Infrared oculographic recordings from three patients with hemianopia due to an occipital lesion showed that these patients employed a consistent set of (presumably unconscious) compensatory strategies to find and fixate objects. For targets in the blind hemifield, patients at first used a staircase strategy consisting of a series of stepwise saccadic search movements. This is safe but slow. When retested later, one patient had adopted a more efficient strategy employing one large saccade calculated to overshoot the target. Other strategies for finding targets in the blind hemifield were employed in response to specific situations presented by our experiments: a predictive strategy using past experience to anticipate where the target would be found, and special strategies for recovering a lost target and for awaiting the reappearance of the target. To fixate targets in the seeing hemifield, our subjects undershot the target to prevent losing it in the blind hemifield, then held it off-fovea on the seeing side of the macula.

Single transcranial magnetic pulsed stimuli were applied over the cortical area of the putative right frontal eye field (FEF) in 11 healthy subjects. An especially designed figure of eight shaped twin coil was used, to focus the stimulus, the strength of which was adjusted to the individual motor threshold of the left hand muscles. Eye positions and movements were recorded by an infrared reflection technique. Three different experiments were performed: 1. Stimulation during different primary gaze position did not evoke any discernible eye movement. 2. Stimulation just prior to visually elicited horizontal saccades did not cause a significant alteration of the latency, velocity, or amplitude of the saccades. 3. Only stimulation during an antisaccade task induced a significant latency prolongation, when the stimulus was applied between 50 to 90 ms after the target flashed up. This latency prolongation was found in all subjects for the antisaccades to the right, with a statistically significant average latency difference of +66 +/- 55.5 ms. In contrast, the antisaccades to the left were prolonged in the female subjects only by an average of +98 +/- 41.8 ms (p = 0.0064), whereas in the male subjects they did not alter with stimulation (average difference: -3 +/- 41.9 ms, p = 0.753). Significant latency prolongations were only obtained when the magnetic FEF stimuli were applied within a vulnerable period, which varied from subject to subject.

SYNOPSIS 82 adolescent or adult patients in whom the diagnosis of basilar artery migraine (BAM) had been made or suspected were reviewed. When rigorous criteria were used, the diagnosis could be confirmed in 49 patients (32 women and 17 men). Seven other patients probably had BAM, but did not totally fulfill the criteria. In 26 cases reevaluation did not confirm the diagnosis. In the 49 patients with definite BAM the age of onset ranged from 10 to 62 years, 65% of them having their first attack in the second or third decade. 40% had BAM attacks only, while 60% had additionally other types of migraine attacks. A typical pattern of attacks with an “ischemic” aura followed by predominantly occipital headache was found in only 57%. The most frequent “ischemic” symptom was bilateral visual impairment (86%). Symptoms and signs of brain stem dysfunction were vertigo (63%), gait ataxia (63%), bilateral paresthesia (61%), bilateral weakness (57%), and dysarthria (57%). 77% of the cases had disorders of consciousness (mainly syncope, confusion and prolonged amnesia). 4 patients (8%) had epileptic seizures during the migraine attacks. 73% had a family history of migraine and 12% of epilepsy. EEG's were always abnormal during the attacks with predominantly localized or generalized mostly paroxysmal slow wave activity. CT scans were normal except for 2 women with repeated BAM attacks, who were smokers and taking contraceptive drugs, and who during an attack experienced a cerebellar and an occipital lobe infarction respectively. Of the 26 patients in whom the diagnosis of BAM could not be confirmed 13 had other types of migraine, while the remaining cases had temporal lobe epilepsy, intermittent vertebral basilar artery insufficiency, orthostatic hypotension or hysterical attacks.

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