ContentsSynopsisCodesLook ForDiagnostic PearlsDifferential Diagnosis & PitfallsBest TestsManagement PearlsTherapyReferencesView all Images (2)
Normal pressure hydrocephalus
Print Captions OFF
Other Resources UpToDate PubMed

Normal pressure hydrocephalus

Print Images (2)
Contributors: Carolyn Zyloney MD, Richard L. Barbano MD, PhD
Other Resources UpToDate PubMed

Synopsis

Normal pressure hydrocephalus (NPH) is a common neurologic disorder resulting in slowly progressive gait abnormalities, cognitive deterioration, and urinary incontinence.

The syndrome is often divided into 2 groups, idiopathic and secondary, based on etiology. Idiopathic NPH is thought to occur due to increased resistance to cerebrospinal fluid (CSF) absorption, leading to temporary elevations in intracranial pressure and mechanical compression of structures adjacent to the ventricles. However, the underlying etiology of idiopathic NPH has not yet been identified. Secondary causes of NPH include the sequelae of brain infections such as meningitis, trauma, or subarachnoid hemorrhage. This article will focus on the diagnosis, evaluation, and treatment of idiopathic NPH.

The incidence of NPH increases with advancing age, and most patients are over the age of 60. There is no difference in incidence between men and women. NPH has an estimated incidence of 1-5 cases per 100 000 people per year. Its prevalence is reported to be less than 1% in persons under the age of 65, and up to 3% for persons aged 65 or older. Among individuals with dementia, the incidence of NPH is thought to be between 2% and 6%.

Gait and balance dysfunction typically develop early in the course of NPH, whereas cognitive symptoms and incontinence usually appear as the disease progresses. The typical gait abnormality in NPH is a broad-based, slow, short-stepped, "stuck to the floor" or "magnetic" movement. Postural stability is usually impaired, and a history of falls may be reported. The cognitive deficits are typically impairments in attention, psychomotor speed, and executive dysfunction. Patients with more advanced NPH can develop generalized cognitive dysfunction. Disturbances of bladder function in NPH result from detrusor hyperactivity secondary to a loss of central inhibitory control. Increased urinary frequency and subsequent incontinence can develop.

Approximately 40%-75% of patients with suspected NPH are subsequently found to have other comorbid neurodegenerative diseases such as Alzheimer disease. NPH patients with other comorbid neurodegenerative conditions are thought to have a poorer response to CSF shunting.

For more information, see OMIM.

Codes

ICD10CM:
G91.2 – (Idiopathic) normal pressure hydrocephalus

SNOMEDCT:
30753002 – Normal pressure hydrocephalus

Look For

Subscription Required

Diagnostic Pearls

Subscription Required

Differential Diagnosis & Pitfalls

Best Tests

Subscription Required

Management Pearls

Subscription Required

Therapy

Subscription Required

References

Subscription Required

Last Reviewed: 04/09/2018
Last Updated: 04/16/2018
Copyright © 2019 VisualDx®. All rights reserved.
Normal pressure hydrocephalus
Captions OFF Print 2 Images
View all Images (2)
(with subscription)
Normal pressure hydrocephalus : Gait disturbance, Mental status alteration, Urinary incontinence, Memory loss
Imaging Studies image of Normal pressure hydrocephalus
Axial CT image demonstrates bilateral ventriculomegaly out of proportion to the degree of sulcal enlargement. In this patient who presented with falls and urinary incontinence, the imaging findings supported the clinical diagnosis of normal pressure hydrocephalus.
Copyright © 2019 VisualDx®. All rights reserved.