A 74-year-old man is brought to the office by his wife due to a change in behavior. Over the last year, the patient has had difficulty recognizing his grandchildren and has gotten lost in his local grocery store more than once. He enjoys playing Sudoku in the Sunday newspaper but has had increasing difficulty completing the puzzles. He has also been increasingly distractible during conversation and says that he sometimes sees animals in the house despite the couple not owning any. The patient has not seen a doctor in 20 years and takes no medications. His wife says that he started "slowing down" and talking about stiffness and a tremor approximately 4 years ago, which was before he experienced any behavioral symptoms; they never sought medical care because they assumed it was "just part of getting older." Examination shows intact cranial nerves as well as pinprick and light touch sensations. There is rigidity in the bilateral upper and lower extremities that is worse on the left. Tremor is present in both hands at rest and is worse in the left hand. Movement and speech are slowed. Gait is unsteady and marked by a shortened stride. Which of the following is the most likely diagnosis?

Question

A 74-year-old man is brought to the office by his wife due to a change in behavior.  Over the last year, the patient has had difficulty recognizing his grandchildren and has gotten lost in his local grocery store more than once.  He enjoys playing Sudoku in the Sunday newspaper but has had increasing difficulty completing the puzzles.  He has also been increasingly distractible during conversation and says that he sometimes sees animals in the house despite the couple not owning any.  The patient has not seen a doctor in >20 years and takes no medications.  His wife says that he started "slowing down" and talking about stiffness and a tremor approximately 4 years ago, which was before he experienced any behavioral symptoms; they never sought medical care because they assumed it was "just part of getting older."  Examination shows intact cranial nerves as well as pinprick and light touch sensations.  There is rigidity in the bilateral upper and lower extremities that is worse on the left.  Tremor is present in both hands at rest and is worse in the left hand.  Movement and speech are slowed.  Gait is unsteady and marked by a shortened stride.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient's >4-year history of asymmetric rigidity, resting tremor, and bradykinesia is consistent with undiagnosed Parkinson disease. Approximately one-third of patients with Parkinson disease develop Parkinson disease dementia (PDD). Risk factors include age, duration, and severity of symptoms of Parkinson disease. Although signs/symptoms of PDD are similar to those of dementia with Lewy bodies, by definition, PDD is diagnosed when parkinsonism predates cognitive impairment by >1 year; this pattern is clearly evident in this patient. PDD typically presents with executive and visuospatial dysfunction (eg, impaired attention and planning, inability to recognize familiar people [eg, grandchildren], getting lost in familiar locations [eg, grocery store]) with only mild memory impairment at first. Although visual hallucinations, delusions, and sleep disorders may occur in Parkinson disease without dementia, these symptoms occur at higher rates in PDD. The cognitive impairment of PDD may be treated symptomatically with cholinesterase inhibitors (eg, donepezil). Psychotic symptoms of PDD may be treated by a dose reduction of antiparkinsonian agents and/or low-potency antipsychotics (eg, pimavanserin, quetiapine). (Choice A) Alzheimer disease presents with early, prominent memory impairment accompanied by executive and visuospatial dysfunction. Motor symptoms are rare early in the disease process. (Choice B) Dementia with Lewy bodies presents with dementia plus ≥2 of the following features: visual hallucinations, parkinsonism, fluctuating cognition, and REM sleep behavior disorder. Cognitive impairment would develop in this condition before or at the same time as parkinsonism, not years later, as seen in this patient. (Choice D) Progressive supranuclear palsy is a rare syndrome that presents with falls, impaired vertical gaze, and parkinsonism. This patient has preserved extraocular movements. (Choice E) Vascular dementia classically presents with mild memory impairments, prominent executive dysfunction, and focal neurologic deficits corresponding to cerebrovascular pathology. This patient's presentation is more consistent with PDD. Educational objective: Parkinson disease dementia (PDD) is characterized by executive and visuospatial dysfunction with relatively mild memory impairment at first. PDD may be distinguished from dementia with Lewy bodies by the timing of symptom onset: If parkinsonism predates cognitive impairment by >1 year, PDD should be diagnosed. References: Parkinson disease and dementia. (http://www.ncbi.nlm.nih.gov/pubmed/27502301)

A 74-Year-Old Man Is Brought to the Office by His