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.