Vol. 41, No. 1-2, 1997
Progressive epileptogenesis in Creutzfeldt-Jakob disease (CJD) cases
DROBNÝ, M.
Neurologic Clinic of the Jessenius Faculty of Medicine in Martin
Comenius University in Bratislava
Summary
Three groups of patients with CJD are described according to occurrence. Among 12 cases there were 10 with a definate and 2 with an initially probable and later definate CJD diagnosis. Judging from clinical and EEG investigation, dissociation of electric and clinical behavioral epileptic activity exists. In the two cases demostrated, the specific epileptic EEG samples were not followed by epi seizures and occured at a time when EEG samples contained a high number of bursts (rhythmical or unrhythmical) which are considered to be unspecific epileptic activity.
The high threshold for epi seizures seems to be the result of substantia nigra (SN) pathological activity. The SN inhibites the irradiation of the convulsant activity of the nucleus reticularis pontis oralis, which is responsible for tonic seizure activity and its connection with clonic activity of the forebrain. The separated activity of both these parts of the brain appears to be a sustained muscular rigidity and an isolated myoclonia of particular muscles. These two components, however, did not appear at all with synchronous activity in GTC (two cases), and only very rarely with synchronous activity in GTC, one or two times in the remaining 10 cases.
However, according to specific EEG epileptic bursts usually observed many more epileptic seizures ought to occur in clinical behavioral manifestations. Therefore the author does not consider GTC to be one of the cardinal clinical syndromes of Creutzfeldt-Jakob disease. There are others, which could be considered more pathognomonic in CJD conditions, for example mixed pyramidal and extrapyramidal signs, disassociation of specific epileptic EEG samples, and either none at all or very few epileptic seizures disclosed in clinical experience. The latter circumstances result from the "antikindling" activity of the substantia nigra which is specificaly focused on the inhibition of the spread of epi behavioral activity, but not on the inhibition of "kindling" epi bursts. A split brain condition could be another antiepileptic mechanism in the first patient.
Key words: Creutzfeld-Jakob disease (CJD); epileptogenesis; EEG changes
References
Folia Veterinaria / 1997