Study of a patient population investigated for excessive daytime sleepiness (EDS)

This study included all patients referred to the out-patient department of our sleep disorders centre from 1993 to 1999 on account of excessive daytime sleepiness (EDS). As a first step, patients in whom a diagnosis was established following appropriate polysomnography were excluded: this included sleep apnea syndrome, increased upper airway resistance syndrome, narcolepsy, periodic movements during sleep or other parasomnia, and epilepsy. Patients regularly taking psychotropic substances or with psychiatric disorders were also excluded. Finally, 128 patients remained in whom no clear diagnosis had been established for EDS, 70 women and 58 men, their ages ranging from 16 to 77 years. They underwent a 48-h recording (night 1-MSLT-night 2-continuous day). The aim of the study was to establish, define and characterise different groups of undiagnosed EDS patients using clinical, electrophysiological and immunological data with the help of hierarchical cluster analysis. Eight groups were characterised: group 1: mild hypersomnia type 1 (n = 11); group 2: hypersomnia frequently associated with HLA type DR2-DQw1 (n = 11); group 3: mild hypersomnia type 2 (n = 28); group 4: morning recovery from disrupted sleep (n = 19); group 5: young "long sleepers with difficulty at waking up" (n = 17); group 6: idiopathic hypersomnia (n = 15); group 7: poor or short sleepers since childhood (n = 8); group 8: older poor sleepers with a late onset of symptoms (n = 19). Characteristic features of these different groups provided consistent and objective arguments leading to a more precise diagnosis for these patients, and helped the initiation of appropriate management and treatment.

[Electrophysiologic study in a patient presenting with expanding cerebral lacunae]

A 42-year-old man was affected with multiple cerebral lesions suggesting expanding lacunae. He had suffered for about 15 years of headaches and blurred vision. Neurological examination showed a Parinaud syndrome and a skew deviation. Magnetic resonance imaging showed an enlargement of the third and lateral ventricles and multiple intraparenchymatous lesions with a signal similar to that of the cerebrospinal fluid. These lesions were located in the mesencephalon and right thalamic region. Important discrepancies between the topography of the lesion and the clinical data were observed. Neurological examination, ocular movements during wake and neuropsychological testing suggested sub-cortical dysfunction. These results suggest functional rather than lesional repercussion of expansive lacunae.

[Effect of modafinil in narcoleptic patients. Electrophysiologic and psychometric studies]

Clinical efficiency of Modafinil was clearly demonstrated in narcoleptic patients but only a few electrophysiological studies were carried out to confirm these observations. Since Modafinil did not change the propensy to fall asleep, the aim of this work was to study maintenance of wakefulness and performance levels in treated narcoleptic patients. Of the 16 treated patients, 12 responded as expected to Modafinil. These 12 patients were studied. After a one night polysomnography, electrophysiological tests included: baseline spectral analysis, maintenance of wakefulness tests carried out respectively eyes open in diffused light and eyes closed in darkness during which sleep latency, duration of test and changes in the theta/alpha ratio were measured. Psychometric performances were evaluated using verbal or non verbal tests: visual and auditory reaction time tests. Trail Making Test, Stroop, verbal Fluency and WAIS-R. Modafinil improved the ability of narcoleptic patients to remain awake only when the situation or the environmental conditions were favorable. Some psychometric performances also trended towards on improvement.

Modafinil in diurnal sleepiness. A study of 123 patients

The efficacy of modafinil, a psychostimulant drug acting on postsynaptic alpha-1 adrenergic receptors, as a treatment for excessive daytime sleepiness was studied in 123 patients. Subjects included 94 narcoleptic patients (76 with cataplexy), 23 hypersomnia patients and 6 patients with disrupted nocturnal sleep (DNS) and excessive daytime sleepiness (EDS). Clinical efficacy of the treatment on each symptom (EDS, cataplexy and DNS) was evaluated on a four-point scale from excellent to absent. The effectiveness of modafinil as a treatment for EDS was excellent in 17% of all patients, good in 63%, fair in 17% and absent in 3%. The incidence of side effects was rather low (14 of 123 patients) and most of them disappeared (11 patients) when doses were reduced.

Modafinil: a double-blind multicentric study

Modafinil is a central putative alpha-1 postsynaptic agonist with vigilance-promoting properties. Fifty narcoleptics (33 male and 17 female) participated in a multicentric study aimed at assessing the effects of the compound on night sleep, feeling on awakening, excessive daytime sleepiness and cataplexy. Modafinil was administered in a double-blind cross-over design at a daily dosage of 300 mg versus placebo. The duration of the study was 12 weeks, including a 2-week "run in" period with placebo, a first 4-week treatment period with either modafinil or placebo, a 2-week wash-out period with placebo and a second 4-week treatment period with either placebo or modafinil. Daily evaluation was based on a sleep log, visual analog scales, a sleep questionnaire and a clinical global index. Sleep laboratory evaluation took place on nights 1, 28, 42 and 70. It included 1 night of polysomnography preceded by a questionnaire on therapeutic and side effects, and a maintenance of wakefulness test (MWT). Sleep logs did not show any modification of night sleep, but a reduction of daytime sleepiness and sleep. Feeling on awakening was not modified. An overall benefit was noted by physicians as well as by patients. MWT disclosed a positive effect of modafinil on excessive daytime sleepiness. Cataplexy was not modified.

Auditory evoked responses (AER) and augmenting-reducing phenomenon in patients with progressive supranuclear palsy (PSP)

Variations in amplitude and latency of P1, N1 and P2 waves of AER induced by increasing the stimulus intensity (augmenting-reducing) were measured in PSP patients and compared to those observed in normal subjects. The studied population included 17 patients (10 male, 7 female, mean age 66 +/- 8 yr) with a typical PSP symptomatology and 17 normal subjects (10 male, 7 female, mean age 66 +/- 9 yr). All subjects from both the groups showed a normal auditory threshold (less than 30 db SPL or a moderately increased threshold never exceeding 10 db SPL). Nine patients had normal BAER; 4 patients showed an abnormal III wave; 3 patients showed an abnormal V wave. One patient had a poorly individualized BAER. Latencies and amplitudes of P1, N1 and P2 waves derived from Cz and Fz (linked ear reference) were studied with 50, 60, 70 and 80 db intensities and for each patient slopes of amplitude-stimulus intensity and latency-stimulus intensity curves were studied. Although patients showed decreased AER amplitudes, the augmenting-reducing phenomenon was not different from controls regarding either latency or amplitude changes with increasing stimulus intensity. Previous studies had established a negative correlation between the augmenting-reducing responses and HVA levels in the cerebrospinal fluid (CSF). Similarity of augmenting-reducing mechanisms in PSP and normal subjects favors the hypothesis of unimpaired mesocortical and mesolimbic dopaminergic pathways in PSP. This hypothesis is also supported by postmortem studies using biochemical markers.

[Efficacy of uvulopalatopharyngoplasty (UPPP) and modifications in sleep structure in the sleep apnea syndrome (SAS)]

Thirty-four patients (32 male, 2 female; mean age 53 +/- 7 years) with confirmed sleep apnea syndrome (SAS) were studied before and after uvulopalatopharyngoplasty (UPPP). Clinical symptoms were tiredness, excessive daytime sleepiness and snoring. All patients were overweight. Patients underwent a thorough physical and oropharyngeal examination and polysomnography before and 3 months after surgery. On the basis of post-operative results, patients are divided into 3 groups: --group 1: 16 cured patients: apnea index (A.I./h) 38 +/- 17 before and 4.4 +/- 4 apneas/h sleep after surgery. Improved nocturnal hypoxemia: mean minimum oxyhemoglobin saturation (SAO2) before and after UPPP in NREM sleep 83 +/- 4% v. 90 +/- 4% in REM sleep 76 +/- 11% v. 85 +/- 7%. Uninterrupted sleep is restored; --group 2: 8 improved patients: A.I./h of 64 +/- 11 before and 20 +/- 6 after UPPP: improved nocturnal hypoxemia: mean minimum SAO2 in NREM sleep 74 +/- 10% before and 86 +/- 6% after UPPP: in REM sleep 59 +/- 9% before and 79 +/- 6% after UPPP, lower amount and percentage of fragmented sleep; --group 3: 10 non-improved patients: A.I./h unchanged 55 +/- 22% before and 50 +/- 20% after UPPP. Persistent nocturnal hypoxemia: mean minimum SAO2 in NREM sleep 76 +/- 13 before and 81 +/- 12% after UPPP: in REM sleep 63 +/- 16% before and 65 +/- 24% after UPPP. Sleep remains fragmented. In this last group patients are more overweight and all suffer from severe SAS with greater nocturnal oxyhemoglobin desaturation. Surgical treatment by UPPP is shown to be effective for 70% of our patients. Better results are obtained when SAS is less severe and overweight less important.

Effect of age on auditory evoked responses (AER) and augmenting-reducing

Auditory evoked responses (AER) were obtained from Cz and Fz in 30 adults (14 male, 16 female) from 20-80 years old. Sound bursts (1000 Hz-200 msec) of four different intensities were used. Peak to trough amplitudes of P1N1 and N1P2 and latencies of P1, N1 and P2 peaks were measured with increasing stimulus intensity and slopes of amplitude - intensity and latency - intensity curves were analysed for assessment of an age effect. The main result is that the increase in P1N1 amplitude with increasing stimulus intensity is more pronounced in older persons. Previous studies have established a negative correlation between the augmenting-reducing responses and HVA levels in the CSF (with lower amounts of HVA in the CSF of "augmenters"). Decreased dopamine metabolism in old subjects could account for our results, so further studies should focus on patients with pathological dopamine deficiencies.

A syndrome of REM and non-REM sleep reduction and lateral gaze paresis after medial tegmental pontine stroke. Computed tomographic scans and anatomical correlations in four patients

A common pattern of reduction in both rapid eye movement and non-rapid eye movement sleep associated with various lateral gaze paralyses was present in four cases of brain-stem stroke. From computed tomographic scan data, clinical inferences, and, in two cases, neuropathologic sections, the common lesions were localized in the medial pontine tegmentum, ie, the inner part of the gigantocellular and pontis centralis caudalis nuclei. These data in humans were compared with lesions obtained experimentally in cats.

[Sleep abnormalities and evoked potentials (VEP-BAER-SEP) in progressive supranuclear palsy]

Few physiological studies have been performed in PSP. We studied: sleep abnormalities in 36 h polygraphic recordings; changes of PEV after pattern-reversal stimulation, of BAER and of short latency SEP after stimulation of the median nerve. The population was for the 1st group: 18 patients with full typical symptomatology, for the 2nd group: 7 patients with likely diagnose of PSP and for the 3rd group: 10 normal subjects as control sample. All patients of the 1st group had sleep abnormalities: decrease of total sleep time; decrease of the percentage of REM sleep; morphological abnormalities (specially horizontal ocular square wave jerks). Detail is given of the repartition of such abnormalities in the two groups of patients. There is no correlation between sleep abnormalities and the natural history of the disease. The PEV and BAER, abnormalities were present in 50% of the cases. The PES were always normal. The help that can be provided by electrophysiological studies in the diagnose of PSP is discussed (particularly in group 2).

[Sleep and dreams in Korsakoff's amnesia due to alcoholism]

Sleep and dreams in 15 chronic alcoholic patients with amnesia were compared with sleep and dreams of 15 age- and sex-adjusted normal subjects. The patients were subjected to psychological tests in order to determine their I.Q. and their memory disturbances. All subjects had two nights of polygraphic recordings; the first tested the natural sleep organization. During the second night, they were awakened 7 min after the onset of each REM sleep episode, and, at least once, 20 min after the onset of a stage II episode, in order to record on a tape their dream reports according to a standardized protocol. The sleep patterns of the amnesic patients did not show any significant alteration. However, after wakening during the night, patients exhibited a higher tendency to return to REMS than controls. There was still some dream activity in those patients, although noticeably less frequently, and their dream activity had a very poor verbal expression. However, there was no change with respect to the spatio-temporal organization, sensorial perceptions, motor activity and verbalizations during their dreams.

[EEG spectral analysis in sylvian ischemia with normal value tracings]

The EEG power spectral analysis of 8 patients with a definite sylvian ischemia, the standard EEG of which was normal, was determined in comparison with the date of a control group (N = 14). We calculated the right-left power spectral differences in 4 symmetrical bipolar leads for 5 rhythms (delta: 1.2-3.1 Hz, theta: 3.5-7 Hz, alpha: 7.4-12.3 Hz, beta 1: 12.9-14.1 Hz and beta 2: 15.2-17.2 Hz). For each patient, the spectral difference is measured in comparison with the normal range of the control group with an alpha risk of 5%. There are 54 asymmetries favouring the lesioned side (mostly in 5 patients) and 6 the opposite, without predominance of a particular rhythm with the exception of the beta 2 rhythm which presents no asymmetries.

Two distinct classifications of adult epilepsies: by time of seizures and by sensitivity of the interictal paroxysmal activities to sleep and waking

Two hundred and thirty-six adult epileptic outpatients were classified twice: firstly according to the time of seizures reported by the patient or his family in diurnal, nocturnal, awaking and diffuse epilepsies (Es) and secondly according to the sensitivity to sleep or waking of the interictal paroxysmal activities (PA) observed during a polysomnographic night session with a sleep PA increase, with a waking PA increase, with PA indifferent to sleep and waking or with few or no PA. The stability of the sensitivity of the PA to sleep and waking was 84%. Patients with diurnal epilepsy have more frequently myoclonic attacks and a lower seizure frequency. Patients with a sleep PA increase have less frequently generalized motor seizures, more frequently partial complex seizures, a higher seizure frequency, higher total night PA density and more frequently the appearance of new PA during sleep. Patients with a waking PA increase had more frequently massive myoclonus, rarely the appearance of new PA during sleep and a high total night PA density. There is no significant relationship between the two classifications. Neither classification succeeds in discriminating the electro-clinical type of the epilepsies.

Electroencephalographic spectral power and lateralized motor activities

The powers of the theta (3.5-7 Hz), alpha (7.4-12.3 Hz) and beta 1 (12.9-14.8 Hz) rhythms were analysed in symmetrical derivations. Sixteen right-handed young male adults were observed: at rest, with eyes closed (EC) (4 sequences) and eyes open (EO) (4 sequences); during right then left tonic alternate or sequential movements of the hand and while gazing to the right then to the left. At rest there exists a clear and significant spectral dominance to the right which does not appear in all the rhythms or in all the derivations. As far as the alpha rhythm EC is concerned, individual analysis of the sequences shows that of those which are significantly lateralized, three-quarters are lateralized towards the right. Right motor activity exaggerates, left motor activity diminishes, this right electrical dominance. Lateral gaze is the most powerful activity in this respect. At each derivation, comparison of intensities during right and left activities shows that the contralateral movements diminish the spectral power in the 3 bands studied. This effect seems to be obtained most frequently at the centro-parietal level. The spectral power at rest compared with that during motor activity is higher constantly for theta rhythm, in almost half the cases for the alpha and occasionally for the beta 1.

[Frontal evoked potentials and sensitivity to methylphenidate. Individual differences]

Auditory evoked potentials (AEPs) were recorded from 2 sites (Cz and Fz) on 17 subjects while awake. Five sound intensities were used (40-50-60-70-80 dB). Regression slopes relating AEP amplitude (N1-P2 component) to stimulus intensity were used to describe augmentation or reduction (A/R) of amplitude with increasing intensity. The individual differences thereby obtained have been related with the individual responsiveness to methylphenidate (MPD) measured by the modifications of polygraphic sleep parameters after absorption of this substance. The sleep parameters were recorded under 3 conditions: N1, night of habituation; N2, reference night (placebo); N3, night after 20 mg of methylphenidate (MPD); nights 2 and 3 consisted of a double blind cross-over. For the placebo condition, the lower the A/R slope while awake (and particularly the Fz slope), the higher the sleep efficiency, with scarcity of nocturnal awakening and precocity of the morning awakening. Individual differences concerning MPD responsiveness measured with sleep parameter modifications are significantly correlated with the frontal A/R slopes: the wakefulness effect of MPD increases as the frontal A/R slope weakens while a paradoxal drowsiness effect is observed at the other extreme (frontal augmenters). Moreover, sleep modifications due to the first night effect show similarities with those due to MPD and are correlated in the same way with frontal A/R slopes.

Sleep disturbances in a case of brain-stem lesions; pharmacological study

A pharmacological study was carried out of a case of severe insomnia following brain-stem lesions; several polygraphic controls were used. Initially total duration of sleep was brief (less than 4 h) with a high REM/NREM ratio and a short paradoxical sleep (PS) latency. In addition, periodic breathing and tremor were observed. Slow injection of delta-sleep-inducing peptide (DSIP) improved sleep both quantitatively and qualitatively, although PS latency remained short. These effects were reversible. The effects of 5-HTP + benzerazide, of L-DOPA + benzerazide (Modopar) and of clonazepam (Rivotril) were compared.

[Paroxysmal nocturnal activity in partial epilepsy in the adult]

Thirty-four adults with partial epilepsy underwent polysomnographic sessions. Three sub-groups of patients were determined by timing their EEG paroxysmal activities (PA) according to the possible increase in PA related to their sleeping or awake state. Twenty-seven had an increase in PA when sleeping, 5 when awake and no significant difference was found in two other patients. Patients who suffered from nocturnal or partial elementary epileptic seizures were those who showed a PA increase when in a sleep state. These patients had a lower PA density during a waking state than the patients with a PA increase when awake. The more synchronized (stages 3 + 4) and desynchronized (waking) cortical states influence the PA densities in such a way that there is a significant difference between both sub-groups. The PA density modulation found with the slow-wave sleep stages adds to that induced by sleep and waking states.

Influence of waking and sleep stages on the inter-ictal paroxysmal activity in partial epilepsy with complex seizures

Twenty-six patients suffering from partial epilepsy with complex seizures underwent polysomnographic recording. Paroxysmal activity (PA) densities in waking and sleep stages were assessed. Total PA densities of one night were found to be an increasing function of the seizure frequency in the previous period. Nineteen patients had more PA during sleep, 5 others in the waking state and the two remaining patients exhibited no differences in PA densities between sleep and waking. Nocturnal seizures were reported by patients showing the sleep PA increase pattern; they also used more anti-convulsants than patients showing the waking PA increase pattern. Differences in PA densities between these two groups were more pronounced in the more desynchronized (waking) and the more synchronized (stages 3 + 4) cortical states. The modulation by slow wave sleep stages was independent of, and superimposed on, the sleep/waking one.

[Various factors affecting the onset of paroxysmal nocturnal interictal activities in primary generalized epilepsy in adults]

The relationships between the states of vigilance and the interictal EEG, paroxysmal activities (PA) were studied in 20 adults with generalized primary epilepsy. Each patient was submitted to 1-5 nocturnal polygraphic recordings. Sleep and waking modify the PA densities: 8 patients had a waking PA increase, 7 a sleep PA increase and 5 exhibited no differences of PA density between sleep and waking. Within these groups there was also an influence of slow wave sleep stages on PA densities. The function of auto-correlation of PA did not exhibit any periodicity even after correction of the effects of the states of vigilance. In patients monitored several nights the evolution of the PA densities during the successive sleep cycles throughout the night did not usually reveal a clear and stable pattern.

Organization and role of platelet membrane phospholipids as studied with phospholipases A2 from various venoms and phospholipases C from bacterial origin

Phospholipases A2 from various snake or bee venoms and phospholipases C secreted as exotoxins by several bacteria have been used to study the transverse distribution of phospholipids in the platelet plasma membrane and their role in platelet activation. An asymmetric distribution was described for phospholipids, characterized by a preferential localization of sphingomyelin and phosphatidylcholine in plasma membrane outer leaflet, whereas the inner half contains almost all of the anionic procoagulant phosphatidylserine and phosphatidylinositol. Such a distribution might explain the latency of procoagulant activity in resting platelets and implies an intracellular localization of arachidonic acid, the precursor of prostaglandins and thromboxanes. The external arachidonic acid is involved in phospholipase A2-induced aggregation, whereas phospholipase C from Clostridium welchii stimulates platelets through a thromboxane-independent pathway. The latter one is directly linked to the formation of phosphatidic and lysophosphatidic acids, which are able to activate cells through calcium mobilization. So, phospholipase C represents an interesting tool for studying the biochemical processes accompanying stimulation, since it is shown that it mimics the effects of an intracellular phospholipase C, the role of which in platelet activation is discussed.

Effect of salbutamol, a putative cerebral beta agonist on sleep stages and interictal epileptic discharges

The effects of Salbutamol 1.5 mg in 250 ml dextrose solution was tested on 14 epileptic patients following a double blind cross-over design. Sleep parameters and interictal paroxysmal activities density were measured. No seizures were encountered during the experiment. No modification of either sleep parameters (duration of sleep stages, latency of sleep and paradoxical sleep, duration of sleep cycles and awaking) or density of P. A. during waking state, on stage I, II, III and IV and paradoxical sleep were observed. In other respects, 5 patients had no P. A. during polygraphic sessions. They exhibited a longer duration of paradoxical sleep and a shorter duration of awaking than the 9 other patients with P. A. So with the dosage used here no implication of central beta-adrenoceptors in sleep mechanisms and production of epileptic activity are suggested.

[Acquired aphasia in epileptic children--four cases with electrical infraclinic status epilepticus during sleep (author's transl)]

Four cases of acquired aphasia in epileptic children, associated with sub-continuous bitemporal paroxysmal activities (PA) during sleep, are described. Clinical improvement always followed the decrease or the unilateralization of PA. Persistence or aggravation of aphasia was observed when PA again became bitemporal and sub-continuous. Electroencephalographic characteristics of PA during sleep stages are described. Relationships of these cases with the 'sub-clinical electrical status epilepticus induced by sleep' and the physiopathology of aphasia are discussed.

Studies on topological distribution of arachidonic acid replacement in platelet phospholipids and on enzymes involved in the phospholipid effect accompanying platelet activation

In this short review recent results obtained on platelet phospholipid metabolism are summarized. The first part reports a topological study of arachidonic acid (AA) replacement in platelet phospholipids. It is shown that incubation of platelets with radioactive free arachidonic acid leads to a labelling of the phospholipids present inside the platelet, whereas the exchange of intact phosphatidylcholine (PC) molecules with the plasma lipoproteins occurs on the platelet outer surface. This should allow a selective labelling of the small external pool of AA in order to follow its behaviour during platelet activation. In the second part, some enzymes involved in the metabolism of phosphatidylinositol (PI) have been further characterized. The first one is a diglyceride-lipase, which is located in the plasma membrane and releases the two fatty acids esterifying the diglycerides formed from PI by the action of the platelet phospholipase C. Such an enzyme is probably responsible for the release of AA from PI occurring upon platelet activation. On the other hand, cytosolic phospholipid exchange proteins able to catalyse the transfer of PI between membranes have been identified. The possible role of the enzymes involved in the acceleration of PI turnover occurring during platelet activation is discussed.

[The place of Gelineau's syndrome (narcolepsy) among diurnal attacks of sleep and somnolence (author's transl)]

A clinical and electroencephalographic study was conducted in 41 patients (25 men and 16 women) complaining of diurnal attacks of sleep, and the results were compared with those obtained in 15 control subjects (7 men and 8 women) of the same age. EEG tracings were recorded during 33 hours in each subject. The total duration of the various phases of nocturnal sleep and the mean duration of each phase were the same in both groups. The incidence of EEG peculiarities, such as short delay in the onset of sleep and in the first stage of desynchronized sleep, and prolonged nocturnal periods of vigilance, was assessed in both groups, but no correlation was found between clinical and electrical data. The three criteria of Gelineau's syndrome (irresistible sleepiness, cataplexy and onset of sleep in desynchronized phase) were present in 35% of the patients.

Event-related potentials evoked by sensory stimulation in normal mentally retarded and autistic children

Evoked potentials (EPs) and slow potentials (SPs) were recorded during two sessions of sound (S) and light (L) conditioning (habituation: S alone; conditioning: coupling of SL; extinction: S alone after SL series). 125 children from 0 to 15 were examined: 82 exhibited signs of autistic behaviour and/or mental retardation; 43 were normally adapted. Two studies were performed. The first was an analysis of relationships: 65 clinical characters were noted for each child with behaviour scales and psychometric tests, 88 electrophysiological data were measured on averaged tracings. The second compared with t and chi 2 square methods the electrophysiological data of 3 groups clinically defined for age and typical syndrome. Results of the two studies supplemented each other. From the clinical point of view 3 major groups appeared: (1) autism, (2) mental retardation, (3) normal adaptation. From an electrophysiological point of view 2 major groups could be defined: (1) few conditioned EPs with small amplitude, generalized conditioned SPs, small unconditioned EPs, generalized unconditioned SPs, conditioning 'to time'; (2) many conditioned EPs, many conditioned rhythmic potentials, absence of generalized SPs, many localized vertex negative SPs (CNVs), large unconditioned EPs, no conditioning to time. Some differences were observed in generalized SPs, small and positive in mentally retarded children, negative or positive in autistic children. EP and SP data clearly help to differentiate pathological groups from a normal group but are insufficient to distinguish the autistic from the mentally retarded children.

[Short-term effects of gamma-globulins on sleep organization in epileptic patients (author's transl)]

A study of the effect of gamma-globulins on sleep was conducted in 8 patients aged 1 to 35 years with epilepsy not responding to any of the conventional treatments. Two polygraphic recordings were carried out during the 4th and 5th nights following a placebo injection and then an injection of gamma-globulin 16 Merieux (1 ml/kg). The short-term effects of the gamma-globulins were : --reduction in percentage of paroxysms, --an acceleration in the electroencephalographic tracings of the different stages of sleep and those of the waking period, --a statistically significant increase in the percentage of paradoxical sleep, though the general organization of sleep remained unchanged.

A study on sleep in amyotrophic lateral sclerosis

A polygraphic study of sleep has been performed on 12 patients with ALS and 12 normal controls. Neither the total duration of sleep, nor the proportion of different stages of sleep differed significantly between the patient and control groups. A variety of morphologic peculiarities were observed in certain patients: frequent and repetitive blinking movements during the waking state (under quiet, dark conditions); persistence of EMG activity during both PS and SWS; and an early appearance of marked slow delta wave activity at the beginning of sleep. We observed in patients increased PS latency, and longer and more frequent awakenings. Certain patients also showed both qualitative and quantitative abnormalities of respiratory rhythm. A longitudinal study was performed on one patient. Results are discussed in relation to the existing literature.

[Polygraphic study of nocturnal sleep in three degenerative diseases: ALS, oligo-ponto-cerebellar atrophy, and progressive supranuclear palsy]

A polygraphic study of nocturnal sleep was carried out on 12 patients suffering from amyotrophic lateral sclerosis (ALS), 6 patients suffering from olivio-ponto-cerebellare-atrophia (OPCA) and 9 patients suffering from the Steele-Richardson disease (SR). A disturbance of sleep--if it exists--always runs parallel with the course of the disease. No disturbances were registered in the group of patients suffering from ALS, in the OPCA group a specific disease of paradoxal sleep is observed. The sleep disturbances are more global in the group of patients suffering from the SR disease. A particular electrooculogram was taken from the patients from the awakening and from the paradoxal sleep. Respiratory difficulties were registered on certain patients of each of the three groups. These sleep disturbances, registered by the polygraph, were compared with those observed on patients presenting a cortical disease.

Sleep respiratory arrhythmias in control subjects, narcoleptics and non-cataplectic hypersomniacs

Normal subjects may present central-type apneas or periodic respiration during sleep (stages I and II and paradoxical sleep). The importance of these respiratory disorders increases with age. Hypersomniac patients can manifest either similar or more significant sleep respiratory disorders than normal subjects. The presence of cataplexy or obesity does not permit the prediction of the existence of respiratory arrhythmias or of their type. Sleep respiratory arrhythmias of central type are not likely to cause hypersomnia; however, an aggravating role may be played by obstructive apneas.

[Study of the relation between disorders of nocturnal respiratory rhythm and hypersomnia]

Sleep and respiration were recorded during two consecutive nights in 15 normal subjects, 18 patients suffering from narcolepsy and 9 with non-cataplectic hypersomnia. The normal subjects showed episodes of central apnea, the degree of which increased with age and periodic respiration. In both categories of hypersomniacs, the patients were divided into three groups according to the severity of disturbances in nocturnal respiratory rhythm:--group 1: identical to the normal subjects,--group 2: moderate qualitative or quantitative abnormalities,--group 3: presence of a large number of episodes of obstructive apnea. On the basis of these results, it was concluded that disturbances in nocturnal respiratory rhythm are not specific for any particular type of hypersomnia, nor were they the main cause of hypersomnia when present to a large extent, but that obstructive apnea could be an aggravating factor.

[Electrophysiologic abnormalities in chronic alcoholism, disclosed by the methods of evoked potentials and Hoffman's reflex. Study of a possible metabolic pathogenesis]

During a preliminary study comparing 5 normal subjects and 5 alcoholics (25 experiments) changes in evoked potentials were found in these patients. There was mainly a reduction in these potentials during the first 100 milleseconds following stimulation. Such a reduction generally means a disorder of the arrival of the influx at the level of the cortex and may be found mainly in peripheral nerve involvement. A complementary study of the H reflex (34 experiments) showed that this reflex was affected in 60% of chronic alcoholics whether or not they had liver cirrhosis. The theory according to which the EEG abnormalities observed may be linked to a metabolic disorder of the amino-acids was not confirmed. The changes of the first 100 milleseconds of the evoked potential associated with the change in Hoffman's reflex are in favour of early peripheral involvement even in alcoholics who do not appear to have any peripheral neuritis. These signs are different from those which are observed in marijuana or psylocybine poisoning where the EEG signs are due to central involvement.

[Determination of the degree of mental alertness in the enderly (author's transl)]

Telemetric polygraph recordings lasting from 10-18 hours were performed in 22 elderly and institutionalised patients whose ages ranged from 82 to 97 years in an attempt to determine whether they were able to maintain alertness throughout the course of the day. By combining the standard E.E.G. data with that from the telemetric recording it was possible to subdivide the patients into 4 groups: 1 Normal E.E.G. Stable state of awareness varying only between active waking and relaxed waking, apart from a clearly demarcated siesta period (8 subjects). 2 Normal E.E.G. State of awareness moderately stable but containing as well as one or two clearly defined, siestas some somnolent episodes (6 subjects). 3 Numerous fluctuations of alertness with several levels of drowsiness corresponding either to the classical stages of sleep or to undifferentiated stages (5 subjects, 4 with normal E.E.G.). 4 Abnormal E.E.G. and only two levels of alertness which were difficult to correlate with the behavioural state. All 4 subjects in this group had severe organic impairment. There was a good correlation between the data obtained from the standard E.E.G. and that from the telemetric recording. Patients having a normal E.E.G. maintained their alertness well, and those with the highest proportion of fast activity best of all. The possible limits of variation become very narrow in severe organic impairment.