What neurological deficit is most commonly observed in a thrombotic stroke affecting the non-dominant MCA territory?

• A. Contralateral hemineglect
• B. Global aphasia
• C. Visual agnosia
• D. Pure motor hemiplegia

Answer: (A)

In cases of a thrombotic stroke affecting the non-dominant middle cerebral artery (MCA) territory, the most commonly observed neurological deficit is contralateral hemineglect. This phenomenon occurs when there is damage to regions of the brain that are critical for attention and spatial awareness, particularly in the right hemisphere, which is typically dominant for these functions in individuals who are left hemisphere dominant (right-handed).

Contralateral hemineglect manifests as a failure to attend to or respond to stimuli on the side of the body opposite to the stroke. For example, if the right MCA territory is affected, the patient may ignore objects or even the entire left side of their visual field. This neglect is not due to a visual field defect or a motor impairment but rather arises from an impairment in the brain's ability to process and attend to spatial information.

Understanding this provides valuable insight into the clinical presentations of strokes in different brain regions and their correlation with neurological deficits. In contrast, other deficits, such as global aphasia, visual agnosia, or pure motor hemiplegia, are typically associated with strokes in the dominant hemisphere or specific pathways, rather than the non-dominant MCA territory.