Seizure's outcome after cortical resections including the face and tongue rolandic areas in patients with refractory epilepsy and normal MRI submitted to subdural grids' implantation

PURPOSE

To study the seizure's outcome in patients with refractory epilepsy and normal MRI submitted to resections including the rolandic cortex.

METHODS

Four adult patients were studied. All patients had motor or somatosensory simple partial seizures and normal MRI and were submitted to subdural grids' implantation with extensive coverage of the cortical convexity (1 in the non-dominant and 3 in the dominant hemisphere).

RESULTS

ECoG was able to define focal areas of seizures' onset in every patient. All patients were submitted to resection of the face and tongue motor and sensitive cortex; two patients had resections including the perirolandic cortex and 2 had additional cortical removals. Three patients are seizures' free and one had a greater then 90% reduction in seizure frequency.

CONCLUSION

Resections including the face and tongue rolandic cortex can be safely performed even within the dominant hemisphere.

Paradigms for subdural grids' implantation in patients with refractory epilepsy

RATIONALE

The need for invasive monitoring in patients with refractory epilepsy has been greatly reduced by the introduction of new technologies such as PET, SPECT and MRI in the clinical practice. On the other hand, 10 to 30% of the patients with refractory epilepsy have non-localizatory non-invasive preoperative work-up results. This paper reports on the paradigms for subdural electrodes implantation in patients with different refractory epileptic syndromes.

METHODS

Twenty-nine adult refractory epileptic patients were studied. Patients were divided into five different epileptic syndromes that represented the majority of the patients who needed invasive recordings: bitemporal (Group I; n=16 ), bi-frontal-mesial (Group II, n=5), hemispheric (Group III; n=2), anterior quadrant (Group IV; n=3) and posterior quadrant (Group V; n=3). All of them were submitted to extensive subdural electrodes' implantation (from 64 to 160 contacts) covering all the cortical surface potentially involved in epileptogenesis under general anesthesia.

RESULTS

All patients tolerated well the procedure. There was no sign or symptom of intracranial hypertension except for headache in 22 patients. In all except one Group II patient, prolonged electrocorticographic monitoring using the described subdural cortical coverage patterns was able to define a focal area amenable for resection. In all Groups II-V patients cortical stimulation was able to adequately map the rolandic and speach areas as necessary.

CONCLUSION

Despite recent technological advances invasive neurophysiological studies are still necessary in some patients with refractory epilepsy. The standardization of the paradigms for subdural implantation coupled to the study of homogeneous patients' populations as defined by MRI will certainly lead to a better understanding of the pathophysiology involved in such cases and an improved surgical outcome.

[Quality of life of patients after epilepsy surgery]

Drug resistant epilepsy impairs patients' quality of life making social interaction more difficult. Surgical treatment is an option for seizure control in medically refractory patients. We evaluated pre-operative and post-operative quality of life using a standardized questionnaire based on the QOLIE-10. The questionnaire included ten questions dealing with psychosocial and drug's side effects and was applied before surgery and eight months post-operatively. The studied sample comprised twelve consecutive adult patients with epilepsy treated surgically who were seizure free. Differences were found between the pre-operative and post-operative periods in 70% of the questions, with a better post-operative profile. Successful epilepsy surgery has a great impact in the quality of life of these patients.

Insular epilepsy. Similarities to temporal lobe epilepsy. Case report

Insular epilepsy has been rarely reported and its clinical and electrographic features are poorly understood. The electrographic study of the insula is difficult since it is hidden from the brain surface by the frontal and temporal lobe. A 48 years-old woman started having simple partial autonomic and complex partial seizures with automatisms and ictal left arm paresis 8 years prior to admission. Seizure's frequency was 1 per week. Pre-operative EEG showed a right temporal lobe focus. Neuropsychological testing disclosed right fronto-temporal dysfunction. MRI showed a right anterior insular cavernous angioma. Intraoperative ECoG obtained after splitting of the sylvian fissure showed independent spiking from the insula and temporal lobe and insular spikes that spread to the temporal lobe. The cavernous angioma and the surrounding gliotic tissue were removed and the temporal lobe was left in place. Post-resection ECoG still disclosed independent temporal and insular spiking with a lower frequency. The patient has been seizure-free since surgery. Insular epilepsy may share many clinical and electroencephalographic features with temporal lobe epilepsy.

[Sexual differences in functional hemispheric asymmetry: verbal tachistoscopic evaluation using microcomputers]

Study of sexual differences for the hemispheric prevalence on visual verbal stimuli using a microcomputer-based tachistoscope technic. Seventeen right-handed individuals, 10 males and 7 females (mean age 32 years old), without neurological or visual abnormalities were studied. The subjects performed a verbal trigram tachistoscope test, using a IBM PC microcomputer compatible. The trigram consists of 80 consonant-vowel-consonant pairs of stimuli presented randomly to right and left visual fields. The evaluation was made through two conditions: T1 and T2. In T1 Experiment stimuli exposition time was 260 ms, and in T2 Experiment the stimuli exposition time was 160 ms. In T1 Experiment 80% of females showed a Right Hemispherical Preference while 100% of males showed a Left Hemispherical Preference. In T2 Experiment, both sexes showed Left Hemispheric Preference. A close relationship between sexual difference and hemispheric preference was found. We point out the importance of stimuli exposition time in determination of sexual differences in lateral hemispherical asymmetry.