Table 2
Investigation results
| Patient | Nystagmus characteristics | Neuroimaging | ERG | VEP | Horizontal OKN | Diagnosis | ||||||
| 1 | Circumrotatory in primary, vertical in lateral gaze | no | poor cone mediated ERGs | att pattern VEPs to all check sizes | present | cone dysfunction | ||||||
| 2 | Upbeat in primary and upgaze, horizontal in lateral gaze | MRI: N | poor cone mediated ERGs | att pattern VEPs to all check sizes | absent | cone dysfunction | ||||||
| 3 | Fine vertical pendular | MRI: N | poor cone mediated ERGs | att pattern VEPs to all check sizes | present | cone dysfunction | ||||||
| 4 | Fine vertical pendular | no | poor cone mediated ERGs | att pattern VEPs to all check sizes | not tested | cone dysfunction | ||||||
| 5 | Asymmetric fine horizontal pendular mainly in LE | MRI and CT: N | poor cone mediated ERGs | pattern VEPs to medium and large checks (50′–400′) | present | cone dysfunction | ||||||
| 6 | Fine vertical pendular | no | poor cone mediated ERGs | pattern VEPs to medium and large checks (50′–400′) | not tested | cone dysfunction | ||||||
| 7 | Fine vertical pendular and circumrotatory, head shake | CT: N | poor cone mediated ERGs | pattern VEPs to medium and large checks (50′–400′) | present | cone dysfunction | ||||||
| 8 | Fine vertical pendular | no | poor cone mediated ERGs | att pattern VEPs to all check sizes | not tested | cone dysfunction | ||||||
| 9 | Vertical pendular, worse in LE, horizontal in lateral gaze | MRI and CT: N | poor cone and rod mediated ERGs | pattern VEPs to large checks only (200–400′) | present | cone-rod dystrophy | ||||||
| 10 | Asymmetric (LE worse) fine horizontal pendular in primary and L gaze, jerk in R gaze | MRI: N | poor cone and rod mediated ERGs | att pattern VEPs to all check sizes | present | cone-rod dystrophy | ||||||
| 11 | Asymmetric fine horizontal pendular mainly in LE | MRI: N | normal | att pattern VEPs to all check sizes | present | albinism | ||||||
| Crossed asymmetry flash VEP | ||||||||||||
| 12 | Vertical upbeat some horizontal pendular | MRI: N | well preserved a wave, poor b wave (negative ERG) | att and delayed pattern VEPs to all check sizes | absent | X linked CSNB | ||||||
| 13 | Vertical upbeat and pendular, horizontal jerk on lateral gaze | MRI: N | normal | pattern VEPs smaller than average to all check sizes | present | CIN | ||||||
| 14 | Downbeat worse in upgaze | MRI: N | normal | pattern VEPs smaller than average to all check sizes | present | CIN | ||||||
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VEP “attenuated VEPs” refer to clinically significant degradation of the responses, “VEPs smaller than average” implies small responses that are just within the normal amplitude range. (N=normal; att=attenuated, CSNB=congenital stationary nightblindness; CIN congenital idiopathic nystagmus; poor=significantly attenuated or absent.)
