1/3. Long-term neuropsychological follow-up and nosological considerations in five patients with continuous spikes and waves during slow sleep.Continuous spikes and waves during slow sleep (CSWSS) is a well-known EEG pattern that can be associated with cognitive and behavioural deterioration. We present the long-term neuropsychological follow-up and nosological considerations of five patients who developed CSWSS during childhood. All five of our patients presented CSWSS, although the duration and severity of this pattern varied. The outcome was of three basic types: acquired frontal dementia, language deficits and normal. Four of our patients were initially diagnosed with landau-kleffner syndrome but have had markedly diverse outcomes in terms of the severity and type of compromise. Our data suggest that the initial diagnosis, according to current nosological categories, has almost no prognostic significance, while the length and the age of onset of CSWSS, the site of epileptiform activity and the individual neuropsychological profile are more useful for identifying the long-term outcome of patients with CSWSS.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
2/3. mutation in the Na channel subunit SCN1B produces paradoxical changes in peripheral nerve excitability.To determine the effect of an established mutation of the beta1 subunit of Na( ) channels on nerve excitability, studies were undertaken in patients diagnosed with generalized epilepsy with febrile seizures plus (GEFS ). Multiple nerve excitability measurements were used to investigate the membrane properties of sensory and motor axons in five patients (aged 18-55 years) who were currently experiencing no seizures and were not on anticonvulsants. There was no history of paraesthesiae, fasciculation or cramps to suggest hyperexcitability of peripheral nerve axons. The median nerve was stimulated at the wrist, and compound muscle action potentials (CMAPs) were recorded from abductor pollicis brevis and the antidromic compound sensory nerve action potential (CSAPs) from digit 2. Stimulus-response behaviour, strength-duration time constant, threshold electrotonus, current-threshold relationship and the recovery of excitability following a supramaximal conditioning stimulus were recorded using threshold tracking. Compared with normal controls (n = 29), the axons of patients were of higher threshold. CMAPs and CSAPs were relatively small, although individual values remained within the normal ranges. Refractoriness and relative refractory period (markers of transient Na( ) channel function) were significantly reduced in GEFS patients with established mutations in SCN1B (P < 0.05), and strength-duration time constants (dependent on persistent Na( ) conductances) were reduced. It is suggested that, in peripheral nerve axons, the mutation underlying GEFS reduces the number of functioning Na( ) channels at the node of Ranvier and that this rather than any change in gating of individual channels dominates axonal excitability in these patients.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
3/3. Nonconvulsive status epilepticus with generalized 'fast activity'.We report the case of a 55-year-old patient with infrequent generalized tonic-clonic seizures since the age of 40 years and additional frequent episodes of disturbed behaviour and impaired cognition. The latter last from several hours up to one day with sudden onset and end of electroencephalographic (EEG) changes and clinical manifestations. They occurred about once a week before they were successfully treated with valproate and lamotrigine. From clinical, therapeutic and EEG findings we conclude that the patient suffers from nonconvulsive status epileptici, although the ictal EEG showed an untypical pattern of monomorphic generalized alpha rhythm. Many EEG characteristics point towards a primary generalized seizure disorder but a focal origin with secondary bilateral synchrony has to be considered as well. However, this is obviously a rare type which has not been described previously.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |