Surgical treatment of hypothalamic hamartomas.

Hypothalamic hamartomas are aberrant masses, composed of abnormally distributed neurons and glia. Along endocrine and cognitive symptoms, they may cause epileptic seizures, including the specific gelastic and dacrystic seizures. Surgery is the treatment of drug-resistant hamartoma epilepsy, with associated positive results on endocrine, psychiatric, and cognitive symptoms. Recently, alternatives to open microsurgical treatment have been proposed. We review these techniques and compare their efficacy and safety. Open resection or disconnection of the hamartoma, either through pterional, transcallosal, or transventricular approach, leads to good epileptological control, but its high complication rate, up to 30%, limits its indications. The purely cisternal peduncular forms remain the only indication of open, pterional approach, while other strategies have been developed to overcome the neurological, endocrine, behavioral, or cognitive complications. Laser and radiofrequency thermocoagulation-based disconnection through robot-guided stereo-endoscopy has been proposed as an alternative to open microsurgical resection and stereotactic destruction. The goal is to allow safe and complete disconnection of a possibly complex attachment zone, through a single intraparenchymal trajectory which allows multiple laser or radiofrequency probe trajectory inside the ventricle. The efficacy was high, with 78% of favorable outcome, and the overall complication rate was 8%. It was especially effective in patients with isolated gelastic seizures and pure intraventricular hamartomas. Stereotactic radiosurgery has proved as efficacious and safer than open microsurgery, with around 60% of seizure control and a very low complication rate. Multiple stereotactic thermocoagulation showed very interesting results with 71% of seizure freedom and 2% of permanent complications. Stereotactic laser interstitial thermotherapy (LiTT) seems as effective as open microsurgery (from 76 to 81% of seizure freedom) but causes up to 20% of permanent complications. This technique has however been highly improved by targeting only the epileptogenic onset zone in the hamartoma, as shown on preoperative functional MRI, leading to an improvement of epilepsy control by 45% (92% of seizure freedom) with no postoperative morbidity. All these results suggest that the impact of the surgical procedure does not depend on purely technical matters (laser vs radiofrequency thermocoagulation or stereotactic vs robot-guided stereo-endoscopy) but relies on the understanding of the epileptic network, including inside the hamartoma, the aim being to plan an effective disconnection or lesion of the epileptogenic part while sparing the adjacent functional structures.

[Intracranial dural arteriovenous fistula with perimedullary venous drainage: Anatomical, clinical and therapeutic considerations about one case, and review of the literature]. / Fistule durale intracrânienne à drainage veineux périmédullaire : considérations anatomiques, cliniques et thérapeutiques à propos d'un cas, et revue de la littérature.

Intracranial dural arteriovenous fistulae with perimedullary venous drainage are unusual type of vascular brain malformations. Patients may present with a rapidly progressive ascending myelopathy associated with autonomic dysfunction, which can cause a misdiagnosis and delay the therapeutic management. These clinical signs must be quickly recognized to avoid a poor outcome. The authors report the case of a 60-year-old woman presenting with a progressive myelopathy due to a dural arteriovenous fistula with perimedullary venous drainage. The diagnosis was suspected on brain-spinal MRI and confirmed by brain arteriography visualizing the arteriovenous shunt in the middle segment of the superior petrous sinus. MRI showed edema in the medulla oblongata. The treatment was performed early by endovascular glue embolization of the arteriovenous shunt and of the origin of the vein. Brain arteriography and clinical follow-up, one month later, showed complete disappearance of the dural fistula and regression of clinical symptoms. MRI control showed the reduction of the brain stem edema. Because of the early pejorative prognosis of these kinds of fistulae, early diagnosis and treatment are needed.

[Gait disturbances and normal pressure hydrocephalus]. / Troubles de la marche et hydrocéphalie à pression normale.

Normal pressure hydrocephalus must be considered when gait disturbance, cognitive impairment and sphincter disorders are associated. Symptoms of normal pressure hydrocephalus, especially gait disturbance, are potentially curable by surgery. Our paper provides a summary review of gait disorders associated with normal pressure hydrocephalus detailing their characteristics and the best assessment methods. Although the pathogenic mechanisms underlying normal pressure hydrocephalus remain poorly understood, advances in imaging have enabled considerable progress in our fundamental knowledge of the condition. Tapping the cerebrospinal fluid by lumbar puncture or external lumbar drainage remains the diagnostic test and is predictive of a favorable response to surgical treatment. Clinical severity scores validated for walking and for sphincter dysfunction and cognitive disorders provide the best means of assessing each patient's response to treatment.