Week 3 - Neuro 2.2 Flashcards
What is Nystagmus and what may cause it?
Abnormal eye movements may occur because:
• Inability to maintain fixation
• Loss of normal inhibitory influences on eye movement control system
• Loss of normally symmetrical input from one of the vestibular pathways to the ocular motor nuclei
Why do Albino’s have Albinism?
• Inability to maintain fixation, with OCT of a patient with albinism:
Absence of a normal foveal contour, therefore no central point of fixation
What are the different phases of Nystagmus, and what does amplitude and frequency relate to nystagmus?
• Slow phase and rapid recovery phase
• slow phase - abnormal movement, drifting away from object of interest
• Rapid phase - recovery saccadic motion
• Amplitude (how far eyes move): coarse or fine
• Frequency (how fast eyes move): low, moderate, high
What are the 3 types of eye movements with nystagmus?
• Jerk: Slow drift, fast saccadic correction
• Pendular: Non-saccadic in both directions, slow
• Mixed: Pendular in primary position
Jerk on lateral gaze
What are the 8 types of acquired nystagmus?
• See-Saw
• Downbeat
• Upbeat
• Abducting nystagmus of INO
• Periodic alternating
• Pendular nystagmus
• Spasmus Nutans
• Gaze evoked
What causes See-Saw and downbeat nystagmus?
• See-Saw
- Midbrain lesions
- Pituitary tumours
- Severe visual loss
• Downbeat
- Cerebellum lesions
- Medulla lesions
- Idiopathic
What causes Upbeat and Abducting nystagmus of INO?
• Upbeat
- Medullary lesions
- Cerebellum lesions
- Benign positional paroxysmal vertigo
• Abducting nystagmus of INO
- Demyelination
- Brainstem stroke
What causes Periodic alternating and Pendular nystagmus?
• Periodic Alternating
- Arnold-Chiari
- Demyelination
- Trauma
- Encephalitis
- Syphilis
- Posterior fossa tumours
- Visual deprivation
• Pendular nystagmus
- Demyelination
- INO
- Brain stem dysfunction
What causes spasmus Nutans and Gaze-evoked nystagmus?
• Spasmus Nutans
- Idiopathic in children
- Glioma
• Gaze-evoked
- Drugs
- Alcohol
What needs to be asked during history of nystagmus?
• Onset
- Age, constant or intermittent, aggravating or alleviating factors (head position)
• Associated symptoms
- Symptoms of demyelinating disease
- Vertigo or oscillopsia; vestibular system abnormality
- Deafness/tinnitus in vestibular lesions
- Blurred vision
- Double vision in particular positions of gaze
How must motility be assessed with nystagmus?
First assess ocular stability in primary position.
Then examine in 9 cardinal positions to:
• Monocular or binocular
• Conjugation - do eyes behave similarly?
• Abnormal movements are horizontal, vertical, torsional or mixed
• Abnormal movements are continuous or are induced by particular eye positions
• Only, slow, fast, both phases are seen
•There is a null point
How is Nystagmus managed?
• Acquired - investigate for cause
• Advice
• Refractive management; spectacle choices
• Low vision aids
What is a Migraine?
• Periodic headaches with complete resolution between attacks
• 80% have 1st attack before 30yrs
• Prevalence increases until 40yrs then decreases
• 6-8% of men, 15-25% of women
• 15% of females only have attacks around menstruation
What are migraines caused by and what are the stages?
Can be associated with:
• certain foods (cheese, chocolate, coffee, red wine, shell fish)
• nausea or vomiting
• photophobia
Typical stages of an attack:
• Prodrome (warning symptoms of attack)
• Aura (visual disturbance, motor or sensory disturbance)
• Headache
• Resolution
Many types, variations of the above
What is a common migraine and its symptoms?
• Migraine without aura
• Headache and autonomic nervous system dysfunction (pallor, nausea)
• Prodrome: changes in mood, yawning, poor concentration
• Headache: pounding/throbbing, can start anywhere and spreads to half or whole head, photophobic and sensitive to sound
• Lasts from hours to a day