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Unlabelled: MATERIAL, METHOD: Authors present the results of surgical treatment in a series of 93 patients with medically intractable epilepsy and large epileptogenic foci, in whom multilobar resections have been performed. They constituted 13% of a group of 716 patients subjected to surgery due to drug resistant epilepsy in the period 1957-1996, in the Department of Neurosurgery, Medical University of Warsaw, Poland. Patients treated with multilobar resection constituted the group, characterised by the most severe course of epilepsy, so they usually had a long seizures' history at the time of operation (more than 10 years duration of the disease in 37% of patients), albeit they were qualified to surgery at a relatively young age (mean age at the time of surgery: 16-th year of life). Trauma was the most frequent underlying aetiologic factor (perinatal trauma and other major head injury were documented in 28% and 30% of patients respectively). Morphological abnormalities of the resected brain tissue were found on pathological examination (light microscope) in 68% of patients in this series., Results: Perioperative mortality was 3%. At a follow-up examination (mean follow-up period 7 years postoperatively): 30% of patients were seizure free, in 13% of patients drug discontinuation was possible. In 23% of patients less than 2-3 seizures per year occurred. So totally in 53% of patients, good result of treatment was achieved (none or only very rare seizures). In 35% of patients surgery failed to control seizures' frequency. 9% of patients were lost from follow-up evaluation., Conclusions: Multilobar resection (if acceptable from the clinical point of view) may be an effective treatment choice in patients with medically uncontrollable seizures and huge epileptogenic foci. This treatment modality may offer recovery from seizures or significant improvement to 53% of patients treated. The radical removal of epileptogenic foci, age of the patients higher than 18 year of life at the time of operation, focal character of EEG abnormalities and occurrence of only one type of seizures, were found to be good prognostic factors. On the other hand younger age of the patients operated, the presence of generalized slow waves in the interictal EEG recordings and the occurrence of various types of seizures, influenced adversely on the prognosis.

Unlabelled: The acute (ECoG) was examined in 291 patients with intractable epilepsy, without structural brain lesion--from 1971 to 1997. Temporal lobectomy was performed in 198 cases and extratemporal (frontal, parietal or occipital) in remaining 93 cases to achieve seizure control. Epileptic foci was activated during acute ECoG by i.v. administration of ketamine (154 cases) or short-acting barbiturates--methohexital (110 cases) and thiopental (27 cases)., Results: Ketamine significantly more often caused ECoG identified electrographic seizures than methohexital: p = 0, 00001 or thiopental, which in no cases resulted in seizures. Also electrographic seizures occurred more frequently after administration of ketamine in patients with the extratemporal seizure focus localisation in comparison with temporal focus (p < 0.05). Electrographic seizures provoked after administration of ketamine improved the localisation of the area to be resected, more often in extratemporal epileptic foci., Conclusions: The results of our investigations indicate that ketamine more effectively activated epileptic focus than short-acting barbiturates.

Unlabelled: The aim of this study was to investigate the value of structural neuroimaging with MRI in the selection of patients for epilepsy surgery. We sought to determine whether MRI influenced decision concerning resective surgery and whether MRI provided much more useful information than enhanced CT., Materials and Methods: Neuroimaging studies, MRI and CT, of 300 patients; 265 with partial and 35 with primary generalized seizures, evaluated for surgical treatment of epilepsy were analysed. The MRIs and CTs were interpreted using visual diagnostic criteria and findings were correlated with the EEG changes and clinical semiology., Results: MRIs identified structural lesions in 142, CTs in 96 of all patients. The clinical semiology (partial seizures), MRI, CT and EEG focal findings were concordant in 72 cases. The group of 34 patients had resective surgery. The 7 patients were also operated with MRI and CT focal abnormalities discordant with EEG changes. Also one patient with primary generalized epilepsy and temporal lobe lesion (glioma) had resective surgery. MRI studies revealed structural lesions in 48 patients with normal CT studies. The 43 patients with partial epilepsy had normal CTs and lesions in MRIs; the 34 cases revealed correlation with the EEG findings in 29 temporal and 5 extratemporal regions. Surgery were performed in 23 cases. Also one with partial seizures and MRI detected hippocampal atrophy was operated, despite of generalized EEG patterns. In contrast CT revealed two patients with normal MRI and focal changes. The patients with partial seizures and only CT abnormalities (focal calcifications) were not operated due to discordant EEG findings. In group of 132 patients with normal neuroimaging studies and EEG identified seizure focus only 27 had anterior temporal lobectomy., Conclusion: MRI studies gave additional information in case of 16% patients with intractable epilepsy in comparison with CT findings. Resective epilepsy surgery was almost twice as often performed when MRIs revealed structural abnormality. In operated patients, diagnostic sensitivity of structural MRI, CT and EEG to neurophatology were 70.6%, 46.7 and 92.4% respectively.

The authors evaluate in the presented prospective study the incidence of late epilepsy after aneurysm surgery. 121 consecutive patients were operated on for ruptured aneurysm and were discharged home without any prophylactic anticonvulsant treatment and were followed-up for 12 months. The diagnosis of late epilepsy was made, if two or more seizures occurred during that time. Epilepsy occurred in 8 patients, so the incidence was 7%. Additionally in 3 patients a single seizure was observed during follow-up time but any anticonvulsant treatment was installed and the seizures did not recur for up to 24 months. The analysis of epileptic patients showed that in most of them the aneurysm was located on MCA and SAH was complicated by intracerebral haematoma or symptomatic vasospasm. On the basis of own experience and review of the literature the authors discuss the necessity of anticonvulsant prophylaxis after aneurysm surgery.

New diagnostic possibilities make possible a more precise localization of epileptogenetic foci and surgical treatment of epilepsy is associated presently with minimal risk. This was the reason of a surge of interest in recent years even in those countries where this method has not been used. In our country operations for chronic refractory epilepsy have been performed since over 35 years and the gathered experience is sufficient to reach conclusions about the results. The results depend in a certain degree on the location of the focus and the surgical possibility of its removal. In about 50% of the cases cure was effected, and in 15% improvement was achieved near cure. Considering that the treated patients had long-standing and refractory epilepsy with very frequent seizures the results of surgical removal of epileptogenic focus were very good. The authors believe that patients with chronic, focal and refractory epilepsy should be treated surgically, and conservative treatment without considering this possibility is erroneous.

The authors present palliative therapy of severe epilepsy, i.e. callosotomy. Experimental studies and numerous clinical trials indicate possible use of this technique. However, there are no precise indications and contraindications to the treatment with this technique. The authors discuss own experience with 8 epileptic patients refractory to preservative therapies. These patients were treated surgically with anterior callosotomy. Small number of patients and relatively short period of the follow-up do not allow more general conclusions to be drawn. However, in 3 out of 4 operated patients an improvement was noted within one year or more, including one case of significant improvement. No improvement was seen in one case. The authors will collect other cases. However, it is worth emphasizing that callosotomy is performed in Poland, already.

An incidence of tumors of the brain as a cause of drug-resistant epilepsy have been analysed. The analysis included patients operated for epilepsy at the Department of Neurosurgery, Medical Academy in Warsaw between 1987 and 1991. Malignant tumors were found in 21 out 85 patients (24.7%) treated surgically, 22.4% were benign tumors, and 52.9%--lesions of cicatricial character. The most frequent malignant tumor was fibrillary astrocytoma, noted in 57.1% of cases. Neurological examination has revealed discrete symptoms only in 2 out of 21 patients. CT scans have showed non-characteristic focus of decreased density in 12 patients (57.1%). Differentiation of tumor-produced epilepsy and those due to other focal lesions could not be made with the clinical course of seizures and EEG records. Actually, an incidence of tumors of the brain causing seizures refractory to pharmacologic treatment is increasing. Not characteristic clinical course and EEG records as well as CT scans are the main causes of delays in the surgery.

The study was performed on cerebral tissue resected during temporal lobectomy in 16 patients whose long-standing cryptogenic epilepsy did not submit to anticonvulsive drugs. Cases presenting definite etiological factors such as CNS trauma, infection or neoplasm were excluded. Neuropathological investigations disclosed microangiomas and focal vascular malformations in the meninges and tissue in 7 patients. Neuronal heterotopias in the white matter and of the white matter in the cortex were observed in 3 cases. Main cortical changes were: neuronal loss, chronic neuronal degeneration, perineuronal satellitosis, and GFAP-positive submeningeal gliosis, especially at the bottom of sulci, perivascular gliosis and laminar or diffuse gliosis. The changes in the hippocampus were most enhanced in the end-plate and in the sector H3 of the pyramidal layer. Astrocytic gliosis in the white matter presented distinct GFAP and S-100 immunostaining; the latter involved in some cases a wider area than the GFAP reaction. The above named changes are analysed with regard to the presumed epileptogenic factors and to the postepileptic damage.

This prospective study was undertaken to evaluate the risk of epilepsy after aneurysm operations. The patients were discharged after operation without any anticonvulsant prophylactic treatment and followed-up for 12 months. Out of 128 such patients 121 were submitted for final evaluation. Epilepsy was diagnosed if two or more seizure attacks occurred during that time. Such attacks occurred in 8 patients, so the risk of epilepsy was estimated at 7% for the 12 months after operation in patients without prophylactic treatment. In another 3 patients single seizures occurred during the follow-up, they were not treated with anticonvulsant drugs; seizures did not recur for up to two years. Detailed analysis of the patients with late epilepsy revealed that most of them were pre-operatively in the 3rd clinical group according to WFNS scale. The rationale for the use of prophylactic anticonvulsants after aneurysm surgery seems to be doubtful in view of this study and data from the literature.

Unlabelled: Stereoencephalotomy remains often the only therapeutic method in severe cases of drug-resistant epilepsy in which it is not possible to use the classic resection methods. In the light of literature data we chose Forel's field as the site for producing stereotaxic lesions since it is the most strategically situated site in the pathways of propagation of epileptic seizures., Surgical Technique: we used Leksell's stereotaxic apparatus for the operations. The contrast medium for filling the ventricular system was Dimer X. The parameters used in accordance with Jinnnai were calculated from the intercommissural line. The clinical and electrophysiological features of these cases are reported. Eleven patients were operated upon who could not be qualified for other surgical treatment methods because of generalized EEG changes. The main criterion accepted for qualification of patients by us were frequent seizures (at least 1 daily) despite systematic treatment conducted under control of serum drug levels. The indication for selecting the side of the operation was preponderance of EEG changes or presence of any lateralizing signs in the seizures. The duration of follow-up sufficient for evaluating the effectiveness of the operation was obtained in 7 patients. The following results were achieved: very good in 1 case, good in 3, improvement in 2 and poor in 1. In the light of these preliminary observations we consider that unilateral destruction of Forel's field is an operation indicated in severe generalized seizures, especially in the primary generalized form.

The authors report a statistical analysis of the levels of phenobarbital (PH) and diphenylhydantoin (DPH) in a group of 100 patients with different types of epilepsy mostly resistant to pharmacological treatment. The mean values of PH and DPH were compared with the types of epilepsy, duration of the disease, additional treatment, EEG changes and therapeutic results. The following conclusions have been reached: a) therapeutic ranges of the PH and DPH levels in this group of patients were greater than those reported by others. b) no significant correlation is found between the levels of these drugs and the type of epilepsy, disease duration and EEG changes, with the exception of a positive correlation with PH level. c) Clonazepam, diazepam and mysodin raised the serum PH level in the serum, while only amizepine raised the DPH level. d) higher levels of PH and DPH were found in patients with poor therapeutic results.

The authors studied 14 patients with epileptic seizures occurring from one to about 20 daily despite monitored pharmacological treatment. Two pairs of silver, properly insulated electrodes were applied to the subtentorial surface of both cerebellar hemispheres through burr-holes. The cerebellar surface was stimulated once daily for 30 min to 1 hour with electrical current at 10 Hz, 1 msec, 1-7 V during 10 to 16 days. During that time epileptic seizures disappeared completely in 5 cases, in 6 patients their frequency was reduced to one seizure every several days, in 2 cases the improvement was slight and one patient failed to improve. After cessation of electrostimulation and removal of electrodes in most cases the seizures increased again in frequently gradually. Twelve months after the procedure in only 4 cases a significant improvement remained. The authors believe that this method of cerebellar cortex stimulation should be regarded as a trial before making decision about chronic implantation of cerebellar electrostimulator for selecting patients responding well to this treatment. This group amounts to about 30% of such drug-resistant cases.