title: Isolated unilateral oculomotor paresis in pure midbrain stroke.
abstract: OBJECTIVE
  Pure midbrain stroke can cause isolated unilateral oculomotor paresis. We attempted to determine whether there is a difference in the oculomotor paresis pattern between pure midbrain infarction and midbrain hemorrhage.
  
  
  METHODS
  Pure midbrain stroke patients who presented with isolated unilateral oculomotor paresis were identified from a group of 2447 consecutive patients hospitalized for acute cerebral infarction or hemorrhage during the period May 2008 through April 2014. Detailed oculomotor findings were evaluated in the identified patients per the cause of the stroke.
  
  
  RESULTS
  Five patients with infarct and 1 with hemorrhage became our study subjects. Lesions were located in the paramedian area of the midbrain involving the oculomotor fascicles. The pupillary sphincter and inferior rectus muscles were selectively spared in the infarct patients, whereas these muscles were selectively affected in the hemorrhage patient.
  
  
  CONCLUSIONS
  Fibers in the oculomotor fascicle that innervate the levator palpebrae, superior rectus, and inferior oblique muscles appear to be more susceptible to ischemic damage than those that innervate the pupillary sphincter and inferior rectus muscles. Isolated impairment of the pupillary sphincter and inferior rectus muscles may be suggestive of a non-ischemic process.
authors: Department of Neurology, Yokohama Brain and Spine Center, Yokohama, Japan.
authors: Yu
authors: Y
authors: Amano
authors: Department of Neurology, Yokohama Brain and Spine Center, Yokohama, Japan.
authors: Yosuke
authors: Y
authors: Kudo
authors: Department of Neurology, Yokohama Brain and Spine Center, Yokohama, Japan.
authors: Hideyuki
authors: H
authors: Kikyo
authors: Department of Neurology, Yokohama Brain and Spine Center, Yokohama, Japan.
authors: Ryoko
authors: R
authors: Imazeki
authors: Department of Neurology, Yokohama Brain and Spine Center, Yokohama, Japan.
authors: Masahiro
authors: M
authors: Yamamoto
authors: Department of Neuroendovascular Therapy, Yokohama Brain and Spine Center, Yokohama, Japan.
authors: Kazumitsu
authors: K
authors: Amari
authors: Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors: Fumiaki
authors: F
authors: Tanaka
authors: Department of Neurology, Yokohama Brain and Spine Center, Yokohama, Japan. Electronic address: ke00-johkura@city.yokohama.jp.
authors: Ken
authors: K
authors: Johkura
mesh_terms: D000368:Aged; D002543:Cerebral Hemorrhage / Q000150:complications*; D002544:Cerebral Infarction / Q000150:complications*; D006801:Humans; D008297:Male; D008636:Mesencephalon / Q000473:pathology*; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000294:innervation*; D015840:Oculomotor Nerve Diseases / Q000209:etiology*
keywords: Hemorrhage; Infarction; Midbrain; Oculomotor fascicle; Oculomotor palsy