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E Mervaala

Publications and source records attributed to E Mervaala.

At least 19 recordsLinked to original sources
PubMed1992

Slowing of the dominant occipital rhythm in electroencephalogram is associated with low concentration of noradrenaline in the thalamus in patients with Alzheimer's disease.

The thalamus is involved in the regulation of the neocortical rhythmicity reflected in EEG as the alpha rhythm. Recent evidence suggests that the thalamus is affected in Alzheimer's disease (AD). We studied the relationship between the dominant occipital rhythm of the lifetime EEG and the choline acetyltransferase activity (ChAT) and monoamine concentrations in the postmortem thalamus of 20 histologically verified AD patients. The AD patients were divided into 3 groups (5-6 Hz, 7 Hz and 8-9 Hz) according to the frequency of the dominant occipital rhythm (FOC). Noradrenaline (NA) concentrations were significantly lower for the 5-6 Hz and 7 Hz subgroups as compared to the 8-9 Hz subgroup. The NA content of the thalamus correlated significantly with the FOC (r = 0.46, P = 0.04). The ChAT activity or concentrations of dopamine or serotonin did not correlate with the FOC or differ across the AD subgroups. The results suggests that the noradrenergic deficit of the thalamus may contribute to slowing of the dominant occipital rhythm in AD.

Aged↗
PubMed1992

Memory and attention in newly diagnosed epileptic seizure disorder.

Interictal disturbances of memory and attention were evaluated in 74 adults with newly-diagnosed untreated epileptic seizures and no other known brain pathology. In approximately 30% of the patients with cryptogenic seizures, the average memory and attention scores indicated subtle dysfunction compared with normal control group. The patients had difficulties in tasks requiring memory, sustained attention and flexible mental processing, whereas they had normal attention span, simple speed of tracking and simple psychomotor speed. The memory difficulties may be related to attentional dysfunction leading to impaired or slowed initial encoding of memory trace, and also to a deficit in storing process and hippocampal dysfunction. These findings could have important implications for establishing criteria for identifying patients who develop chronic epilepsy and who thereby would benefit from early therapeutic intervention.

Adolescent↗
PubMed1992

Clinical benefits of scalp EEG studies in intractable seizure disorders.

Intractable seizure disorder is a clinical as well as a diagnostic problem. We evaluated the clinical role of extensive EEGs among patients (n = 64) considered to suffer from intractable paroxysmal neurologic symptoms. By reducing antiepileptic medication, ictal events were recorded in 89% of the cases. From the clinical point of view, intensive EEG-videomonitoring (IVM) was superior to all the other EEG studies. Combined interictal routine EEG (rEEG) and ictal ambulatory EEG (aEEG) findings proved to be surprisingly successful, in some clinical settings equal to IVM. Comprehensive EEG investigations and subsequent treatment in a neurologic ward resulted in proper medication and markedly improved seizure control, confirmed by a prospective clinical follow-up of two years.

Adolescent↗
PubMed1990

Efficacy of a 1- to 3-day ambulatory electroencephalogram in recording epileptic seizures.

The duration of an ambulatory electroencephalogram (aEEG) necessary to record epileptic seizures was studied in neurological patients. A total of 2221 aEEG recordings were made for 2035 inpatients. Ambulatory EEG lasting 1 to 8 days (mean, 1.6 days) included seizures or typical undiagnosed symptomatic attacks in 750 recordings (34%), and 266 of them were epileptic in origin. Symptomatic attacks without simultaneous EEG discharges were exhibited in 27% of the epileptic patients. Of the total number of epileptic seizures, 81% were encountered during the first 24 hours, an additional 10% during the next 24 hours, and 7% during the third 24-hour period. Our conclusion was that, in patients exhibiting epileptic seizures during the aEEG recording, the diagnosis will be confirmed by a 2-day recording in the vast majority of the cases.

Adult↗
PubMed1990

Common dopaminergic mechanism for epileptic photosensitivity in progressive myoclonus epilepsies.

We studied the effect of apomorphine, a dopamine receptor agonist, on epileptic photosensitivity in 7 patients with progressive myoclonus epilepsy (PME). Specific diagnoses included Baltic PME (Unverricht-Lundborg disease), Lafora disease, Kufs' disease, juvenile neuroaxonal dystrophy, and action myoclonus-renal failure syndrome; 2 patients had PME of uncertain etiology. Apomorphine blocked the epileptic photosensitivity in all patients and also reduced intention myoclonus in a patient with Baltic PME. There is a common deficit of dopaminergic inhibitory neurotransmission at the level of the striate cortex in patients with PME, regardless of the nature of the specific underlying neuropathologic process.

Adolescent↗
PubMed1989

The importance of the electrocardiogram in ambulatory electroencephalographic recordings.

The role of an ambulatory electroencephalogram performed simultaneously with an electrocardiogram was studied in 861 neurologic inpatients. In total, 123 patients (14%) had interictal cardiac rhythm abnormalities, and 31 (4%) had neurologic symptoms considered to be of cardiac origin. The occurrence of cardiac arrhythmias was related to medical history of cardiovascular disease, but not to organic cerebral disorders. The ictal increase of heart rate was significantly higher and more abrupt in epileptic seizures than in psychogenic attacks. The ictal electroencephalogram/electrocardiogram may thus be applicable to the differential diagnosis between the epileptic and psychogenic seizures.

Ambulatory Care↗
PubMed1989

Cardiac arrhythmias in the differential diagnosis of epilepsy.

Symptomatic attacks or seizures associated with cardiac arrhythmias may cause difficulty in differential diagnosis. Two patients are reported in whom disturbances of cardiac conduction induced attacks which clinically resembled attacks of psychogenic and epileptic origin and were abolished after implantation of a demand-type pacemaker. A third patient is described who had epileptic seizures resulting in cardiac arrhythmias. In the differential diagnosis of these cases, simultaneous ambulatory EEG and ECG recording was essential.

Adult↗
PubMed1989

Vigabatrin in epilepsy in mentally retarded patients.

1. The anticonvulsant potency of vigabatrin (gamma-vinyl GABA, GVG) was studied in an open trial in a group of 21 mentally handicapped patients with drug-resistant epilepsy. 2. With this treatment one third of these patients had more than 50% reduction in seizure frequency. The anticonvulsant effect appeared during the first month of therapy and was maintained during a 7-month study. The side effects were mild: mainly tiredness, aggressiveness, and ataxia. Other anticonvulsant drugs remained at baseline levels during GVG therapy. GVG was not found to modulate EEG recordings. 3. According to our results, GVG is effective for treating intractable epilepsy in mentally handicapped patients.

Adult↗
PubMed1988

Effect of vigabatrin on epilepsy in mentally retarded patients: a 7-month follow-up study.

We studied the antiepileptic potency of vigabatrin (gamma-vinyl GABA, GVG) as an open trial in a group of 36 mentally handicapped patients with drug-resistant epilepsy (30 had seizures of partial onset and 6 had primary generalized [PG] tonic-clonic convulsions). With this treatment, 13 (43%) of the patients with seizures of partial onset and 2 (33%) with PG had more than 50% reduction in seizure frequency. The antiepileptic effect appeared during the first month of therapy and continued throughout the 7-month study. The side effects were mild: tiredness, aggressiveness, and ataxia. Other antiepileptic drugs remained at baseline levels during GVG therapy. GVG did not alter EEG recordings. Our results suggest that GVG is effective for treatment of intractable epilepsy, especially the partial type, in mentally retarded patients. Longer follow-up is needed, however, to determine that the clinical effect is maintained and that no severe side effects appear.

Adolescent↗
PubMed1987

The effects of carbamazepine and sodium valproate on SEPs and BAEPs.

SEPs and BAEPs were studied in 36 previously untreated epileptics receiving either carbamazepine (CBZ) or sodium valproate (VPA) monotherapy. CBZ prolonged central conduction times in SEPs and BAEPs. SEP latency prolongation correlated with serum CBZ levels. VPA had minimal effects on evoked potentials. The present study gives evidence of similar effects of carbamazepine and phenytoin on central neural conduction.

Adult↗