Oculomotor findings mimicking a cerebellar disorder and postural control in severe Meniere's disease.
OBJECTIVE
We explored whether vestibular derangement in patients with severe Meniere's disease is related to gaze and fixation difficulties and could explain complains of visual blurring and visual neglect.


METHODS
Twenty-six patients with severe Meniere's disease treated with intratympanically applied gentamicin of the affected ear were examined. Saccades (with pseudo-random timing, size and side of the step) and pursuit eye movements (PEMs; pseudo-random target trajectory made of a combination of two sinusoidal waves of different frequencies) and posturography were tested in patients. For normative data of voluntary eye movements, 45 control subjects were tested, and for posturography 29 control subjects. Severity of symptoms in Meniere patients was assessed according to the total handicap score of AAO-HNSF (1985).


RESULTS
Saccadic eye movements and postural stability were severely deteriorated in Meniere patients, and these disturbances correlated significantly with each other. Most of PEM parameters were significantly worse in Meniere patients than in control subjects. Prolongation of saccadic latency and reduced gains due to saccadization in PEMs were characteristic features for Meniere's patients. Severity of symptoms in Meniere patients correlated with prolongation of latency in saccades and with poorer gains in PEMs. Postural instability measured with posturography correlated with saccadic latency and PEMs.


CONCLUSIONS
In severe Meniere's disease, programming of oculomotor and postural responses show the same pattern of disturbance, an increased delay of processing and inaccuracy in the motor output. A fluctuant vestibular lesion with advanced severity can cause disorders of voluntary eye movements that are reflected with clinical complaints of difficulties in reading and visual scanning of surrounding.
Isotalo
Elina
E
Department of ENT, Helsinki University Central Hospital, Haartmaninkatu 4 E, FI-00029 HUS, Helsinki, Finland. elina.isotalo@helsinki.fi
Heikki
Aalto
A
Ilmari
Pyykkö
P
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D005839:Gentamicins / Q000627:therapeutic use; D006801:Humans; D008575:Meniere Disease / Q000503:physiopathology* / Q000628:therapy; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D012438:Saccades / Q000502:physiology*; D012720:Severity of Illness Index; D055815:Young Adult
D000900:Anti-Bacterial Agents; D005839:Gentamicins