Ventricular meningioma is the most common intramedullary tumor, accounting for 40% to 60% of all intramedullary tumors. Although ventricular meningiomas are mostly found in the cervical and thoracic segments, the incidence of ependymoma originating from the conus and filum terminale at the conus and filum terminale is increasing year by year, and there are specificities in their biological behavior, clinical manifestations, surgical techniques and prognosis. The main clinical manifestations are symptoms of spinal nerve roots and spinal conduction tracts in the corresponding segments caused by tumor growth compression, abnormal muscle strength in the lower extremities, sphincter dysfunction, sensory disturbances in the lower extremities, sensory disturbances in the saddle area, nerve root pain and local pain. Near conus (T10~L1) Ventricular meningioma with complete paralysis of both lower extremities, major and minor incontinence with bilateral hip decubitus ulcers. Recurrence after surgery in an outside hospital. The tumor grew outside the spinal canal. MRI scan mostly showed slightly low signal in T1-weighted image and uniform slightly high signal in T2-weighted image. All patients were placed in the prone position under tracheal intubation and combined with sedation anesthesia, with the head slightly below the body level to prevent excessive loss of cerebrospinal fluid. Preoperative needle electrodes were routinely inserted into the anal sphincter, gluteus maximus, gastrocnemius, and anterior tibialis muscles after localization of the tumor segment with a C-arm machine for intraoperative electrophysiological monitoring throughout the procedure. The length of laminectomy and dural dissection was limited to reveal the upper and lower poles of the tumor without revealing the spinal cord cavity. Under the microscope, the arachnoid membrane was opened first, and the posterior median sulcus of the spinal cord was identified according to the bilateral nerve roots and the dentate ligament, and the soft spinal membrane and the spinal cord were sharply dissected together along the most obvious point of the posterior median sulcus elevation. In case of combined spinal cord cavity, the cavity should be opened at the end of the tumor. The upper pole and anterolateral side of the ventricular meningioma of the conus are mostly clear with the spinal cord interface, and can be separated bluntly along the periphery of the tumor first. However, the lower pole of the tumor is often not clearly defined with the conus, and the tumor body is often closely adhered to the conus, so close reference should be made to electrophysiological monitoring indicators, and sharp separation should be the main focus. If the electromyography shows multiple action potential superimposed burst electromyographic activity during the separation process, the corresponding operation should be stopped immediately, and the operation should be performed again after the waveform returns to resting state. In addition, because of the soft texture of the tumor, when dealing with the residual tumor, it can be carefully aspirated from the cauda equina nerve (the suction force of the suction device should be strictly controlled), paying attention to preserving the anatomical continuity of the cauda equina nerve. Postoperatively, all specimens are subjected to routine pathological and immunohistochemical examinations to confirm the subtype of ventricular meningioma. According to WHO classification: grade I is mucinous papillary ventricular meningioma, grade II is ventricular meningioma, and grade III is mesenchymal ventricular meningioma. Intramedullary ventricular meningioma originates from the ventricular meningeal cells of the central canal of the spinal cord and is the first intramedullary tumor of the spinal cord. Unlike ventricular meningiomas in the cervical and thoracic segments, ventricular meningiomas of conical and terminal filament origin are more common in adults. Preoperative diagnosis and total surgical resection of the tumor is the ultimate goal of ventricular meningioma treatment. The specificity of the preoperative diagnosis of the tumor location determines its clinical symptoms to be dominated by nerve root pain and sphincter dysfunction. The former is mainly manifested as radiating pain along the nerve path; while the sphincter dysfunction is mainly based on dysfunction of the diaphoresis, including urinary frequency, urinary urgency, urinary retention, urinary incontinence, constipation and fecal incontinence. In addition, sensory and muscle dysfunction in the lower limbs and saddle area are also common symptoms. Nerve root pain and local pain are the most frequent, followed by sensory disorders in the lower extremities and saddle area, and sphincter dysfunction. MRI is the best method to diagnose intramedullary spinal cord tumor. The main manifestations are: local thickening of the spinal cord, T1-weighted equal or slightly low signal, T2-weighted high signal, mild enhancement on enhancement scan, and clear border contour. MRI scan and enhancement examination were performed before surgery. Once the diagnosis of ventricular meningioma is clear, in principle, active surgical treatment and total resection of the tumor are recommended in order to reduce the damage to neurological function. Microsurgery supplemented by intraoperative electrophysiological monitoring can increase the total resection rate of the tumor while reducing the harassment of the normal spinal cord. The experience is as follows: ① Microsurgery is the key: At present, microsurgery is still the preferred method for the treatment of intramedullary tumors. During surgery, attention should be paid to the gentle microscopic manipulation, and the minimum stretching of the cauda equina should be strived for. The two poles of the tumor should be fully exposed before separation to avoid blind operation. In addition, intraoperative hemostasis strictly prohibits the use of bipolar electrocoagulation with high output power to avoid electrocoagulation damage to the peripheral nerve. For small bleeding, slight compression with small pieces of cotton or hemostatic gauze is effective in hemostasis. For non-giant ventricular meningioma, resection of the tumor in pieces should be avoided as much as possible to reduce intraoperative bleeding, decrease tumor residual and improve the total tumor resection rate. Intraoperative electrophysiological monitoring: the upper pole of ventricular meningioma in the cone is easy to be bluntly peeled off, but the lower pole is closely attached to the nerve; ventricular meningioma originating from the terminal filament is closely attached to the cauda equina nerve root and needs to be sharply separated. Skinner et al. concluded that intraoperative electromyographic monitoring of abnormal brain or peripheral nerve discharges suggests the possibility of postoperative neurological impairment. At the same time, electromyography monitoring requires less anesthetic drugs, does not require the assistance of inotropic drugs, is easy to perform, and the results are intuitive. Intraoperative electrophysiological monitoring was performed in all patients: anterior tibialis (L4~5), gluteus maximus (L5~S2), gastrocnemius (S1~2), and anal sphincter (S2~4) were selected as the monitored muscles in order to maximize the patient’s postoperative quality of life. The corresponding operation was stopped immediately once the stimulation waveform appeared during the operation to avoid irreversible nerve injury, and the subsequent operation was performed after the waveform returned to normal. No surgery-related neurological dysfunction occurred in any of the cases with total surgical resection, demonstrating that intraoperative EMG monitoring can effectively protect spinal cord function while improving the rate of total surgical resection. Intraoperative EMG monitoring is even more essential in cases of tumor recurrence where it is difficult to distinguish spinal cord tissue from scar tissue purely by the naked eye and the probability of spinal cord injury increases compared to the first operation. In conclusion, ventricular meningiomas of conical and terminal filament origin are closely adherent to the spinal cord and cauda equina. Microsurgery is currently an effective treatment for this disease, and the extent of tumor resection and intraoperative spinal cord injury are important factors in determining the patient’s prognosis. Neurophysiological monitoring technology can effectively prevent intraoperative nerve injury and maximize the total tumor resection rate, which has good clinical application prospects and values.