UpToDate:Outcome in idiopathic normal pressure hydrocephalus

To date, there is no standard outcome assessment scale for shunt treatment.

In designing such scale, the relative weight of each of the common presentations of the condition from the patient’s or his/her carer’s point of view should be taken into consideration.

Clinical improvement of patients with iNPH can be sustained for 5-7 years in some patients, even if shunt revision surgery is needed multiple times. With earlier diagnosis and treatment and the increasing lifespan of the ageing population, the need for long-term follow-up after shunt surgery may be greater than it was in the past. Monitoring, identification and treatment of shunt obstruction is a key management principle 1).

Gait and Incontinence

Postoperative improvement of Gait and Urinary incontinence is obtained at an early stage 2) 3). In contrast, Dementia tends to improve gradually from after the third postoperative month. The family satisfaction increases as the symptom of Dementia improve. The satisfaction of the medical personnel tends to remain high after the first postoperative month 4).

Independent predictors

Independent predictors of improvement are the presence of gait impairment as the dominant symptom and shorter duration of symptoms 5).

Caregiver Burden

Shunt operations reduced the caregiver burden of iNPH patients 6)7).

Thirty-seven patients (median age 70 years, range 50-89 years) with Idiopathic normal pressure hydrocephalus were evaluated before and 6 months after surgery. Symptoms and signs were assessed by the iNPH scale, activities of daily living (ADL) with the Functional Independence Measure (FIM) and Assessment of Motor and Process Skills (AMPS), autonomy and participation with Impact on Participation and Autonomy (IPA), and caregiver burden with the Caregiver Burden Scale (CBS). HRQOL was evaluated with the EQ-5D (EuroQol Group-5 Dimension health survey).

Twenty-four patients (65%) improved clinically (iNPH scale score) and 31 (86%) improved their HRQOL after surgery, almost to the same level as found in the normal population. The patients became more independent in physical and cognition, and participation and autonomy improved. The caregiver burden was decreased among caregivers to male patients but remained unchanged on the overall group level. After shunt surgery, patients with iNPH showed improvement in most aspects of social life, they became more independent, and their quality of life returned to nearly normal 8).

1) Pujari S, Kharkar S, Metellus P, Shuck J, Williams MA, Rigamonti D. Normal pressure hydrocephalus: long-term outcome after shunt surgery. J Neurol Neurosurg Psychiatry. 2008 Nov;79(11):1282-6. doi: 10.1136/jnnp.2007.123620. Epub 2008 Mar 20. PubMed PMID: 18356257.
2) Savolainen S, Hurskainen H, Paljärvi L, Alafuzoff I, Vapalahti M: Five-year outcome of normal pressure hydrocephalus with or without a shunt: predictive value of the clinical signs, neuropsychological evaluation and infusion test. Acta Neurochir (Wien) 144:515–523, 2002
3) , 4) Takeuchi T, Goto H, Izaki K, Tamura S, Sasanuma Z, Maeno K, Kikuchi Y, Tomii M, Koizumi Z, Watanabe Z, Numazawa S, Ito Y, Ohara H, Kowada M, Watanabe K. Postoperative patterns of improvement of symptoms and degrees of satisfaction in families of patients after operations for definite idiopathic normal pressure hydrocephalus: a long-term follow-up study]. No Shinkei Geka. 2007 Aug;35(8):773-9. Japanese. PubMed PMID: 17695775.
5) McGirt MJ, Woodworth G, Coon AL, Thomas G, Williams MA, Rigamonti D. Diagnosis, treatment, and analysis of long-term outcomes in idiopathic normal-pressure hydrocephalus. Neurosurgery. 2005 Oct;57(4):699-705; discussion 699-705. PubMed PMID: 16239882.
6) Kazui H, Mori E, Hashimoto M, Ishikawa M, Hirono N, Takeda M. Effect of shunt operation on idiopathic normal pressure hydrocephalus patients in reducing caregiver burden: evidence from SINPHONI. Dement Geriatr Cogn Disord. 2011;31(5):363-70. doi: 10.1159/000328625. Epub 2011 May 27. PubMed PMID: 21625136.
7) , 8) Petersen J, Hellström P, Wikkelsø C, Lundgren-Nilsson A. Improvement in social function and health-related quality of life after shunt surgery for idiopathic normal-pressure hydrocephalus. J Neurosurg. 2014 Oct;121(4):776-84. doi:10.3171/2014.6.JNS132003. Epub 2014 Jul 18. PubMed PMID: 25036194.

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