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
• LP: normal opening pressure
  • Symptom improvement supports diagnosis
• CT brain: Ventriculomegaly without signs of obstruction at the level of the third or fourth ventricles

Management

• Diagnostic and therapeutic large volume CSF removal
  • 30-50 mL of CSF with documentation of patient's gait (speed, stride length, number of steps to turn 180 deg) before and within 30-60 minutes after procedure
• Additional work up warranted for surgical candidate
• Assessment for Surgical CSF shunting

Disposition

• Workup typically is extensive and performed as an outpatient.
• Refer to neurosurgery

Also See

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