Clinical Reasoning: A 55-year-old man with rapidly progressive dementia and parkinsonism

Abstract

A 55-year-old right-handed man presented with a history of rapidly progressive apathy and behavior changes, speech loss, bladder and bowel incontinence, and gait loss in the previous month. He had been diagnosed with depression 7 months before and tried to commit suicide with carbon monoxide poisoning 2 months before, needing treatment in a hyperbaric chamber, with a good recovery. He had no history of other comorbidities and an unremarkable family history. At the first neurologic evaluation at our department, he presented with marked apathy and mutism, pseudobulbar affect, marked frontal release signs, generalized rigidity with hypomimia, global hyperreflexia with a left extensor plantar reflex, infrequent generalized myoclonus, and gait apraxia. Basic laboratory tests including electrolytes, complete blood count, carboxyhemoglobin, and liver function tests and CT scan had normal results. He had been medicated with lorazepam and mirtazapine but abandoned medication 2 weeks after the suicide attempt. He denied drug use or substantial alcohol consumption.Questions for consideration: