Review Question - QID 214378

This patient is presenting with visual hallucinations (e.g., seeing a dog and being agitated by things no one else sees) and features of parkinsonism (e.g., limb rigidity and bradykinesia) which are highly suggestive of dementia with Lewy bodies.

Dementia with Lewy bodies (DLB) is neurodegenerative dementia believed to be due to alpha-synuclein deposition within neurons. Patients with DLB present with fluctuating cognition (i.e., level of alertness and attention), visual hallucinations (can be formed images, seeing humans and animals or simple shape and colors), parkinsonism (bradykinesia or akinesia, rigidity, postural instability leading to falls, and resting tremor), and rapid eye movement (REM) sleep disorder. The diagnosis is clinically made when at least 2 of these findings are met. Magnetic resonance imaging will typically demonstrate generalized atrophy of the brain. The mean age of presentation is around 75 years of age and is more common in men. DLB is considered the second most common cause of dementia with Alzheimer being the first.

Incorrect Answers:
Answer 1: Alzheimer dementia is a neurodegenerative dementia. Alzheimer dementia does not present with visual hallucinations and parkinsonism. Typically, patients with Alzheimer presents with short-term memory loss, spatial disorientation, and language deficits.

Answer 3: Frontotemporal dementia is a neurodegenerative dementia that classically presents with disinhibition (e.g., making inappropriate remarks and urinating in public), compulsive behavior, apathy, and atrophy of the frontotemporal region of the brain.

Answer 4: Parkinson disease is a neurodegenerative disorder that leads to decreased dopaminergic neurons, especially in the basal ganglia. Patients present with resting tremor, rigidity, bradykinesia or akinesia, and postural instability. Visual hallucinations and fluctuating cognition are not typically seen in Parkinson disease compared to dementia with Lewy bodies.

Answer 5: Vascular dementia is a form of dementia that is caused by cerebrovascular disease. Patients classically present with a stepwise cognitive decline such that patients may initially have a cognitive decline that is temporally related to cerebrovascular events. Impaired executive function is classically associated with this dementia. MRI will demonstrate cerebrovascular disease.

Bullet Summary:
Dementia with Lewy bodies presents with at least 2 of the following: fluctuating cognition, visual hallucinations, parkinsonism, and rapid eye movement (REM) sleep disorder.