[Spinocerebellar degeneration, optic atrophy, epilepsy, myoclonus and mitochondrial myopathy: a case report (author's transl)]. / Dégénérescence spino-cérébelleuse - atrophie optique épilepsie - myoclonies - myopathie mitochondriale.

A 23-year-old man presented with a history characterized by a myoclonic syndrome developing over a period of seven years. Predominant symptoms were intention and activity myoclonus, generalized epileptic seizures occurring infrequently from the age of 20, a slowly progressive cerebellar syndrome first apparent at 19 years, and the sudden onset of loss of visual acuity at 19, which then partially regressed; optic atrophy and clinical and campimetric signs were suggestive of Leber's disease. Intellectual ability was not affected. E.E.G. records showed generalized spike-waves with photosensitivity, progressive reduction in basal rhythm, and sleep organization disturbances with focal abnormalities. Obvious clinical signs of muscle disease were lacking but muscle biopsy confirmed the presence of a mitochondrial myopathy (ragged-red fibers). An indefinite history of familial neurological disease was obtained. Diagnosis was established as myoclonic cerebellar dyssynergy with spastic hereditary ataxia and Leber's disease. Their association with a mitochondrial myopathy has been previously reported by Tsairis et al, Fukuhara et al, Fitzimons et al (familial case), and Niedermeyer et al (sporadic case). In spite of the non-specific nature of associated mitochondrial abnormalities, all these cases would appear to correspond to a single nosological entity.

[Lafora disease (author's transl)]. / La maladie de Lafora.

On the basis of 21 personal observations as well as those (82) from the litterature, it is concluded that the progressive myoclonic epilepsy with Lafora bodies (P.M.E.) constitutes a disease on its own. The clinical features are those described in the litterature observations and completed by some characteristics; the high frequency of visual symptoms (47 p. 100 personal cases); the relatively less bad evolution of epilepsy, perhaps in relation with use of modern drugs; the relatively moderate intensity of myoclonus which becomes complete only at the end of the evolution. From E.E.G. point of view, we can distinguish three periods: an initial one at the very onset of disease, who will show the same features as observated in primary generalized epilepsy, i.e. a well preserved background activity with superimposed generalized fast spikes and waves facilitated by the I.L.S. Then follows a period of evolutive E.E.G. (1-2 years after the onset of the disease) characterized by progressive slowing of the posterior background, enlargement of posterior slow activity and appearance of diffuse theta and delta activity. Simultaneously spikes and waves are taking less typical and bisynchronous aspect. Finally after 3 to 5 years from the onset there is a diffusely slow E.E.G. with superimposed fast multiple spikes. The E.E.G. findings in litterature usually refer only to this last period (stationary or terminal period). Occipital independent multiple spikes are frequently observed and could correlate with the visual symptoms observated in the Lafora disease. Some elements of differential diagnosis are given with respect to primary generalized epilepsy at the onset of the disease and later on with respect to dyssynergia cerebellaris myoclonica and to the progressive myoclonic epilepsy without Lafora bodies.

[Excessive 7-14-sec positive spikes during REM sleep in monozygotic non-epileptic twins with speech retardation (author's transl)]. / Quantité excessive de 7-14 positive spikes pendant la P.M.O. chez deux jumeaux monozygotes avec retard du langage.

6-14/sec positive spikes (PS) (in our cases 7-14) were observed during 6 all-night sleep, recordings in one pair of monozygotic twins (aged 7 years), who had severe speech retardation, no epilepsy and were otherwise normal (CAT were normal). The EEG during wakefulness and sleep showed multifocal independent spikes over the left mid-temporal and right parieto-occipital area. The 7-14 PS, which were similar in both twins, occurred slightly during light sleep, were absent during slow sleep and were most prominent during REM sleep (mean=6.3 sec of PS bursts/min of REM). During REM sleep, the 7-14 PS bursts were negatively related to bursts of eye movements; PS were 7 times more frequent in the intervals between than during bursts of eye movements. In addition, long bursts of PS (up to 6 sec) might interupt the bursts of eye movements suggesting a functional antagonism between mechanisms (still unclear) responsible for PS and for REM. The predominance of PS during REM sleep and the inverse relationship with eye movements are not peculiar to our case, since similar findings have been reported in other cases (TSUZUKI 1967; OKUMA et al. 1968). During the sleep stages when Ps occurred spontaneously, PS could also be evoked by a click or a tone, with a latency of 1, 5-2 sec.