Pure Motor Monoparesis in the Upper Extremity Due to a Medial Medullary Infarction

Abstract

A 69-year-old man with essential hypertension abruptly presented with moderate pure motor monoparesis (PMM) in the left-sided upper extremity. There were no other neurologic abnormalities. Cranial magnetic resonance imaging demonstrated a small infarction in the caudal and lateral region of the right-sided medial medulla oblongata. Thereafter, intravenous anti-thrombin agent was initiated, and she became asymptomatic within 14 days. This is a first reported case of PMM in the upper extremity due to medial medullary infarction (MMI). In the medulla oblongata, we speculated that the corticospinal tract fibers innervating the lower extremity might decussate rostral to the fibers innervating the upper extremity.




J Med Cases. 2015;6(1):8-9
doi: http://dx.doi.org/10.14740/jmc1989w