1604 - Utilizing Nerve Conduction Studies and Electromyography to Unravel Right Upper Extremity Hemiplegia in Right Middle Cerebral Artery Stroke

Right Brachial Plexopathy with Left-Sided Stroke

Case Description: 40-year-old male with no known past medical history presented as level one trauma on 06/13/2025 after gunshot wound resulting in right common carotid artery and right vagus nerve dissection status post vascular repair. On 06/15, the patient was noted to have left upper extremity hemiplegia. Subsequent CTH demonstrated right middle cerebral artery (MCA) stroke in watershed distribution with cortical embolic infarcts. Further imaging studies demonstrated bullet fragments in the right deltoid. After medical clearance, patient was transferred to Bellevue inpatient rehabilitation where physical exam uncovered a right upper extremity hemiplegia with proximal greater than distal muscle weakness not consistent with right MCA stroke. An inpatient nerve conduction study (NCS) and electromyography (EMG) were performed which demonstrated findings consistent with right upper trunk brachial plexopathy. Subsequent follow-up MRI imaging on 09/02 demonstrated diffuse right brachial plexopathy, involving the nerve roots and trunks, most conspicuous at C5-C7 with right C6 root transection.

Discussions: ^{The cerebral cortex has been mapped to the extent to which certain areas can be attributed to a specific sensory or motor function. Ischemic events in the cerebral vasculature produce predictable neurologic deficits that can be detected with thorough neurologic examination. Deviations from expected neurologic deficits warrant further investigation. NCS/EMGs are useful in localizing lesions and provide great utility in identifying structural abnormalities that are the result of lower motor neuron pathologies. For this patient, it was able to help determine the cause of the patient’s hemiplegia that could not otherwise be explained by his stroke}

Conclusions:

Inpatient NCS/EMGs can be useful in helping to elucidate inconsistent neurologic findings that do not fit with the clinical picture.