Summary of patients with abnormal vertical optokinetic nystagmus
| Sex | Age | U | D | L | R | MRI results/diagnosis | |
| 1 | M | 10y7m | Lu | + | + | + | MRI, midline abnormality of the midbrain, periaqueductal grey matter, symmetrical abnormality of dorsal pons. Symmetry of the lesions favours a metabolic disorder |
| 2 | F | 7y6m | Lu | Lu | + | + | MRI, bilateral occipital infarcts, right frontoparietal lesion. Haemorrhagic ischaemic infarct following mild birth asphyxia |
| 3 | M | 7y9m | Lu | Lu | + | + | Niemann–Pick disease type C |
| 4 | F | 14y | Lu | Lu | + | + | Niemann–Pick disease type C |
| 5 | F | 8y5m | Lu | Lu | + | + | Gaucher disease type I. MRI, haemorrhagic lesion in the rostral midbrain of unknown aetiology |
| 6 | F | 0y9m | Lu | Lu | Lu | Lu | Gaucher disease type II |
| 7 | F | 5y5m | Lu | Lu | Lu | Lu | Gaucher disease type III |
| 8 | F | 10y9m | Lu | + | Lu | Lu | Gaucher disease type III |
| 9 | F | 4y7m | Lu | + | Lu | Lu | Gaucher disease type III |
| 10 | F | 3y10m | Lu | + | Lu | Lu | Gaucher disease type III |
| 11 | F | 4y1m | + | Lu | Lu | Lu | Gaucher disease type III |
| 12 | M | 4y9m | + | Lu | Lu | Lu | MRI, dysmorphic basal ganglia, small corpus callosum, underdeveloped brainstem, particularly the pons |
| 13 | F | 2y5m | Lu | Lu | – | – | MRI, generalised decrease in bulk of the brain and delay in maturation of myelin |
| 14 | F | 5y11m | + | – | + | + | MRI, abnormality in right cerebellar white matter, right cerebellar peduncles and the right medulla. Appearances consistent with acute inflammatory or neoplastic lesion |
| 15 | F | 2y | – | + | + | + | MRI, dilatation of the whole ventricular system, as a result of hydrocephalus |
| 16 | M | 3y | – | + | + | + | MRI, lesion within the medial thalamic nuclei. Aetiology not known, possibly a metabolic disorder or post-viral encephalitic damage |
| 17 | F | 8y9m | + | – | + | + | MRI, bilateral symmetrical abnormality in upper part of the cerebral peduncles extending into the lower parts of the thalami on both sides. Leigh disease |
| 18 | M | 2y2m | – | – | Lu | – | MRI, discrete white matter lesions, lesions in basal ganglia and abnormality in the thalamus on both sides. Aetiology not known, possibly because of atypical infection |
| 19 | M | 1y7m | – | – | Lu | + | MRI, incomplete cerebellar and dorsal pontine myelination, marked maturational delay |
| 20 | M | 1y | + | – | Lu | – | MRI, cerebellar vermis hypoplasia, increased prominence of superior cerebellar peduncles. Joubert syndrome |
| 21 | M | 2y6m | – | – | – | – | MRI, absent cerebellar vermis, arachnoid cyst in the left posterior fossa. Joubert syndrome |
| 22 | M | 6y2m | – | – | – | – | MRI, multiple cerebral infarcts, due to antenatal thrombosis of aorta. Cortical blindness |
| 23 | M | 5y5m | – | – | – | – | MRI, white matter changes adjacent to posterior aspect of lateral ventricles, abnormality at cerebellar pontine angle. Appearances consistent with degeneration/demyelination |
| 24 | M | 4y10m | – | – | – | – | MRI, lesion in the brainstem near the IIIrd nerve nucleus. Focal ischaemia most likely aetiology |
| 25 | M | 16y7m | – | – | – | – | Cerebral palsy. No MRI |
| 26 | F | 1y7m | – | – | – | – | Undiagnosed neurodevelopmental disorder. MRI, no abnormality |
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y = years, m = months, U = response to an upward moving optokinetic stimulus, D = response to a downward moving optokinetic stimulus, L = response to a leftward moving optokinetic stimulus, R = response to a rightward moving optokenetic stimulus, + = OKN present, − = OKN absent, Lu = lock up.
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The first 13 patients listed are those with a vertical saccade initiation failure (in either direction, up/down, or both). The final 13 patients listed had absent VOKN (in either direction, up/down or both).
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nb Lock up in response to an upward moving stimulus indicates a saccade initiation failure of down saccades. Lock up in response to a downward moving stimulus indicates a saccade initiation failure of up saccades.
