Brainstem stroke presenting as isolated bilateral ptosis

Abstract

Pure midbrain infarctions not involving surrounding structures are an uncommon clinical phenomenon. A midbrain infarction that results in isolated bilateral ptosis as the only neurological deficit is much rarer and an easy diagnosis to miss; therefore, potentially leading to further downstream complications. We describe the case of an elderly patient who presented with isolated bilateral ptosis, initially thought to be consequent to myasthenia gravis but subsequently identified to have a perforator infarct in the midbrain, resulting in his symptoms.

Uraemic brainstem encephalopathy mimicking ocular myasthenia: a case report

“…Bilateral asymmetrical ptosis due to a midbrain pathology has been previously described [9,10]. This has been attributed to a single nuclear complex (centro.-caudal subnucleus of the oculomotor nuclear complex) that innervates the levator palpebrae superioris muscles bilaterally [11] However, the cause of fatigability of the ptosis, a hallmark sign of myasthenia gravis, observed in our patient remains elusive given that his lesion was central.…”

Paramedian Midbrain Infarction Presenting with Bilateral Ptosis and Unilateral Median Longitudinal Fasciculus Syndrome: A Peculiar Midbrain Syndrome

“…Bilateral ptosis is a rare manifestation and has been reported in 5% of patients with pure midbrain infarction in a previous case series [ 1 ]. Isolated bilateral ptosis has also been reported in a few cases [ 3 , 4 , 5 , 6 ], and the majority of these patients had small lesions in the paramedian or central regions of the midbrain. The CCN, which is a single structure and located in the midline dorsomedial to the caudal pole of the oculomotor nucleus in the midbrain, emits crossed and uncrossed fibers that innervate the bilateral levator palpebrae muscles [ 2 ].…”