A 76-year-old man is brought to the office by his wife for follow-up of recent behavioral changes. The patient has been much more withdrawn than usual over the past 6 months and often appears sad. He stopped driving a year earlier after getting lost several times in his own neighborhood. He now needs help with grocery shopping, meal preparation, and finances. His wife says, "He has good days and bad days. Sometimes he's almost like his old self; other times, he seems confused." She reports that while the patient sleeps, he frequently seems to act out his dreams and has kicked her on occasion. Medical history includes hypertension and hypercholesterolemia. Temperature is 37.3 C (99.1 F), blood pressure is 137/78 mm Hg, pulse is 78/min, and respirations are 14/min. On neurologic examination, there is bilateral resistance to passive movement of the upper extremities, and the patient walks with an unsteady gait. Montreal cognitive assessment score is 21/30 (normal: ≥26). The remainder of the examination shows no abnormalities. Which of the following is the most likely diagnosis in this patient?

Question

A 76-year-old man is brought to the office by his wife for follow-up of recent behavioral changes.  The patient has been much more withdrawn than usual over the past 6 months and often appears sad.  He stopped driving a year earlier after getting lost several times in his own neighborhood.  He now needs help with grocery shopping, meal preparation, and finances.  His wife says, "He has good days and bad days.  Sometimes he's almost like his old self; other times, he seems confused."  She reports that while the patient sleeps, he frequently seems to act out his dreams and has kicked her on occasion.  Medical history includes hypertension and hypercholesterolemia.  Temperature is 37.3 C (99.1 F), blood pressure is 137/78 mm Hg, pulse is 78/min, and respirations are 14/min.  On neurologic examination, there is bilateral resistance to passive movement of the upper extremities, and the patient walks with an unsteady gait.  Montreal cognitive assessment score is 21/30 (normal: ≥26).  The remainder of the examination shows no abnormalities.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d760_e151_bc81_5bc9b3ee68a8_MD0003_00 This patient's presentation is most consistent with dementia with Lewy bodies (DLB). Diagnosis of probable DLB requires the presence of dementia (eg, low Montreal cognitive assessment score) and 2 of 4 additional core features: parkinsonism (eg, limb rigidity) fluctuating cognition (eg, "good days and bad days," periodic confusion) visual hallucinations (occur in 2 of 3 patients, but not required for diagnosis) rapid eye movement sleep behavior disorder (RBD). RBD, a parasomnia characterized by dream enactment behavior during loss of normal REM sleep atonia, is a common and early symptom of DLB. Patients often also have early deficits in executive function (eg, needing help with finances, shopping) and visuospatial ability (eg, getting lost in the neighborhood). Depression, as seen in this patient, is common and occurs in most patients at some point in the illness. Other symptoms include dopamine antagonist (eg, antipsychotics) sensitivity, repeated falls, syncope, autonomic dysfunction, and delusions. (Choice A) Alzheimer disease typically presents with early and prominent memory loss. This patient's pattern of early deficits in executive function and visuospatial ability and his core features of fluctuating cognition, RBD, and parkinsonism make DLB more likely. (Choice B) Creutzfeldt-Jakob disease is a rare prion disease characterized by behavioral changes, rapidly progressive dementia, and myoclonus. (Choice D) Although depression can present with cognitive impairment, it would not explain this patient's RBD, parkinsonism, and fluctuating cognition. (Choice E) Frontotemporal dementia is characterized by early personality changes (eg, euphoria, disinhibition, apathy), compulsive behaviors (eg, peculiar eating habits, hyperorality), and impaired memory. Visuospatial functions usually remain intact. (Choice F) Normal-pressure hydrocephalus is characterized by the triad of cognitive changes (eg, decreased attention and concentration, apathy), gait dysfunction, and urinary incontinence. (Choice G) Vascular dementia is typically associated with focal neurologic findings specific to the location of causal infarct(s) and stepwise decline in function. Educational objective: Dementia with Lewy bodies is characterized by early visuospatial and executive dysfunction and at least 2 of 4 additional core features: visual hallucinations, parkinsonism, fluctuating cognition, and rapid eye movement sleep behavior disorder. References: Diagnosis and management of dementia with Lewy bodies: fourth consensus report of the DLB Consortium. (http://www.ncbi.nlm.nih.gov/pubmed/28592453) Diagnosis and management of cognitive and behavioral changes in dementia with Lewy bodies. (http://www.ncbi.nlm.nih.gov/pubmed/28990131)

A 76-Year-Old Man Is Brought to the Office by His