Category Archives: Articles

Glioma talámico

Actualización de glioma talámico

Según su histología

Según su localización:

Glioma talámico unilateral

Glioma talámico bilateral

En un estudio retrospectivo durante un período de 5 años (2006-2010), la edad media de estos pacientes fue de 20,4 años (rango, 2-65 años). Veinte (49%) tumores eran talámicos, 19 (46%) eran tálamopedunculares, y 2 (5%) fueron bilaterales.

El limbo de la cápsula interna estaba desplazada anterolateralmente en 23 (56%) casos y lateralmente en 6 (14%) de los casos, infiltrada en ocho (20%) casos y no se pudo identificar en cuatro (10%) casos.

La resección, en pacientes con lesión bien definida, se realizó en 34 (83%) de los casos, y una biopsia en 7 (17%) casos.

La resección total o resección casi total (> 90%) se logró en 26 (63%) casos.

El abordaje de la circunvolución temporal media, se utiliza cuando el limbo de la cápsula interna se desplaza anterolateralmente, como ocurrió en el 63,5% de los casos.

Las patologías más comunes fueron el astrocitoma pilocítico (58%) en niños y astrocitoma grado III / IV en adultos (86%).

Los déficits motores preoperatorios mejoraron en el 64% de los pacientes con lesiones pilocíticas en comparación con 0% en los pacientes con lesiones grado III / IV .

Tras la intervención, dos pacientes (5%) presentaron empeoramiento marginal de la fuerza.

Dos pacientes desarrollaron defectos del campo visual, y un paciente desarrolló una parálisis del III par.

La resección total de los gliomas talámicos es una modalidad de tratamiento útil en un subconjunto seleccionado de pacientes y es el tratamiento de elección para los astrocitomas pilocíticos.

Adaptar la técnica quirúrgica, dependiendo de la posición relativa del limbo de la cápsula interna, tiene una influencia importante en el resultado (Sai Kiran y col., 2013).


Sai Kiran, Narayanam Anantha, Sumit Thakar, Ravi Dadlani, Dilip Mohan, Sunil Valentine Furtado, Nandita Ghosal, Saritha Aryan, and Alangar S Hegde. 2013. “Surgical Management of Thalamic Gliomas: Case Selection, Technical Considerations, and Review of Literature.” Neurosurgical Review (January 25). doi:10.1007/s10143-013-0452-3.

El glioblastoma que se hace pasar por encefalitis herpética

Los tumores cerebrales primarios y metastásicos , incluyendo el glioblastoma , se presentan de forma rara como encefalitis o encefalopatía aguda.

Ginsberg y Compston publicaron que un 1,5 % de pacientes con encefalitis aguda en realidad tenía un tumor cerebral (oligodendroglioma) (Ginsberg y Compston, 1994).

Whitley y col., un 5,3 % tuvieron tumores cerebrales, de los cuales 3 fueron tumores primarios del SNC (2 pacientes con glioblastomas y 1 paciente con linfoma primario del SNC ) y 2 metástasis de adenocarcinoma de colon (Whitley y col., 1989).

Rees y Howard publicaron 3 pacientes con gliomas de alto grado que imitan la encefalitis viral aguda. Sugirieron que la biopsia cerebral estereotáctica debe ser considerada en pacientes con masas del lóbulo temporal (Rees y Howard, 1999).

Este hecho puede dar lugar a retrasos en el diagnóstico, y el tratamiento de los pacientes con aumento significativo de la morbilidad y mal pronóstico (Kleffmann y col., 2012; Nam y col., 2011).

Véase Encefalitis herpética

Magnetic resonance guided focused ultrasound thalamotomy for neuropathic pain

In 12 patients suffering from chronic therapy-resistant neuropathic pain, tcMRgFUS CLT was proposed. In 11 patients, precisely localized thermal ablations of 3-4 mm in diameter were produced in the posterior part of the central lateral thalamic nucleus at peak temperatures between 51 ° C and 64 ° C with the aid of real-time patient monitoring and MR imaging and MR thermometry guidance. The treated neuropathic pain syndromes had peripheral (5 patients) or central (6 patients) origins and covered all body parts (face, arm, leg, trunk, and hemibody).

Patients experienced mean pain relief of 49% at the 3-month follow-up (9 patients) and 57% at the 1-year follow-up (8 patients). Mean improvement according to the visual analog scale amounted to 42% at 3 months and 41% at 1 year. Six patients experienced immediate and persisting somatosensory improvements. Somatosensory and vestibular symptoms were always observed during sonication time because of ultrasound-based neuronal activation and/or initial therapeutic effects. Quantitative electroencephalography (EEG) showed a significant reduction in EEG spectral overactivities. Thermal ablation sites showed sharply delineated ellipsoidal thermolesions surrounded by short-livedvasogenic edema. Lesion reconstructions (18 lesions in 9 patients) demonstrated targeting precision within a millimeter for all 3 coordinates. There was 1 complication, a bleed in the target with ischemia in the motor thalamus, which led to the introduction of 2 safety measures, that is, the detection of a potential cavitation by a cavitation detector and the maintenance of sonication temperatures below 60 ° C.

Jeanmonod et al. assert that tcMRgFUS represents a noninvasive, precise, and radiation-free neurosurgical technique for the treatment of neuropathic pain. The procedure avoids mechanical brain tissue shift and eliminates the risk of infection. The possibility of applying sonication thermal spots free from trajectory restrictions should allow one to optimize target coverage. The real-time continuous MR imaging and MR thermometry monitoring of targeting accuracy and thermal effects are major factors in optimizing precision, safety, and efficacy in an outpatient context 1).

1) Jeanmonod D, Werner B, Morel A, Michels L, Zadicario E, Schiff G, Martin E. Transcranial magnetic resonance imaging-guided focused ultrasound: noninvasive central lateral thalamotomy for chronic neuropathic pain. Neurosurg Focus. 2012 Jan;32(1):E1. doi: 10.3171/2011.10.FOCUS11248. PubMed PMID: 22208894.

Update: Radiography in Spinal epidural metastases

Most of the spinal epidural metastases are osteolytic, but at least 50 % of the bone must be eroded before plain x ray abnormality 1).

Not very specific.

see Winking owl sign

Plain x-rays are quite good at evaluating bony metastases, but not good at evaluating the spinal cord and surrounding soft tissues. Metastatic epidural spinal cord compression most commonly occurs at the site of vertebral involvement on plain x-ray, especially where there is evidence of vertebral collapse. Most common findings on x-rays include pedicle erosion, paravertebral soft shadow, vertebral collapse, and pathologic fracture or dislocation 2).

In the past, if there was back pain or a localizing sign and spinal x-ray was abnormal, the probability of epidural disease was 0.9, but if the x-ray was normal, the probability was only 0.1 3) 4).

In 1990, x-rays were found to have a 10% to 17% false negative rate 5).

The rate of missed metastatic epidural spinal cord compression is unacceptable.

1) Gabriel K, Schiff D. Metastatic spinal cord compression by solid tumors. Semin Neurol. 2004 Dec;24(4):375-83. Review. PubMed PMID: 15637649.
2) Perrin RG. Metastatic tumors of the axial spine. Curr Opin Oncol 1992;4(3):525-32.
3) Rodichok LD, Harper GR, Ruckdeschel JC, et al. Early diagnosis of spinal epidural metastases. Am J Med 1981;70(6):1181-8.
4) Portenoy RK, Galer BS, Salamon O, et al. Identification of epidural neoplasms. Radiography and bone scintigraphy in the symptomatic and asymptomatic spine. Cancer 1989;64(11):2207-13.
5) Bach F, Larsen BH, Rohde K, Børgesen SE, Gjerris F, Bøge-Rasmussen T, Agerlin N, Rasmusson B, Stjernholm P, Sørensen PS. Metastatic spinal cord compression. Occurrence, symptoms, clinical presentations and prognosis in 398 patients with spinal cord compression. Acta Neurochir (Wien). 1990;107(1-2):37-43. PubMed PMID: 2096606.

Update: Spinal arachnoid cyst

Spinal arachnoid cyst


Almost always dorsal, most common in the thoracic spine.

Most are extradural and these are sometimes referred to as arachnoid diverticula – these may be associated with kyphoscoliosis in juveniles or with spinal dysraphism.


Intradural arachnoid cysts may be congenital or may follow infection or trauma.

Clinical features

Usually asymptomatic, even if large.

Differential diagnosis

Vith a ventral cyst, consider a neurenteric cyst.


When indicated, treatment options include:

1. percutaneous procedures: may be done under MRI 1). or CT guidance. CT guidance usually requires use of intrathecal contrast to delineate the cyst

A. needle aspiration.

B. needle fenestration.

2. open surgical resection or fenestration

Case report

Takahashi et al. describe the case of a high cervical, intradural extramedullary cyst located anterior to the spinal cord in a 13-year-old boy. The lesion was fenestrated percutaneously by using real-time magnetic resonance (MR) imaging guidance and a local anesthetic agent. The patient’s symptom, severe exercise-induced headache, immediately resolved after treatment. Nine months later, complete disappearance of the cyst was confirmed on MR imaging and computerized tomography myelography. Magnetic resonance imageing-guided fenestration can be considered a minimally invasive option for intradural cystic lesions 2).

1) , 2) Takahashi S, Morikawa S, Egawa M, Saruhashi Y, Matsusue Y. Magnetic resonance imaging-guided percutaneous fenestration of a cervical intradural cyst. Case report. J Neurosurg. 2003 Oct;99(3 Suppl):313-5. PubMed PMID: 14563151.

Update: Pallidotomy



Pallidotomy is an alternative to deep brain stimulation for the treatment of the involuntary movements known as dyskinesias which can become a problem in people with Parkinson disease after long-term treatment with levodopa — a condition known as levodopa-induced dyskinesia.

It is also sometimes used in alternative to deep brain stimulation to treat difficult cases of essential tremor.

Unilateral posteroventral pallidotomy can be effective at reducing Parkinsonism, but is associated with impaired language learning (if performed on the dominant hemisphere) or impaired visuospatial contructional ability (if performed on the non-dominant hemisphere). It can also impair executive functions.

Bilateral pallidotomy will not reduce Parkisonistic symptoms but will cause severe apathy and depression along with slurred unintelligable speech, drooling, and pseudobulbar palsy.

Pallidotomy has long been an accepted procedure and the indications for this surgery, in the opinion of the responding centers of a survey of current practice in North America (1996), were rated on a scale of 1 (poor) to 4 (excellent) and demonstrated dyskinesia as the best indication (median = 4); on-off fluctuations, dystonia, rigidity, and bradykinesia as good indications (median = 3); and freezing, tremor and gait disturbance as fair indications (median = 2). Most centers used MRI alone (50%) or in combination with CT scan (n = 6) or ventriculopathy (n = 5) to localize the target. The median values of pallidal coordinates were: 2 mm anterior to the midcommissural point 21 mm lateral to the midsagittal plane and 5 mm below the intercommissural line. Microrecording was performed by half of the centers (n = 14) and half of the remaining centers were considering starting it (n = 7). Main criteria used to define the target included the firing pattern of spontaneous neuronal discharges (n = 13) and the response to joint movement (n = 10). Most centers performed motor (n = 26) and visual (n = 23) macrostimulation. Twenty four centers performed test lesions using median values of 55 degrees C temperatures for 30 s. Final lesions consisted of 3 permanent lesions placed 2 mm apart, each lesion created with median values of 75 degrees C temperatures for 1 minute. Median hospital stay was 2 days 1).

1) Favre J, Taha JM, Nguyen TT, Gildenberg PL, Burchiel KJ. Pallidotomy: a survey of current practice in North America. Neurosurgery. 1996 Oct;39(4):883-90; discussion 890-2. PubMed PMID: 8880789.

Update: Intraventricular oligodendroglioma

Intraventricular oligodendroglioma (IVO)


Neurosurgery Department, University Hospital Son Dureta, Palma de Mallorca, Spain

Oligodendrogliomas usually arise in the cerebral hemispheres, less frequently they are found in the cerebellar hemispheres and very rarely they adopt an intraventricular location.


Intraventricular oligodendroglioma remains a rare diagnosis, with high-grade/anaplastic IVO being an even rarer subtype.


These lesions vary in regard to tumor grading and clinical presentation, as compared with their intraparenchymal counterparts.

see Anaplastic intraventricular oligodendroglioma.

Clinical Features

They occur in the younger age, an interval between clinical onset and diagnosis or operation is shorter, and initial symptoms are most often limited to those of increased intracranial pressure, although the patient may occasionally present mild organic dementia, callosal disconnection syndrome, and/or mild gait ataxia 1).


Analysis of the clinical and CT characteristics of 11 cases in the literature and eight new examples revealed specific radiographic features, which included the presence of an anterior, midline mass within the lateral ventricles composed of clumped calcifications within a dense, enhancing matrix.

Hydrocephalus is a constant feature, and these tumors present with signs of increased intracranial pressure. Eighteen of the 19 cases were benign and all were pure oligodendrogliomas, without admixture of other cellular elements.

Intraventricular oligodendrogliomas can be distinguished from other intraventricular lesions by fairly specific CT characteristics. 2)3).

Angiography showed slightly increased vascularity in the mass, and displacement of subependymal veins near the tumor 4).

Magnetic resonance imaging proved to be most useful as a radiologic diagnostic procedure 5)


Intraventricular oligodendrogliomas grow slowly and are associated with prolonged survival but, due to their location, are difficult to remove and frequently require shunting. Subsequently developing symptoms, including herniation and death, are more frequently associated with complications related to hydrocephalus than with tumor growth.

The ability to recognize them is helpful in prognosis, and awareness of associated complications related to hydrocephalus may assist in the long-term survival of affected patients 6).

Differential diagnosis

Oligodendrogliomas of the lateral ventricle are rare but should be included in the differential diagnosis of intraventricular tumors near the foramen of Monro 7).

The possibility of central neurocytoma should be considered in all young patients including children presenting with an intraventricular lesion. Definitive diagnosis requires electron microscopic and immunohistochemical studies 8).

Case reports


Two cases of primary intraventricular oligodendrogliomas which were successfully removed by a transventricular approach using microtechniques are presented 9).


Two cases of primary intraventricular oligodendrogliomas are presented. Total excisions of well-demarcated large tumors in the lateral ventricle were successfully performed in young women by means of a frontal transventricular approach. An evaluation by computed tomography and positron emission tomography was attempted to obtain definite diagnosis of not only the location of the tumor but also the histologic grade of malignancy 10).


Ng et al. report two cases 11).

Martinez-Lage et al. report a case of a ventricular oligodendroglioma associated with a cortical arteriovenous malformation. The patient presented with subarachnoid hemorrhage. Computed tomographic scan showed an intraventricular hyperdense lesion, mimicking a hematoma. Angiography revealed a superficial arteriovenous malformation in the right parietal lobe, unrelated to ventricular cavities. Both lesions were treated during the same operation 12).


Two cases of oligodendroglioma primarily involving the lateral ventricle are reported in female patients, aged 29 and 19, respectively, with sole complaints of an increased intracranial pressure.

The tumor was radically removed via a parafalcine transcallosal approach without causing any persistent neurological deficits 13).


A 39-year-old woman harbouring a primary oligodendroglioma of the left lateral ventricle was treated by subtotal removal of the tumour through a left frontal transcortical transventricular approach. The clinical, radiological and surgical details of the case are presented in correlation with the current data on oligodendrogliomas. Benefits of postoperative irradiation are stressed 14).


Romero et al. describe two cases of intraventricular oligodendroglioma.

Case No. 1: 18-year old woman with a clinical history of headache, vertigo and dizziness of 6 months duration. Central Nervous System imaging revealed a right lateral ventricle tumor.

Case No. 2: 38 year old man with a chief complaint of positional headache and visual impairment. C.N.S. imaging showed a third ventricular lesion15).

1) , 5) , 13) Nioka H, Nakasu S, Nakasu Y, Matsuda M, Handa J. [Oligodendroglioma of the lateral ventricle–report of 2 cases and a review]. No Shinkei Geka. 1987 Feb;15(2):201-5. Japanese. PubMed PMID: 3561685.
2) , 6) Dolinskas CA, Simeone FA. CT characteristics of intraventricular oligodendrogliomas. AJNR Am J Neuroradiol. 1987 Nov-Dec;8(6):1077-82. PubMed PMID: 3120535.
3) , 4) , 7) Hasuo K, Fukui M, Tamura S, Yasumori K, Uchino A, Nakagaki H, Ogawa H, Nagasaka S, Masuda K. Oligodendrogliomas of the lateral ventricle: computed tomography and angiography. J Comput Tomogr. 1987 Oct;11(4):376-82. PubMed PMID: 3443012.
8) Yuen ST, Fung CF, Ng TH, Leung SY. Central neurocytoma: its differentiation from intraventricular oligodendroglioma. Childs Nerv Syst. 1992 Oct;8(7):383-8. PubMed PMID: 1458495.
9) Markwalder TM, Huber P, Markwalder RV, Seiler RW. Primary intraventricular oligodendrogliomas. Surg Neurol. 1979 Jan;11(1):25-8. PubMed PMID: 451839.
10) Kikuchi K, Kowada M, Mineura K, Uemura K. Primary oligodendroglioma of the lateral ventricle with computed tomographic and positron emission tomographic evaluations. Surg Neurol. 1985 May;23(5):483-8. PubMed PMID: 3872482.
11) Ng SH, Lui CC, Wai YY, Liu YH, Tsai CC, Chen L. Primary intraventricular oligodendroglioma–report of two cases. Changgeng Yi Xue Za Zhi. 1986 Mar 20;9(1):33-40. PubMed PMID: 3454696.
12) Martinez-Lage JF, Poza M, Esteban JA, Sola J. Subarachnoid hemorrhage in the presence of a cerebral arteriovenous malformation and an intraventricular oligodendroglioma: case report. Neurosurgery. 1986 Jul;19(1):125-8. PubMed PMID: 3748333.
14) Tekkok IH, Ayberk G, Saglam S, Onol B. Primary intraventricular oligodendroglioma. Neurochirurgia (Stuttg). 1992 Mar;35(2):63-6. PubMed PMID: 1603222.
15) Romero Z, Mora-La Cruz E, Cardozo J. [Intraventricular oligodendroglioma. Description of 2 cases]. Invest Clin. 1996 Mar;37(1):51-9. Review. Spanish. PubMed PMID: 8920031.