Foix-Chavany-Marie syndrome caused by a disconnection between the right pars opercularis of the inferior frontal gyrus and the supplementary motor area.

Foix-Chavany-Marie syndrome (FCMS) is a rare type of suprabulbar palsy characterized by an automatic-voluntary dissociation of the orofacial musculature. Here, the authors report an original case of FCMS that occurred intraoperatively while resecting the pars opercularis of the inferior frontal gyrus. This 25-year-old right-handed man with an incidentally diagnosed right frontotemporoinsular tumor underwent surgery using an asleep-awake-asleep technique with direct cortical and subcortical electrical stimulation and a transopercular approach to the insula. While resecting the anterior part of the pars opercularis the patient suffered sudden anarthria and bilateral facial weakness. He was unable to speak or show his teeth on command, but he was able to voluntarily move his upper and lower limbs. This syndrome lasted for 8 days. Postoperative diffusion tensor imaging tractography revealed that connections of the pars opercularis of the right inferior frontal gyrus with the frontal aslant tract (FAT) and arcuate fasciculus (AF) were damaged. This case supplies evidence for localizing the structural substrate of FCMS. It was possible, for the first time in the literature, to accurately correlate the occurrence of FCMS to the resection of connections between the FAT and AF, and the right pars opercularis of the inferior frontal gyrus. The FAT has been recently described, but it may be an important connection to mediate supplementary motor area control of orofacial movement. The present case also contributes to our knowledge of complication avoidance in operculoinsular surgery. A transopercular approach to insuloopercular gliomas can generate FCMS, especially in cases of previous contralateral lesions. The prognosis is favorable, but the patient should be informed of this particular hazard, and the surgeon should anticipate the surgical strategy in case the syndrome occurs intraoperatively in an awake patient.

[Controversy in the management of WHO grade II gliomas in eloquent brain areas: recent literature review]. / Controversias en el tratamiento de los gliomas OMS grado II localizados en áreas elocuentes: revisión de la bibliografía reciente.

Recent studies have shown that diffuse grade II gliomas (GGII) located in eloquent brain areas represent over 80% of all GGII. The optimal management of these tumours is still controversial. It has long been considered that surgery is not an option for GGII within eloquent areas, due to the high risk of inducing postoperative sequelae in patients with normal neurological explorations. However, the safety of these surgeries has significantly improved in recent years due to the rapid development of techniques enabling a precise mapping of brain functions. Noninvasive functional neuroimaging techniques have been recently developed, enabling cortical mapping of the entire brain prior to surgical procedures. Such precise data provide a preoperative estimation of the location of eloquent areas in relation to the tumour, which is essential for surgical planning and preoperative assessment of morbidity for various surgical approaches. The intraoperative electrical stimulation (IES) mapping technique consists in the application of a bipolar electrode on the brain tissue, enabling an accurate location of brain functions. This provides unique assistance in GGII resection, as it generates a discrete and transient "virtual" lesion within the eloquent tissue. Tumour removal is then tailored according to functional boundaries in order to optimise the quality of resection and to minimise the risk of postoperative sequelae, preserving quality of life. For patients with a GGII in an eloquent area, the possibility of an early resection should be evaluated by a multidisciplinary neuro-oncology team specialising in the management of such tumours.

Controversias en el tratamiento de los gliomas OMS grado II localizados en áreas elocuentes: revisión de la bibliografía reciente / Controversy in the management of WHO grade II gliomas in eloquent brain areas: recent literature review

Estudios recientes han demostrado que los gliomas difusos de grado II (GGII), localizados en áreas elocuentes del cerebro, representan más del 80% del total de los GGII. El tratamiento de los GGII en áreas elocuentes es todavía hoy controvertido. El abordaje clásico de un GGII en un área elocuente considera que no es posible plantear una cirugía, porque hay un riesgo alto de secuelas neurológicas en un paciente con una exploración neurológica normal. Sin embargo, en los últimos años ha aumentado de forma significativa la seguridad de las cirugías de estos tumores, gracias al desarrollo de técnicas para mapear con precisión la función cerebral. Mediante las técnicas no invasivas de neuroimagen funcional, se obtiene un mapa de la función cortical de todo el cerebro, lo que es de gran ayuda para anticipar los hallazgos durante la cirugía y para planificar el abordaje. La técnica de mapeo por estimulación eléctrica intraoperatoria consiste en la aplicación, durante la intervención quirúrgica, de un electrodo bipolar sobre el tejido cerebral, lo que permite localizar las funciones con gran precisión. Esta técnica se considera hoy día como el procedimiento de elección para realizar una cirugía de un GGII en un área elocuente con seguridad, ya que ha demostrado ser capaz de aumentar el grado de resección y reducir de forma importante el riesgo de secuelas. En todo paciente con la sospecha de un GGII en un área elocuente, debe valorarse la posibilidad de una extirpación tumoral temprana por parte de un equipo multidisciplinario de profesionales especializados en el manejo de estos tumores (AU)

Recent studies have shown that diffuse grade II gliomas (GGII) located in eloquent brain areas represent over 80% of all GGII. The optimal management of these tumours is still controversial. It has long been considered that surgery is not an option for GGII within eloquent areas, due to the high risk of inducing postoperative sequelae in patients with normal neurological explorations. However, the safety of these surgeries has significantly improved in recent years due to the rapid development of techniques enabling a precise mapping of brain functions. Noninvasive functional neuroimaging techniques have been recently developed, enabling cortical mapping of the entire brain prior to surgical procedures. Such precise data provide a preoperative estimation of the location of eloquent areas in relation to the tumour, which is essential for surgical planning and preoperative assessment of morbidity for various surgical approaches. The intraoperative electrical stimulation (IES) mapping technique consists in the application of a bipolar electrode on the brain tissue, enabling an accurate location of brain functions. This provides unique assistance in GGII resection, as it generates a discrete and transient "virtual" lesion within the eloquent tissue. Tumour removal is then tailored according to functional boundaries in order to optimise the quality of resection and to minimise the risk of postoperative sequelae, preserving quality of life. For patients with a GGII in an eloquent area, the possibility of an early resection should be evaluated by a multidisciplinary neuro-oncology team specialising in the management of such tumours (AU)