chronic cerebellar electrical stimulation

In 1973, Cooper found that stimulating the cerebellum significantly inhibited brain, medulla, and spinal nerve activity. It can also inhibit experimental chronic epilepsy and cerebral cortex-induced activities. Clinical physiology also confirmed that stimulation of the cerebellum can inhibit H, V1, V2 reflexes in the spinal cord (H reflex is a single synaptic reflex of the spinal cord, V1, V2 reflex is a multi-synaptic reflex of the spinal cord), while inhibiting thalamic and cortical evoked responses. Therefore, the first successful treatment of epilepsy with chronic cerebellar electrical stimulation was successful. Most scholars believe that its mechanism of action is that the cerebellum is stimulated and acts through brain stem network activation and thalamic inhibition. Cooper himself believes that cerebellar stimulation is an afferent nerve block. Currently, there are two main types of devices for cerebellar stimulation: one is a radio frequency coupled stimulator. It consists of an implant part (electrode, wire and receiver) and an extracorporeal device (transmitter and antenna). Such as foreign Medtronic1743 cerebellar stimulator and domestically developed domestic J-63 cerebellar stimulator. The second is a cerebellar stimulator that can be completely implanted in the body, such as the Neurolith Model 601, which is a fully implanted lithium battery pulse transmitter. Davis comprehensive literature 87 cases, the effective rate of control of epilepsy is 70%. Cooper (1978) reported 32 cases with an average follow-up of 32.4 months, and 56% of cases had a 50% reduction in seizures. There were 12 cases of research application in China. After 7 to 29 months of observation, 2 cases were not used, and seizures were significantly reduced (3 times in 1 year). Six patients were still taking the drug, and seizures were significantly reduced or not. 2 cases of seizures decreased by >50% (medication), 2 cases were ineffective (1 case of wire fracture, the other case of stimulation is not regular, throwing away the stimulator, is invalid). However, some reports have been invalid. For example, Van Buren and Wright reported that 5 cases and 12 cases were considered invalid by double-blind trials, but most people think it is effective. As Rossi believes: 1 animal experiment support. 2 objectively reduce the frequency and severity of seizures. 3 treatment methods have been standardized. 4 surgery is less dangerous, less complications, it is worth using. Treatment of diseases: refractory epilepsy epilepsy Indication In patients with intractable epilepsy, EEG has abnormal epileptic waves, and patients with IQ (IQ) scores of 70 or higher can choose chronic cerebellar electrical stimulation. Contraindications Those with brain lesions are banned. Children and people with mental disorders who are unable to cooperate are relatively contraindicated. Preoperative preparation 1. The frequency and severity of seizures should be evaluated in detail before surgery, and the family members of the patients should be taught to observe and record the episodes. 2. Perform neuropsychological tests such as WAIS (Wechsler adult intelligence scale) and WMS (Wechsler memory scale) tests. Neurophysiological examinations such as H, V1, V2 reflexes, somatosensory evoked potentials (SSEP), and visual evoked potentials (VEP) should also be performed for postoperative observation. 3. Teach the patient to apply the stimulator. Surgical procedure Under the occipital approach, a straight incision is made in the middle, and the occipital scaly is exposed. One of the bone holes is drilled under the trochanter and the bone window is slightly enlarged. The dura mater is cut under the transverse sinus. Coagulate under direct vision and cut off the bridge between the cerebellum and the cerebellum. The two electrodes were placed on the cerebellum on both sides of the midline, and the electrode leads were fixed on the dura mater. Strictly suture the dura mater and, if necessary, use a muscle block to prevent leakage of cerebrospinal fluid. The electrode lead is introduced into the subcutaneous tissue of the right lower clavicle wall through a subcutaneous tunnel, and the receiver is buried in the subcutaneous tissue to connect the lead to the receiver. And sealed with silicone tube, completely stop bleeding, do not let the drainage, suture the incision. EEG should be performed after surgery to confirm that the stimulation current is smooth and the stimulation system is intact, otherwise it needs to be re-adjusted. complication 1. Intracranial hematoma. 2. Cerebrospinal fluid leakage or effusion around the wire and receiver. 3. Wound infection. 4. Some patients have headaches when they are stimulating. It may be that the electrodes are placed too far outside the cerebellar hemisphere.