A 65-year-old man with frontal lobe meningioma exhibits socially inappropriate behavior, perseveration, impaired abstract reasoning, and disinhibition, but retains relatively intact memory and language. This presentation is consistent with dysfunction of which prefrontal circuit?
- A Orbitofrontal circuit ✓
- B Dorsolateral prefrontal circuit
- C Anterior cingulate circuit
- D Amygdalo-hippocampal circuit
Correct answer: A. Orbitofrontal circuit
Explanation
The orbitofrontal circuit (OFC) connects the orbitofrontal cortex to the caudate nucleus and thalamus. Dysfunction causes disinhibition, impulsivity, socially inappropriate behavior, and euphoria — the 'frontal lobe personality change.' The dorsolateral prefrontal circuit governs executive function (planning, working memory); its dysfunction causes apathy and cognitive rigidity. The anterior cingulate circuit dysfunction causes akinetic mutism and apathy.
Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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