title: Clinical Study of Eleven Patients with Midbrain Infarction-Induced Oculomotor Nerve Palsy.
abstract: BACKGROUND
  Midbrain lesion-induced oculomotor nerve palsy can be divided into the nuclear and infranuclear types. In the infranuclear type, the degree of each subtype of ocular muscle palsy usually varies.
  
  
  METHODS
  The neuroradiological findings of 11 patients with midbrain infarction-induced oculomotor nerve palsy were analyzed. Their infarcts were grouped into rostral and caudal lesions. Each group was then divided into lesions that occurred in the paramedian and lateral regions before being subdivided further into lesions that occurred in the tegmental, central, and ventral areas.
  
  
  RESULTS
  Unilateral and bilateral infarcts were seen in 9 and 2 patients, respectively. The ventrocentral area of the rostral paramedian region was the most commonly affected part. External ocular muscle palsy was observed in all 11 patients. Ten patients had infranuclear oculomotor nerve palsy. Of these 10 patients, 9 had adduction palsy. Internal ocular muscle palsy was detected in 4 patients. The patient with nuclear type had bilateral ptosis and bilateral elevation palsy and did not exhibit Bell's phenomenon; however, her lesion was unilateral. Vertical gaze palsy was detected in 3 patients who continued to exhibit Bell's phenomenon.
  
  
  CONCLUSIONS
  In the 3 cases in which patients with vertical gaze palsy continued to exhibit Bell's phenomenon, it was considered that the palsy was caused by impairment of the rostral interstitial nucleus of the medial longitudinal fasciculus. Our study suggested that the intra-axial fascicular fibers innervating the medial rectus muscle are particularly susceptible to infarction, possibly because they are the most centrally located in the intra-axial oculomotor fascicular fibers.
authors.affiliation: Division of Neurology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan. Electronic address: ogawa.katsuhiko@nihon-u.ac.jp.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Division of Neurology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Division of Neurology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Division of Neurology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kamei
authors.affiliation: Division of Ophthalmology, Department of Visual Sciences, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002544:Cerebral Infarction / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003941:Diagnostic Techniques, Ophthalmological; D038524:Diffusion Magnetic Resonance Imaging; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D008636:Mesencephalon / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008875:Middle Aged; D009760:Nystagmus, Physiologic; D009801:Oculomotor Muscles / Q000294:innervation*; D009802:Oculomotor Nerve / Q000503:physiopathology*; D015840:Oculomotor Nerve Diseases / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D012189:Retrospective Studies
keywords: Oculomotor nerve palsy; intra-axial oculomotor fascicular fibers; medial rectus muscle; midbrain infarction; nuclear palsy