Review Question - QID 217634

This patient presenting with psychomotor slowing, executive function changes, urinary incontinence, and a wide-based, “magnetic” gait (small, slow steps) most likely has normal pressure hydrocephalus (NPH). NPH appears on brain MRI as ventriculomegaly without sulcal enlargement.

NPH is caused by excess cerebrospinal fluid production, which accumulates in the brain’s ventricular system, causing ventriculomegaly. Because intracranial pressure is not elevated, there is no effacement of the sulci. Patients present with the classic triad of urinary incontinence, gait ataxia, and dementia (“wet, wobbly, and wacky”). The diagnosis involves cognitive evaluation, MRI of the brain, and a high-volume lumbar puncture. Relief of symptoms with the high-volume lumbar puncture is diagnostic and prognostic for symptomatic relief after ventriculoperitoneal (VP) shunt placement. The gold standard treatment for NPH is placement of a VP shunt, which functions by preventing the repeated accumulation of cerebrospinal fluid.

Shprecher et al. review the diagnosis and management of NPH. They highlight the presenting symptoms of cognitive deficits and bladder detrusor overactivity. They recommend using a combination of clinical, imaging, and response to lumbar puncture signs as a guide to evaluate a patient's likely response to surgery.

Incorrect Answers:
Answer 1: Cortical ribboning is a sign of Creutzfeldt-Jakob disease (CJD). CJD presents with dementia, startle myoclonus, and ataxia. The disease is rapidly progressive and typically leads to death within 1 year of onset. This patient does not have startle myoclonus, and the associated urinary incontinence makes NPH more likely. There is no specific treatment for CJD other than supportive therapy.

Answer 2: Decreased hippocampal volume is a sign of Alzheimer disease. Alzheimer disease is characterized by marked memory deficits in the early stage, followed by deficits in executive function and other cognitive domains. Incontinence is a late finding, and gait ataxia would be atypical. Alzheimer can be treated symptomatically using acetylcholinesterase inhibitors and lifestyle modifications.

Answer 3: Empty sella is a finding that is commonly associated with idiopathic intracranial hypertension (ICH), also known as pseudotumor cerebri. ICH presents with headache, visual field disturbances, and pulsatile tinnitus. Papilledema is frequently appreciated on physical exam as a sign of elevated intracranial pressure. Limiting fluid and salt intake, serial lumbar punctures, as well as acetazolamide are helpful in this condition.

Answer 4: Frontal lobe atrophy is a finding of frontotemporal dementia (FTD), which presents with marked impairment in executive function. Disinhibition (excessive gambling, promiscuous behavior, public urination) and hyperorality are common findings. Incontinence and gait ataxia are not common findings in FTD. No specific treatment is available for FTD.

Bullet Summary:
Normal pressure hydrocephalus ("wacky, wet, and wobbly") presents on MRI with ventriculomegaly without sulcal enlargement.