Morning Session: Oculomotor System LOW FREQUENCY MAGNETOTHERAPY IN TREATMENT OF PAIN D. Leki6, D. Djordjevi6, D. Pucar. School of Medicine University of Belgrade Department of Pathologic Physiology, Belgrade, Yugoslavia During last 2 years, in our institution we treated 31 patients with clearly defined pain syndromes of different genesis with magnetotherapy (1-10 Hz, 30 mT). The time course of every treatment was up to 14 days. The number of treatment sessions was 11 4- 2. Using The MeGill Pain Questionnaire, we found decrease in present pain intensity (PPI) for 82.1 4- 8.3% and pain rating index (PRI) for 84.9 4- 8.7%. There was statistically significant difference between initial and terminal, initial and average, but not average and terminal PPI and PRI. These preliminary results suggest that low frequency magnetotherapy may be very important method of pain treatment in future.
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REFLEXOTHERAPY IN TREATMENT OF NEURALGIC PAIN
D. Pucar, D. Djordjevid, D. Lekir. School of Medicine University of
Belgrade Department of Pathologic Physiology, Belgrade, Yugoslavia We investigated efficacy of reflexotherapy (acupuncture, laseropuncture, magnetopuncture and vibropuncture) in treatment of 42 patients with clearly defined neuralgic pain. The stimulation was done in different reflexogenic points of the body depending of pain origin. The treatment course was up to two weeks. Using The McGill Pain Questionnaire, we got statistically significant difference between initial and terminal present pain intensity (PPI) and pain rating index (PRI). Average decrease in PPI and PRI was 79.2 410.4% and 82.1 -t- I 1.1%, respectively. Considering these encouraging results, we think that reflexotherapy deserves important place in treatment clearly defined neuralgic pain, as primary or adjunctive therapy, especially in refractory cases.
Oz-Fz lead is also in accordance with this hypothesis. We conclude that the spontaneous nystagmus fast phase is probably generated in the brainstem. Our results suggest a uniform processing mechanism for the fast phase which does not depend on the origin of pathological nystagmus nor on the direction of eyeball movements.
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PREMOVEMENT EVOKED POTENTIALS RELATED TO THE FAST PHASE OF SPONTANEOUS NYSTAGMUS
R. Jech, E. Rti~i~:ka. Department of Neurology, 1st Medical Faculty,
Charles University, Prague, Czech Republic The fast phase of vestibular nystagmus is considered to be a compensatory movement returning the eyeballs to the original position from which they were displaced by the slow phase. There is not common agreement about the localization of the nystagmus fast phase generators. While in optokinetic nystagmus, the fast phase is voluntary and has cortical origin, in vestibular, caloric, brainstem or cerebellar nystagmus, it is probably triggered involuntary from the brainstem reticular formation. The goal of the study was to find out, if there is any reproducible electroencephalographic activity preceding the nystagmus fast phase. Seven patients with spontaneous nystagmus of different origin, degree, direction, frequency, regularity and amplitude were examined. The evoked potential data collection was synchronized with the fast phase onset in the time window from - 2 0 ms to +20 ms. The leads Oz-Fz, Cz-MI,2, and Fz-shoulder were used. 200 responses were averaged together and each examination was done at least twice to verify the reproducibility. Reproducible evoked potentials were obtained in all of the patients. The largest responses were recorded from the Cz-MI,2 and Fz-shoulder leads. On the other hand, in the Oz-Fz lead, evoked potentials were missing or had very low amplitude. Evoked potential waveform comparisons within the patients group showed that certain waves are present in each subject. In the Cz-M1,2 lead we found the N-14, P-12, P-8, N-6, P-4, N-2, P-I waves, which preceded the fast phase and N1, P4, N6, P8, NI0 waves, which followed the fast phase onset. Similar components also appeared in the Fz-shoulder lead. Aside from the corneo-fundal potential change and neuromuscular activity, the evoked potentials seem to be related to the brainstem generators activity. This is supported by the fact that the wave latencies and amplitudes were within the same range as responses obtained from the Cz-MI,2 lead in the brainstem auditory evoked potentials. The absent activity in the cortical
ALTERATIONOF OPTOKINETIC NYSTAGMUS IN HYSTERICAL BLINDNESS AND MALINGERING
Dirk Reichel, Hans W. Krlmel. Neurologische Kinik am Klinikum Erfurt,
Germany Introduction: Neurophysiological methods in testing the optic system are a useful diagnostic tool if a non-organic cause of blindness is suspected. Firstly, we report a case where optokinetic nystagmus (OKN) revealed the correct diagnosis of functional visual loss. Secondly, we tried to alter OKN voluntarily. Case report: In a 28 year old female the ophthalmological diagnosis of arachnopathia opticochiasmatica was established 9 years ago. The patient herself complained of complete blindness. Clinical findings raised the suspicion of functional visual loss. Along with normal flash evoked visual potentials a normal optokinetic nystagmus provided the correct diagnosis of functional blindness. Alteration of OKN: Consecutively we tested, if optokinetic nystagmus can voluntarily be suppressed by one of us (D.R.). Tests included strabismus, defocusing, sideward gaze, meditation, performing arithmetic tasks etc. In some instances OKN could be altered or suppressed. Control of cooperation by a second person resulted in a significantly false negative rate. Conclusion: We found that, although performance of OKN can substantially be altered by some manoeuvres, testing of OKN is a useful tool in providing the correct diagnosis in hysterical blindness and malingering.
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Oculomotor System
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THE ROLE OF OCULOGRAPHIC RECORDINGS IN MITOCHONDRIAL ENCEPHALOMYOPATHIES
S. Traccis, G. Serra ~, M. Pugliatti, P.G. Masala, C. Boe, MJ. Pirastru, 1. Aiello, G. Rosati. 1st. Clinica Neurological, Universitd degli Studi,
Sassari, Italy; t Ist. Neuropsichiatria Infantile, Universitdt degli Studi, Sassari, haly The neuroophthalmologic sign most frequently described in mitochondrial encephalomyopathies is progressive external ophthalmoplegia (PEO) in Kearns-Sayre syndrome. PEO is also been reported to be present in 10% of patients suffering from MELAS, but such observations mostly base on clinical neurologic evaluation aimed at simply revealing ophthalmoplegia and/or eye-lid ptosis. The aim of our study is to investigate oculomotor function in patients with MELAS/MERRF by means of oculographic recordings. We studied eye movements of 4 patients bearing a mutation of tRNA Lys at nucleotide 8356 (overlap MELAS/MERRF) with no clinical evidence of oculomotor impairment. Horizontal and vertical saecades were recorded by using infrared oculography and the analysis of tracings compared with a group of control subjects. Decreased velocity peak values, dysmetria and saccadic intrusions were the most frequently observed abnormalities. Such findings were markedly evident in the patient with a higher percentage of mtDNA heteroplasmy (57%). Our study suggests that qualititative and quantitative analysis of eye movement tracings allows to reveal subclinic abnormalities and identify the site of oculomotor system involvement. We believe that such test should be included in the diagnostic protocol for mitochondrial encephalopathy in which the investigation of oculomotor system is not considered.
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SACCADIC EYE MOVEMENTS DURING INTRACAROTID AMOBARBITALANESTHESIA
W. Koehler, M. Melchers, D.B. Linke, L. Solymosi, H. Urbach, C.E. Elger, J. Schramm. Universitdt Bonn, Nervenzentrum, S-Freud-Sir.
25, D-53105 Bonn, Deutschland Sakkadic eye movements are dependent on the function of cortical, brainstem and cerebellar centres. Intracarotid amobarbital injection (Wada-Test) functionally inactivates the territory supplied by the carotid artery providing an opportunity to observe the effect on eye movements. What are
Morning Session: Oculomotor System
384
the potential consequences on neuropsychological evaluation? Methods: 37 epileptic patients received an (18 bilateral) amobarbital test as part of their pre-surgical diagnostic program. Eye movements were registered with continuous electro-oculography (EOG) while neuropsychological evaluation was going on. Results: 1) First effects on fast eye movements follow injection by a few seconds 2) typically a loss of fixation and fast components is prominent 3) slowed but persistent saccades are possible 4) sudden return of function often coincides with return of speech and other cognitive abilities. 5) no directional deficit is prominent. 6) in initial and late phases sometimes gaze evoked nystagmus can be observed. Conclusion: Beyond the symptoms of a regional cortical functional deficit more global functional deficits are evident suggesting a direct or indirect involvement of brain stem and/or cerebellar centres.
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SQUARE WAVE JERKS IN RELATION TO NOREPINEPHRIN BLOOD CONCENTRATION IN PARKINSONIAN PATIENTS
Ksenija Ribaric-Jankes I, Nadezda Covickovic-Sternic i, Bogdan Gjuricic 2, Vladimir Kostic ]. i lnstitat za neurologiju, UKC
Srbije, 11000 Beograd, SR Jugoslavija, 2 Institut za biohemiju, UKC Srbije, 11000 Beograd, SR Jugoslavija After metyrosine administration (which causes a marked reduction of dopamine and norepinephrine blood concentration), Tychsen and Sitaram (1989) registered an increased frequency of square wave jerks (SWJ) during ocular fixation and smooth pursuit (SP) in a group of healthy young volunteers. In order to contribute to the unsolved question of transmitters necessary for square wave jerk generation, we measured norepinephrine and 3-methoxy-4-hydroxy-phenylethylene glycol (MHPG) blood and urine concentration in a group of 40 progressive supranuclear palsy, Parkinson's disease plus and Parkinson's disease patients. Ocular movements (SWJ and SP) were registered by means of a 4-channel electrooculography. The obtained results are described and discussed.
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POSTURAL SWAY AND OPTOKINETIC REFLEX DEPENDENT ON SENSORY INTEGRATION IN PATIENTSWITH CENTRAL VESTIBULAR DISORDERS
V. Grigorova, I. Ivanov l K. Stambolieva. Institute of Physiology, t State
University Hospital of Neurology and Psychiatry, Sofia, Bulgaria The purpose of this study was to estimate the effects of available sensory information and central sensory integration on optokinetic reflex and postural sway in body balance maintenance. We examined patients (P) with 1) multiple sclerosis (MS) and 2) state after infarct in the middle cerebral artery (IP), and 3) healthy humans (N). Horizontal and vertical optokinetic stimulation (OKS) with 5 and 15 deg/s was applied on computer monitor screen at 50 cm in front of eyes of standing subjects on 1) stable force plate and 2) covered by foam rubber plate. The background body sway of the subjects, N and P, showed considerable greater body sway on foam rubber. There was not found significant difference between background body sways of N and P on stable force, while on foam rubber the body sway of P was significantly greater than body sway of N. OKS with 15 deg/s caused an increase of body sway in P on stable plate but there was not evident enhancement of body sway on foam rubber. Gains of OKR measured during OKS were not influenced by foam rubber in N as well in P. OKR gain of P was up to 0.5 during OKS with 15 deg/s and significantly smaller than that one of N on stable plate and foam rubber. We suggest that 1) body sway is strongly dependent on somatosensory input even the visual and vestibular information are available, while the OKR is not; 2) there is a close relation between postural sway and OKR when central sensory integration is disturbed.
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LESIONS OF THE CEREBELLAR HEMISPHERE EFFECT THE INITIATION AND MAINTENANCE OF SMOOTH PURSUIT IN HUMANS
A. Straube, W. Scheuerer, Th. Eggert. Department of Neurology,
University of Munich, Germany Traditionally the only known areas of the cerebellum involved in the generation of smooth pursuit are the flocculus/paraflocculus and the posterior
vermis/nucleus fastigii. How these areas interact in smooth pursuit is still unknown but based on the available neuronal data it is suggested that the caudal nucleus fastigii is involved in the control of the acceleration and the flocculus/parafloccuhis in the control of the steady state phase of smooth pursuit. We recorded the initial smooth pursuit in patients with localized lateral cerebellar lesions, in order to prove whether such localized lesions do have an influence on the smooth pursuit performance, The eye movements of ten patients with lesions of the neocerebelhim due to neurosurgical intervention by hemorrhagia, tumor or infarction were recorded by use of monocular infra red oculography (AMTECH, Heidelberg). The subjects were asked to follow a dim red laser spot which moved with a constant velocity of 10°Is, 30°/s or 50°Is and randomized directions (Rashbass paradigm). The average latency to the onset of the eye movements, the mean velocity of the first 20 ms period, the period after 80-100 ms, and a 100 ms period after 300 ms of 10-20 responses was calculated. There was a significant reduction of the ipsiversive initial smooth pursuit compared to the contraversive initial smooth pursuit by about 20% in all patients compared to a maximal difference of 3-4% in the controls. There was also a significant reduction of the smooth pursuit velocity in the later phase of the smooth pursuit response. The results suggest that areas in the cerebellar hemisphere may be involved in the control of smooth pursuit in humans.
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SACCADIC EYE MOVEMENTS IN PATIENTSWITH SCHIZOPHRENIC DISORDERS
A. Hochrein, N. Kathmann, E. Meisenzahl. Psychiatric Hospital of the
University, Munich, German)' Saccadic eye movements are elicited by a real or an imagined object. Saccades made in response to a visual stimulus are reflexive, saccades made without a real object in the visual field are voluntary directed. It has often been reported that schizophrenic patients show abnormalities in saccadic eye movements, but it is unclear whether the dysfunction of the saccadic system depends on the saccadic type (reflexive versus voluntary). To answer this question we have examined prosaccades elicited by a peripheral target, saccades directed by a central cue and antisaccades (subjects were required not to look at a target light but to look in the opposite direction). A sample of medicated and unmedicated schizophrenic patients and healthy controls participated in this study. Vertical and horizontal EOGs were recorded to measure blinks and saccadic eye movements. While the schizophrenic patients showed normal latencies in the visually guided prosaccade task (reflexive saccades), they differed from healthy subjects in showing significantly longer latencies of saccades directed by a central cue and of antisaccades. It is concluded that schizophrenic patients have disturbances in voluntary control of saccades.
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SPEM-DYSFUNCTION IN FAMILIES OF SCHIZOPHRENICS AND PATIENTSWITH AFFECTIVE DISORDERS
N. Kathmann, A. Hochrein, B. Bondy. Psychiatrische Klinik der Ludwig-Maximilians-Universitgit, Miinchen, Germany Abnormalities of smooth pursuit eye movements (SPEM) are hypothesized to qualify as a genetic vulnerability marker for schizophrenia. We conducted a family study to further evaluate the familial specificity of SPEM dysfunction. A sample of 209 subjects (41 schizophrenia spectrum patients, 28 affective psychotics, 36 healthy first-degree relatives of schizophrenics, 17 healthy first-degree relatives of affective psychotics, 87 healthy controls) were examined. Horizontal eye movements were recorded by electrooculography. Pursuit gain was calculated as the ratio of average eye velocity to target velocity. Both schizophrenia spectrum patients and affective psychotics had lower overall pursuit gain than healthy controls (p < 0.002) whereas the patient groups did not differ from each other (p > 0.5). Relatives of the schizophrenia spectrum patients as well as those of the affective psychotics showed worse smooth pursuit than healthy controls (p < 0,05). No difference was found between groups of relatives (p > 0.5). It is concluded that SPEM dysfunction is not limited to schizophrenia spectrum families. Pursuit impairment may reflect a genetically based vulnerability for the development of various forms of major psychotic illness. (Supported by DFG).