1 / 20

THE ENG BATTERY

THE ENG BATTERY. ENG & VNG. Clinical Eye Movement Videos. Calibration. Confirming relation between: Voltage/Infrared video feed and Eye position Fixed Targets/Sinusoidal Tracking. Gaze testing. Gaze at visual targets. Eye movements are recorded Spontaneous nystagmus

ginger-brock
Download Presentation

THE ENG BATTERY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. THE ENG BATTERY

  2. ENG & VNG Clinical Eye Movement Videos

  3. Calibration • Confirming relation between: • Voltage/Infrared video feed and • Eye position • Fixed Targets/Sinusoidal Tracking

  4. Gaze testing • Gaze at visual targets. • Eye movements are recorded • Spontaneous nystagmus • gaze evoked nystagmus • other extraneous movments • Pt. asked to close there eyes without shifting gaze.

  5. strongest on gaze in direction of beating never vertical declines quickly (within days to a couple of weeks) Alexander's Law:1st degree Nystagmus: present only on lat. gaze2nd deg: both on center and lat. side of beat3rd deg: on center, and both lateral gazes. Video Periph Gaze Peripheral Gaze Nystagmus:

  6. Alexander's Law

  7. Central Nervous System Lesions: • Often bilateral beating • Can have vertical beating • declines slowly if at all

  8. Some Central Gaze Nystagmi: • Bilateral Horiz. Gaze (Brun's) Nystagmus: • Rebound Nystagmus: • Periodic Alternating Nystagmus: • Vertical Nystagmus: • Congenital Nystagmus: What is Going on here?:Voluntary Nystagmus

  9. Bilateral Horiz. Gaze (Brun's) Nystagmus: • in large CPA tumors. • Gaze ipsi to lesion generates large slow nyst, with exp. decay in slow phase. • Gaze contra to lesion generates small fast nyst, in opposite direction of ipsi resp. • Video Bruns

  10. Rebound Nystagmus: • Cerebellar disease • movement-generated, decays rapidly (10-20s) • Beats in direction of movement • Video Rebound

  11. Periodic Alternating Nystagmus: • Medullary disease. Periodic Alternating Video • cyclic, 90 s one direction, • 10 s nothing or vertical, • then 90s in other direction, 10 s down time, • and back again. • present w/ eyes open or closed. • strongest in middle of phases>>visual impairment.

  12. Vertical Nystagmus: • Brainstem/Cerebellar or Inf. olivary disease • Can be generated by alcohol, drugs, too. • Upbeat Video • Downbeat Video

  13. Congenital Nystagmus: • From fixed brain defect either genetic or developmental in origin. • Pendular and/or jerk-type • Disorder of slow eye movement sub-system. • Null points or periods. • Convergence inhibition • Congenital Video

  14. Saccade Testing • Horizontal • Vertical • Regular pattern or random • Through 20 to 30 degrees. 

  15. Saccadic Disorders: • Occular dysmetria: CBL lesion • akin to dysdiadochokinesia • overshoots/undershoots • Saccadic Slowing: basal ganglia lesion • normal saccade for 20 deg = 188/sec • Internuclear Ophthalmoplegia: MLF lesion • rounded tracings • one eye lags, smoothing curve. • separate eye recordings to confirm INO VIDEO

  16. Watch out for: • Superimposed nystagmii) gaze nystagmusii) congenital nystagmus • Drug effects: usually dysmetria • Patient problems:i) inattentionii) eye blinksiii) head movement: scalloped tracings

  17. Tracking Tests: • Following pendular movements • Problems to look for • saccadic pursuit-eyes snap repeatedly to keep up with movement = CNS lesion • disorganized pursuit, wandering, slow, inaccurate tracking - CNS lesion, usually above the level of theocculomotor nuclei • disconjugate pursuit, eyes don't stay together in tracking - CNS lesion

  18. Things to look out for: • Drug influences • Inattention: multiple, rapid gaze deviations • Head movement: depressed amplitude • superimposed nystagmus • gaze: R, L, or bil. >> jerks at extremes • congenital: often overlies entire tracing

  19. Optokinetic test • Repeated tracking of moving target, producing nystagmatic motion. • Disorders: • Asymmetry: CNS lesiondiff of > 30 degs, at more than one stim rate. • Flat / declining resp. to faster rates. brainstem lesion, possible MS • Inverted movement: Congenital nystagmus

More Related