[Midbrain infarction presenting isolated inferior rectus nuclear palsy].
We presented a patient of isolated inferior rectus muscle palsy from midbrain lacunar infarction involving the oculomotor nucleus. The patient noticed sudden onset diplopia gazing to the right side, especially to the right-lower direction. He did not have any other symptom, and neurological examination revealed no other findings. Brain MRI documented the focal hyperintense lesion on T2-weighted images in the right-median midbrain ventral to the aqueduct at the level of the superior colliculus. This lesion involved the right oculomotor nucleus, especially the dorso-lateral subnucleus extend to the inferior rectus muscle. The oculomotor nuclear complex consists of one unpaired subnucleus and four paired subnuclei. Among them, the inferior rectus subnucleus lies dorso-laterally. So nucleus lesion may cause isolated weakness of one of muscles innervated by the oculomotor nerve. Among them the isolated inferior rectus muscle palsy can occur relatively.
Takano
M
M
Department of Neurology, Toyama Prefectual Central Hospital.
Aoki
K
K
D000368:Aged; D002544:Cerebral Infarction / Q000150:complications*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000098:blood supply*; D009801:Oculomotor Muscles / Q000294:innervation*; D009802:Oculomotor Nerve / Q000473:pathology; D015840:Oculomotor Nerve Diseases / Q000209:etiology*