RESUMO
OBJECTIVES: We designed a prospective, individual-controlled study to evaluate the effect of cardiac-based VNS (cbVNS) in a cohort of patients with generalized epilepsy (GE). MATERIALS AND METHODS: Twenty patients were included. They were followed up for six months under regular VNS (rVNS) and subsequently for six months during cbVNS. Stimulation parameters were 500 µsec, 30 Hz, and up to 2.5 mA. Seizure frequency was documented after two, four, and six months during the rVNS and cbVNS phases. Patients with at least 50% seizure frequency reduction were considered responders. The total and relative amount of stimulation cycles generated by both rVNS and cbVNS activation were documented. Findings during rVNS were compared to baseline and cbVNS data were compared to those during rVNS. RESULTS: There was a significant decrease in mean seizure frequency (61% [95% CI, 48-74]; p < 0.001) during the rVNS phase compared to baseline. There was no additional significant (16% [95% CI, 4-35]; p = 0.097) mean seizure frequency reduction during cbVNS compared to the rVNS phase. Fifteen patients (75%) were considered responders after rVNS. Four patients (20%) were considered responders after six months of cbVNS. During the cbVNS phase, the mean total number of cycles/day was 346, 354, and 333 for months two, four, and six, respectively; the cycles generated by rVNS were 142, 138, and 146 for months two, four, and six, respectively; and cycles generated by cbVNS were 204, 215, and 186 for months two, four, and six, respectively. There was no relationship between the mean total number of cycles (-6[95% CI, -85 to 72]; p = 0.431), the mean number of auto-stimulation cycles (27[95% CI,-112 to 166]; p = 0.139), the mean number of regular cycles (-33[95% CI,-123 to 57]; p = 0.122), or the mean percentage of auto-stimulation cycles (13[95% CI,19- 45]; p = 0.109) and outcome during the cbVNS phase. Eight patients showed some decrease in seizure frequency during cbVNS. CONCLUSIONS: rVNS was effective in reducing seizure frequency in patients with generalized epilepsy, but activation of the cbVNS feature did not add significantly to rVNS efficacy. On the other hand, although not statistically significant, 40% of the patients showed some reduction in seizure frequency, which might prove useful at an individual level.
Assuntos
Epilepsia Generalizada , Estimulação do Nervo Vago , Epilepsia Generalizada/terapia , Humanos , Estudos Prospectivos , Convulsões/terapia , Resultado do Tratamento , Nervo VagoRESUMO
OBJECTIVE: We present the findings related to seizure outcome during hippocampal deep brain stimulation (Hip-DBS) in patients with refractory temporal lobe epilepsy. METHODS: Twenty-five patients submitted to Hip-DBS were studied. All patients were evaluated with interictal and ictal electroencephalography (EEG) and high-resolution 1.5 T magnetic resonance imaging (MRI). The hippocampus was targeted directly on MRI using a posterior occipital burr hole approach. Bipolar continuous stimulation was ramped up until 3.0 V (300 µs, 130 Hz). Patients were considered responders if at least 50% seizure frequency reduction was obtained. RESULTS: Median age was 39 years; median follow-up time was 57 months (16 women). All patients had focal with impaired awareness seizure (FIAS) and 23 patients had focal aware seizure (FAS). Baseline median FAS and FIAS frequency was 8. Ictal EEG showed unilateral (n = 10) or bilateral (n = 15) seizure onset. MRI showed unilateral (n = 11) or bilateral (n = 8) mesial temporal sclerosis (MTS) and was normal in six6 patients. Fifteen patients were submitted to bilateral and 10 patients to unilateral Hip-DBS. Median reduction in FAS frequency was 66%. Eighteen patients with FAS were considered responders and five (21%) were free of FAS. Median FIAS frequency (n = 25) reduction was 91%. Twenty-two patients were considered responders and eight (32%) were free of FIAS. FIAS were significantly more reduced then FAS (P = .017). There was no relation between any contact's position within the hippocampus and outcome for either FAS (P = .727) or FIAS (P = .410). There was no difference in outcome in patients submitted to either unilateral or bilateral Hip-DBS regarding FAS (P = .978) or FIAS (P = .693). SIGNIFICANCE: Hip-DBS significantly reduced the frequency of both FAS and FIAS in this cohort of patients with refractory temporal lobe epilepsy. Hip-DBS might represent a good therapeutic option in such patients not amenable to resective surgery.
Assuntos
Estimulação Encefálica Profunda/métodos , Epilepsia Resistente a Medicamentos/terapia , Epilepsia do Lobo Temporal/terapia , Hipocampo , Adolescente , Adulto , Epilepsia Resistente a Medicamentos/fisiopatologia , Eletroencefalografia , Epilepsia do Lobo Temporal/fisiopatologia , Feminino , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose , Resultado do Tratamento , Adulto JovemRESUMO
A female adult patient with extensive bilateral periventricular nodular heterotopia (PNH), who was referred for bilateral hippocampal deep brain stimulation (Hip-DBS), was investigated. She presented with daily focal aware and impaired-awareness seizures with automatism and weekly generalized tonic-clonic seizures. Her EEG showed bilateral independent ictal and interictal neocortical temporal lobe discharges and her MRI showed extensive, symmetric PNH. She was treated with bilateral Hip-DBS which led to a major decrease in her seizure frequency (one seizure per trimester). The outcome was stable over three years, and there was no additional neuropsychological deficits or device-related adverse effects. This is the first reported patient to be undergo long-term continuous Hip-DBS to treat bilateral PNH. DBS, a non-lesional, reversible, neuromodulatory technique, may prove to be a good therapeutic option in patients with extensive bilateral epileptogenic networks who present with temporal lobe epilepsy and who are usually considered poor candidates for resective surgery.
Assuntos
Estimulação Encefálica Profunda , Epilepsia/terapia , Hipocampo , Heterotopia Nodular Periventricular/terapia , Adulto , Eletroencefalografia , Epilepsia/etiologia , Feminino , Humanos , Heterotopia Nodular Periventricular/complicaçõesRESUMO
OBJECTIVE: We designed a prospective, randomized, controlled, double-blind study to evaluate the efficacy of hippocampal deep brain stimulation (Hip-DBS) in patients with refractory temporary lobe epilepsy (TLE). METHODS: Sixteen adult patients with refractory TLE were studied. Patient's workup included medical history, interictal and ictal electroencephalography (EEG), and high-resolution 1.5T magnetic resonance imaging (MRI). Patients were randomized on a 1:1 proportion to an active (stimulation on) or to a control (no stimulation) arm. After implantation, patients were allowed to recover for 1 month, which was followed by a 1-month titration (or sham) period. The 6-month blinded phase started immediately afterward. A postoperative MRI confirmed the electrode's position in all patients. All patients received bipolar continuous stimulation. Stimulus duration was 300 µs and frequency was 130 Hz; final intensity was 2 V. Patients were considered responders when they had at least 50% seizure frequency reduction. RESULTS: All patients had focal impaired awareness seizures (FIAS, complex partial seizures), and 87% had focal aware seizures (FAS, simple partial seizures). Mean preoperative seizure frequency was 12.5 ± 9.4 (mean ± standard deviation) per month. MRI findings were normal in two patients, disclosed bilateral mesial temporal sclerosis (MTS) in three, left MTS in five, and right MTS in six patients. An insertional effect could be noted in both control and active patients. In the active group (n = 8), four patients became seizure-free; seven of eight were considered responders and one was a nonresponder. There was a significant difference regarding FIAS frequency between the two groups from the first month of full stimulation (p < 0.001) until the end of the blinded phase (p < 0.001). This was also true for FAS, except for the third month of the blinded phase. SIGNIFICANCE: Hip-DBS was effective in significantly reducing seizure frequency in patients with refractory TLE in the active group, as compared to the control group. Fifty-percent of the patients in the active group became seizure-free. The present study is the larger prospective, controlled, double-blind study to evaluate the effects of Hip-DBS published to date.
Assuntos
Estimulação Encefálica Profunda/métodos , Epilepsia Resistente a Medicamentos/terapia , Epilepsia do Lobo Temporal/terapia , Hipocampo , Adolescente , Adulto , Método Duplo-Cego , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Eletroencefalografia , Epilepsia do Lobo Temporal/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVE: We studied patients treated with chronic DBS in whom there was depletion of the generator's battery, in order to get insight on the modulatory potential of chronic DBS in refractory epilepsy. MATERIAL: Nine adult patients with refractory epilepsy treated with at least three years of deep brain stimulation (DBS), and who were followed up for at least six months after battery depletion were studied. One patient was treated with hippocampal DBS (Hip-DBS), two to centro-median DBS (CM-DBS) and six to anterior nucleus stimulation (AN-DBS). RESULTS: Two patients did not have seizure's frequency modification after battery depletion; the other seven patients had seizure frequency increase, including those three patients that were seizure-free. Five of those seven patients who had seizure frequency increase after battery's depletion had seizure's frequency lower than their pre-DBS baseline seizure frequency; two of such patients returned to their pre-DBS baseline seizure frequency. CONCLUSIONS: In the majority of the patients, three years of chronic DBS did not show a permanent effect on epileptogenesis. On the other hand, the post-battery depletion seizure's frequency was usually much lower than the baseline (pre-DBS) seizure's frequency, suggesting that there was actual network neuromodulation.
Assuntos
Estimulação Encefálica Profunda/métodos , Epilepsia/terapia , Resultado do Tratamento , Núcleos Anteriores do Tálamo/fisiologia , Anticonvulsivantes/uso terapêutico , Feminino , Hipocampo/fisiologia , Humanos , Núcleos Intralaminares do Tálamo/fisiologia , Estudos Longitudinais , MasculinoRESUMO
RATIONALE: The rationale for using a non-linear (proportional) paradigm for determining the extent of the neocortex to be removed in temporal lobe resection was based on anatomical and intra-operative cortical mapping findings. We present our results regarding speech preservation in patients submitted to CAH using the central artery as an anatomical landmark for determining the posterior border of neocortical resection. METHODS: Two hundred and fifty consecutive right-handed patients with left unilateral mesial sclerosis were studied. All patients were submitted to CAH under general anesthesia and without intraoperative electrocorticography. The posterior border of the lateral neocortical resection was defined by a line perpendicular to the temporal axis at the level of the central artery. RESULTS: Seven patients had transient (1-3 weeks; mean=9 days) receptive speech disturbance. There was no permanent speech deficit. Imaging documented edema or contusion at the posterior temporal cortical border in all patients who had transient speech deficits. The mean extent of cortical resection was 3.9 cm in adults and 3.1cm in kids. DISCUSSION: This is the first report in the literature discussing the use of a non-linear paradigm to determine the extent of lateral neocortical removal in this patient population. We found no permanent speech disturbances in this series. The non-linear approach used in this series proved to be safe and effective to avoid post-operative speech disorders. It was able to compensate for different brain and head sizes, and allowed smaller neocortical removal when compared to traditional linear approaches.
Assuntos
Tonsila do Cerebelo/cirurgia , Epilepsia do Lobo Temporal/cirurgia , Hipocampo/cirurgia , Neocórtex/cirurgia , Dinâmica não Linear , Fala , Adolescente , Adulto , Tonsila do Cerebelo/patologia , Criança , Epilepsia do Lobo Temporal/patologia , Hipocampo/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Neocórtex/patologia , Esclerose/patologia , Esclerose/cirurgia , Distúrbios da Fala/prevenção & controle , Lobo Temporal/patologia , Lobo Temporal/cirurgia , Adulto JovemRESUMO
PURPOSE: Deep brain stimulation (DBS) has been used in an increasing frequency for treatment of refractory epilepsy. Acute deep brain macrostimulation intraoperative findings were sparsely published in the literature. We report on our intraoperative macrostimulation findings during thalamic and hippocampal DBS implantation. METHODS: Eighteen patients were studied. All patients underwent routine pre-operative evaluation that included clinical history, neurological examination, interictal and ictal EEG, high resolution 1.5T MRI and neuropsychological testing. Six patients with temporal lobe epilepsy were submitted to hippocampal DBS (Hip-DBS); 6 patients with focal epilepsy were submitted to anterior thalamic nucleus DBS (AN-DBS) and 6 patients with generalized epilepsy were submitted to centro-median thalamic nucleus DBS (CM-DBS). Age ranged from 9 to 40 years (11 males). All patients were submitted to bilateral quadripolar DBS electrode implantation in a single procedure, under general anesthesia, and intraoperative scalp EEG monitoring. Final electrode's position was checked postoperatively using volumetric CT scanning. Bipolar stimulation using the more proximal and distal electrodes was performed. Final standard stimulation parameters were 6Hz, 4V, 300µs (low frequency range: LF) or 130Hz, 4V, 300µs (high frequency range: HF). KEY FINDINGS: Bilateral recruiting response (RR) was obtained after unilateral stimulation in all patients submitted to AN and CM-DBS using LF stimulation. RR was widespread but prevailed over the fronto-temporal region bilaterally, and over the stimulated hemisphere. HF stimulation led to background slowing and a DC shift. The mean voltage for the appearance of RR was 4V (CM) and 3V (AN). CM and AN-DBS did not alter inter-ictal spiking frequency or morphology. RR obtained after LF Hip-DBS was restricted to the stimulated temporal lobe and no contralateral activation was noted. HF stimulation yielded no visually recognizable EEG modification. Mean intensity for initial appearance of RR was 3V. In 5 of the 6 patients submitted to Hip-DBS, an increase in inter-ictal spiking was noted unilaterally immediately after electrode insertion. Intraoperative LF stimulation did not modify temporal lobe spiking; on the other hand, HF was effective in abolishing inter-ictal spiking in 4 of the 6 patients studied. There was no immediate morbidity or mortality in this series. SIGNIFICANCE: Macrostimulation might be used to confirm that the hardware was working properly. There was no typical RR derived from each studied thalamic nuclei after LF stimulation. On the other hand, absence of such RRs was highly suggestive of hardware malfunction or inadequate targeting. Thalamic-DBS (Th-DBS) RR was always bilateral after unilateral stimulation, although they somehow prevailed over the stimulated hemisphere. Contrary to Th-DBS, Hip-DBS gave rise to localized RR over the ipsolateral temporal neocortex, and absence of this response might very likely be related to inadequate targeting or hardware failure. Increased spiking was seen over temporal neocortex during hippocampal electrode insertion; this might point to the more epileptogenic hippocampal region in each individual patient. We did not notice any intraoperative response difference among patients with temporal lobe epilepsy with or without MTS. The relationship between these intraoperative findings and seizure outcome is not yet clear and should be further evaluated.
Assuntos
Estimulação Encefálica Profunda/métodos , Epilepsia/terapia , Hipocampo/fisiologia , Monitorização Intraoperatória/métodos , Tálamo/fisiologia , Adolescente , Adulto , Criança , Eletroencefalografia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
RATIONALE: We describe seizure and neuropsychological outcome obtained after CAH in patients with TLE and normal MRI evaluated in the modern imaging era. METHODS: Forty-five adult consecutive patients with TLE and normal MRI were studied. All patients had neuropsychological testing, interictal and ictal EEG recordings and MRI. They were divided into two groups: Group 1 (n=18), included patients in whom non-invasive neurophysiological evaluation was lateralizing and Group 2 (n=27) included patients with non-lateralizing neurophysiological data who were submitted to invasive recordings. RESULTS: Seventy-seven percent of the Group 1 patients were rated as Engel I; 11% were rated as Engel II and 11% as Engel III. In Group 2, there were 57% of patients seizure-free, 26% in Engel II and 14% in Engel III. Pre-operatively, mean general IQ was 82 and 78 in Groups 1 and 2, respectively; post-operatively, mean general IQ was respectively 86 and 71. Some degree of verbal memory decline was noted in all patients submitted to dominant temporal lobe resection in both Groups 1 and 2. At last follow-up visit, 22% of Group 1 and 11% of Group 2 patients were receiving no antiepileptic drugs (AED). CONCLUSIONS: Our data showed that patients with TLE and normal MRI could get good surgical results after CAH although 60% of them would need invasive recordings and their results regarding seizure control and cognition were worse than those obtained in patients with MRI defined temporal lobe lesions. Caution should be taken in offering dominant temporal lobe resection to this subset of patients.
Assuntos
Tonsila do Cerebelo/cirurgia , Córtex Cerebral/cirurgia , Epilepsia do Lobo Temporal/cirurgia , Hipocampo/cirurgia , Adolescente , Adulto , Idade de Início , Tonsila do Cerebelo/patologia , Córtex Cerebral/patologia , Eletroencefalografia , Epilepsia do Lobo Temporal/patologia , Feminino , Seguimentos , Lateralidade Funcional/fisiologia , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Memória/fisiologia , Transtornos da Memória/etiologia , Transtornos da Memória/psicologia , Transtornos da Memória/terapia , Testes Neuropsicológicos , Convulsões/etiologia , Convulsões/cirurgia , Resultado do Tratamento , Adulto JovemRESUMO
We studied the effects of vagus nerve stimulation (VNS) on eating seizures, which theoretically would be triggered by neural activity and signaling from organs innervated by the vagus nerve. Three adult patients with daily nonreflex and reflex eating seizures were studied; one patient also had hot-water seizures. One patient had bilateral polymicrogyria and two had normal magnetic resonance imaging (MRI) findings. All patients were submitted to VNS implantation and had at least 2 years of postimplantation follow-up. Final stimulation parameters were 2.0-2.5 mA, 500 micros, and 30 Hz. Eating seizures decreased 70-95% and nonreflex seizures decreased 0-40% after VNS. There was no improvement in hot-water seizures. VNS seems to be an especially useful treatment modality in patients with reflex eating seizures not amenable to resective surgery.
Assuntos
Epilepsia Reflexa/terapia , Estimulação do Nervo Vago/métodos , Adulto , Anticonvulsivantes/uso terapêutico , Terapia Combinada , Eletrodos Implantados , Eletroencefalografia/estatística & dados numéricos , Epilepsia Parcial Complexa/diagnóstico , Epilepsia Parcial Complexa/cirurgia , Epilepsia Parcial Complexa/terapia , Epilepsia Reflexa/diagnóstico , Epilepsia Reflexa/cirurgia , Epilepsia do Lobo Temporal/diagnóstico , Epilepsia do Lobo Temporal/cirurgia , Epilepsia do Lobo Temporal/terapia , Feminino , Seguimentos , Lateralidade Funcional/fisiologia , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Prognóstico , Resultado do TratamentoRESUMO
We describe a child with epilepsy associated with double-cortex syndrome in whom vagus nerve stimulation (VNS) generated parkinsonian symptoms. A 13-year-old girl presented with refractory secondary generalized epilepsy from the age of 6 years and mental retardation. Her electroencephalography (EEG) showed diffuse polyspike and wave discharges. Magnetic resonance imaging (MRI) showed double-cortex syndrome. She was submitted to extended callosal section at the age of 10 years, which yielded 50% seizure frequency reduction. She was submitted to VNS by the age of 12 years. As stimulation intensity was increased, there was appearance of extrapyramidal symptoms: She developed bilateral tremor and rigidity, and gait and postural disturbance. All symptoms disappeared 7-10 days after VNS was turned off. Several attempts to reactivate VNS led to the same results. During the periods when VNS was on she presented with marked seizure frequency reduction. This is the first report of a clinically evident direct effect of VNS on the basal ganglia.