Spinocerebellar ataxia type 2 (SCA2): identification of early brain degeneration in one monozygous twin in the initial disease stage.

Spinocerebellar ataxia type 2 (SCA2) is a progressive autosomal dominantly inherited cerebellar ataxia and is assigned to the CAG repeat or polyglutamine diseases. Recent morphological studies characterized the pathoanatomical features in heterozygous SCA2 patients and revealed severe neuronal loss in a large variety of cerebellar and extra-cerebellar brain sites. In the present study, we examined the brain pathoanatomy of a monozygous twin of a large Hungarian SCA2 family with pathologically extended CAG repeats in both SCA2 alleles. This unique patient was in the initial clinical stage of SCA2 and died almost 3 years after SCA2 onset. Upon pathoanatomical investigation, we observed loss of giant Betz pyramidal cells in the primary motor cortex, degeneration of sensory thalamic nuclei, the Purkinje cell layer, and deep cerebellar nuclei, as well as select brainstem nuclei (i.e., substantia nigra, oculomotor nucleus, reticulotegmental nucleus of the pons, facial, lateral vestibular, and raphe interpositus nuclei, inferior olive). All of these degenerated brain gray matter structures are known as consistent targets of the underlying pathological process in heterozygous SCA2 patients. Since they were already involved in our patient within 3 years after disease onset, we think that we were for the first time able to identify the early brain targets of the pathological process of SCA2.

Quantitative EEG effects of carbamazepine, oxcarbazepine, valproate, lamotrigine, and possible clinical relevance of the findings.

UNLABELLED: Quantitative EEG (QEEG) effects of therapeutic doses of carbamazepine (CBZ), oxcarbazepine (OXC), valproate (VA) and lamotrigine (LA) monotherapy were investigated in patients with beginning epilepsy. Baseline waking EEG (EEG1) was recorded in the untreated state, the second EEG (EEG2) was done after 8 weeks of reaching the therapeutic dose. Left occipital data were used for analysis. QEEG target parameters were absolute band-power (delta: AD, theta: AT, alpha: AA, beta: AB), and alpha mean frequency (AMF). Group effects (untreated versus treated condition in the CBZ, VA, OXC, LA groups) were computed for each target parameter. One group with benign rolandic epilepsy remained untreated for clinical reasons and served to estimate the QEEG test-retest differences. In addition, the individual QEEG response to each drug was calculated as (EEG2-EEG1). RESULTS: statistically significant (p<0.05) group differences indicated the QEEG domain systematically affected by the drugs. CBZ caused AT increase and AMF decrease. OXC caused AMF decrease. VA and LA did not decrease AMF (LA even increased it), but reduced broad-band power. Individual power and AMF changes showed considerable variability in each group. >0.5 Hz AMF decrease (that was reported to predict cognitive impairment in prior studies) occurred in 10/41 patients in the CBZ group but never in the OXC, VA, LA groups. The results may be utilized in planning further studies addressing the relationship between antiepileptic drugs and their CNS effects. In addition, the relationship of AED-related cognitive impairment and AMF changes was discussed.

Epilepsy caused by retrosplenial tumor.

We present a patient in whom retrosplenial tumour was associated with epileptic symptoms characterized by complex partial seizures and widespread interictal and ictal epileptiform EEG abnormalities. The patient had verbal memory deficit symptoms as well. After surgical removal of the tumour (oligoastrocytome) the clinical symptoms and EEG signs disappeared. The characteristics of our patient demonstrate the possible role of the retrosplenial area in widespread epileptic symptoms and in the regulation of secondary bilateral synchrony, in addition to its recently described importance in the memory functions.