Involvement of which of the following structures will lead to right-sided hemiplegia and aphasia?

NHM MP Staff Nurse - 2015

Medical & Surgical Nursing

Hard

Appeared in: NHM MP Staff Nurse - 2015

Explanation

The left cerebral hemisphere controls motor function for the right side of the body due to the decussation (crossing over) of motor pathways.
A stroke affecting the Left Middle Cerebral Artery (MCA) can damage the motor cortex, resulting in right-sided hemiplegia (paralysis) or hemiparesis (weakness).
In most individuals, the language centers (Broca's area for speech production and Wernicke's area for comprehension) are located in the left hemisphere.
The Left MCA supplies these critical language areas, so an occlusion leads to aphasia (language dysfunction).

Option B: The vertebral arteries are part of the posterior circulation, supplying the brainstem, cerebellum, and posterior aspects of the brain. A stroke here would cause symptoms like vertigo, ataxia (impaired coordination), diplopia (double vision), and cranial nerve palsies, not the classic combination of hemiplegia and aphasia.
Option C: A brainstem lesion can cause severe motor deficits, including quadriplegia, and can affect consciousness. While it can cause slurred speech (dysarthria) due to weakness of the muscles of articulation, it does not cause aphasia, which is a disorder of language processing originating in the cerebral cortex.
Option D: A stroke in the Right Middle Cerebral Artery would cause left-sided hemiplegia. Because the right hemisphere is non-dominant for language in most people, it does not typically cause aphasia. Instead, it is associated with deficits like left-sided neglect (inattention to the left side of space) and anosognosia (unawareness of the deficit).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Localization of Neurological Deficits in Stroke as background academic context rather than a clinical decision trigger.
Recognizing stroke syndromes is a core nursing skill. Linking specific deficits (like right weakness + aphasia) to a specific vascular territory (Left MCA) allows nurses to anticipate patient needs, such as communication aids, fall precautions on the right side, and swallowing difficulties.
The FAST acronym (Face, Arm, Speech, Time) is a public health and nursing tool used to promote rapid identification of stroke and activation of emergency services, as 'time is brain'.
Nurses play a vital role in the acute phase by monitoring for changes in neurological status, managing blood pressure, and preventing complications like aspiration, which are directly related to the deficits caused by the stroke.

How to Approach the Question

First, break down the clinical signs presented in the question: 'right-sided hemiplegia' and 'aphasia'.
Recall the principle of contralateral brain control: the left side of the brain controls the right side of the body. Therefore, right-sided hemiplegia points to a lesion in the left cerebral hemisphere.
Next, consider the location of language centers. For most people, language functions (speech and comprehension) are localized to the left hemisphere.
Both key signs (right-sided weakness and language loss) point to a problem in the left hemisphere.
Evaluate the options. The Middle Cerebral Artery (MCA) supplies the largest area of the lateral cerebral cortex, including the motor cortex and the primary language areas.
Conclude that an occlusion of the Left Middle Cerebral Artery is the only option that explains both right-sided hemiplegia and aphasia.

Concept Tested & Keywords

Concept Tested: Localization of Neurological Deficits in Stroke
Stem keywords: right-sided hemiplegia, aphasia, structure involvement
Lead-in keywords: which of the following
Clinical cues: Combination of motor deficit on one side and a specific cortical function deficit (language).

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E6 Medicine Harrison 22e Part 2 pp. 1334-1336, 1333-1335