Week 8 Flashcards
What are the 2 types of strabismus?
Non-restrictive
Binocular disorder
Conjugate eye movements reveal what?
subtle muscle paresis
What are the 2 types of innervation incomitant strabismus?
- Supranuclear/Internuclear
2. Nuclear/Infranuclear
What are the types of Supranuclea/internuclear strabismus?
- Skew Deviation
- INO
- Thalamic Esotropia
What are the types of Nuclear/Infranuclear strabismus?
- OMN Palsy
- Peripheral Neuropathy
- Disorders of neuromuscular junction
- Congenital cranial dysinnervation syndrome
What are the types of mechanical incomitant strabismus?
- Restrictive
2. Others
What are the types of restrictive strabismus?
- Brown’s syndrome
- Postoperative
- Trauma
What are the types of “other” strabismus?
- Orbital inflammation
- Orbital infection
- Orbital lesion
- Orbital Trauma
What type of head movement is found in a lateral rectus palsy?
Head turn
What type of head movement is found in an oblique muscle paresis?
Head tilt to shoulder
T/F: Saccades, pursuits OKN and VOR are impaired toward the side of the lsion
True
What % of CN VI palsies heal in 6 months?
60-75%
What are the 3 tx for a CN palsy?
- Prism
- Range of Motion exercises
- Head turn
What are the pros of Fresnel prism?
- Low cost
- Thin and light weight
- Cosmesis is OK
- Up to 40 pd
- Horiz. and Verti.
What are the cons of Fresnel prism?
- Blurry Vision
- Reduced contrast
- Age and Dirty
- Peel/fall off
What are the pros for prism goggles?
- Better clarity
- Low cost
- Easily ordered
- Switch prism power
- up to 30pd
What are the cons of prism goggles?
- No temples
- Uncomfortable frame
- Distortions
- Cosmesis
Deafness has what % association w/ Duane’s Retraction syndrome?
10%
Convergence spasm is caused by what?
trauma
What is the most common cause of acquired vertical strabismus?
CN IV palsy
Where is diplopia greatest in CN IV palsy?
downgaze
WIT: mechanical restriction of superior oblique muscle causing difficulty of eye moving up on adduction?
Brown Syndrome
What are the common causes of 3rd nerve palsies in adults?
- Aneurysms
- Vascular Disease
- Trauma
- Migraine
What are the common causes of 3rd nerve palsies in kids?
- Birth trauma
- Accidental trauma
- Neonatal hypoxia
- Migraine
WIT: 3rd NP + contralateral hemiparesis
Weber’s syndrome
WIT: 3rd NP + contralateral tremor
benedikt’s syndrome
WIT: 3rd NP + ipsilateral cerebellar ataxia
Nothnagel’s syndrome
WIT: Benedikt’s + Nothnage’s syndrome
Claude’s syndrome
What is the most common cause of 3rd nerve palsy with pupillary involvement?
Intracranial aneurysms
- junction of internal carotid + PCA
What is the most common cause of 3rd NP w/ pupil sparing?
Ischemia
- DM, HTN, Migraine, SLE, Temporal Arteritis
WIT: Involuntary eye oscillations that drive the eye away from the target?
Nystagmus
Nystagmus is called by lesions of what 3 things?
- VOR
- Gaze-holding system
- Smooth Pursuits + OKN
What are the characteristics of pendular nystagmus?
both phases slow
What are the characteristics of jerk nystagmus?
1 fast phase, 1 slow phase
What are the characteristics of plane nystagmus?
Horizontal, vertical, torsional rotary
What are the characteristics of conjugacy nystagmus?
Direction, amplitude, frequences
Oscillopsia of greater than __ degrees per second impairs vision
5 degrees
What is the main difference between peripheral and central vestibular nystagmus?
Peripheral = can be suppressed with vision/adaptive
Central = no suppression/no adaptation
A downbeat nystagmus is caused by what 6 things?
- Arnold-Chiari
- Cerebellar degeneration
- Vertebrobasilar infarction
- MS
- Drugs
- Idiopathic
An upbeat nystagmus is caused by what 4 things?
- Cerebelllar degeneration
- Brainstem/Cerebellar infarct
- MS
- Tumors
Gaze-evoked nystagmus is due to normal pulse but ___?
unsustained step signal
What is the only normal nystagmus not associated with disease?
Physiological End-Point Nystagmus
When does physiological end-point nystagmus start?
After 30 seconds of sustained view in lateral gaze (fatigue effect)
A person with congenital nystagmus will have what 2 issues?
- head tremor
2. gaze-holding issues
What are the 3 components that prevent drift nystagmus?
- VOR
- Neural integrator
- Long Term Recalibration
What nerve accounts for most cases of acquired vertical strabismus?
CN4
What is the triad for the ocular tilt reaction?
- Skew Deviation
- Ocular torsion
- Head tilt 10-13 deg
Ocular tilt reaction is perceived when?
In the darkness
In a skew deviation, they ___ eye is extorted, while in CN4 deviation the ___ eye is extorted
Skew = hypo eye CN4 = hyper eye (up and out)
Convergence retraction nystagmus is due to ?
due to lesion in the rostral midbrain