Neuro-Ophthalmology



Neuro-Ophthalmology





Ophthalmology


I. Nystagmus



  • Congenital



    • Decreased with convergence


    • Increased with fixation


    • Optokinetic nystagmus inversion


    • Uniplanar in all directions


  • Latent



    • Seen only when one eye is covered


    • Fast component away from covered eye


    • Decreased visual acuity


  • Downbeat—cervicomedullary junction



    • Arnold-Chiari syndrome


    • Spinocerebellar degeneration


    • Brainstem stroke


    • Multiple sclerosis (MS)


  • Upbeat



    • Localizes weakly to medulla


  • Rotary



    • Localizes to thalamus


  • See-saw (pendular)



    • Localizes to suprasellar region


  • Convergence-retraction



    • Dorsal midbrain (Parinaud syndrome)


    • Poor OKNs downward


    • Differential diagnosis by age



      • 10 years: pinealoma


      • 20 years: head trauma


      • 30 years: vascular malformation


      • 40 years: MS


      • 50 years: basilar stroke


  • Gaze-evoked



    • Drugs: antiepileptic drugs or sedatives


    • Bilateral brainstem lesions


    • Cerebellar lesions



  • Ocular myoclonus



    • Localizes to Mollaret triangle


  • Ocular bobbing



    • Rapid downward jerk with slow drift to primary gaze


    • Localizes to pons


    • Differential diagnosis



      • Hydrocephalus


      • Metabolic encephalopathy


      • Hemorrhage


      • Trauma


  • Opsoclonus (dancing eyes)



    • Localizes to dentate nucleus


    • Differential diagnosis



      • Neuroblastoma


      • Postinfectious


      • Visceral carcinoma


II. Cerebellar Lesions



  • Ipsilateral smooth pursuit defect (become saccadic)


  • Transient eye deviation contralateral to lesion


III. Frontal Lesions



  • Ipsilateral eye deviation


  • Intact slow pursuit


  • Eyes can doll past the extent of the palsy


  • Optokinetic nystagmus abnormal toward lesion


  • Frontal abnormalities are typically transient (days to weeks)


  • Parapontine reticular formation lesions result in permanent abnormalities.


IV. Parietal Lesions



  • Contralateral homonymous hemianopia


  • Normal saccades


  • Pursuit abnormal toward side of lesion


  • OKNs abnormal toward side of lesion


V. Parinaud Syndrome



  • Supranuclear upgaze palsy


  • Lid retraction


  • Convergence-retraction nystagmus


  • Light-near dissociation


VI. Tolosa-Hunt Syndrome (cavernous sinus syndrome)

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Sep 8, 2016 | Posted by in NEUROLOGY | Comments Off on Neuro-Ophthalmology

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