American Board of Psychiatry and Neurology (ABPN) Practice Exam 2026 - Free ABPN Practice Questions and Study Guide

Subcortical dementia typically involves changes and degeneration in the brain structures beneath the cortex, such as the basal ganglia and thalamus. These structures are integral to regulating motor functions, emotions, and certain cognitive processes. Motor abnormalities, such as bradykinesia, rigidity, and tremors, are hallmark features of subcortical dementia. This includes conditions like Parkinson's disease dementia and Huntington's disease, where motor symptoms are prominent alongside cognitive decline.

In contrast, cortical dementia, which includes Alzheimer's disease, primarily affects the cortical areas of the brain responsible for higher cognitive functions such as memory, language, and problem-solving. These types of dementia are more associated with aphasia (language impairment) and may not prominently feature the motor symptoms typical of subcortical involvement.

The other symptoms mentioned, such as depression and insidious cognitive decline, can be present in both types of dementia. However, the specific motor abnormalities are a distinguishing characteristic more closely linked to subcortical dementia, making them the correct choice in this context.