Two sisters with cluster headache were studied with respect to the pupillary responses to instillation into the conjunctival sac of a single drop of a 1% solution of phenylephrine and a 2% solution of tyramine. The changes in pupillary diameters were documented by photographic pupillometry prior to and at 15, 30, 60, and 90 minutes after the instillations. Of the two sisters, one (case A) was examined during a symptom-free interval, when she had been free from cluster headache attacks for 2 1/2 years. When the cluster headaches recurred, retesting was performed. The other sister (case B) had been free from cluster headaches for 9 years, when she was examined. The findings indicate hypofunction within the postganglionic sympathetic nerve fibers during a cluster headache period. The hypofunction is bilateral, and thus, can not be a consequence of the unilateral cluster headache attacks. During remissions, tyramine induces a marked mydriasis, particularly on the symptomatic side, tentatively indicating an excessive release of stored monoamines.

Adult↗

PubMedDate not supplied

Eye movements in cerebellar and combined cerebellobrainstem diseases.

We report a quantitative analysis of eye movement disturbances in patients with isolated cerebellar disorders and patients with cerebellar disorders and concomitant brainstem involvement. The most characteristic abnormalities in the exclusively cerebellar patients were increased velocities of the slow phases of vestibular nystagmus induced by rotation in the dark and increased peak velocities of the fast phases of optokinetic nystagmus induced by full-field optokinetic stimuli. Dysmetria of saccades was found in three of six cerebellar patients and gaze nystagmus in all six patients. The typical findings in the combined cerebellobrainstem group were reduced peak velocities of voluntary saccades, defective smooth pursuit and reduced peak velocities of the fast component of nystagmus during rotation in both the dark and light. All patients with combined cerebellobrainstem disorder had dysmetric voluntary saccades and gaze nystagmus. The numbers of superimposed saccades during smooth pursuit were uniformly increased. Release of inhibition in cerebellar disorders may explain the hyperresponsiveness and inaccuracy of eye movements found in this study. In addition, when lesions also involve the brainstem, however, integrative centers coding eye velocity are affected, leading to slow and inaccurate eye movements. These features elicited clinically may be useful in the diagnosis of cerebellar and brainstem disorders.

Adult↗

PubMedDate not supplied

Eye movements in brainstem lesions.

The eye movements of 10 patients with brainstem lesions were examined, using an electro-oculo-graphic technique. An analysis was made of the responses in the following tests: smooth pursuit, saccade, rotation, optokinetic, optovestibular and caloric. Chief interest was directed towards the peak velocity. The results were compared with the corresponding velocities in 20 normal subjects. In the same patient, one or several types of eye movements could be normal, while others were pathological. In the whole group, voluntary eye movements (smooth pursuits and voluntary saccades) were more vulnerable than reflexive ones (nystagmus). Next to the smooth pursuit test and the voluntary saccade test, the optovestibular test was the most sensitive in discriminating patients with brainstem lesions from normal subject.

Adolescent↗

PubMedDate not supplied

Eye movements in patients with speech dyspraxia.

Saccades, smooth pursuit and angular acceleration induced nystagmus were analysed quantitatively in 10 patients with speech dyspraxia. The saccades were less accurate, had a prolonged reaction time and showed a tendency to reduced peak velocity, though only contralateral to the lesion. Smooth pursuit was imparied, with a reduction in maximum velocity gain. The vestibular responses tended to be hyperactive, indicating facilitated brain-stem reflexes. The findings show that a lesion in the frontal eye field can produce various oculomotor disturbances, in which the triggering of eye movements and their control, and pacing of the various movement sequences are disturbed. In addition, anticipation of a movement pattern requiring volition may be greatly impaired.

Adult↗