury ranges 4-25%.

The true incidence of PTE in children is still uncertain, because most research has been based primarily on adults.

PTE in a pediatric population with mild traumatic brain injury (MTBI), was found to confer increased risk for the development of PTE and intractable PTE, of 4.5 and 8 times higher, respectively. As has been established in adults, these findings confirm that MTBI increases the risk for PTE in the pediatric population 1).

Risk

The risk of developing PTE relates directly to TBI severity, but the latency to first seizure can be decades after the inciting trauma. Given this “silent period,” much work has focused on identification of molecular and radiographic biomarkers for risk stratification and on development of therapies to prevent epileptogenesis.

Research suggests that there are reciprocal relationships between mental health (MH) disorders and epilepsy risk.

Data suggest that PTE is associated with mental health (MH) outcomes 2years after TBI, findings whose significance may reflect reciprocal, biological, psychological, and/or experiential factors contributing to and resulting from both PTE and MH status post-TBI. Future work should consider temporal and reciprocal relationships between PTE and MH as well as if/how treatment of each condition influences biosusceptibility to the other condition 2).

Treatment

The control of early post-traumatic seizure is mandatory because these acute insults may add secondary damage to the already damaged brain with poor outcome. Prophylactic use of antiepileptic drugs have been found to be have variable efficacy against early post-traumatic seizures.

Based on current studies, however, anticonvulsants have been shown to reduce early PTE occurring within the first 7 days, but little to no benefits have been shown in late PTS occurring after 7 days 3).

Clinical management requires vigilant neurologic surveillance and recognition of the heterogeneous endophenotypes associated with PTE.

Appropriate treatment of patients who have or are at risk for seizures varies as a function of time after TBI, and the clinician’s armamentarium includes an ever-expanding diversity of pharmacological and surgical options.


The lack of evidence on which antiepileptic drug to use in PTE is surprising given the number of patients prescribed an antiepileptic drug therapy for TBI. On the basis of currently available Level III evidence, patients treated with either levetiracetam or phenytoin have similar incidences of early seizures after TBI 4).

There is no statistically significant difference in the efficacy of Phenytoin and Levetiracetam in prophylaxis of early posttraumatic seizures in cases of moderate to severe traumatic brain injury 5).


Most recently, neuromodulation with implantable devices has emerged as a promising therapeutic strategy for some patients with refractory PTE 6).

Systematic review

During June and July 2015, a systematic literature search was performed that identified 6097 articles. Of these, 7 met inclusion criteria. A random-effects meta-analysis was performed. A total of 1186 patients were included. The rate of seizure was 35 of 654 (5.4%) in the levetiracetam cohort and 18 of 532 (3.4%) in the phenytoin cohort. The meta-analysis revealed no change in the rate of early PTS with levetiracetam compared with phenytoin (relative risk, 1.02; 95% confidence interval, 0.53-1.95; P = .96).

The lack of evidence on which antiepileptic drug to use in PTS is surprising given the number of patients prescribed an antiepileptic drug therapy for TBI. On the basis of currently available Level III evidence, patients treated with either levetiracetam or phenytoin have similar incidences of early seizures after TBI 7)

Case series

2016

In a retrospective multicenter cohort study including 5 regional pediatric trauma centers affiliated with academic medical centers, the authors examined data from 236 children (age < 18 years) with severe traumatic brain injury (TBI) (admission Glasgow Coma Scale score ≤ 8, ICD-9 diagnosis codes of 800.0-801.9, 803.0-804.9, 850.0-854.1, 959.01, 950.1-950.3, 995.55, maximum head Abbreviated Injury Scale score ≥ 3) who received tracheal intubation for ≥ 48 hours in the ICU between 2007 and 2011.

Of 236 patients, 187 (79%) received seizure prophylaxis. In 2 of the 5 centers, 100% of the patients received seizure prophylaxis medication. Use of seizure prophylaxis was associated with younger patient age (p < 0.001), inflicted TBI (p < 0.001), subdural hematoma (p = 0.02), cerebral infarction (p < 0.001), and use of electroencephalography (p = 0.023), but not higher Injury Severity Score. In 63% cases in which seizure prophylaxis was used, the patients were given the first medication within 24 hours of injury, and 50% of the patients received the first dose in the prehospital or emergency department setting. Initial seizure prophylaxis was most commonly with fosphenytoin (47%), followed by phenytoin (40%).

While fosphenytoin was the most commonly used medication for seizure prophylaxis, there was large variation within and between trauma centers with respect to timing and choice of seizure prophylaxis in severe pediatric TBI. The heterogeneity in seizure prophylaxis use may explain the previously observed lack of relationship between seizure prophylaxis and outcomes 8).

1)

Keret A, Bennett-Back O, Rosenthal G, Gilboa T, Shweiki M, Shoshan Y, Benifla M. Posttraumatic epilepsy: long-term follow-up of children with mild traumatic brain injury. J Neurosurg Pediatr. 2017 Jul;20(1):64-70. doi: 10.3171/2017.2.PEDS16585. Epub 2017 May 5. PubMed PMID: 28474982.

2)

Juengst SB, Wagner AK, Ritter AC, Szaflarski JP, Walker WC, Zafonte RD, Brown AW, Hammond FM, Pugh MJ, Shea T, Krellman JW, Bushnik T, Arenth PM. Post-traumatic epilepsy associations with mental health outcomes in the first two years after moderate to severe TBI: A TBI Model Systems analysis. Epilepsy Behav. 2017 Jun 25;73:240-246. doi: 10.1016/j.yebeh.2017.06.001. [Epub ahead of print] PubMed PMID: 28658654.

3)

Kirmani BF, Robinson DM, Fonkem E, Graf K, Huang JH. Role of Anticonvulsants in the Management of Posttraumatic Epilepsy. Front Neurol. 2016 Mar 22;7:32. eCollection 2016. Review. PubMed PMID: 27047441.

4)

Khan NR, VanLandingham MA, Fierst TM, Hymel C, Hoes K, Evans LT, Mayer R, Barker F, Klimo P Jr. Should Levetiracetam or Phenytoin Be Used for Posttraumatic Seizure Prophylaxis? A Systematic Review of the Literature and Meta-analysis. Neurosurgery. 2016 Sep 30. PubMed PMID: 27749510.

5)

Khan SA, Bhatti SN, Khan AA, Khan Afridi EA, Muhammad G, Gul N, Zadran KK, Alam S, Aurangzeb A. Comparison Of Efficacy Of Phenytoin And Levetiracetam For Prevention Of Early Post Traumatic Seizures. J Ayub Med Coll Abbottabad. 2016 Jul-Sep;28(3):455-460. PubMed PMID: 28712212.

6)

Rao VR, Parko KL. Clinical Approach to Posttraumatic Epilepsy. Semin Neurol. 2015 Feb;35(1):57-63. Epub 2015 Feb 25. PubMed PMID: 25714868.

7)

Khan NR, VanLandingham MA, Fierst TM, Hymel C, Hoes K, Evans LT, Mayer R, Barker F, Klimo P Jr. Should Levetiracetam or Phenytoin Be Used for Posttraumatic Seizure Prophylaxis? A Systematic Review of the Literature and Meta-analysis. Neurosurgery. 2016 Dec;79(6):775-782. PubMed PMID: 27749510.

8)

Ostahowski PJ, Kannan N, Wainwright MS, Qiu Q, Mink RB, Groner JI, Bell MJ, Giza CC, Zatzick DF, Ellenbogen RG, Boyle LN, Mitchell PH, Vavilala MS; PEGASUS (Pediatric Guideline Adherence and Outcomes) Study.. Variation in seizure prophylaxis in severe pediatric traumatic brain injury. J Neurosurg Pediatr. 2016 Oct;18(4):499-506. PubMed PMID: 27258588.

Update: Propionibacterium acnes

Propionibacterium acnes is the relatively slow-growing, typically aerotolerant anaerobic, Gram positive bacteria linked to the skin condition of acne; it can also cause chronic blepharitis and endophthalmitis, the latter particularly following intraocular surgery. The genome of the bacterium has been sequenced and a study has shown several genes can generate enzymes for degrading skin and proteins that may be immunogenic (activating the immune system).

This bacterium is largely commensal and part of the skin flora present on most healthy adult humans’ skin.

It is usually just barely detectable on the skin of healthy preadolescents. It lives primarily on, among other things, fatty acids in sebum secreted by sebaceous glands in the follicles. It may also be found throughout the gastrointestinal tract in humans and many other animals.

It is named after its ability to generate propionic acid.


Propionibacterium acnes was cultured from intervertebral disc tissue of ~25% of patients undergoing microdiscectomy, suggesting a possible link between chronic bacterial infection and disc degeneration. However, given the prominence of P. acnes as a skin commensal, such analyses often struggled to exclude the alternate possibility that these organisms represent perioperative microbiologic contamination

A study confirms that P. acnes is prevalent in herniated disc tissue. Moreover, it provides the first visual evidence of P. acnes biofilms within such specimens, consistent with infection rather than microbiologic contamination 1).


The presence of 36/46 modic changes in patients with lumbar disc herniation, positive for P. acnes suggests that P. acnes can lead to edema on the vertebrae endplates near to infected area 2).


In a study, 145 patients including 25 cases with cervical and 120 cases with lumbar disc herniation were enrolled. There was no significant difference in the age of male and female patients (p = 0.123). P. acnes infection was detected in nine patients (36%) with cervical disc herniation and 46 patients (38.3%) with lumbar disc herniation and no significant differences were reported in P. acnes presence according to the disc regions (p = 0.508.). Moreover, there was a significant difference in the presence of P. acnes infection according to the level of lumbar disc herniation (p = 0.028).

According to the results, the presence of P. acnes is equal in patients with cervical and lumbar disc herniation. There was a significant difference in the distribution of P. acnes infection according to level of lumbar disc herniation 3).

Case series

Clinical data obtained from 14 cases of P. acnes infection and 28 controls infected with other pathogens were analyzed. Craniotomy, malignancy, and prolonged duration of operation were significantly associated with the onset of P. acnes infection. No fatal cases were reported 4).

Case reports

2017

Hemiparesis may be the result of lesions in the contralateral pyramidal tract in the brain or, less frequently, in the ipsilateral pyramidal tract in the upper cervical spinal cord. However, although rare, multiple lesions that simultaneously occur in both of these regions may be the cause of acute hemiparesis, and the clinical symptoms can often be misdiagnosed as a stroke. In addition, the correct diagnosis of these multiple central nervous system (CNS) lesions is very challenging if they are caused by infection from an unexpected microorganism. We evaluated an elderly healthy woman who presented with acute hemiparesis and multiple brain and spinal cord lesions that were confirmed to occur from an infection with Propionibacterium acnes. In this report, the differential diagnosis and histopathological findings are discussed for these multiple CNS lesions in this healthy woman 5).

1)

Capoor MN, Ruzicka F, Schmitz JE, James GA, Machackova T, Jancalek R, Smrcka M, Lipina R, Ahmed FS, Alamin TF, Anand N, Baird JC, Bhatia N, Demir-Deviren S, Eastlack RK, Fisher S, Garfin SR, Gogia JS, Gokaslan ZL, Kuo CC, Lee YP, Mavrommatis K, Michu E, Noskova H, Raz A, Sana J, Shamie AN, Stewart PS, Stonemetz JL, Wang JC, Witham TF, Coscia MF, Birkenmaier C, Fischetti VA, Slaby O. Propionibacterium acnes biofilm is present in intervertebral discs of patients undergoing microdiscectomy. PLoS One. 2017 Apr 3;12(4):e0174518. doi: 10.1371/journal.pone.0174518. eCollection 2017. PubMed PMID: 28369127; PubMed Central PMCID: PMC5378350.
2)

Aghazadeh J, Salehpour F, Ziaeii E, Javanshir N, Samadi A, Sadeghi J, Mirzaei F, Naseri Alavi SA. Modic changes in the adjacent vertebrae due to disc material infection with Propionibacterium acnes in patients with lumbar disc herniation. Eur Spine J. 2016 Nov 24. [Epub ahead of print] PubMed PMID: 27885471.
3)

Javanshir N, Salehpour F, Aghazadeh J, Mirzaei F, Naseri Alavi SA. The distribution of infection with Propionibacterium acnes is equal in patients with cervical and lumbar disc herniation. Eur Spine J. 2017 Jul 15. doi: 10.1007/s00586-017-5219-z. [Epub ahead of print] PubMed PMID: 28712017.
4)

Haruki Y, Hagiya H, Takahashi Y, Yoshida H, Kobayashi K, Yukiue T, Tsuboi N, Sugiyama T. Risk factors for Propionibacterium acnes infection after neurosurgery: A case-control study. J Infect Chemother. 2017 Apr;23(4):256-258. doi: 10.1016/j.jiac.2016.10.003. Epub 2016 Nov 23. PubMed PMID: 27889246.
5)

Lee JH, Heo SH, Lee JS, Chang DI, Park KH, Sung JY, Hong IK, Kim MH, Park BJ, Choi WS. Acute Hemiparesis in a Healthy Elderly Woman: Where and What Is the Lesion? Front Neurol. 2017 Mar 21;8:109. doi: 10.3389/fneur.2017.00109. eCollection 2017. PubMed PMID: 28377743; PubMed Central PMCID: PMC5359233.

Update: NeuroVR

CAE Healthcare NeuroVR Surgical Simulator from CAE Healthcare on Vimeo.

https://caehealthcare.com/surgical-simulation/neurovr


Simulation technology identifies neurosurgical residency applicants with differing levels of technical ability. These results provide information for studies being developed for longitudinal studies on the acquisition, development, and maintenance of psychomotor skills. Technical abilities customized training programs that maximize individual resident bimanual psychomotor training dependant on continuously updated and validated metrics from virtual reality simulation studies should be explored 1).


“Experts” display significantly more automaticity when operating on identical simulated tumors separated by a series of different tumors using the NeuroVR platform. These results support the Fitts and Posner model of motor learning and are consistent with the concept that automaticity improves after completing residency training. The potential educational application of the findings is outlined related to neurosurgical resident training 2).


Ultrasonic aspirator force application was continually assessed during resection of simulated brain tumors by neurosurgeons, residents, and medical students. The participants performed simulated resections of 18 simulated brain tumors with different visual and haptic characteristics. The raw data, namely, coordinates of the instrument tip as well as contact force values, were collected by the simulator. To provide a visual and qualitative spatial analysis of forces, the authors created a graph, called a force pyramid, representing force sum along the z-coordinate for different xy coordinates of the tool tip.

Sixteen neurosurgeons, 15 residents, and 84 medical students participated in the study. Neurosurgeon, resident and medical student groups displayed easily distinguishable 3D “force pyramid fingerprints.” Neurosurgeons had the lowest force pyramids, indicating application of the lowest forces, followed by resident and medical student groups. Handedness, ergonomics, and visual and haptic tumor characteristics resulted in distinct well-defined 3D force pyramid patterns.

Force pyramid fingerprints provide 3D spatial assessment displays of instrument force application during simulated tumor resection. Neurosurgeon force utilization and ergonomic data form a basis for understanding and modulating resident force application and improving patient safety during tumor resection 3).

1)

Winkler-Schwartz A, Bajunaid K, Mullah MA, Marwa I, Alotaibi FE, Fares J, Baggiani M, Azarnoush H, Zharni GA, Christie S, Sabbagh AJ, Werthner P, Del Maestro RF. Bimanual Psychomotor Performance in Neurosurgical Resident Applicants Assessed Using NeuroTouch, a Virtual Reality Simulator. J Surg Educ. 2016 Nov – Dec;73(6):942-953. doi: 10.1016/j.jsurg.2016.04.013. Epub 2016 Jul 7. PubMed PMID: 27395397.
2)

Bugdadi A, Sawaya R, Olwi D, Al-Zhrani G, Azarnoush H, Sabbagh AJ, Alsideiri G, Bajunaid K, Alotaibi FE, Winkler-Schwartz A, Del Maestro R. Automaticity of Force Application During Simulated Brain Tumor Resection: Testing the Fitts and Posner Model. J Surg Educ. 2017 Jul 3. pii: S1931-7204(17)30114-9. doi: 10.1016/j.jsurg.2017.06.018. [Epub ahead of print] PubMed PMID: 28684100.
3)

Azarnoush H, Siar S, Sawaya R, Zhrani GA, Winkler-Schwartz A, Alotaibi FE, Bugdadi A, Bajunaid K, Marwa I, Sabbagh AJ, Del Maestro RF. The force pyramid: a spatial analysis of force application during virtual reality brain tumor resection. J Neurosurg. 2017 Jul;127(1):171-181. doi: 10.3171/2016.7.JNS16322. Epub 2016 Sep 30. PubMed PMID: 27689458.