Stereotactic surgery for neurocysticercosis of the 4th ventricle: illustrative cases

BACKGROUND Neurocysticercosis, caused by the larval stage of Taenia solium, affects the cerebral ventricles in 20–30% of cases and may lead to hydrocephalus and other neurological morbidity. Conventional treatment for cysts in the 4th ventricle includes open surgery (suboccipital approach) and neuroendoscopy, with the latter being the option of choice. Stereotactic surgery, minimally invasive, offers a good alternative for this type of deep lesion. OBSERVATIONS The authors report the cases of two women, 30 and 45 years old, who presented with headache, dizziness, and ataxia and were diagnosed with 4th ventricle cysticercosis. Magnetic resonance imaging (MRI) revealed dilated 4th ventricles (approximately 2.5 cm in both cases, with cystic images inside the ventricular cavity). Both patients were treated with stereotactic surgery via a suboccipital transcerebellar approach. Cyst material was extracted, and the diagnosis was confirmed by pathological examination. The surgeries had no complications and resulted in clinical improvement. Control MRI scans showed reduction of the volume of the ventricle without residual cysts. LESSONS Minimally invasive stereotactic surgery provided a safe alternative for 4th ventricle neurocysticercosis cysts, with more benefits than risks in comparison with conventional techniques.

Investigation of stereotactic surgery for avian brain stimulation by a fully implanted wireless system

OBJECTIVEThe authors’ goal was to study avian motor brain mapping via wireless stimulation to induce certain behaviors. In this paper, the authors propose an electrode design that is suitable for avian brain stimulation as well as a stereotactic implant procedure for the proposed electrode.METHODSAn appropriate breed for avian brain study was chosen. A fully implantable remote-controlled electrical stimulation system was inserted to minimize discomfort. A suitable electrode design and stereotactic surgery method based on the electrode design were investigated.RESULTSUsing a wireless stimulation system, flapping and rotation behaviors were induced by stimulating the ventral part of the nucleus intercollicularis and formatio reticularis medialis mesencephali both on the ground and during flight.CONCLUSIONSThe authors were able to implant the entire brain stimulation system inside the avian body without any surgical complications. Postoperative observations suggested that the bird did not find the implant uncomfortable.