Modern surgical treatment of otosclerosis - Helda - Helsinki.fi

Results and comments
Table 4. The number and percentage of patients with different planes of pre- and
postoperative nystagmus recorded while the eyes are covered. Percentage values are
calculated from all patients recorded for that time period. HSN=head-shaking nystagmus.
Nystagmus Spontaneous HSN
Preoperative Horizontal 1 (9%) 0
Vertical 1 (9%) 0
Both 1 (9%) 0
One week postoperative Horizontal 4 (15%) 3 (11%)
Vertical 1 (4%) 1 (4%)
Both 1 (4%) 0
One month postoperative Horizontal 2 (7%) 3 (11%)
Vertical 1 (4%) 0
Both 1 (4%) 0
3-4 months postoperative Horizontal 2 (11%) 1 (5%)
Vertical 1 (5%) 1 (5%)
Both 0 1 (5%)
Short-term evaluation (IV)
In this study, VOG was measured on average four hours (range 1.5-6 hours) after the
operation. No nystagmus was found when fixation was allowed, and three patients (14%)
had pathological nystagmus when the eyes were covered. Two patients had spontaneous
horizontal nystagmus with an SPV of 1.9 º/s and 1.5 º/s. In both cases, the fast phase
beated away from the operated ear, and with the latter patient there was also a minute
torsional component. The third patient had vertical nystagmus with a maximum SPV of
2.2 º/s, and the fast phase beated upwards. The nystagmus was persistent when the other
eye was covered. These patients did not complain of any postoperative vertigo or nausea.
Seven patients had latent, spontaneous horizontal nystagmus that manifested during the
lateral gaze in the direction of the fast phase only, with a gaze angle of less than 30 º. One
patient had an upbeating component related to the horizontal nystagmus, and the
remaining patients had primary horizontal nystagmus with an SPV between 1 and 3 º/s
accompanied by a minor torsional component. The horizontal direction of nystagmus was
excitatory in four patients, and inhibitory in three patients. The prevalence of latent,
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