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Biomedical subjects

O Meienberg

Publications and source records attributed to O Meienberg.

At least 37 records · Page 2Linked to original sources
PubMed1986

Clinical and oculographic examinations of saccadic eye movements in the diagnosis of multiple sclerosis.

Saccades were examined clinically and with an improved version of infrared reflection oculography in 79 patients with multiple sclerosis (31 definite, 17 probable, 31 possible cases). With regard to employing saccade recordings in the diagnosis of multiple sclerosis, suitability of saccadic parameters and examination technique for routine use was investigated. Accuracy and peak velocity of 30 degrees and 20 degrees saccades detected mild abnormalities most reliably. Latencies were not reliable enough for routine examinations. The yield of pathology with infrared reflection oculography was improved by using separate normal ranges for abduction, adduction, and interocular differences. Additional examination of vestibulo-ocular reflex suppression seemed to be a reliable supplement to saccade testing, while smooth-pursuit testing cannot be recommended for routine diagnosis. Clinical examination of saccades revealed about half of the dissociated and half of the conjugate hypermetric disorders.

Adolescent↗
PubMed1986

Oculographic diagnosis of hemineglect in patients with homonymous hemianopia.

Two patients with complete dense left homonymous hemianopia of acute onset are presented. There was a striking difference in visuospatial orientation between them in the early stages of their disease, due to additional left hemineglect in the second patient. While eye movement patterns known to be typical for homonymous hemianopia were found in the first patient by means of infrared reflection oculography, the second showed several findings which could be attributed to hemineglect. Based on these observations and those described in earlier literature, oculographic criteria are listed that enable hemineglect to be detected in the presence of homonymous hemianopia. The practical importance of diagnosing hemineglect with objective and quantitative methods is stressed.

Adult↗
PubMed1986

The contribution of oculography to early diagnosis of myasthenia gravis. A study of saccadic eye movements using the infrared reflection method in 22 cases.

Saccadic eye movements were examined by infrared reflection oculography in 22 patients with suspected myasthenia gravis. In all of them the diagnosis was confirmed either by electromyography, by the presence of acetylcholine-receptor antibodies (15 cases), by a positive clinical Tensilon test (4 cases), or by the course of the disease (3 cases). The aim of the study was to find out which of the saccade disorders described in myasthenic patients can be found in the early stage of the disease, and to discover their diagnostic value. Typically, saccade abnormalities were also seen in clinically uninvolved eyes. Intrasaccadic disorders mainly consisted of "decrescendo" of the velocity profiles (two-thirds of the cases) and "hypometria" (half of the cases). Postsaccadic "waver" was present in about two-thirds of the patients. The most frequent finding was "intersaccadic variation" (i.e., variation between repeated corresponding saccades) which occurred in 18 of the 22 patients, and particularly affected the velocity profiles. A standardized fatigue test proved to be useful in accentuating mild, or provoking latent pathology in most of the patients. A standardized combined examination of saccades with Tensilon yielded pathological results less frequently than hitherto described in the literature. In 4 of the 9 patients with purely ocular myasthenia gravis oculography led to the diagnosis. The problems in attempting to delimit the observed saccade abnormalities from those found in other eye movement disorders are discussed.

Adult↗
PubMed1986

[Effect of contact lenses and visual acuity on the registration of saccadic eye movements using an infrared reflection method].

In order to examine the influence of contact lenses and visual acuity on recordings of saccadic eye movements with the infrared reflection method, horizontal 20 and 30 degrees saccades were recorded with and without contact lenses in 16 subjects (32 eyes) usually wearing contact lenses. As far as the main parameters of the saccades (accuracy, peak velocity and duration) were concerned, the reliability of the measurements (recognizable through the mean values) was not essentially influenced by the contact lenses. The precision of the measurements (recognizable through the standard deviation) was with the contact lenses significantly but, for clinical use, not essentially worse. The velocity waveforms of the saccades, however, were considerably changed by contact lenses in some cases. This is why examinations, in which saccadic velocity waveforms are used for diagnosis, should be performed without contact lenses. Visual acuity had no measurable influence on the main parameters of the saccades. However, considerably more corrective saccades were observed with contact lenses than without. There were reasons to believe that not the contact lenses themselves, but better visual acuity was responsible for the larger number of corrective saccades.

Adult↗
PubMed1985

Visual evoked response abnormality in myoclonus epilepsy with large pupils. Occurrence in a family with acorpuscular myoclonus epilepsy.

Flash and pattern evoked responses were recorded from three siblings with myoclonus epilepsy who all had strikingly large pupils in daylight. Comparison with the visual evoked responses (VERs) of 15 normal and eight epileptic control subjects (including one with myoclonus epilepsy but normal pupils) disclosed a substantial reduction of the amplitude of the flash response as compared with the normal pattern response in these three patients. It is suggested that the VER constellation and the pupillary abnormality, together with the normal electroretinogram and diffusely distributed relative scotomas, were due to a ganglion cell loss in the retina.

Adult↗
PubMed1985

The clinical spectrum of internuclear ophthalmoplegia in multiple sclerosis.

The eye movements of 100 patients with multiple sclerosis were examined clinically, including a saccade test. Thirty-four cases of internuclear ophthalmoplegia were found, of which 14 were bilateral and 20 were unilateral. Only three patients had full restriction of adduction, whereas 16 had no restriction at all. A continuous dissociated nystagmus was present in one patient only, while in 15 just a few beats of the abducting eye could be observed. In ten cases both restriction of adduction and dissociated nystagmus were lacking, and the diagnosis could only be made with the saccade test, which in all 34 patients showed a clearly visible disjunction of horizontal saccades. In 15 cases, infrared oculography was performed, which in all cases confirmed the clinical findings, and which in some cases disclosed an additional subclinical internuclear ophthalmoplegia on the opposite side.

Adult↗
PubMed1985

Ischaemic oculomotor nerve palsy. Clinical features and vascular risk factors in 23 patients.

Of 61 patients with isolated third nerve palsy, 23 (38%) had the characteristic clinical features of an ischaemic oculomotor nerve palsy. The essential sign of this usually painful disorder of acute onset was a marked discrepancy between complete or severe paresis of the extraocular muscles innervated by the third nerve, and sparing of the pupillary sphincter. All patients had completely recovered within 3 months. Fourteen had a history or on follow-up had other cranial mononeuropathies. Except for two patients, all were above the age of 60 years. Of the 23 cases, 11 had diabetes mellitus and 8 an abnormal glucose tolerance test, while in 4 the latter was normal. Almost all had hypertension and were overweight, and half were smokers. In 18 patients, four or five vascular risk factors were present.

Aged↗
PubMed1985

Saccadic eye movement disorder in cephalic tetanus.

A 64-year-old woman presented with complaints about facial spasms, difficulty in opening her mouth and intermittent short episodes of horizontal diplopia. The diagnosis of a purely cephalic tetanus was made. While her eye movements appeared normal on clinical examination, infrared reflection oculography revealed a saccadic abnormality which could explain her diplopia. In view of today's pathophysiological concepts on tetanus an attempt is made to explain the eye movement disorder by disturbed inhibitory mechanisms in the brainstem.

Brain Stem↗
PubMed1984

Evaluation of endocrine ophthalmopathy with saccadic eye movements.

Horizontal saccades were examined in 25 patients with hyperthyroidism and/or endocrine ophthalmopathy (EOP) using the infrared reflection method. With one exception none had restriction of horizontal eye movements. Conventional saccadic parameters were usually normal. A standardized test for muscle fatigue, however, gave pathological results in all but one of the patients with EOP, and also in three of seven patients with hyperthyroidism but no clinical EOP. In one of the latter the oculographic abnormality disappeared with treatment, while another developed clinical EOP. Performing a saccadic fatigue test seems to be useful for detecting early EOP and especially for monitoring its course.

Adult↗
PubMed1984

Neurologic disorder of vitamin E deficiency in acquired intestinal malabsorption.

Fifteen years after onset of a malabsorption syndrome, a 49-year-old man had sensory and oculomotor disorder with marked vitamin E deficiency. After 6 months of treatment with high parenteral doses of vitamin E, the neurologic signs slowly receded, but the patient died of gastrointestinal hemorrhage. Autopsy and sural nerve biopsy showed the changes in both central and peripheral nerves; these changes are considered characteristic of vitamin E deficiency.

Adult↗
PubMed1984

[Saccadic eye movements as a measure of the pharmacodynamics of benzodiazepines. Evaluation of various occulographic parameters].

Effects of a single dose of 0.25 mg triazolam p.o. on saccadic eye movements were studied in 6 healthy volunteers. Triazolam was chosen because of its short half-life of 2.5 hours. Peak velocity, duration, acceleration/deceleration index, ratio of hypometric saccades and number of corrective saccades were measured before and at repeated intervals after triazolam administration over a period of 9 hours. Maximal change compared with baseline was observed 90 min. after drug administration. After 9 hours baseline values were reached. As with other benzodiazepines, peak velocity and duration of saccades were the most reliable parameters. Additionally, the number of corrective saccades was found to be a sensitive indicator of drug-induced impairment of oculomotor performance. The present study again emphasises the importance of saccadic eye movements for assessing effects of sedative drugs.

Adult↗
PubMed1983

[Irreversible neurologic injuries in lithium therapy].

Severe lithium intoxication and irreversible neurologic damage was observed in two patients during long-term treatment with lithium salts. In one case intoxication was caused by overdosage, in the other an acute febrile disorder was pathogenetically relevant. Both patients had previously tolerated treatment with lithium without problems thus leading to underestimation of the risk of intoxication. Besides medical control of treatment by assessment of serum levels patients should be particularly informed about early symptoms of intoxication and critical situations facilitating occurrence of an intoxication.

Adult↗
PubMed1983

Supranuclear eye movement disorders in Fisher's syndrome of ophthalmoplegia, ataxia, and areflexia. Report of a case and literature review.

Eye movements in a patient with Fisher's syndrome were examined clinically and documented photographically when palsies were most severe and on repeated occasions during the recovery period. Two recordings of horizontal eye movements were made using the infrared reflection method. Particular attention was paid to signs indicating supranuclear eye movement disorders. We also reviewed cases in which signs suggesting brain-stem involvement were reported. Mild ptosis in the presence of severe ophthalmoplegia, preservation of Bell's phenomenon despite paralysis of voluntary upward gaze, conjugate palsies of vertical gaze, and horizontal dissociated nystagmus have been found relatively often. Convergence spasm was reported only once, however, and there were no prior reports of rebound nystagmus or vertical vestibulo-ocular reflex disorder.

Ataxia↗
PubMed1983

The effect of central retinal lesions on optokinetic nystagmus in the monkey.

In alert monkeys (Macaca mulatta and fascicularis) the effect of central retinal lesions on 'fast' optokinetic responses was investigated during high velocity optokinetic and visual-vestibular conflict stimulation. The 'fast' component of the optokinetic response manifests itself as a rapid rise in the slow-phase eye velocity after light-on, during high velocity optokinetic stimulation; and a sudden drop in eye velocity after light-off. In contrast, the 'velocity storage' component leads only to gradual changes in eye velocity during continuous optokinetic stimulation and after light-off (optokinetic after-nystagmus). Retinal lesions were placed by laser coagulation in and around the fovea. Responses of the normal and lesioned eye were compared. It was found that central lesions up to 12 deg (fovea diameter 6 deg) had only a negligible effect on 'fast' optokinetic responses. With lesions of more than 25-30 deg diameter centered on the fovea definite 'fast' responses could still be obtained, on average reduced to about 50% of the responses of the normal eye. Some monkeys showed initially no 'fast' optokinetic responses and had, therefore, to be excluded from lesion experiments. The results demonstrate that 'fast' optokinetic responses also can be obtained from extrafoveal areas, i.e. areas which are not generally involved in smooth pursuit eye movements. These results are discussed in relation to reports that the 'smooth pursuit' eye movement system is also used to generate 'fast' optokinetic responses.

Animals↗