Modern surgical treatment of otosclerosis - Helda - Helsinki.fi

Results and comments
5.3 Video-oculography studies (III, IV)
Long-term evaluation (III)
Three (27%) of the 11 patients measured preoperatively had spontaneous nystagmus with
an SPV of 1.3-3.3 º/s when the eyes were covered. There was no preoperative headshaking
nystagmus (HSN) in any of the patients. After the operation, 11-15% of the
patients had HSN (SPV 6.6-17.8 º/s), but statistically, this was not significantly different
from the preoperative level (p=0.18). None of the patients had spontaneous nystagmus
when fixation was allowed. The number of patients with nystagmus and the dimensions of
nystagmus are shown in Table 4.
Nine patients (27%) experienced some vestibular symptoms, especially during rapid head
or body movements during the first postoperative week. One of these patients had nausea
and vomiting during the first week. Only three of these patients had pathological findings
in the VOG. Two patients had horizontal HSN (SPV 11.1 º/s and 8.9 º/s). One patient had
horizontal nystagmus that followed Alexander’s law for peripheral nystagmus, with an
increasing SPV (2.4-6.7 º/s) when the gaze was in the same direction as the nystagmus. In
all of these patients, the nystagmus was directed away from the operated ear. There were
also four patients with pathological horizontal spontaneous nystagmus who experienced
no vestibular symptoms. Three of these patients had nystagmus directed towards the
operated ear and in one patient it was directed away from the operated ear. The remaining
patients who experienced HSN (SPV 13.3 º/s) towards the operated ear had no vestibular
symptoms.
After one month, only one patient (3%) had subjective vestibular symptoms. This patient
still reported minor dizziness five months after the operation, but only during rapid head
movements. She had horizontal nystagmus beating away from the operated side after head
shaking, with an SPV of 8.8 º/s, which appeared in the VOG recordings one month after
the surgery.
After one month, three patients (11%) had spontaneous horizontal nystagmus (SPV 1.3-
3.8 º/s), and in all cases it was directed away from the operated ear. Two of these patients
had vertically oriented nystagmus without a horizontal component one week following
surgery. One of these was the patient with nystagmus that followed Alexander’s law one
week after operation who now had spontaneous nystagmus with an SPV of 1.3 º/s. Two
patients had HSN, but no vestibular symptoms one month after the operation. One of these
had no nystagmus one week after the operation, but did experience vestibular symptoms at
that time. She now had HSN with an SPV of 8.9 º/s directed away from the operated ear.
The second one had HSN with an increased SPV of 17.8 º/s (13.3 º/s one week
postoperatively) directed towards the operated ear.
52