Monthly Archives: February 2016

VVOR test positive in CANVAS

62yr woman with instability as main complain, lasting for 7 years, which deteriorated in last two years. She felt down for two times completely conscious. Six months ago she noticed double vision when looking to the right. She has slight headaches in occipital part and she is very forgetful. Paresthesias in extremities and clumsiness with hands. Her MRI is still normal.

gaze evoked Ny, from time to time down beat Ny
her speech is slight dysarthric
Romberg is positive: she falls to the right
cerebellar signs positive: dysmetria on the left
patellar reflexes exaggerated, Achilles reflexes absent
diminished sensitivity in the hands and foots
caloric test absent response at both sides
VHIT: absent vestibulo-ocular reflex at all canals
VNG: no smooth pursuit, saccades with prolonged latency to the right, slight overshoot dysmetria to the right and undershoot dysmetria to the left
CANVAS

For CANVAS patients very caracteristic sign is positive VVOR test: this test is positive due to lack of smooth pursuit and lack of vestibulo-ocular reflex and lack of optokinetic reflex.

At this video there’s obvious Horner sign on the right side.
Caracteristic hystory of slowly progressive instability with clinical signs of cerebellar dysfunction and bilateral vestibulopathy and peripheral neuropathy. More about CANVAS at: link

Inferior Vestibular Neuritis – How often do we diagnose it?

Patient in late 50thies feels one week slight instability from time to time, and describes it as difficulty walking straight and also has a short vertigo spells (discomfort in the head) when moving head, especially quick turns. Also, he complains to have left-sided tinnitus (pulsating hissing) since this instability problems has started. He had no nausea or other symptoms.

This history doesn’t sound like a vestibular neuritis.

He had no spontaneous Ny and head-impulse test was normal, but Fukuda step test showed marked turning to the right.

VHIT showed normal gains in all canals expect left posterior, where gain was markedly reduced. cVEMP showed vestibulo-infraocular reflex bilaterally but significantly lower amplitude at the left side.

inf Vestibular Neuritis inf Vestibular Neuritis

Caloric test was normal, no asymmetry at all and audiometry showed bilateral mild hearing loss at high frequencies.

VHIT (6 canals) and cVEMP allowed us to diagnose acute lesion of inferior vestibular nerve branch in this patient.
Link with interesting videos of pt with inferior vestibular neuritis, showing spontaneous torsional nystagmus and positive head impulse test in the plane of the affected posterior canal.