s71
A-18.03 CHANGES IN SLEEP ORGANIZATION OF UNTREATED EPILEPTIC PATIENTS AND UNDER ACUTE AND CHRONIC TREATMENT WITH PHENOBARBITAL (PB) AND PHENYTOIN(DPH).U.U. R'dder and P.Wolf (Berlin, W. Germany)
In a prospective study, the sleep of 40 hitherto untreated patients was investigated polygraphically (EEG, EMG, EOG, ECG) and compared with the sleep of the same persons under the with placebo; on first following conditions: drug administration of PB or DPH; with therapeutic drug levels; after 6 months of treatDPH and PB were given to each patient ment. as sole drugs in a cross-over design. The effects of first administration of PB were the same as known from non-epileptic persons (especially reduction of REM sleep). The immediate effects of DPH were unimpressive. In steady state conditions, REM sleep was still decreased with PB, and there was a modification the first REM cvcle of of the sleeo structure: the night became longer by an increase o? NREM sleep, especially the deep stages, whereas during the late REM cycles, deep sleep decreased. The natural sleep structure with a maximum of deep sleep early in the night was thus sharp, DPH in therapeutic ened by PB. Contrariwise doses seemed to reverse this structure by flattening the early REM cycles. The differences in the therapeutic efficiency of these major antiepileptic drugs might partly be due to their different actions on sleep. C-17.03 EEG ACTIVITY AND THE LINKAGE OF BRAIN H.P. Meles, T.M.Darcey AREAS DURING SEIZURES. and H.G. Wieser (Ziirich, Switzerland) We have measured intracortical seizure activity at 32 sites simultaneously and computed correlations between all possible pairs of recording locations. We then relate these correlations to anatomical proximity, so as to characterize the linkage of distant, and the isolation of adjacent, brain areas before, during and after seizures. We interpret changes of the correlation matrix with time in terms of changes in the functionality of neural pathways, although we cannot yet exclude the contribution of volume conduction. C-14.03 FIBER TYPE ZONING IN NORMAL MOUSE MUSCLE. J. Brasseur, J.L. Melvin and R.L. Curtis (Milwaukee, Wis, USA) Electromyographers observe depth-dependent differences in the motor unit potentials they observe during muscle contraction. This requires standard placement of recording electrodes when quantifying motor unit amplitudes and duration. Motor unit potentials recorded from human muscles with Type I fiber predominance demonstrate characteristic electrical differences from those with Type II predominance (Warmolts and
Engel Arch. Neurol, 1972, 27: 512). The authors designed the present study to determine if depth-dependent EMG differences are due to differential distributions of fiber types within a muscle. They analyzed the distribution of muscle fiber classed within the medial head of the gastrocnemius muscle of 7 adult In all samoles. Tvoe I male C57BL/6J mice. fibers predominate in zones within the-central portion of the medial division of this muscle. Type II fibers predominate in other zones, inThese cluding the entire lateral division. data suggest that electromyographic differences within a muscle may be due to differential concentrations of motor unit types in different Therefore, electromyoportions of a muscle. graphers should standardize their studies with consideration of potential zonal distributions which may exist within a muscle. D-12.05 BRAIN-STEM AUDITORY EVOKED POTENTIALS FOR EVALUATING THE PROGNOSIS OF PRIMARY PONTINE HEMORRHAGE. M.S. Hsi, S.J. Ryu and C.Y. Chee (Taipei, Taiwan) From Dec. 1979 to Dec. 1980, 20 cases with computer tomography verified primary pontine hemorrhage (PPH), 8% of all hypertensive intracerebra1 hemorrhages, were found. Thirteen out of these 20 cases received serial studies of brainstem auditorv evoked Potentials (BAEP). with the stimulation rate of alternating clicks'at 20/set and the intensity of ,the clicks at 80 dB or higher in cases with poorly developed response wave form recorded from vertex to earlobe ipsilateral to acoustic stimulation. At least two averages of 2048 responses were performed for data analvsis. The interoeak latencies (IPL) of 1-111,-111-V and I-V, the voltages of‘individual response components and the voltage ratios of III/I and V/I were measured. The results were correlated with the clinical condition and the final outcome of these cases. All living cases (8) clearly showed at least the first 3-4 components on BAEP, with normal or abnormally prolonged IPL (esp. the IPL of IIIIn addition, the voltage ratios of III/I V). were over 0.5. The voltage ratio seems to play a major role for evaluating the prognosis of a patient. None of our cases without clear first 3 components in BAEPs could survive, nor cases with a voltage ratio of III/I below 0.5, associated with illdefined wave IV and V. We conclude that repeated studies of BAEP can provide an objective estimation of a patient's brain-stem function and are helpful for the evaluation of the prognosis of a patient. The presence of a clear wave III on BAEP with a voltage ratio of III/I over 0.5 suggests that a satisfactory recovery can be predicted.