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29 Cards in this Set
- Front
- Back
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Alexander's law
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-jerky nystagmus increased amp in dir of gaze
-fast phase to the right=nystag increases in r dir |
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Null point/null zone
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dir of gaze where the nystag has max dampening
-often move head to this center for max VA |
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neutral zone
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gaze in which the jerky nystag reverses dir
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dissociated vs. conjugacy vs. disjugate
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dissociated:
diff amplitude of nystag in each eye conjugate: same amp and frequency in each eye disjugate: different type in each eye |
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nystagmus definition
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rhythmic involuntary to and fro oscillations
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what are anomalous pursuits
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cogwheel pursuits
stepwise pursuits saccadic intrusion |
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Causes of anomalous pursuits
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basal ganglion lesion
cerebellar lesion gaze specific; asymmetric aging medication: anti-anxiety, tranquilizers |
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some anomalous saccades
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ocular flutter
opsoconlus macro-square wave jerks square wave jerks |
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nystagmus observations in primary gaze:
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type: pendular, jerky, jerky with long fix, jerky with short fix
trajectory: horizontal (infant), vertical (neuro) amplitude frequency manifest latent (congen) |
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CEMAS
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Classification of Eye Movement Abnormalities and Strabismus
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types of physiological nystagmus
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end point nystagmus
optokintetic (OKN) nystagmus Calorid (COWS) Rotational Voluntary |
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types of specific nystagmus
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latent nystagmus
congenital nystagmus nystagmus block syndrome spasm nutans |
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subclassifications of infantile nystagmus
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idiopathic
associated with sensory lack of foveation: ocular albinism, aniridia, achromatopsia, hypoplasia, ON atrophy assoc. with other congenital anomalies: cerebral palsy, periventricualr leucomalacia |
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infantile/congenital nystagmus is SLOFUN+
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S: symptoms, none
L: latent=manifest O: OKN is abnormal (inversion) F: Forced to look gives worse VA U: uniplanar: stays the same in all positions of gaze N: null point +: + no nystag in sleep -head nod is compensatory |
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nystagmus block syndrome (specific)
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ET blocks nystagmus
normal AC:A but asso with convergence excess congen/infant ET 2ndry to nystag jerk in ABduct |
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Spasmus nutans triad+
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1. head turn
2. head nodding, NOT COMPENSATORY 3. nystagmus with varied waveform +. often self resolved onset 18 months-10 years |
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Main areas in eye movement
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FRONTAL LOBE (lets get going!)
-Frontal eye field (FEF) -Supplementary eye field (SEF) -Dorsolateral prefrontal cortex (DLPFC) PARIETAL LOBE (how far?0 -superior parietal lobule -anterior intraparietal areas -parietal eye field -middle temporal area (MT) -medial superior temporal area (MST) |
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congenital ocular motor apraxia
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normal V purs, sac, OKN
Abnormal H saccades (oft absent) Normal H pursuits and OKN head thrusts to make saccades maybe associated with: 1. agenesis of corpus callosum, Joubert's disease (cerebellar vermian dysplasia), and asso visual perception deficits. |
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gaze evoked internuclear ophthalmoplegia
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-lesion along MLF-internuclear lesion
1. unable to make horizontal version--adduction absent or lagging in ONE eye 2. other eye has "nystagmoid mvmt" 3. normal intact convergence (EW is good) 4. affected side is IPSALATERAL. causes: MS and vascular lesions in midbrain |
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vertical gaze evoqued nystagmus
DOWN BEAT nystagmus |
1. fast phase down in primary position
2. frequently obey alexander's law 3. lesion at cranio-cervical junction causes: arnold chiari malformation brainstem lesion/stroke cerebellar degeneration MS with lesion in brainstem head trauma toxic or drug induced metabolic |
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vertical gaze evoqued nystagmus
UPBEAT nystagmus |
1. jerky nystagmus with fast phase upward in 1-ary gaze
2. increased frequency in upgaze/elevation 3. frequently obeying alexander's law 4. brun's nystagmus c/s bruns disorder causes: posterior fossa lesion astrocytomas in children cerebellar lesions MS brainstem stroke toxic or drug induced |
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paget's disease
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ossification
-abnormal bone growth, thickening of occipital bone, impinging on gaze center -secondary platybasia |
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other names for parinaud's syndrome
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convergence-retraction nystgamus
dorsal-midbrain syndrome sylvian aqueduct syndrome pretectal syndrome |
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parinaud's syndrome
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-inability to make upgaze saccade so there's a "nystagmoid movement" upon attempt
-there's also a lid retraction at the attempt and often associated with: convergence palsy/spasm, and accommodative palsy/spasm |
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gaze related nystagmus
VESTIBULAR nystagmus |
mixed directions, often with torsional component
-suppressed c visual fixation, increase when fixations stops -fast phase is away from damaged ear -associated with vertigo, tinnitus, and loss of hearing causes: neuritis and demyelinating disease, meniere's disease, vascular ischemia, stroke, trauma, toxicity |
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TBI
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traumatic brain injury:
acquired by a trauma insult to the head from an external force, may lead to permanent or temporary impairments: cognitive, physical, psycho-social functions, associated diminished/altered state of consciousness -loss of consciousness -post traumatic amnesia -alterations in mental state -focal neurological deficit -glasgow coma scale |
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non-traumatic brain injuries
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acquired by non-mechanical causes:
toxins; accidental or recreational , inflammation, and infections, lack of oxygen |
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what are the two sub-classifications of TBI
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1. Penetrating
2. Closed head injuries--difficult to diagnose with objective testing/imaging |
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common visual symptoms in TBI
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1. blurred vision
2. intermittent diplopia 3. light sensitivity 4. loss of place 5. skipping lines 6. diff shifting to next line 7. sensation of visual "motion" 8. reduced reading speed |
