The acetylcholinesterase activity (AChE) in the human subfornical organ (SFO) was detected by the... more The acetylcholinesterase activity (AChE) in the human subfornical organ (SFO) was detected by the method of Koelle and Friedenwald in 16 human brains collected between 6 and 12 hrs postmortem. The only AchE-positive structures found were neuronal cell bodies and processes, morphologically classified as stellate and fusiform neurons of large, medium and small size. Large ones prevailed in the dorsal zone. The neurons were homogeneously distributed in the rostral area of the SFO. The penetration and ramification of large blood vessels produced a decreasing neuronal density in the medium-caudal area. The architecture of the SFO in sagittal sections comprised a central zone with neurons juxtaposed to the walls of the vascular plexus, whose dendritic and axonal processes showed an intricate pattern without a special arrangement. This neuronal zone of the SFO was surrounded by a peripheral layer of neurons with axonal projections to the rostral area. This layer was thicker in the dorsal zone of the SFO, where axonal fibers "climbing-up" from the central perivascular neurons could be demonstrated. In coronal sections some neurons with prolongations of arcuate distribution connected the dorsal and ventral zones.
To evaluate a novel approach to control epileptic drop attacks through a selective posterior call... more To evaluate a novel approach to control epileptic drop attacks through a selective posterior callosotomy, sparing all prefrontal interconnectivity. Thirty-six patients with refractory drop attacks had selective posterior callosotomy and prospective follow-up for >4 years. Falls, episodes of aggressive behavior, and IQ were quantified. Autonomy in activities of daily living, axial tonus, and speech generated a functional score ranging from 0 to 13. Subjective effect on patient well-being and caregiver burden was also assessed. Median monthly frequency of drop attacks decreased from 150 to 0.5. Thirty patients (83%) achieved either complete or >90% control of the falls. Need for constant supervision decreased from 90% to 36% of patients. All had estimated IQ below 85. Median functional score increased from 7 to 10 (p = 0.03). No patient had decrease in speech fluency or hemiparesis. Caregivers rated the effect of the procedure as excellent in 40% and as having greatly improved functioning in another 50%. Clinical, EEG, imaging, and cognitive variables did not correlate with outcome. This cohort study with objective outcome assessment suggests that selective posterior callosotomy is safe and effective to control drop attacks, with functional and behavioral gains in patients with intellectual disability. Results are comparable to historical series of total callosotomy and suggest that anterior callosal fibers may be spared. This study provides Class III evidence that selective posterior callosotomy reduces falls in patients with epileptic drop attacks.
O conhecimento da anatomia microcirúrgica do hipocampo tem importância fundamental na cirurgia da... more O conhecimento da anatomia microcirúrgica do hipocampo tem importância fundamental na cirurgia da epilepsia do lobo temporal. Uma das técnicas mais utilizadas na cirurgia da epilepsia é a técnica de Niemeyer. OBJETIVO: Descrever em detalhes a anatomia do hipocampo e mostrar uma técnica na qual pontos de referências anatômicos pré-operatórios visualizados na RNM são usados para guiar a corticotomia. MÉTODO: Foram utilizados 20 hemisférios cerebrais e 8 cadáveres para dissecções anatômicas microcirúrgicas do lobo temporal e hipocampo para identificação e descrição das principais estruturas do hipocampo. Foram estudados prospectivamente 32 pacientes com epilepsia do lobo temporal refratários ao tratamento clínico submetidos a amígdalo-hipocampectomia seletiva pela técnica de Niemeyer três parâmetros anatômicos foram mensurados na RNM pré operatória e transferidos para o ato cirúrgico. RESULTADOS: O hipocampo foi dividido em cabeça, corpo e cauda e sua anatomia microcirúrgica descrita e...
We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced b... more We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced by perfusion of human hippocampal slices with artificial cerebrospinal fluid lacking Mg2+ or N-methyl-D-aspartate. Hippocampi were surgically removed from patients with refractory medial temporal lobe epilepsy, sliced in the surgical room and taken to the laboratory immersed in normal artificial cerebrospinal fluid. Epileptiform activity was induced by perfusion with Mg2+-free artificial cerebrospinal fluid or by iontophoretically applied N-methyl-D-aspartate and intracellular and field recordings of CA1 neurons were performed. The ictal-like discharges induced by Mg2+-free artificial cerebrospinal fluid and N-methyl-D-aspartate were blocked by incubation with JSTX-3. This effect was similar to that obtained with the N-methyl-D-aspartate receptor antagonist DL (-)2-amino-5 phosphonovaleric acid. Our findings suggest that in human hippocampal neurons, the antiepileptic effect of JSTX-3 is mediated by its action on N-methyl-D-aspartate receptor.
We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced b... more We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced by perfusion of human hippocampal slices with artificial cerebrospinal fluid lacking Mg2+ or N-methyl-D-aspartate. Hippocampi were surgically removed from patients with refractory medial temporal lobe epilepsy, sliced in the surgical room and taken to the laboratory immersed in normal artificial cerebrospinal fluid. Epileptiform activity was induced by perfusion with Mg2+-free artificial cerebrospinal fluid or by iontophoretically applied N-methyl-D-aspartate and intracellular and field recordings of CA1 neurons were performed. The ictal-like discharges induced by Mg2+-free artificial cerebrospinal fluid and N-methyl-D-aspartate were blocked by incubation with JSTX-3. This effect was similar to that obtained with the N-methyl-D-aspartate receptor antagonist DL (-)2-amino-5 phosphonovaleric acid. Our findings suggest that in human hippocampal neurons, the antiepileptic effect of JSTX-3 is mediated by its action on N-methyl-D-aspartate receptor.
To evaluate a novel approach to control epileptic drop attacks through a selective posterior call... more To evaluate a novel approach to control epileptic drop attacks through a selective posterior callosotomy, sparing all prefrontal interconnectivity. Thirty-six patients with refractory drop attacks had selective posterior callosotomy and prospective follow-up for >4 years. Falls, episodes of aggressive behavior, and IQ were quantified. Autonomy in activities of daily living, axial tonus, and speech generated a functional score ranging from 0 to 13. Subjective effect on patient well-being and caregiver burden was also assessed. Median monthly frequency of drop attacks decreased from 150 to 0.5. Thirty patients (83%) achieved either complete or >90% control of the falls. Need for constant supervision decreased from 90% to 36% of patients. All had estimated IQ below 85. Median functional score increased from 7 to 10 (p = 0.03). No patient had decrease in speech fluency or hemiparesis. Caregivers rated the effect of the procedure as excellent in 40% and as having greatly improved functioning in another 50%. Clinical, EEG, imaging, and cognitive variables did not correlate with outcome. This cohort study with objective outcome assessment suggests that selective posterior callosotomy is safe and effective to control drop attacks, with functional and behavioral gains in patients with intellectual disability. Results are comparable to historical series of total callosotomy and suggest that anterior callosal fibers may be spared. This study provides Class III evidence that selective posterior callosotomy reduces falls in patients with epileptic drop attacks.
The deep knowledge of hippocampal microsurgical anatomy is paramount in epilepsy surgery. One of ... more The deep knowledge of hippocampal microsurgical anatomy is paramount in epilepsy surgery. One of the most used techniques is those proposed by Niemeyer. To describe the hippocampal anatomy in detail and to present a technique in which preoperative anatomical points in MRI are identified to guide the corticotomy. Microsurgical dissections were performed in twenty brain hemispheres and eight cadaveric heads to identify temporal lobe and hippocampus structures. Thirty two patients with drug-resistant temporal lobe epilepsy underwent a selective amygdalohippocampectomy with Niemeyer's technique being measured three preoperative MRI preoperative distances to guide the corticotomy. The hippocampus was divided in head, body and tail and its microsurgical anatomy described in detail. The MRI measurements are presented and discussed. The knowledge of the complex anatomy of the hippocampus can be achieved in a three-dimensional way during microsurgical dissections. The preoperative MRI measurement is a reasonable guide to perform temporal corticotomy in Niemeyer's technique.
The acetylcholinesterase activity (AChE) in the human subfornical organ (SFO) was detected by the... more The acetylcholinesterase activity (AChE) in the human subfornical organ (SFO) was detected by the method of Koelle and Friedenwald in 16 human brains collected between 6 and 12 hrs postmortem. The only AchE-positive structures found were neuronal cell bodies and processes, morphologically classified as stellate and fusiform neurons of large, medium and small size. Large ones prevailed in the dorsal zone. The neurons were homogeneously distributed in the rostral area of the SFO. The penetration and ramification of large blood vessels produced a decreasing neuronal density in the medium-caudal area. The architecture of the SFO in sagittal sections comprised a central zone with neurons juxtaposed to the walls of the vascular plexus, whose dendritic and axonal processes showed an intricate pattern without a special arrangement. This neuronal zone of the SFO was surrounded by a peripheral layer of neurons with axonal projections to the rostral area. This layer was thicker in the dorsal zone of the SFO, where axonal fibers "climbing-up" from the central perivascular neurons could be demonstrated. In coronal sections some neurons with prolongations of arcuate distribution connected the dorsal and ventral zones.
To evaluate a novel approach to control epileptic drop attacks through a selective posterior call... more To evaluate a novel approach to control epileptic drop attacks through a selective posterior callosotomy, sparing all prefrontal interconnectivity. Thirty-six patients with refractory drop attacks had selective posterior callosotomy and prospective follow-up for >4 years. Falls, episodes of aggressive behavior, and IQ were quantified. Autonomy in activities of daily living, axial tonus, and speech generated a functional score ranging from 0 to 13. Subjective effect on patient well-being and caregiver burden was also assessed. Median monthly frequency of drop attacks decreased from 150 to 0.5. Thirty patients (83%) achieved either complete or >90% control of the falls. Need for constant supervision decreased from 90% to 36% of patients. All had estimated IQ below 85. Median functional score increased from 7 to 10 (p = 0.03). No patient had decrease in speech fluency or hemiparesis. Caregivers rated the effect of the procedure as excellent in 40% and as having greatly improved functioning in another 50%. Clinical, EEG, imaging, and cognitive variables did not correlate with outcome. This cohort study with objective outcome assessment suggests that selective posterior callosotomy is safe and effective to control drop attacks, with functional and behavioral gains in patients with intellectual disability. Results are comparable to historical series of total callosotomy and suggest that anterior callosal fibers may be spared. This study provides Class III evidence that selective posterior callosotomy reduces falls in patients with epileptic drop attacks.
O conhecimento da anatomia microcirúrgica do hipocampo tem importância fundamental na cirurgia da... more O conhecimento da anatomia microcirúrgica do hipocampo tem importância fundamental na cirurgia da epilepsia do lobo temporal. Uma das técnicas mais utilizadas na cirurgia da epilepsia é a técnica de Niemeyer. OBJETIVO: Descrever em detalhes a anatomia do hipocampo e mostrar uma técnica na qual pontos de referências anatômicos pré-operatórios visualizados na RNM são usados para guiar a corticotomia. MÉTODO: Foram utilizados 20 hemisférios cerebrais e 8 cadáveres para dissecções anatômicas microcirúrgicas do lobo temporal e hipocampo para identificação e descrição das principais estruturas do hipocampo. Foram estudados prospectivamente 32 pacientes com epilepsia do lobo temporal refratários ao tratamento clínico submetidos a amígdalo-hipocampectomia seletiva pela técnica de Niemeyer três parâmetros anatômicos foram mensurados na RNM pré operatória e transferidos para o ato cirúrgico. RESULTADOS: O hipocampo foi dividido em cabeça, corpo e cauda e sua anatomia microcirúrgica descrita e...
We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced b... more We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced by perfusion of human hippocampal slices with artificial cerebrospinal fluid lacking Mg2+ or N-methyl-D-aspartate. Hippocampi were surgically removed from patients with refractory medial temporal lobe epilepsy, sliced in the surgical room and taken to the laboratory immersed in normal artificial cerebrospinal fluid. Epileptiform activity was induced by perfusion with Mg2+-free artificial cerebrospinal fluid or by iontophoretically applied N-methyl-D-aspartate and intracellular and field recordings of CA1 neurons were performed. The ictal-like discharges induced by Mg2+-free artificial cerebrospinal fluid and N-methyl-D-aspartate were blocked by incubation with JSTX-3. This effect was similar to that obtained with the N-methyl-D-aspartate receptor antagonist DL (-)2-amino-5 phosphonovaleric acid. Our findings suggest that in human hippocampal neurons, the antiepileptic effect of JSTX-3 is mediated by its action on N-methyl-D-aspartate receptor.
We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced b... more We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced by perfusion of human hippocampal slices with artificial cerebrospinal fluid lacking Mg2+ or N-methyl-D-aspartate. Hippocampi were surgically removed from patients with refractory medial temporal lobe epilepsy, sliced in the surgical room and taken to the laboratory immersed in normal artificial cerebrospinal fluid. Epileptiform activity was induced by perfusion with Mg2+-free artificial cerebrospinal fluid or by iontophoretically applied N-methyl-D-aspartate and intracellular and field recordings of CA1 neurons were performed. The ictal-like discharges induced by Mg2+-free artificial cerebrospinal fluid and N-methyl-D-aspartate were blocked by incubation with JSTX-3. This effect was similar to that obtained with the N-methyl-D-aspartate receptor antagonist DL (-)2-amino-5 phosphonovaleric acid. Our findings suggest that in human hippocampal neurons, the antiepileptic effect of JSTX-3 is mediated by its action on N-methyl-D-aspartate receptor.
To evaluate a novel approach to control epileptic drop attacks through a selective posterior call... more To evaluate a novel approach to control epileptic drop attacks through a selective posterior callosotomy, sparing all prefrontal interconnectivity. Thirty-six patients with refractory drop attacks had selective posterior callosotomy and prospective follow-up for >4 years. Falls, episodes of aggressive behavior, and IQ were quantified. Autonomy in activities of daily living, axial tonus, and speech generated a functional score ranging from 0 to 13. Subjective effect on patient well-being and caregiver burden was also assessed. Median monthly frequency of drop attacks decreased from 150 to 0.5. Thirty patients (83%) achieved either complete or >90% control of the falls. Need for constant supervision decreased from 90% to 36% of patients. All had estimated IQ below 85. Median functional score increased from 7 to 10 (p = 0.03). No patient had decrease in speech fluency or hemiparesis. Caregivers rated the effect of the procedure as excellent in 40% and as having greatly improved functioning in another 50%. Clinical, EEG, imaging, and cognitive variables did not correlate with outcome. This cohort study with objective outcome assessment suggests that selective posterior callosotomy is safe and effective to control drop attacks, with functional and behavioral gains in patients with intellectual disability. Results are comparable to historical series of total callosotomy and suggest that anterior callosal fibers may be spared. This study provides Class III evidence that selective posterior callosotomy reduces falls in patients with epileptic drop attacks.
The deep knowledge of hippocampal microsurgical anatomy is paramount in epilepsy surgery. One of ... more The deep knowledge of hippocampal microsurgical anatomy is paramount in epilepsy surgery. One of the most used techniques is those proposed by Niemeyer. To describe the hippocampal anatomy in detail and to present a technique in which preoperative anatomical points in MRI are identified to guide the corticotomy. Microsurgical dissections were performed in twenty brain hemispheres and eight cadaveric heads to identify temporal lobe and hippocampus structures. Thirty two patients with drug-resistant temporal lobe epilepsy underwent a selective amygdalohippocampectomy with Niemeyer's technique being measured three preoperative MRI preoperative distances to guide the corticotomy. The hippocampus was divided in head, body and tail and its microsurgical anatomy described in detail. The MRI measurements are presented and discussed. The knowledge of the complex anatomy of the hippocampus can be achieved in a three-dimensional way during microsurgical dissections. The preoperative MRI measurement is a reasonable guide to perform temporal corticotomy in Niemeyer's technique.
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