system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A previously healthy 5-year-old boy is brought to the physician by his parents because of a 2-day history of poor balance and difficulty walking. He has fallen multiple times and is unable to walk up the stairs unassisted. He has also had difficulty tying his shoes and dressing himself. His family adheres to a vegetarian diet. He has not yet received any routine childhood vaccinations. His mother has a history of anxiety. He is at the 70th percentile for height and 30th percentile for weight. Vital signs are within normal limits. He is alert and oriented to person, place, and time. Physical examination shows a broad-based, staggering gait. He has difficulty touching his nose and cannot perform rapidly-alternating palm movements. Strength is 5/5 in the upper and lower extremities. Deep tendon reflexes are 1+ bilaterally. Skin examination shows several faint hyperpigmented macules on the chest. Which of the following is the most likely underlying cause of this patient's symptoms?
assistant
Varicella zoster infection