Understanding Right MCA Occlusion Symptoms

A stroke in the right middle cerebral artery (MCA) affects the left side of the brain. Since most right-handed individuals have language functions controlled by the left hemisphere, a right MCA occlusion primarily impacts motor and sensory pathways on the contralateral (left) side of the body. It can also affect non-dominant hemisphere functions.

Analyzing the Options for Right MCA Occlusion

• Option 1: Left hemiplegia with left UMN VII cranial nerve palsy: Left hemiplegia (weakness on the left side) is expected from a right MCA stroke damaging the left motor cortex. The motor cortex controlling the left face is located in the right hemisphere; thus, a right MCA occlusion can cause a left UMN VII palsy (affecting the lower left face). This is a potential characteristic feature.
• Option 2: Left hemiplegia with aphasia: Left hemiplegia is expected. However, aphasia (a language disorder) typically results from damage to the dominant hemisphere's language areas (usually the left hemisphere in right-handed people). A right MCA occlusion affects the left hemisphere but generally spares the primary language centers. Therefore, aphasia is not a characteristic feature.
• Option 3: Left hemiplegia with right anosognosia: Left hemiplegia is expected. Anosognosia (unawareness of deficits) can occur with lesions in the non-dominant hemisphere (right side), often related to spatial neglect. A right MCA stroke can affect these areas. This is a potential characteristic feature.
• Option 4: Left hemiplegia with left hemi-anaesthesia: Left hemiplegia is expected. Left hemi-anaesthesia (loss of sensation on the left side) results from damage to the left sensory cortex, which is supplied by the MCA. This is a characteristic feature.

Identifying the Non-Characteristic Sign

Based on the analysis, left hemiplegia occurs due to the stroke affecting the left motor cortex. Left hemi-anaesthesia and left UMN VII palsy can also occur due to damage to the respective areas in the left cerebral hemisphere supplied by the right MCA. Anosognosia is possible due to right-hemisphere involvement. Aphasia, however, is primarily associated with dominant (left) hemisphere lesions. Since the right MCA occlusion affects the left hemisphere's motor and sensory cortex but typically spares the language areas, aphasia is not a characteristic feature in this scenario for a right-handed person.