A 64-year-old woman is evaluated for progressive gait disturbance over the last 2 years. The patient feels her feet are "stuck on the floor" and that she is unsteady while walking. She also recently began experiencing urinary urgency and has wet herself several times due to difficulty getting to the bathroom on time. The patient stopped working 6 months ago because of difficulty concentrating, and she has also lost interest in her hobbies and social activities. She has had no tremor, visual changes, headaches, nausea, or vomiting. The patient has a remote history of closed traumatic brain injury. Vital signs are within normal limits. On physical examination, lower extremity tone and deep tendon reflexes are increased. Sensation to light touch, pain, and vibration are normal. The patient's gait is slow with small steps and a wide base. CT scan of the head is shown below. Which of the following is the most likely diagnosis?

Question

A 64-year-old woman is evaluated for progressive gait disturbance over the last 2 years.  The patient feels her feet are "stuck on the floor" and that she is unsteady while walking.  She also recently began experiencing urinary urgency and has wet herself several times due to difficulty getting to the bathroom on time.  The patient stopped working 6 months ago because of difficulty concentrating, and she has also lost interest in her hobbies and social activities.  She has had no tremor, visual changes, headaches, nausea, or vomiting.  The patient has a remote history of closed traumatic brain injury.  Vital signs are within normal limits.  On physical examination, lower extremity tone and deep tendon reflexes are increased.  Sensation to light touch, pain, and vibration are normal.  The patient's gait is slow with small steps and a wide base.  CT scan of the head is shown below.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient's CT scan demonstrates ventriculomegaly out of proportion to sulci enlargement, consistent with normal pressure hydrocephalus (NPH). NPH is a form of communicating hydrocephalus associated with decreased cerebrospinal fluid (CSF) resorption by the arachnoid granulations. It may be idiopathic or occur secondary to prior brain trauma (as in this patient), infection, or subarachnoid hemorrhage, resulting in scarring of the arachnoid granulations. As CSF accumulates, the ventricles progressively expand to accommodate the increasing volume, thereby maintaining normal intracranial pressure. Symptoms of NPH are progressive and occur due to the disruption of periventricular white matter tracts by the expanding ventricles. Characteristic features include the following: Gait difficulties appear early in the disease course and are characterized by slow, short steps with decreased height. The feet may appear as though stuck to the ground (magnetic gait). Upper motor neuron signs (eg, spasticity, hyperreflexia) may also be evident. Cognitive disturbances, such as difficulty concentrating and apathy, usually become more apparent as the disease advances. Urinary incontinence is typically from urinary urgency. As the disease progresses, patients may develop apathy toward incontinence. Symptoms often improve in response to large-volume CSF removal, and long-term treatment frequently involves placement of a ventriculoperitoneal shunt. (Choice A) Alzheimer disease typically presents with memory deficits out of proportion to other cognitive domains. Although ventricular enlargement may be seen on imaging as the disease progresses, it occurs in proportion to sulci enlargement and is the result of generalized brain atrophy (hydrocephalus ex-vacuo). (Choice B) Frontotemporal dementia causes memory deficits but primarily causes personality changes and aphasia. Neuroimaging demonstrates atrophy of the frontal and temporal lobes. (Choice C) Parkinson disease causes gait abnormalities but is also typically associated with resting tremor and cogwheel rigidity. Cognitive deficits occur later in the disease course. (Choice D) Major depressive disorder can be associated with impaired concentration and loss of interest in activities (anhedonia). However, other features (eg, depressed mood, sleep disturbance) are not evident in this patient. In addition, neuroimaging and neurologic examination are typically normal. (Choice F) Noncommunicating (obstructive) hydrocephalus is typically associated with congenital abnormalities (eg, aqueductal stenosis) and tumors. It causes ventriculomegaly but is associated with elevated intracranial pressure (eg, headache, nausea/vomiting). (Choice G) Vitamin B₁₂ deficiency can cause dementia but is typically associated with peripheral neuropathy (eg, abnormal position, vibration sense) and glossitis. Although MRI of the spinal cord can show degeneration of the posterior columns, CT scan of the head would be expected to be normal. Educational objective: Normal pressure hydrocephalus presents with progressive gait difficulties, cognitive disturbances, and urinary incontinence. It is a form of communicating hydrocephalus characterized by ventriculomegaly without persistent elevations in intercranial pressure. Brain imaging reveals ventricular enlargement out of proportion to sulci enlargement. __________ References: A review of cognitive impairment and differential diagnosis in idiopathic normal pressure hydrocephalus. (http://www.ncbi.nlm.nih.gov/pubmed/26727700)

A 64-Year-Old Woman Is Evaluated for Progressive Gait Disturbance Over