Fascicular arrangement within the oculomotor nerve MRI analysis of a midbrain infarct

J Clin Neurosci. 2000 May;7(3):268-70. doi: 10.1054/jocn.1999.0199.


The fascicular arrangement of the oculomotor nerve within the midbrain is not adequately elucidated in humans. We treated a patient with a partial oculomotor palsy who had impaired adduction and supraduction on the left side, which were attributed to an ipsilateral lacunar infarct. CT and MRI revealed a discrete lesion in the centre of the midbrain tegmentum in the rostrocaudal plane. This case suggests that the oculomotor fibres for extraocular movement are located in the middle of the the midbrain, and supports the fascicular proximity of the superior and medial rectus muscles. The fascicular arrangement of the midbrain oculomotor nerve is speculated to be pupillary component, extraocular movement and eyelid elevation in that rostrocaudal order, based on the previous reports of neuro-ophthalmological impairment and MRI findings, which are analogous to the nuclear arrangement proposed by Warwick.

Publication types

  • Case Reports

MeSH terms

  • Cerebral Infarction / complications*
  • Cerebral Infarction / diagnostic imaging
  • Cerebral Infarction / pathology
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Mesencephalon / diagnostic imaging
  • Mesencephalon / pathology*
  • Middle Aged
  • Models, Neurological
  • Oculomotor Nerve / diagnostic imaging
  • Oculomotor Nerve / pathology*
  • Oculomotor Nerve Diseases / diagnostic imaging
  • Oculomotor Nerve Diseases / etiology*
  • Oculomotor Nerve Diseases / pathology
  • Ophthalmoplegia / etiology*
  • Ophthalmoplegia / physiopathology
  • Remission, Spontaneous
  • Thalamus / pathology
  • Tomography, X-Ray Computed