A 54-year-old homeless man is brought to the emergency department by the police after he was found to be confused and disheveled. The patient is unable to provide a medical history and has no prior hospital record. Temperature is 36.5 C (97.7 F), blood pressure is 110/60 mm Hg, pulse is 90/min, and respirations are 16/min. The patient is thin and appears ill, with temporal muscle wasting. The mucous membranes are dry. The lungs are clear to auscultation, and heart sounds are normal with no murmur. The abdomen is soft, nontender, and nondistended. The patient is disoriented and unable to recognize where he is or state the date. Bilateral pupils are equal and reactive to light, but extraocular motion is restricted on leftward gaze. No obvious motor weakness is present. Deep tendon reflexes are reduced and plantar responses are flexor. The patient has no neck rigidity, but his gait is markedly ataxic. Laboratory results are as follows: With treatment, the patient's gait abnormalities and eye movement gradually improve. He becomes more oriented, but the nurses report that he is forgetful and tells incongruent stories that seem to have never happened. Neuroimaging is most likely to reveal abnormalities in which of the following areas of this patient's brain?

Question

A 54-year-old homeless man is brought to the emergency department by the police after he was found to be confused and disheveled.  The patient is unable to provide a medical history and has no prior hospital record.  Temperature is 36.5 C (97.7 F), blood pressure is 110/60 mm Hg, pulse is 90/min, and respirations are 16/min.  The patient is thin and appears ill, with temporal muscle wasting.  The mucous membranes are dry.  The lungs are clear to auscultation, and heart sounds are normal with no murmur.  The abdomen is soft, nontender, and nondistended.  The patient is disoriented and unable to recognize where he is or state the date.  Bilateral pupils are equal and reactive to light, but extraocular motion is restricted on leftward gaze.  No obvious motor weakness is present.  Deep tendon reflexes are reduced and plantar responses are flexor.  The patient has no neck rigidity, but his gait is markedly ataxic.  Laboratory results are as follows:  With treatment, the patient's gait abnormalities and eye movement gradually improve.  He becomes more oriented, but the nurses report that he is forgetful and tells incongruent stories that seem to have never happened.  Neuroimaging is most likely to reveal abnormalities in which of the following areas of this patient's brain?

Quizplus · Accepted Answer

Explanation: Korsakoff syndrome (KS) is a late-stage complication of chronic thiamine deficiency due to repeated or prolonged episodes of Wernicke encephalopathy (WE). Up to 80% of patients recovering from an acute episode of WE show signs of KS, including significant retrograde and anterograde amnesia, often with confabulation. Cognition, attention, social behavior, and long-term memory are relatively preserved. Patients with KS typically have mammillary body atrophy on MRI of the brain. Unlike WE, the neurocognitive changes of KS rarely improve; most patients require long-term supervision and social support. (Choice A) The basal ganglia is important for voluntary movement, procedural learning, and routine behaviors (eg, teeth grinding). Parkinson disease primarily affects the basal ganglia and is associated with "pill-rolling" tremor, bradykinesia, and cogwheel rigidity. (Choice B) Damage to the corpus callosum can result in problems with learning, hand-eye coordination, and visual/auditory memory. This patient, who developed memory impairment and confabulation after treatment for WE, likely has KS. (Choice C) The frontal lobes contribute to voluntary movements and higher-level cognition that integrates emotion with memory. Although patients with frontal lobe damage may occasionally confabulate, this patient, who developed symptoms shortly after recovering from WE, is far more likely to have KS. (Choice D) The internal capsule is composed largely of the corticospinal tract, which brings information from the primary motor cortex to the lower motor neurons in the spinal cord. Damage to this area typically results in contralateral hemiparesis or hemiplegia. Educational objective: Patients with Korsakoff syndrome often have MRI evidence of mammillary body atrophy, a relatively specific finding for this condition.

A 54-Year-Old Homeless Man Is Brought to the Emergency Department