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Biomedical subjects

R B Daroff

Publications and source records attributed to R B Daroff.

At least 73 records · Page 4Linked to original sources
PubMed1977

"Inverse latent" macro square-wave jerks and macro saccadic oscillations.

A patient recovering from an acute encephalopathy demonstrated several ocular motor disturbances reflecting cerebellar and brainstem dysfunction. Two of these, macro square-wave jerks and macro saccadic oscillations, have never been reported in the same patient. The macro square-wave jerks disappeared with monocular viewing, a previously undescribed "inverse latent" characteristic.

Adult↗
PubMed1977

The ocular motor defects in progressive supranuclear palsy.

The results of quantitative infrared horizontal eye movement recordings in 8 patients with progressive supranuclear palsy are presented. Some of the patients had total paralysis of vertical movements, but none had completely lost the ability to perform horizontal eye movements. All patients had a defect in ocular fixation previously undescribed in this condition: the universal presence of square-wave jerks. Analysis of refixation saccades demonstrated hypometria, slow velocity/amplitude relationships, and profound prolongation of duration. The pursuit abnormality, characterized clinically by "cogwheel" eye movements, represented the inability to match eye velocity to target velocity. The ratio of peak eye velocity to peak target velocity (pursuit gain) was 0.2 to 0.5. Defects in the vestibuloocular reflex included inability to increase the gain of the reflex (ratio of peak eye velocity to head velocity) during viewing of a visible, stationary target and failure to suppress the reflex when viewing a target rotating with the head.

Aged↗
PubMed1977

Vertigo.

Vertigo reflects dysfunction in the vestibular system. Any disease state which changes the firing frequency of a vestibular end-organ and which produces unequal neural input to the brainstem causes vertigo. Caloric stimulation mimics acute end-organ dysfunction and helps establish the diagnosis.

Caloric Tests↗
PubMed1976

Braking saccade--a new fast eye movement.

A new type of fast eye movement (FEM) is described whose main function is to stop a runaway slow eye movement (SEM). It conforms to the velocity-amplitude relationship characteristic of other types of saccades. The identification of this FEM is the result of examination of the many waveforms manifested by subjects with congenital nystagmus. It is a common, repeatable phenomenon present in all subjects with any of six different types of nystagmus waveform. The fact that braking saccades reset SEM to zero velocity, whereas no other type of saccade interacts with SEM, indicates a developmental mechanism in such subjects.

Eye↗
PubMed1975

Congenital nystagmus waveforms and foveation strategy.

Accurate eye movement recordings of sixty-five subjects with congenital nystagmus (CN) provides a firm foundation for the classification of the many types of waveforms observed and results in objective definitions based on measurable quantities rather than subjective clinical impressions. The careful scrutiny of these records along with the utilization of laser-target cinematography have yielded insights into the mechanism of this ocular motor instability. Prolongation of target foveation emerges as the dominant factor in many of the resultant waveforms. This enhances the visual acuity of the subject with CN. An additional observation, related to fixation bias reversals of the CN subject, may be a physiological indicator of foveal function.

Adult↗
PubMed1975

Macro square wave jerks.

Quantitative eye movement recordings in a patient with multiple sclerosis who had both macro square wave jerks and an internuclear ophthalmoparesis supported the concept of an internal brain-stem monitor that mediates corrective eye movements. A brain-stem model of this monitor illustrates the patient's motility disorder and the normal function of providing synergistic version and vergence corrections for dysmetric eye movements. Thus, the careful study of pathologic disturbances provides information relevant to the normal operation of the ocular motor system.

Adult↗
PubMed1975

Edrophonium infrared optokinetic nystagmography in the diagnosis of myasthenia gravis.

Horizontal optokinetic nystagmus was measured by an infrared eye movement recording technique before and after the administration of intravenous edrophonium chloride in 16 patients wtih proved myasthenia gravis. All the patients, even those without clinically apparent ophthalmoparesis, demonstrated an increased amplitude of optokinetic nystagmus after administration of the drug. None of 12 control patients, many with ophthalmoparesis, showed increased optokinetic nystagmographic amplitude. The superiority of infrared recording techniques to electro-ocuography was discussed. Edrophonium infrared optokinetic nystagmography proved to be a sensitive and specific test of myasthenic weakness in extraocular muscles.

Adolescent↗
PubMed1975

Comparative velocities of different types of fast eye movements in man.

The peak velocity-amplitude characteristics of voluntary saccades and the fast phases of caloric, rotational, and optokinetic (OKN) nystagmus were compared in ten human subjects in both light and, except for OKN, darkness. All these fast eye movements had similar velocities and all slowed in darkness. This study supports the presumption that the identical brainstem firing patterns found in monkeys for all fast eye movements also occur in man.

Adult↗