Surgical outcome in patients with refractory epilepsy associated to MRI-defined unilateral mesial temporal sclerosis

INTRODUÇÃO: Protocolos diferentes têm sido utilizados para a investigação pré-operatória de pacientes epilépticos nos diferentes centros. No entanto, o valor relativo de cada teste disponível ainda é controverso na literatura.OBJETIVO: Relatamos os resultados cirúrgicos de pacientes com epilepsia refratária do lobo temporal associada a esclerose hipocampal (EH), cuja investigação pré-operatória consistiu exclusivamente de estudo de eletrencefalograma (EEG) inter-crítico e ressonância magnética (RM). MÉTODO: Foram estudados 41 pacientes com epilepsia refratária do lobo temporal, avaliados pré-operatoriamente somente por meio de EEG interictal e RM encefálica. Foram incluídos somente pacientes em quem a RM mostrava apenas EH unilateral. Todos pacientes possuíam ao menos quatro EEG inter-ictais. Todos os pacientes foram submetidos a córtico-amígdalo-hipocampectomia no lado demonstrado pela RM.RESULTADOS: A análise do EEG interictal revelou atividade epileptiforme unilateral, compatível com os achados da RM em 37 pacientes. Nos outros quatro pacientes, o EEG evidenciou comprometimento bilateral. O tempo médio de seguimento pós-operatório dos pacientes foi 4,3±1,1 anos. No período pós-operatório, 95,1% dos pacientes encontravam-se em classe I de Engel (70,6% em Engel I-A) e 4.9% em classe II de Engel. Todos os pacientes com achados bilaterais ao EEG estavam em classe I de Engel. O estudo anátomo-patológico das amostras cirúrgicas revelou EH em todos os pacientes. CONCLUSÃO: É possível selecionar bons candidatos à ressecção temporal utilizando-se apenas dados de RM e EEG inter-ictal. Nos pacientes com EH unilateral na RM, espera-se um índice de remissão pós-operatória das crises superior a 90%. O achado de EH na RM é, isoladamente, o maior fator indicativo de bom prognóstico após ressecção temporal.

Hemisferectomia funcional precoce na hemimegalencefalia associada à epilepsia refratária / Early functional hemispherectomy in hemimegalencephaly associated to refractory epilepsy

A hemimegalencefalia (HME) é malformação congênita cerebral rara de etiologia desconhecida que pode se apresentar com síndrome epiléptica de início precoce e resistente à terapia com anticonvulsivantes, associada a comprometimento significativo do desenvolvimento neuropsicomotor. A hemisferectomia funcional (HF) tem-se mostrado alternativa eficaz nos casos refratários à terapêutica medicamentosa. Em número diminuto, crianças foram operadas antes dos seis meses de idade. Esse estudo relata duas crianças com idade inferior a 6 meses com HME e síndrome epiléptica catastrófica submetidas a HF e com boa evolução clínica.

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 percent reduction in seizure frequency. CONCLUSION: Resections including the face and tongue rolandic cortex can be safely performed even within the dominant hemisphere

Tratamento cirúrgico de epilepsia refratária da área da língua / Epileptogenic area in the sensorimotor cortical representation of tongue

O presente estudo relata um paciente com foco epiléptico localizado nas áreas motoras e sensitivas da língua, investigado de maneira invasiva com eletrodos subdurais e, subseqüentemente, submetido à ressecção cortical. O paciente de 22 anos, sexo masculino, possuía crises com versãoconsciente da cabeça para a esquerda, evoluindo, eventualmente, para crises tônico-clônicas, diárias, ocorrendo em vigília e no sono, desde os 5 anos de idade, refratárias ao tratamento clínico. Monitorização videoeletroencefalográfica revelou surtos interictais de ondas lentas comprojeção na região frontocentral (C4-T4). O registro ictal sugeria início na mesma região. A ressonância magnética não revelou alterações. Foi submetido ao implante de grades de eletrodos. O registro eletrocorticográfico crônico com eletrodos subdurais mostrou início das descargas nas regiões motora e sensitiva da língua com espraiamento para a região da face. As descargas intercríticas estendiam-se anterior e posteriormente aos giros rolândicos, bem como ao giro temporal superior. A estimulação cortical da área sensitiva da língua reproduziu as crises clínicas. Foi realizada ressecção subpial do córtex pré-motor, motor e sensitivo da língua e face e póssensitiva da língua e face e porções do giro temporal superior, com especial atenção para a preservação do arcabouço vascular da região. Mantém-se sem crises a partir daí. O estudo anatomopatológico demonstrou apenas gliose intensa.O tratamento cirúrgico de pacientes com focos epilépticos em região da língua pode ser realizado com segurança desde que as relações entre as áreas eloqüentes e epileptogênicas sejam bem conhecidas, em casos selecionados.

We report the case of a 22 year-old male patient with an epileptic focus located at the sensorimotor area of the tongue who was evaluated with subdural electrodes and submitted to a subpial cortical resection. He had seizures characterized by head rotation to the left without impairment ofconsciousness. They occurred in a daily basis, either during sleep or awake, since the age of 5 years. Video-EEG monitoring showed interictal slow waves over the right fronto-central region. Ictal recording suggested the onset over the same area. MRI was normal. He was submitted to subdural electrodes implantation over the right frontoparietal region. ECoGobtained through the implanted electrodes showed ictal onset over the motor and sensitive areas of the tongue with early spreading to the face areas. Interictal spiking was more widespread including the premotor gyrus, the postcentral gyrus and the superior temporal gyrus. Corticalstimulation of the tongue areas reproduced the patient?s habitual seizures. A subpial resection of the premotor, motor, sensory and postsensory cortex related to the tongue and an additional superior temporal gyrus resection was performed. Special caution was dedicated to the preservation of the surrounding vascular structures. He has been seizure-free since surgery. Pathological examination showed severe gliosis.The surgical treatment of patients with foci at the tongue area can be performed safely as far as the relationship between the focus and the surrounding eloquent areas is well delimited.

Results of surgery in patients with bilateral independent temporal lobe spiking (BITLS) with normal MRI or bilateral mesial temporal sclerosis (MTS) investigated with bilateral subdural grids

PURPOSE: The introduction of new technologies in the clinical practice have greatly decreased the number of patients submitted to invasive recordings. On the other hand, some patients with refractory temporal lobe epilepsy have normal MR scans or bilateral potentially epileptogenic lesions. This paper reports the results of invasive neurophysiology and surgical outcome in such patients. METHOD: Sixteen patients were studied. Eleven had normal MRI (Group I) and five had bilateral mesial temporal sclerosis (Group II). All patients had BITLS and non-localizatory seizures on video-EEG monitoring. All patients were implanted bilaterally with 32-contacts subdural grids. They were submitted to a cortico-amygdalo-total hippocampectomy at the side defined by chronic electrocorticography (ECoG). RESULTS: In Group I, seizures came from a single side in nine patients. In nine patients, seizures started at one side, spread to the ipsolateral contacts and contralaterally afterwards. On the other hand, in two Group I patients seizures started in one mesial region and spread to the contralateral parahippocampus and neocortex before spreading to ipsolateral contacts. All patients in Group II had seizures starting unilaterally with focal EcoG onset in the mesial regions. Eight Group I patients are seizure-free and three are in Engel's class II. Eighty percent of Group II patients are seizure-free after surgery and one patient is in Engel's class II. CONCLUSION: Good surgical results can be obtained in patients with BITLS. Patients with normal MRI seem to have a worse prognosis when compared to patients with unilateral or even bilateral MTS. Extensive subdural coverage is essential in patients with normal MRI

Doença de Lafora: diagnóstico pela biopsia de músculo esquelético (relato de caso) / Lafora's disease: diagnosis by muscle biopsy (case report)

Uma paciente de 16 anos apresentava epilepsia mioclônica causada pela doença de Lafora. A biopsia muscular mostrou padräo vacuolar nas fibras musculares com as reaçöes nicotinamida adenina tetrazolium redutase desidrogenase, hematoxilina-eosina e PAS. O aspecto morfológico permite o diagnóstico através da biopsia muscular. Este é um procedimento menos agressivo que a biopsia de fígado e de cérebro. A microscopia eletrônica deve ser reservada para casos nos quais as alteraçöes musculares à microscopia óptica säo muito discretas deixando dúvidas quanto ao diagnóstico

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 percent 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