Neuromodulation of the anterior thalamic nucleus as a therapeutic option for difficult-to-control epilepsy.

Deep brain stimulation (DBS) consists of the electrical stimulation of the subcortical structures by implanting electrodes connected to a pulse generator. The thalamus, being a structure that has multiple connections with various parts of the central nervous system, is a suitable target for DBS. The anterior thalamic nucleus (ANT) serves as an important relay site for the limbic system by receiving input from the hippocampus and mammillary bodies, and sending input to the cingulate gyrus; thus forming the Papez circuit. Due to these connections, the ANT constitutes an ideal route for the propagation of epileptogenic activity. ANT-DBS has excellent results in the control of complex partial seizures. The vast majority of patients with ANT-DBS have shown a significant reduction in the frequency of their seizures of more than 50%.

Manejo quirúrgico de ependimomas en médula cervical: A propósito de un caso clínico / Surgical management of ependymomas in the cervical spine: Apropos of a clinical case

Introducción: los ependimomas son tumores cerebrales que surgen de células ependimarias, células de soporte en el cerebro y la médula espinal. Representan entre el 2 y el 3% de todos los tumores cerebrales primarios. Son el cuarto tumor cerebral más común en los niños, donde el 90% de los mismos se localizan en la fosa posterior. En adultos, el 60% de estos tumores se encuentran en la médula espinal pudiendo presentarse a cualquier nivel de ésta; el caso a continuación reporta un ependimoma cervical. Objetivo: reportar un caso de ependimoma medular de ubicación poco frecuente, con resección total, sin recidiva porterior a 2 años de seguimiento.Descripción del caso: se reporta el caso de un paciente adulto, 44 años, masculino, con un síndrome medular cervical completo, progresivo, provocado por un ependimoma cervical. Intervención: se realizó laminectomía de dos espacios [C7 a T1], apertura dural, mielotomía posterior logrando exéresis total de la lesión con durorrafia a sello de agua y posterior cierre por planos sin complicaciones, con seguimiento de 2 años de sobrevida. Conclusiones: la resección total macroscópica de este tipo de tumores es muy importante para poder evitar residiva. El ependimoma cervical puede recidivar, sobre todo cuando existen residuales de la lesión. El manejo oportuno depende de gran manera de que los pacientes acudan tempranamente a valoración especializada; la resección guiada con monitorización neurofisiológica transoperatoria provee mayor oportunidad a los pacientes a no presentar secuelas permanentes y permite asimismo, mejores resultados de la rehabilitación neurológica postoperatoria

Introduction: ependymomas are brain tumors that arise from ependymal cells, supporting cells in the brain and spinal cord. They represent between 2 and 3% of all primary brain tumors. They are the fourth most common brain tumor in children, where 90% of them are located in the posterior fossa. In adults, 60% of these tumors are found in the spinal cord and can occur at any level of the spinal cord; the case below reports a cervical ependymoma. Objective: to report a case of medullary ependymoma of rare location, with total resection, without recurrence after 2 years of follow-up. Case description: a 44-year-old male adult patient with a progressive, complete cervical spinal cord syndrome, caused by a cervical ependymoma, is reported.Intervention: two-space laminectomy [C7 to T1], dural opening and posterior myelotomy were performed, achieving total excision of the lesion with water-seal durorrhaphy and subsequent closure by planes without complications, with a 2-year survival follow-up. Conclusions: macroscopic total resection of this type of tumor is very important to avoid residual. Cervical ependymoma can recur, especially when there is residual lesion. Timely management depends to a great extent on the patients attending early for a specialized evaluation; guided resection with intraoperative neurophysiological monitoring provides a greater opportunity for patients to not present permanent sequelae and also allows better results of postoperative neurological rehabilitation.

Neuromodulation of the anterior thalamic nucleus as a therapeutic option for difficult-to-control epilepsy. / Neuromodulación del núcleo talámico anterior como opción terapéutica para epilepsia de difícil control.

Deep brain stimulation (DBS) consists of the electrical stimulation of the subcortical structures by implanting electrodes connected to a pulse generator. The thalamus, being a structure that has multiple connections with various parts of the central nervous system, is a suitable target for DBS. The anterior thalamic nucleus (ANT) serves as an important relay site for the limbic system by receiving input from the hippocampus and mammillary bodies, and sending input to the cingulate gyrus; thus forming the Papez circuit. Due to these connections, the ANT constitutes an ideal route for the propagation of epileptogenic activity. ANT-DBS has excellent results in the control of complex partial seizures. The vast majority of patients with ANT-DBS have shown a significant reduction in the frequency of their seizures of more than 50%.

Communicating Segment Aneurysm of Internal Carotid Artery Associated with Saltzman's Type III Persistent Trigeminal Artery: A Case Report.

Persistent trigeminal artery (PTA), also called primitive trigeminal artery, represents the most common embryonic remnant of fetal circulation in adulthood, (only after fetal pattern of posterior communicating artery [PComA]) with an estimated incidence of between 0.1% and 0.76%. The permanence of this fetal pattern constitutes an incidental finding in most cases, however, may be associated with aneurysms, arteriovenous malformations, trigeminal neuralgia, and other types of fetal circulation persistency. A patient with giant aneurysm in the communicating segment of the right internal carotid artery, associated with the presence of PTA and fetal pattern of PComA, also on the right side is reported.

Recurrent Herpes Simplex Virus Encephalitis After Neurologic Surgery.

BACKGROUND: The herpes simplex virus (HSV) is the most common cause of sporadic encephalitis worldwide. Even with proper treatment, this infection is associated with a mortality rate of 19%-30% and with potential neurologic sequelae. Recurrences of encephalitis are rare and limited to a few cases in the literature. Although the mechanism of reactivation has not yet been clarified, in our patient, the surgery might have acted as a precipitating factor. CASE DESCRIPTION: The case involved a female 10-year-old patient with a history of type 1 HSV encephalitis since 24 months of age. Secondarily, the patient developed postherpetic epilepsy in the following years. At 10 years old, she was referred to the epilepsy surgery service, and an elective right temporal lobectomy was performed. After surgery, the patient experienced severe clinical deterioration characterized by fever, severe headache, and altered state of consciousness. Encephalitis was diagnosed based on a positive polymerase chain reaction for HSV in the cerebrospinal fluid. The symptoms remitted after 8 weeks of treatment with acyclovir. The histopathologic diagnosis was a chronic encephalitic process with late secondary parenchymal changes without specific viral cytopathic findings. The only limitation that persisted was related to fine movements of the left hand. One year after surgery, the patient rejoined her school activities and is currently free of seizures. CONCLUSIONS: HSV encephalitis is a rare but serious complication that should be suspected in cases of unexplained postoperative fever with altered consciousness, especially in patients with histories of encephalitic states.

Suprameatal extension of retrosigmoid approach for microvascular decompression of trigeminal nerve: Case report.

INTRODUCTION: Trigeminal neuralgia is produced in a significant number of cases by vascular compression at the level of cisternal segment of the nerve at the entry of the pons. It is common to find superior cerebellar artery (SCA) responsible for this compression. The retrosigmoid approach (RA), with asterional craniectomy, clearly exposes the cisternal portion of the trigeminal nerve (TN). PRESENTATION OF CASE: We describe in this case report how vessels at the trigeminal pore level known as "Meckel's segment" can compress the TN. This situation is unusual. One of the reasons why the compression of this Meckel's segment level could be overlooked is a suprameatal tubercle (ST) prominence that would prevent trigeminal pore visualization through retrosigmoid approach. DISCUSSION: The suprameatal extension of this approach has been described for other purposes, especially in tumors invading Meckel's cave resection. We could not find publications for the use of the resection of the suprameatal tubercle in the retrosigmoid approach for microvascular decompression of the trigeminal neuralgia. CONCLUSION: Microvascular decompression of the TN is an effective treatment for trigeminal neuralgia, however in some cases, in which vascular compression is not evident when exploring the cerebellopontine angle, it is important to note that association of a prominent ST can hide a vascular compression of the nerve in this region.