Título
Surgical Management Of Cerebral Cavernous Malformations (Cavernomas) Causing Seizures In Children: The Cheo Experience.
Autor
Enrique C.G. Ventureyra
Munyao Nzau
Fecha
Mayo 2004
Lugar de Realización
Division of Neurosurgery, Department of Surgery, The Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario Canada
Correspondencia
ventureyra@cheo.on.ca
Texto
Rev. Argent. Neuroc. 2004; 18 (S 2) 53
Surgical Management Of Cerebral Cavernous Malformations (Cavernomas) Causing Seizures In Children: The Cheo Experience.
Enrique C.G. Ventureyra, Munyao Nzau
Division of Neurosurgery, Department of Surgery, The Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario Canada
Correspondencia: (*) ventureyra@cheo.on.ca
ABSTRACT
Purpose: To review seizure outcome after surgery for cerebral cavernous malformation (CCM) in children presenting with seizures as the main symptom.
Material and Method: We retrospectively reviewed the cases of 10 patients with cerebral cavernous malformations presenting with seizures as the main symptom. These 10 patients were treated surgically between 1988 and 2004, at our institution. There were 5 males and 5 females, age range from 1 yr 8 months to 1 5 yrs (mean 8 yrs).The clinical histories, and radiological findings, patholog y and operative reports were reviewed. Imaging studies were done asfollows: CT + Angiogram in 4 patients, CT + MRI + MRA in 3 patients, CT + MRI in 2 patients.
The cavernomas were located as follows: temporal lobe: 5 cases; parietal lobe: 3 cases (2 in sensory- motor strip); and frontal lobe: 2 cases. All patients had diagnostic EEG, and vine (90 %) were on antiepileptic drugs. Five patients had partial complex seizures and fine generalized tonic- clonic seizures. Seven (70%) patients underwent tailored complete lesionectorny and epileptic focus resection as determined by the use of intraoperative electrocorticography(ECOG). One patient (10%) underwent complete lesionectomy and partialfocus resection. Two patients (20%) with lesions in the sensory motor cortex underwent complete lesionectomy only. Mean follow up time was 5 yrs (range 3 months - 20 yrs).
Results: All patients tolerated surgery well without morbidity or mortality. All patients are seizurefree. Seven (100%) patients who unclerwent tailored complete lesionectomy and epileptic focus resection are seizure free with no antiepileptic medication. One patient who underwent lesionectomy and partial focus resection is seizure free on rnedication. The two patients who underwent lesionectomy only, are both seizure free, one patient still requiring antiepileptic medication.
Conclusion: For cerebral cavernous malformations presenting with seizures in this age group, complete microsurgical excision is the treatment of choice. Surgery should be preceded by careful electroclinical, neuroimaging, anatomical and functional evaluation. The good seizure outcome results (100%) after surgical intervention in our patients are probably related to both the lesionectomy and the excision of the epileptogenic focus in non eloquent areas (80%). Nevertheless, the two patients with lesions located in eloquent cortex that underwent complete lesionectomy abone (20%), are also seizurefree. Based on thesefindings it would appear that complete lesionectomy is the main variable in determining seizure outcorne after surgeryfor CCMs presenting with seizures. Larger series will be required to statistically support this assumption.
Key words: cavernous angiomas - lesionectomy - seizures
INTRODUCTION
Cerebral Cavernous Malformations (CCM) are angiographically occult vascular lesions with a reported prevalence of about 0.4%-0.5% in the general population1,2. Cerebral cavernous malformations clinically manifest as hemorrhage, seizures or neurological deficits. Seizures are the presenting symptom in 23% - 36% of the patients with CCM3,4,5,6.
In series of pediatric patients with cerebral cavernous malformations, seizures have been reported to be the main symptom in 29%-36
Seizure morbidity from CCM alone is significant, and children are more likely to have disability from seizures than adult patients10.
Considering the long life expectancy of children, even medically controlled seizures present the dilemma of lifetime costs and the side effects of antiepileptic medication. Treatment modalities of these lesions should therefore take into account the seizure related outcome. We therefore retrospectively reviewed seizure outcome after surgery for cerebral cavernous malformations in children presenting with seizures as the only symptom, treated at our institution for the last 16 years.
MATERIALS AND METHODS
We retrospectively reviewed the cases of 10 patients with cerebral cavernous malformations presenting with seizures as the main symptom, treated surgically between 1988 and 2004. The clinical histories, seizure type, radiological finding, electrophysiological tests, pathology and operative reports were reviewed. There were 5 males and 5 females, age range was lyr 8 months to 15 yrs (mean 8 yrs). Nine patients were on antiepileptic medication, with break through seizures at a frequency of 1 seizure per month to 240 seizures per month (mean 15/month). Duration of seizures before surgical treatment was 4 months to 5 years (mean 2 years). One patient with seizure frequency of one per month, with duration of 4 months was not on antiepileptic medication. Imaging studies were performed as follows: CT + Angiogram in 4 patients, CT + MRI + MRA in 4 patients, CT + MRI in 2 patients.
The lesions were located as follows: temporal lobe: 5 cases; one of the patients had multiple CCMs but the one located in the temporal lobe was causing the epileptogenic focus as confirmed by Ictal EEG video telemetry and Intraoperative electrocorticography (EcoG); parietal lobe: 3 cases (2 in the sensory- motor strip); and frontal lobe: 2 cases (Table 1). The Wada test was performed on three right handed patients harbouring lesions on the left temporal lobe.
Table 1. Lesion Location
Clinical seizure type and location
Five patients had complex partial seizures and five patients had simple partial seizures with generalization. Table 2 shows clinical seizure type and lesion location.
Table 2. Clinical seizure type and lesion location
Electrophysiological tests
Interictal scalp EEG recordings were done in all 10 patients. Nine patients had strictly unilateral EEG abnormality. Lateralization of the EEG abnormality correlated/localized to the side of lesion in four patients. One patient with a right parietal lesion showed bilateral EEG abnormality, due to spread of spikes to the left parietal region (Table 3).
Three patients had Ictal EEG video telemetry. One patient had multiple CCM, one had bilateral EEG abnormality in interctal EEG (table 4).
Surgical treatment
Intraoperative electrocorticography (EcoG) was performed in vine patients and the EcoG epileptoform activity correlated well with the location of the lesion. In one patient the EcoG abnormality was found within the lesion and not extending 1 cm beyond the periphery of the lesion. In six patients the abnormal EcoG activity extended beyond 2 cm of the periphery but contiguous to the lesion. One patient had remote abnormal EcoG activity, non contiguous as demonstrated by contra lateral activity on scalp ictal EEG. Intra operative electrocorticography was not performed on one patient only with a lesion located in the motor sensory strip.
Seven patients had tailored complete lesionectomy and epileptic focus excision as determined by the EcoG. The patient with a non contiguous epileptogenic focus underwent complete lesionectomy and partial focus resection. The two patients with lesions (CCM) located in the motor sensory strip underwent complete lesionectomy only.
Table 3.Interictal EEG and lesion location
Table 4. Ictal EEG telemetry
Follow up time ranged from 3 months to 16 years (mean 5 years).
Intraoperative electrocorticograph: Number of patients: Frontal, 2; Temporal, 5; Parietal 2 and Occipital, 0.
RESULTS
Surgery was well tolerated and there was no mortality or morbidity encountered . All patients were seizure free at the last follow up. Eight patients were seizure free with no antiepileptic medications. Two patients had not been weaned from medication, but no breaks through seizures were documented.
All seven patients who underwent tailored complete lesionectomies and epileptic focus excision as determined by EcoG where seizures free with no medication. The patient who underwent lesionectomy with partial epileptic focus resection was seizure free but on medication. The two patients who underwent lesionectomy only were both seizure free , one patient still requiring antiepileptic medication.
In these small series, tailored complete lesionectomy and epileptic focus resection as determined by radiological and EcoG findings (7 patients) in non eloquent amas gave 100% seizure free outcome with no antiepileptic medication. Lesionectomy alone or with partial focus resection resulted in good seizure control: 1 patient was seizure free with no medication (33.3%) and 2 patients were seizure free but on medication (66.7%). Factors that are reported15,16 to influence seizure outcome after surgery, such as duration of seizures before surgical treatment, seizure frequency, anatomical location of the lesion and gender were not of statistical significance in our small series and therefore were not analyzed.
DISCUSSION
In addition to hemorrhage, cerebral seizures are a significant contributor to the morbidity associated with cavernous malformations10. The detrimental effects of persistent epileptic activity on brain development are well recognized11. Various studies have shown that surgical treatment is highly effective in patients with epilepsy secondary to cerebral cavernomas. Surgical intervention leads to a favorable seizure outcome, particularly in patients with concordant electroclinical data and neuroimaging2,12,13,14,15. Nevertheless, there is no agreement concerning the best surgical strategy to treat cerebral cavernous malformations associated with epilepsy. That is, pure lesionectomy versus lesionectomy and epileptic focus resection.
Some authors have reported good immediate seizure outcome (65-70% seizure free) following pure lesionectomy with late seizure recurrence12,13,14,15. Other series have reported 80-90% seizure free outcomes with tailored resection of both the cavernoma and the epileptogenic focus2.The same rate of success has been reported after tailored resection of the lesion and the epileptogenic focus for the surgical treatment of epilepsy secondary to other structural lesions16,17,18,19.
Very few reports in the literature discuss the surgical management of CCMs and seizure outcomes , in the pediatric population2,20. Buckingham and colleagues2 reported a pediatric series of 6 patients with CCM s, with only 4 patients presenting with seizures as the main symptom. In these series, EcoG was used in 4 patients with epileptogenic focus resection in 3 patients. All 4 patients were reported to be seizure free, 2 patients still on medication.
CONCLUSIONS
For cerebral cavernous malformations presenting with seizures in this age group, complete microsurgical excision is the treatment of choice. Surgery should be preceded by careful electro clinical, neuroimaging, anatomical and functional evaluation. The good seizure outcome results (100%) after surgical intervention in our patients are probably related to both the lesionectomy and the excision of the epileptogenic focus in non eloquent areas (80%). Nevertheless, the two patients with lesions located in eloquent cortex that underwent complete lesionectomy alone (20%), are also seizure free. Based on these findings complete lesionectomy appears as the main variable in determining seizure outcome after surgery for CCMs presenting with seizures. Larger series will be required to statistically analyze the impact of both surgical strategies ( complete lesionectomy with and without epileptogenic focus resection ) on seizure outcome
References
1. Robinson JR, Awad IA, Little JR: Natural history of the cavernous angioma. J Neurosurg 1991; 75: 709.
2. Del Curling O Jr, Kelly DL Jr, Elser AD, et al. An analysis of the natural history of cavernous angiomas. J Neurosurg 1991; 75: 702.
3. Kondzioika D, Lundsford LD, Kestler JR. The natural history of cerebral cavernous malformations. J Neurosurg 1995; 83: 820.
4. Porter PJ, Willinsky RA, Harper W, et al. Cerebral cavernous malformations: Natural history and prognosis after clinical deterioration with or without hemorrhage. J Neurosurg 1995; 87: 190.
5. Aiba T, Tanaka R, Koike T, et al: Natural history of intracranial cavernous malformations. J Neurosurg 1995; 83: 56.
6. Awad JA, Robinson J: Cavernous malformations and epilepsy. In Awad IA, Barrow DL (eds): Carvenous malformations. Park Ridge, AANS, 1993, p. 49.
7. Buckingham MJ, Crone KR, Ball WS, et al. Management of cerebral cavernous angiomas in children presenting with seizures. Child's Nerv Syst 1989; 5: 347.
8. Fortuna A, Ferrante L, Mastronardi L, et al: Cerebral cavernous angiomas in children. Child's Nerv Syst 1989; 5: 201.
9. Scott RM, Barnes P, Kupsky W, et al. Cavernous angiomas of the central nervous system in children. J Neurosurg 1992; 76: 38.
10. Robinson JR Jr, Awad IA, Magdinec, et al. Factors predisposing to clinical disability in patients with cavernous malformations of the brain. Neurosurg 1993; 32: 730-6.
11. Holmes GL et al. The long-term effects of seizures on the developing brain: Clinical and laboratory issues. Brain Dev 1991; 13: 393-409.
12. Zevgaridis D, van Velthoven V, Ebeling U et al.: Seizure control following surgery in supratentorial cavernous malformation: a retrospective study of 77 patients. Acta Neurochir 1996; 138: 672-7.
13. Casazza M, Franzini A, Spreafico R and Valentini M C: Supratentorial cavernous angiomas and epileptic seizures: preoperative course and postoperative outcome. Neurosurgery 1996; 39: 26-34.
14. Acciari N, Guilion M, Padovani E et al.: Surgical management of cerebral cavernous angiomas causing epilepsy. J Neurosurgical Sciences 1995; 39: 13-20.
15. Cohen D, Zubay G and Goodman R: Seizure outcome after lesionectomy for cavernous malformations. J Neurosurg 1995; 83: 237-42.
16. Awad I, Rosenfeld J, Hahn J et al. Intractable epilepsy and structural lesions of the brain: mapping, resection strategies, and seizure outcome. Epilepsia 1991; 32: 179-86.
17. Pilcher W, Silbergeld D, Berger M et al. Intraoperative electrocorticography during tumor resection: impact on seizure outcome in patients with gangliomas. J Neurosurg 1993 78: 891-902.
18. Drake J, Hoffman H, Kobayashi J et al.: Surgical management of children with temporal lobe epilepsy and mass lesions. Neurosurgery 1987; 21: 792-797, 1987.
19. Piepgras DG, Sundt TM Jr et al. Seizure outcome in patients with surgically treated cerebral arteriovenous malformations. J Neurosurg 1993; 78: 5-11.
20. Giulioni M, Acciari N, Padovani R et al. Surgical management of cavernous angiomas in children. Surg Neurol 1994; 42: 194-199.
Surgical Management Of Cerebral Cavernous Malformations (Cavernomas) Causing Seizures In Children: The Cheo Experience.
Enrique C.G. Ventureyra, Munyao Nzau
Division of Neurosurgery, Department of Surgery, The Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario Canada
Correspondencia: (*) ventureyra@cheo.on.ca
ABSTRACT
Purpose: To review seizure outcome after surgery for cerebral cavernous malformation (CCM) in children presenting with seizures as the main symptom.
Material and Method: We retrospectively reviewed the cases of 10 patients with cerebral cavernous malformations presenting with seizures as the main symptom. These 10 patients were treated surgically between 1988 and 2004, at our institution. There were 5 males and 5 females, age range from 1 yr 8 months to 1 5 yrs (mean 8 yrs).The clinical histories, and radiological findings, patholog y and operative reports were reviewed. Imaging studies were done asfollows: CT + Angiogram in 4 patients, CT + MRI + MRA in 3 patients, CT + MRI in 2 patients.
The cavernomas were located as follows: temporal lobe: 5 cases; parietal lobe: 3 cases (2 in sensory- motor strip); and frontal lobe: 2 cases. All patients had diagnostic EEG, and vine (90 %) were on antiepileptic drugs. Five patients had partial complex seizures and fine generalized tonic- clonic seizures. Seven (70%) patients underwent tailored complete lesionectorny and epileptic focus resection as determined by the use of intraoperative electrocorticography(ECOG). One patient (10%) underwent complete lesionectomy and partialfocus resection. Two patients (20%) with lesions in the sensory motor cortex underwent complete lesionectomy only. Mean follow up time was 5 yrs (range 3 months - 20 yrs).
Results: All patients tolerated surgery well without morbidity or mortality. All patients are seizurefree. Seven (100%) patients who unclerwent tailored complete lesionectomy and epileptic focus resection are seizure free with no antiepileptic medication. One patient who underwent lesionectomy and partial focus resection is seizure free on rnedication. The two patients who underwent lesionectomy only, are both seizure free, one patient still requiring antiepileptic medication.
Conclusion: For cerebral cavernous malformations presenting with seizures in this age group, complete microsurgical excision is the treatment of choice. Surgery should be preceded by careful electroclinical, neuroimaging, anatomical and functional evaluation. The good seizure outcome results (100%) after surgical intervention in our patients are probably related to both the lesionectomy and the excision of the epileptogenic focus in non eloquent areas (80%). Nevertheless, the two patients with lesions located in eloquent cortex that underwent complete lesionectomy abone (20%), are also seizurefree. Based on thesefindings it would appear that complete lesionectomy is the main variable in determining seizure outcorne after surgeryfor CCMs presenting with seizures. Larger series will be required to statistically support this assumption.
Key words: cavernous angiomas - lesionectomy - seizures
INTRODUCTION
Cerebral Cavernous Malformations (CCM) are angiographically occult vascular lesions with a reported prevalence of about 0.4%-0.5% in the general population1,2. Cerebral cavernous malformations clinically manifest as hemorrhage, seizures or neurological deficits. Seizures are the presenting symptom in 23% - 36% of the patients with CCM3,4,5,6.
In series of pediatric patients with cerebral cavernous malformations, seizures have been reported to be the main symptom in 29%-36
Seizure morbidity from CCM alone is significant, and children are more likely to have disability from seizures than adult patients10.
Considering the long life expectancy of children, even medically controlled seizures present the dilemma of lifetime costs and the side effects of antiepileptic medication. Treatment modalities of these lesions should therefore take into account the seizure related outcome. We therefore retrospectively reviewed seizure outcome after surgery for cerebral cavernous malformations in children presenting with seizures as the only symptom, treated at our institution for the last 16 years.
MATERIALS AND METHODS
We retrospectively reviewed the cases of 10 patients with cerebral cavernous malformations presenting with seizures as the main symptom, treated surgically between 1988 and 2004. The clinical histories, seizure type, radiological finding, electrophysiological tests, pathology and operative reports were reviewed. There were 5 males and 5 females, age range was lyr 8 months to 15 yrs (mean 8 yrs). Nine patients were on antiepileptic medication, with break through seizures at a frequency of 1 seizure per month to 240 seizures per month (mean 15/month). Duration of seizures before surgical treatment was 4 months to 5 years (mean 2 years). One patient with seizure frequency of one per month, with duration of 4 months was not on antiepileptic medication. Imaging studies were performed as follows: CT + Angiogram in 4 patients, CT + MRI + MRA in 4 patients, CT + MRI in 2 patients.
The lesions were located as follows: temporal lobe: 5 cases; one of the patients had multiple CCMs but the one located in the temporal lobe was causing the epileptogenic focus as confirmed by Ictal EEG video telemetry and Intraoperative electrocorticography (EcoG); parietal lobe: 3 cases (2 in the sensory- motor strip); and frontal lobe: 2 cases (Table 1). The Wada test was performed on three right handed patients harbouring lesions on the left temporal lobe.
Table 1. Lesion Location
Clinical seizure type and location
Five patients had complex partial seizures and five patients had simple partial seizures with generalization. Table 2 shows clinical seizure type and lesion location.
Table 2. Clinical seizure type and lesion location
Electrophysiological tests
Interictal scalp EEG recordings were done in all 10 patients. Nine patients had strictly unilateral EEG abnormality. Lateralization of the EEG abnormality correlated/localized to the side of lesion in four patients. One patient with a right parietal lesion showed bilateral EEG abnormality, due to spread of spikes to the left parietal region (Table 3).
Three patients had Ictal EEG video telemetry. One patient had multiple CCM, one had bilateral EEG abnormality in interctal EEG (table 4).
Surgical treatment
Intraoperative electrocorticography (EcoG) was performed in vine patients and the EcoG epileptoform activity correlated well with the location of the lesion. In one patient the EcoG abnormality was found within the lesion and not extending 1 cm beyond the periphery of the lesion. In six patients the abnormal EcoG activity extended beyond 2 cm of the periphery but contiguous to the lesion. One patient had remote abnormal EcoG activity, non contiguous as demonstrated by contra lateral activity on scalp ictal EEG. Intra operative electrocorticography was not performed on one patient only with a lesion located in the motor sensory strip.
Seven patients had tailored complete lesionectomy and epileptic focus excision as determined by the EcoG. The patient with a non contiguous epileptogenic focus underwent complete lesionectomy and partial focus resection. The two patients with lesions (CCM) located in the motor sensory strip underwent complete lesionectomy only.
Table 3.Interictal EEG and lesion location
Table 4. Ictal EEG telemetry
Follow up time ranged from 3 months to 16 years (mean 5 years).
Intraoperative electrocorticograph: Number of patients: Frontal, 2; Temporal, 5; Parietal 2 and Occipital, 0.
RESULTS
Surgery was well tolerated and there was no mortality or morbidity encountered . All patients were seizure free at the last follow up. Eight patients were seizure free with no antiepileptic medications. Two patients had not been weaned from medication, but no breaks through seizures were documented.
All seven patients who underwent tailored complete lesionectomies and epileptic focus excision as determined by EcoG where seizures free with no medication. The patient who underwent lesionectomy with partial epileptic focus resection was seizure free but on medication. The two patients who underwent lesionectomy only were both seizure free , one patient still requiring antiepileptic medication.
In these small series, tailored complete lesionectomy and epileptic focus resection as determined by radiological and EcoG findings (7 patients) in non eloquent amas gave 100% seizure free outcome with no antiepileptic medication. Lesionectomy alone or with partial focus resection resulted in good seizure control: 1 patient was seizure free with no medication (33.3%) and 2 patients were seizure free but on medication (66.7%). Factors that are reported15,16 to influence seizure outcome after surgery, such as duration of seizures before surgical treatment, seizure frequency, anatomical location of the lesion and gender were not of statistical significance in our small series and therefore were not analyzed.
DISCUSSION
In addition to hemorrhage, cerebral seizures are a significant contributor to the morbidity associated with cavernous malformations10. The detrimental effects of persistent epileptic activity on brain development are well recognized11. Various studies have shown that surgical treatment is highly effective in patients with epilepsy secondary to cerebral cavernomas. Surgical intervention leads to a favorable seizure outcome, particularly in patients with concordant electroclinical data and neuroimaging2,12,13,14,15. Nevertheless, there is no agreement concerning the best surgical strategy to treat cerebral cavernous malformations associated with epilepsy. That is, pure lesionectomy versus lesionectomy and epileptic focus resection.
Some authors have reported good immediate seizure outcome (65-70% seizure free) following pure lesionectomy with late seizure recurrence12,13,14,15. Other series have reported 80-90% seizure free outcomes with tailored resection of both the cavernoma and the epileptogenic focus2.The same rate of success has been reported after tailored resection of the lesion and the epileptogenic focus for the surgical treatment of epilepsy secondary to other structural lesions16,17,18,19.
Very few reports in the literature discuss the surgical management of CCMs and seizure outcomes , in the pediatric population2,20. Buckingham and colleagues2 reported a pediatric series of 6 patients with CCM s, with only 4 patients presenting with seizures as the main symptom. In these series, EcoG was used in 4 patients with epileptogenic focus resection in 3 patients. All 4 patients were reported to be seizure free, 2 patients still on medication.
CONCLUSIONS
For cerebral cavernous malformations presenting with seizures in this age group, complete microsurgical excision is the treatment of choice. Surgery should be preceded by careful electro clinical, neuroimaging, anatomical and functional evaluation. The good seizure outcome results (100%) after surgical intervention in our patients are probably related to both the lesionectomy and the excision of the epileptogenic focus in non eloquent areas (80%). Nevertheless, the two patients with lesions located in eloquent cortex that underwent complete lesionectomy alone (20%), are also seizure free. Based on these findings complete lesionectomy appears as the main variable in determining seizure outcome after surgery for CCMs presenting with seizures. Larger series will be required to statistically analyze the impact of both surgical strategies ( complete lesionectomy with and without epileptogenic focus resection ) on seizure outcome
References
1. Robinson JR, Awad IA, Little JR: Natural history of the cavernous angioma. J Neurosurg 1991; 75: 709.
2. Del Curling O Jr, Kelly DL Jr, Elser AD, et al. An analysis of the natural history of cavernous angiomas. J Neurosurg 1991; 75: 702.
3. Kondzioika D, Lundsford LD, Kestler JR. The natural history of cerebral cavernous malformations. J Neurosurg 1995; 83: 820.
4. Porter PJ, Willinsky RA, Harper W, et al. Cerebral cavernous malformations: Natural history and prognosis after clinical deterioration with or without hemorrhage. J Neurosurg 1995; 87: 190.
5. Aiba T, Tanaka R, Koike T, et al: Natural history of intracranial cavernous malformations. J Neurosurg 1995; 83: 56.
6. Awad JA, Robinson J: Cavernous malformations and epilepsy. In Awad IA, Barrow DL (eds): Carvenous malformations. Park Ridge, AANS, 1993, p. 49.
7. Buckingham MJ, Crone KR, Ball WS, et al. Management of cerebral cavernous angiomas in children presenting with seizures. Child's Nerv Syst 1989; 5: 347.
8. Fortuna A, Ferrante L, Mastronardi L, et al: Cerebral cavernous angiomas in children. Child's Nerv Syst 1989; 5: 201.
9. Scott RM, Barnes P, Kupsky W, et al. Cavernous angiomas of the central nervous system in children. J Neurosurg 1992; 76: 38.
10. Robinson JR Jr, Awad IA, Magdinec, et al. Factors predisposing to clinical disability in patients with cavernous malformations of the brain. Neurosurg 1993; 32: 730-6.
11. Holmes GL et al. The long-term effects of seizures on the developing brain: Clinical and laboratory issues. Brain Dev 1991; 13: 393-409.
12. Zevgaridis D, van Velthoven V, Ebeling U et al.: Seizure control following surgery in supratentorial cavernous malformation: a retrospective study of 77 patients. Acta Neurochir 1996; 138: 672-7.
13. Casazza M, Franzini A, Spreafico R and Valentini M C: Supratentorial cavernous angiomas and epileptic seizures: preoperative course and postoperative outcome. Neurosurgery 1996; 39: 26-34.
14. Acciari N, Guilion M, Padovani E et al.: Surgical management of cerebral cavernous angiomas causing epilepsy. J Neurosurgical Sciences 1995; 39: 13-20.
15. Cohen D, Zubay G and Goodman R: Seizure outcome after lesionectomy for cavernous malformations. J Neurosurg 1995; 83: 237-42.
16. Awad I, Rosenfeld J, Hahn J et al. Intractable epilepsy and structural lesions of the brain: mapping, resection strategies, and seizure outcome. Epilepsia 1991; 32: 179-86.
17. Pilcher W, Silbergeld D, Berger M et al. Intraoperative electrocorticography during tumor resection: impact on seizure outcome in patients with gangliomas. J Neurosurg 1993 78: 891-902.
18. Drake J, Hoffman H, Kobayashi J et al.: Surgical management of children with temporal lobe epilepsy and mass lesions. Neurosurgery 1987; 21: 792-797, 1987.
19. Piepgras DG, Sundt TM Jr et al. Seizure outcome in patients with surgically treated cerebral arteriovenous malformations. J Neurosurg 1993; 78: 5-11.
20. Giulioni M, Acciari N, Padovani R et al. Surgical management of cavernous angiomas in children. Surg Neurol 1994; 42: 194-199.