A double-blind, comparative study of zolpidem and placebo in the treatment of insomnia in patients with dementia and age associated memory disorder

154

Abstracts 7th IOP Scientific Meeting/International

“Gain” is defined as the ratio of the eye movement velocity by the target movement velocity, and “gain on target” is defined as the percentage of the duration of accurate smooth-pursuit eye movement. The statistical analysis of results showed, as a major finding, that the mean values of “gain” and “gain on target” of the schizophrenic group were statistically significant lower than the control group values.

Neurophysiological spondylosis

investigation

I. Tsiptsios a, F. Fotiou a, V. Michalopoulos

in

cervical

a, G. Strikis a. P.

Pappa a, K. Sitzoglou a, E. Tsikna a, N. Evangelou a, D. Papakostopoulos ‘, a Neuroloyical Clinic. AHEPA University Hospital, Thessaloniki, Greece, ’ Electrodiognostic Department, Bristol Eye Hospital, Bristol, UK The difficulties in diagnosing myelopathy and spinal due to cervical spondylosis is root involvement well-known in clinical neurology. In order to investigate the contribution of various neurophysiological examinations in the diagnosis in cervical spondylosis, we examined 60 patients suffering from cervical spondylosis, with peripheral nerve conduction studies, F-wave from the upper limb and electromyography from the corresponding muscles. as well as somatosensory evoked potentials (SEPs) from upper and lower limbs. Patients were separated into four groups: 10 patients had cervical spondylosis symptoms only, 15 patients had symptoms and signs of spinal root involvement, 15 patients had symptoms and signs of myelopathy, and 20 patients had symptoms and signs of both myelopathy and root involvement. A group of 20 normal controls were also studied. In all groups of patients SEPs were the most sensitive electrophysiological study. Low-amplitude N13 and increased conduction time of N9-N13 and of central conduction N13-N19 and LP-P27 were the most common finding in SSEP testing. SEPs were affected in many cases without CT findings of spinal cord pressure. From the above findings, SEP proved to be the most sensitive diagnostic investigation in cervical spondylosis.

Application of somatosensory evoked potentials after dermatomal stimulation in diagnosis of lumbar disc disease P. Tsitsopoulos, C. Tsonidis, F. Fotiou. C. Sitzoglou, I. Neurosurgicol Anagnostopoulos, P. Hadjiioannou, B’ Department, A’ Neurological Department, Aristotle Vniversity Thessoloniki, Thessnloniki, Greece This report deals with application of SSEPs recorded af-

Journal of Psychophysiology 18 (1994) 87-159 ter dermatomal stimulation in the diagnosis of lumbar disc protrusion. Our material consists of 12 surgically treated patients with lumbar disc protrusion, in which diagnostic work-up included history, neurological examination, routine lumbar spine films. computerised tomography and MRI of the lumbar spine, in addition to neurophysiological investigation, especially conduction velocity studies, and SSEPs, recorded by the standard methods, as well as after dermatomal stimulation. The retrospective analysis of our cases, concerning the above-mentioned diagnostic methods and the surgical findings, disclosed a correlation of the SSEPs after dermatomal stimulation and clinical, neuroradiological and surgical findings. Subsequently our results led to the conclusion that SSEPs after dermatomal stimulation are a sensitive and accurate diagnostic modality, useful for the diagnosis of lumbar disc protrusion.

A double-blind, comparative study of zolpidem and placebo in the treatment of insomnia in patients with dementia and age associated memory disorder M. Tsolaki. K. Fountoulakis. A. Kazis, 3rd Department of Neurology, Aristotle University of Thessaloniki, Thessaloniki, Greece Clinical studies have shown that zolpidem, an original imidazopyridine derivative, induces and maintains sleep and does not have daytime side-effects. It is interesting that memory impairments are not found on the morning following intake of this hypnotic drug. It can be also used safely in elderly psychiatric patients to treat insomnia without inducing daytime drowsiness. The efficacy and tolerability of this imidazopyridine hypnotic, zolpidem, were investigated in 60 out-patients with insomnia and dementia of Alzheimer type or other dementias and age associated memory impairment in nightly doses of 10 mg. AD was diagnosed on the basis of a history of progressive dementia with an insidious onset according to the diagnostic criteria of DSM-IIIR and NINCDS-ADRDA. Other dementias and vascular dementia were diagnosed according to the diagnostic criteria of DSM-IIIR. To assess the patients before and after three months therapy, we used the MMSE, which was recently validated in Greece. CAMCOG, Hachinski score, for the clinical differentiation between vascular dementia and Alzheimer’s type and FRSSD (Functional Rating Scale for Symptoms of Dementia), Hamilton scale and GDS was used to assess depressed patients. CT scan, biochemical and haematological examinations were performed on all demented patients. MRI was performed in some patients with vascular history and normal CT scan. Vitamin B,, and folate were examined in all patients. The

Abstracts

7th IOP Scientific Meeting /International

Minnesota Regional Sleep Disorders Centre questionnaire was completed by all patients. Our results showed that zolpidem is well tolerated and more effective than placebo in patients with dementia and age associated memory impairment without changing the cognition or functional activities. AD patients with nocturnal agitation and confusion could sleep without using neuroleptics with the known side effects. The present study, therefore suggests that zolpidem has beneficial effects on sleep disorders in demented patients and patients with age-associated memory impairment.

Positive and negative potential: topography performance effects

shifts in the readiness and perceptual/cognitive

SM. Vaez Mousavi, R.J. Barry, Department of Psychology, University of Wollongong, Wollongong, Australia This study was designed to explore the importance of the positive shifts sometimes found in the period of the readiness potential (RP). The significance of early/late components in the RP and their relationship to opposite polarity shifts in the pre-movement period were also examined. Right-handed subjects (n=16) pressed or did not press a key in response to a perceptual/cognitive task (a simulated “shooting” game) presented on a computer screen. Correct/incorrect performance feedback was given to the subjects. EEG activity from nine electrodes was recorded and separately averaged in 3-set epochs beginning 2 set before each response or non-response task completion. Averages were analysed in relation to correct/incorrect performance on the task, press/no-press of the key, and negative/positive shifts in the pre-event potential, The results indicated that if positive potentials occurred in the pre-event period, they developed early in the epoch, and were always followed by a negative component. The first component of the pre-movement potential did not differ as a function of press/no-press, and had a symmetric distribution with Cz maximum. A higher negativity of this potential in correct performance (compared with incorrect performance) confirmed previous findings. The second part of the RP was independent of the polarity of the preceding shift of the pre-event potential and efficiency on the task. This component was found to be largest at Cz but lateralized towards the contralateral area. It is suggested that this potential may indicate specifying and loading the motor programme. The EMG accompanying the task was found to be larger for correct performance and following a positive shift of the pre-event potential.

Evoked potentials

as correlates of speech-hearing

Journal of Psychophysiology 18 (1994) 87-159

155

interaction LA. Vattanian, I. Sechenov Institute of Evolutionary Physiology and Biochemistv, Russian Academy of Sciences, St. Petersburg, Russia The structural and functional associations of the auditory and speech-producing systems of the brain are the neurophysiological basis of human communication. These associations should provide for obtaining current auditory information, its analysis, integration and the achievement of a response adequate for behavioural situations. To evaluate the levels of interaction of auditory flow and the speech-forming system, short-, middle- and long-latency auditory potentials were recorded in parallel with speech production. The study was carried out in normal subjects with symmetrical audiograms for the right and left ears. The electrophysiological and psychoacoustic data depicted different levels of speech-hearing interactions and asymmetries. The first is a “control filtering” level localised at the prereceptor and receptor areas. It was established on the basis of short latency potentials as symmetrical and independent on the higher levels of auditory processing. The next level of speech hearing interaction (identified by means of middle-latency evoked potentials) is localised in the midbrain and probably in thalamic structures. It seems to be slightly lateralized. The highest levels of mutual speech-hearing interactions, previously revealed psychoacoustically are electrophysiologically highly lateralized, while acoustic and emotional information can be processed in parallel and independently.

Etiology of insomnia Department A. Vela-Bueno, UniversiQ Madrid, Spain

of Psychiatry, Autonomous

Insomnia is a symptom of a broad spectrum of situational, medical and psychiatric conditions. When it is chronic and severe, patients may experience it as a disorder in itself. Short-term or transient insomnia is usually the consequence of stressful life events (loss, separation, etc.), psychological conflict or medical illness. All of these may lead to anxiety and psychophysiological arousal and finally to sleeplessness. Also transient sleep difficulties may result from abrupt changes in the time zone. Chronic insomnia results from the interplay between stressful life situations and a vulnerable predisposition due to non adaptive and inadequate coping patterns for stress and conflict. Without therapeutic intervention, this interaction leads to an internalisation of emotions that causes sequentially: emotional arousal, physiological arousal and sleeplessness. Once insomnia is present, the fear of sleeplessness and performance anxiety enhance the pre-existing emotional arousal, thus creat-