Normal pressure hydrocephalus

Background

• Possible reversible cause of dementia
• CSF buildup in the ventricles leading to increased intracranial pressure with edema of the periventricular white matter and corona radiata
  • Sacral motor nerve fibers that produce gait instability; incontinence ensues when compressed

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Clinical Features

• Gait disturbance is most common and earliest finding
  • "Glue-footed" gait: move slowly, take small steps, often wide base, with difficulty turning
• Memory loss and dementia symptoms may be mild, subtle
• Incontinence is usually later stage, though sensation of urinary urgency is usually present before incontinence
• Usually do not have symptoms of increased intracranial pressure, such as headache, nausea, vomiting, visual loss

Differential Diagnosis

• Alzheimer's
• Stroke
• Parkinson's disease
• Electrolyte abnormality
• Malignancy
• Uremic encephalopathy
• Hydrocephalus ex vacuo (diffuse cerebral atrophy on CT)

Evaluation

• CBC
• Chem 7
• CT brain non-con: Ventriculomegaly without signs of obstruction at the level of the third or fourth ventricles

Workup beyond this point should be made in coordination with neurology/neurosurgery. Additional workup may include:

• MRI (done as part of the general work-up, and should be done before LP)
• Diagnosis: LP, with normal opening pressure with normal CSF studies (rarely done in the ED)
  • Symptom improvement supports diagnosis

Management

• Fall precautions
• Consult neurology and/or neurosurgery to decide if patient is candidate for inpatient vs outpatient MRI and LP.
• LP is rarely done in the ED as it requires MRI before LP, and workup is typically non-emergent and can often be done as outpatient.

Disposition

• Workup typically is extensive, but can often be done as outpatient, depending on your institution.
• Decide plan for workup with neurology and/or neurosurgery
• Consider admission if patient lives alone (fall risk), has no follow-up, or is significantly altered.

Also See

• Stroke (Main)
• Ataxia
• Parkinson's Disease