Effect of aging on saccadic eye movements to visual and auditory targets.

Elderly patients with diseases of the central nervous system often show saccadic disorders. Before these disorders can be called pathological, they must be distinguished from the physiological effects of aging. The purpose of this study was to determine the effect of aging on visual and auditory saccadic eye movements. Ninety healthy volunteers were divided into three groups (younger than 30 years; 30-50 years; older than 50 years), with 30 volunteers in each group. Visual and auditory predictive 15-degree saccades were evoked and recorded with electrooculography. Recorded parameters were peak velocity, duration, and latency. Both stimuli showed increasing latencies with increasing age and a higher peak velocity in the middle group as compared to the oldest group. The latter result was significant only for saccades to visual targets. Duration was almost identical for both patterns and all age groups. Between the age groups, latencies were significantly shorter for the saccades to auditory targets, and no differences in peak velocity occurred. The results stress the importance of an age-related assessment for saccadic parameters. The increasing latency and decreasing peak velocity in elderly people probably result from age-related degenerative changes in central nervous system parts that are involved in the generation of saccadic eye movements. We found no indications of a different effect of aging through either the visual or the auditory pathway for saccadic parameters.

[Choreoacanthocytosis. A neurologic-hematologic syndrome]. / Die Choreoakanthozytose. Ein neurologisch-hämatologisches Syndrom.

A 43 year old male patient is reported who presented at the age of 33 years with a hyperkinetic movement disorder. At the time of presentation orofacial dyskinesias, tic-like hyperkinesias with vocalisation and behavioural disturbance dominated the clinical picture. In the course of his illness he developed a marked truncal choreoathetosis and a symmetrical, distal, predominantly motor polyneuropathy with wasting of lower leg muscles. Serum creatinine kinase levels were markedly elevated. Serum lipids and lipoproteins were within normal limits. These clinical features in combination with an increased number of acanthocytes, clearly visible after dilution of whole blood with normal saline (1:1), led to the diagnosis of choreoacanthocytosis (CA). Both parents were neurologically and behaviourally normal, but were found to have acanthocytes in saline diluted whole blood. The literature concerning CA is reviewed.

[Vertigo as the main symptom. Diagnosis and therapy from the neurologic viewpoint]. / Leitsymptom Schwindel. Diagnostik und Therapie aus neurologischer Sicht.

Vertigo is very often an unspecific symptom. The author differentiates between vestibular or systematic vertigo and non-vestibular or unsystematic vertigo. The diseases of the central vestibular system are described. Not only the special diagnostic methods (e.g. electronystagmography) but also the anamnesis and simple clinical investigation are presented. The overview includes drug therapy and physical therapy of vertigo from a neurological point of view.

Brainstem auditory evoked potentials in migraine--evidence of increased side differences during the pain-free interval.

Brainstem auditory evoked potentials (BAEPs) were recorded in 38 unselected patients (6 m./32 f.; age 18-54 yrs.) with various forms of migraine, during the pain-free interval. The values were compared to those of 50 control persons (18 m./32 f.; age 17-75 yrs.). Peak latencies (PL I-VI), interpeak latencies (IPL I-III, III-V, I-V) and side differences of all peaks (delta I-VI) were calculated. In contrast to PL's of migraine patients, all PL's of control persons were normally distributed. In 6 migraine patients (2 with basilar migraine) PL's were pathologically delayed. Statistical analysis did not show any significant difference in regard to PL's and IPL's between migraine patients and controls. However, side differences of all peaks (except peak IV,VI) were significantly increased in migraine patients as compared to controls. Our results indicate a slight but permanent impairment of brainstem function in migraine.

Electronystagmographic investigations in migraine and cluster headache during the pain-free interval.

An involvement of vestibulocochlear functions has been assumed to occur in migraine even in headache-free intervals. To obtain further information on this subject, we investigated an unselected group of patients with various forms of migraine (n = 94) and cluster headache (n = 8) during pain-free periods by means of electronystagmography (ENG). The investigation showed a normal ENG in all patients with cluster headache and in 85 (90.4%) patients with migraine. Five patients showed increased occurrence of horizontal deviations, indicating an impairment of vigilance. A pathological ENG was observed in only four patients, of whom one with "basilar migraine" showed a disturbance of central vestibular functions. Based on the employed methods, it is concluded that vestibular dysfunctions, and in particular those of central origin, are not common in cluster headache and in migraine-with the possible exception of basilar artery migraine.

[The effect of Ginkgo biloba extract on neurophysiological and psychometric measurement results in patients with psychotic organic brain syndrome. A double-blind study against placebo]. / Einfluss von Ginkgo biloba-Extrakt auf neurophysiologische und psychometrische Messergebnisse bei Patienten mit hirnorganischem Psychosyndrom. Eine Doppelblindstudie gegen Plazebo.

The range of typical symptoms of cerebro-organic syndrome such as dizziness, memory and concentration loss, and orientation disorders can either be measured objectively within a clinical trial or can be observed subjectively. Thirty-six patients with classical symptoms of organic syndrome were recruited into a placebo-controlled double-blind trial in which the therapeutic effect of Ginkgo biloba extract EGb 761 (rökan) was measured by the following objective criteria: quantified EEG, saccadic eye movements and psychometric tests (Wiener Determination Test, Number Connection Test). Following 2 weeks' wash-out, 40 mg. EGb 761 was administered 3 times daily (= 120 mg daily dose) for 8 weeks. The control group received placebo capsules of identical external appearance. The tests listed above were carried out prior to treatment and after 4 and 8 weeks' therapy with the exception of quantitative EEG which was recorded at the beginning and end of treatment only. Patients presenting with pathological findings for at least two of the four test criteria were admitted to the trial. Patients receiving unpermitted supplementary medication or suffering from acute cardiovascular disturbances or digestive and metabolic disorders were excluded from the trial. A highly significant difference could already been seen after 4 weeks of therapy and also after 8 weeks in the results of both the saccadic test and the psychometric tests compared to the placebo control group. Saccade duration was shortened and the latency reduced. In parallel, the number of correct answers given in the Wiener Determination Test and Number Connection Test increased significantly compared to the control group. (ABSTRACT TRUNCATED AT 250 WORDS)

New model of cerebral thrombosis in dogs.

Experimental in situ thrombosis of the middle cerebral artery was produced in dogs by use of intravasally placed copper coils, which subsequently gave rise to an obstructing autologous thromboembolus. The resulting thrombosis was produced in the middle or rostral cerebral artery within 5-15 minutes after delivery of the thrombogenic device. The correlation of location of the coil in the intracranial vasculature of the internal carotid artery with the anatomic distribution of resulting cerebral infarcts suggests that this experimental model can produce a selective acute local occlusion of cerebral vessels in a high proportion of dogs without violating the cranium. The composition of the autologous thromboembolus, the low mortality rate, and the excellent reproducibility will make the correlative study of thrombolytic agents and their therapeutic efficacy possible.

[Experimental thrombolysis of thromboembolisms in the middle cerebral artery circulatory area]. / Experimentelle Thrombolyse von Thrombembolien im Arteria-cerebri-media-Stromgebiet.

Since the majority of ischaemic cerebral infarcts is caused by thromboemboli, we determined the benefit of fibrinolytic therapy in acute stroke. Thromboemboli were induced in the middle cerebral artery of 21 dogs. Urokinase was started at different time intervals after infarction (1, 3 and 5 hours) at a rate of 1000 IU/kg/min. Angiographically controlled thrombolysis was achieved in all 15 treated cases, whereas in the control group (n = 6) no case of recanalisation was observed. Systemic fibrinolysis occurred in all cases. Postmortem examinations of the brains showed no intracerebral haemorrhages. Our findings indicate that urokinase treatment may be of value in acute ischaemic stroke.

The effect of flunarizine and nimodipine on rotatory evoked potentials in rabbit.

Rotatory evoked potentials were recorded in 6 normal albino rabbits before and after administration of flunarizine and nimodipine. Latencies of REP were unchanged by the Ca-antagonists whereas their amplitudes showed some characteristic alterations. There was a significant lowering of amplitude in those peaks which had previously been shown to be of vestibular origin. The peaks that reflect somatosensory activity were amplified by the drugs. Flunarizine showed a more marked effect on the vestibular part of the response than nimodipine. A selective action of Ca-antagonists on brainstem nuclei is suspected.

Treatment of vertebrobasilar insufficiency. Use of calcium antagonists.

The influence of various calcium-entry blockers on the vestibular system was investigated. This paper reports results from animal experiments and also from clinical studies with Flunarizine and Nimodipine. An animal experimental model of vertebrobasilar insufficiency was developed. The effect of these drugs on vestibular nystagmus was studied in Alsatian dogs before and after occluding one vertebral artery. In order to analyse the influence of these drugs on the vestibular nystagmus and on the clinical symptoms in patients with vertebrobasilar insufficiency, different open and double-blind studies were performed.

Calcium antagonists in an animal model of vertebrobasilar insufficiency.

Vertigo as a symptom of vertebrobasilar insufficiency (VBI) is a serious clinical problem in elderly patients. Recent epidemiologic studies have shown that patients with VBI run the same risk of developing complete cerebral infarction as do patients with TIAs. In order to study the efficacy of calcium antagonists in vertebrobasilar insufficiency, an animal model of VBI was developed by occluding one vertebral artery with a balloon catheter. Judging by the reversal of the nystagmic pattern of petite ecriture, the calcium antagonists flunarizine and nimodipine are effective drugs in this animal model of VBI.

[Thrombolysis of cerebral thromboembolism by urokinase in an animal model]. / Untersuchungen zur Thrombolyse zerebraler Thrombembolien mittels Urokinase an einem Tiermodell.

The majority of ischemic cerebral insults are caused by thromboembolism. In animal experiments we have investigated the possibility of reperfusing ischemically damaged brain tissue by thrombolysis of cerebral emboli. 1, 3 and 5 hours after cerebral infarction due to thromboembolism, thrombolytic treatment with urokinase (1000 IU/kg/min) was started. Thrombolysis, monitored by angiography, was successful in all cases (n = 15). In all cases the fall in fibrinogen, alpha 2-antiplasmin and plasminogen reflected systemic fibrinolytic effects. Anatomo-pathologic investigation of the brains revealed no intracerebral bleeding complications. The results of the study suggest a favourable effect of urokinase on acute ischemic cerebral infarction.

Saccadic eye movements as a measure of residual effects: temazepam compared with other hypnotics.

Eye movements are classified into two categories: quickly running saccades and smooth pursuit movements. Saccades are fast conjugate eye movements with a preprogrammed direction, amplitude, and speed course; their purpose is to register new objects in the visual field. The duration and velocity of saccadic eye movements are very much dependent on vigilance. Comparisons were made with a number of psychometric tests [d 2 Durchstreichtest (cross out test), Viennese determination apparatus, and flicker fusion frequency] and the velocity of fast eye movements. The results of three separate investigations are presented. Standardization was undertaken in 100 healthy volunteers, 50 male and 50 female subjects aged between 20 and more than 50 years were included. In an open parallel group study, comparisons were made between various hypnotics with different half-lives (temazepam, flunitrazepam, flurazepam, and phenobarbital). There were 10 healthy volunteers in each group, and medication was taken as a single night-time dose for 7 nights. In a double-blind study, temazepam (20 mg/day) was tested against flunitrazepam (2 mg/day). Dosing lasted 7 days. A marked impairment of the saccadic eye movements was observed with flunitrazepam but not with temazepam. Of all the benzodiazepines tested, only temazepam had no influence on the parameters of the saccade test. These results can be explained by temazepam's short half-life and also by the fact that no active metabolites are formed.

Calcium entry blockers in the treatment of vertebrobasilar insufficiency.

The influence of different calcium entry blockers on the vestibular system was investigated. The paper reports results from animal experiments and also from clinical studies with flunarizine and nimodipine. An animal experimental model of vertebrobasilar insufficiency was developed. The effect of the two drugs on the vestibular nystagmus was studied in Alsatian dogs before and after occluding one vertebral artery. In order to analyze the influence of the drugs on the vestibular nystagmus and on the clinical symptoms in patients with vertebrobasilar insufficiency, different open and double-blind studies were performed.