What symptom may result from a lesion in the uncus of the brain?

A lesion in the uncus, which is a part of the temporal lobe located near the limbic system, can lead to olfactory hallucinations. This is primarily because the uncus contains the primary olfactory cortex, the area responsible for processing smells. When this region is damaged, it can misfire or overactivate, leading to abnormal or distorted perceptions of odors, causing a person to smell things that are not present, known as olfactory hallucinations.

While visual disturbances, auditory processing issues, and cognitive deficits can arise from lesions in other parts of the brain, they are less directly connected to damage in the uncus itself. The association of the uncus specifically with olfactory processing makes olfactory hallucinations the most likely symptom resulting from a lesion in that area.