Remote epileptogenic focus detected by electrocorticogram in a case of cavernous angioma

De novo formation of cerebral cavernous malformation in a patient with intractable epilepsy: case report and review

AIM

The exact origin and process of development of cerebral cavernous malformations (CCMs) is currently unknown. In this article, the authors present de novo CCM formation in a patient with intractable epilepsy and discuss the pathogenesis of CCM in light of several current theories.

CASE DESCRIPTION

A 34-year-old man presented with a 10-year history of intractable seizures. His neurological examination was normal, and the initial magnetic resonance imaging (MRI) was suggestive of right mesial temporal sclerosis (MTS). Follow-up MRI study showed development of CCM in the right frontal region. Subsequently, invasive monitoring revealed right temporal seizure source, prompting right temporal lobectomy that resulted in abolition of epilepsy. Histological diagnosis of CCM was confirmed after the lesion was removed in a separate surgery. The patient recovered to normal lifestyle without any complications.

CONCLUSION

This appears to be a first documented case of de novo CCM formation in the setting of intractable epilepsy with ipsilateral MTS. Since the possibility of lesion development cannot be ruled out based on clinical examination, updated imaging and thorough neurophysiological workup are needed for successful treatment of patients with intractable epilepsy.

Prediction of postoperative outcome with special respect to removal of hemosiderin fringe: A study in patients with cavernous haemangiomas associated with symptomatic epilepsy

PURPOSE

In this study 30 patients with symptomatic epilepsy caused by cavernomas were investigated in a postoperative follow up study to assess predictors for postoperative outcome with respect to indications, time and approach of surgery.

METHODS

Thirty patients with cavernomas refractory to medical treatment were scheduled for surgery based on the findings of high-resolution MR imaging and intensive EEG-video monitoring. Postoperative outcome of epilepsy was assessed by follow-up examinations based on the basis of classification by Engel and the International League against epilepsy (ILAE).

RESULTS

The following variables were associated with good postoperative outcome: (1) complete resection of hemosiderin fringe surrounding the cavernoma was correlated to less postoperative seizure frequency versus incomplete resection of the hemosiderin fringe according to the outcome protocol of ILAE. (2) Lower duration of epilepsy at the time of operation was correlated to a better postoperative outcome with a benefit for recovery. (3) Absence of hemorrhage before surgery and unifocal seizure onset was a predictor for a favorable outcome, whereas bilateral or multifocal seizure onset zones showed poorer postoperative outcomes. (4) In patients with dual pathology (hippocampal sclerosis in addition to a cavernoma), lesionectomy plus hippocampectomy as opposed to lesionectomy only, had a better outcome than single lesionectomy.

CONCLUSION

Postoperative outcome in patients with cavernomas should be the topic of further prospective multicenter studies involving a large number of patients. In addition to the ideal operation time and handling of dual pathology the role of extended resection including perilesional hemorrhages should be taken into account.

Intraoperative electrocorticography and successful focus resection in a case of Sturge-Weber syndrome

This paper reports a surgically treated case of Sturge-Weber syndrome (SWS) in which the epileptic foci and haemangiomatosis were successfully resected under monitoring of intraoperative electrocorticography. The patient was a 19-month-old female infant who was referred to our hospital because of frequent hemi-tonic-clonic convulsions that were resistant to anticonvulsant therapy. Serial MRI showed progressive atrophy in the left fronto-parieto-temporal lobe, and gyral enhancement by gadolinium corresponded to venous haemangiomatosis of SWS. Three-dimensional reconstruction of the MR images was performed using the Viewing Wand System. Conventional EEG taken before the operation showed slow activity in the left frontal lobe. Intraoperative ECoG revealed spike focus at the posterior temporal cortex to the margin of the haemangiomatosis. Lesionectomy with lobar corticectomy of the total frontal and parietal lobe and part of the temporal lobe was performed. The epileptogenic focus detected by ECoG in the posterior temporal lobe was also resected. In post-excisional ECoG, epileptogenic activities had disappeared. The patient had hemiparesis and hemihypesthesia just after the surgery, but gradually recovered from the paresis and almost has normal motor function except for right-hand clumsiness up to 1 year after Surgery. The present study demonstrated that lobar corticectomy of the haemangiomatosis-affected cortex with resection of the neighbouring epileptogenic focus is a good surgical alternative even if a haemangiomatosis of the SWS affected multilobar corti of the hemisphere.

Mapping epileptic foci by the dipole tracing method in a brain tumor patient with olfactory seizures: comparison with intraoperative electrocorticograms

We estimated the position of the epileptic foci in a case of brain tumor with olfactory seizures using the Dipole Tracing Method (DTM) and compared the results with electrocorticograms (ECoGs) recorded during surgical resection. The case was a 24-year-old male. Electroencephalograms (EEG) showed frequent focal spikes in the right temporal area. Magnetic resonance imaging revealed a tumor in the right hippocampus region. We analyzed the spikes using DTM with a CDT-1000 EEG analyzer. The locations of two independent foci were analyzed; one was thought to be in the right hippocampus and the other in the right superior temporal gyrus. When the ECoG was taken, the results were in very close correlation with those of DTM, demonstrating the accuracy of DTM in the estimation of the location of epileptic foci in epileptic seizures with brain lesions.

[Surgical treatment of cerebral vascular pathologies in epileptic patients]

Surgery of arteriovenous malformations (AVM) and of cavernous angiomas (cavernoma) in the majority of cases is indicated subsequently to episodes of bleeding. With the development of techniques for diagnosis and surgery for epilepsy of difficult control, indication for surgery of these vascular lesions has become greater. We present nine patients with cerebral vascular lesions and very frequent crises in spite of adequate clinical treatment. Ages ranged from 12 to 42 years with an average of 25 years; there was a prevalence of the male sex (2:1). Surgery consisted of exercises of the lesion in all cases and in four there was also resection of the perilesional irritative area shown by electrocorticography. The pathologic study of lesions showed five cases of cavernoma, three cases of AVM, and one case of venous angioma. As to localization, we observed three lesions in the temporal lobe, four in the frontal, and two in the parietal region. Outpatient follow-up showed a reduction in crises in all of the patients, and seven evolved seizure free following surgery.

Cavernomas of the central nervous system in children. A report of 22 cases

A series of 22 patients under the age of 15 years with cavernomas were treated at the Section of Paediatric Neurosurgery of the Catholic University of Rome between 1981 and 1995. The most common symptoms at presentation were epilepsy, in 12 children, and intracranial hypertension, in 9 children; seizures were present on admission in 14 patients; no patient had a family history of cerebro-vascular malformations, two had multiple lesions. Radiological signs of significant acute and subacute haemorrhage were found in 17 cases. The supratentorial compartment was the most frequent location of the lesions, with only three subtentorial cavernomas. The post-surgical results were good: only four children had a persistence of pre-surgical neurological signs, even though they were ameliorated by the treatment. No patient showed a progression of pre-operative neurological signs, nor the onset of new deficits. Only one child died, but his clinical condition was critical before surgery, because of deep coma, with bilaterally dilated and fixed pupils, and no response to any stimulation. Our results suggest that the younger children present significant haemorrhage more frequently than the older ones; this is demonstrated by the analysis of the mean age of the patients with macro-haemorrhage (= 7 years) and the average age of those without macro-haemorrhage (= 11 years). The removal of cavernomas was always able to control the seizure disorders of our patients, proving that in these cases lesionectomy alone may be sufficient to resolve epilepsy.