there are different kind of nystagmus depending on influence whether alcohol, injury, tumor, bleed or virus.
- peripheral nystagmus occurs as a result of either normal or diseased functional states of the vestibular system and may combine a rotational component with vertical or horizontal eye movements and may be spontaneous, positional, or evoked.
- positional nystagmus occurs when a person's head is in a specific position. an example of disease state in which this occurs is benign paroxysmal positional vertigo (bppv).
- gaze induced nystagmus occurs or is exacerbated as a result of changing one's gaze toward or away from a particular side which has an affected vestibular apparatus.
- post rotational nystagmus occurs after an imbalance is created between a normal side and a diseased side by stimulation of the vestibular system by rapid shaking or rotation of the head.
- spontaneous nystagmus is nystagmus that occurs randomly, regardless of the position of the patient's head.
- central nystagmus occurs as a result of either normal or abnormal processes not related to the vestibular organ. for example, lesions of the midbrain or cerebellum can result in up- and down-beat nystagmus.
refers to uncontrolled eye movement. opsoclonus consists of rapid, involuntary, multifactorial (horizontal and vertical), unpredictable, conjugate fast eye movements without inner saccadic intervals. it is also referred to as saccadomania
or reflexive saccade. the movements of opsoclonus may have a very small amplitude, appearing as tiny deviations from primary position.
possible etiologies of opsoclonus include neuroblastoma and encephalitis in children, and breast, lung, or ovarian cancer in adults. other considerations include multiple sclerosis, toxins, or medication effects. it can also be caused by a lesion in the omnipause neurons which tonically inhibit initiation of saccadic eye movement (until signaled by the superior colliculus) by blocking paramedian pontine reticular formation (pprf) burst neurons in the midbrain. it frequently occurs along with myoclonus in opsoclonus myoclonus syndrome.
nystagmus is very noticeable but little recognized. nystagmus can be clinically investigated by using a number of non-invasive standard tests. the simplest one is caloric reflex test, in which one external auditory meatus is irrigated with warm or cold water or air. the temperature gradient provokes the stimulation of the horizontal semicircular canal and the consequent nystagmus.
doll's eye reflex is more correctly called the oculocephalic reflex. it is where rotation/flexion of the of the head cause transient eye movement in the opposite direction (lindsay, bone and calendar 1997 neurology and neurosurgery illustrated p30
doll's eye reflex is only seen on unconscious patients and it only shows brain stem functioning so depending on the patient it can be a good sign - not good when it is the only sign still intact.
ping pong gaze
examination disclosed periodic eye movements with an initial downward deviation followed by rapid upward correction (dipping), which lasted 10 to 15 seconds (figure, a
; video e-1, on the neurology
web site at www.neurology.org
). intermittently, these movements were followed by slow to-and-fro horizontal eye motion (ping-pong gaze) immediately or with a latency of several seconds
i hope this helps....:0