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Objective: To analyze the vessels compressing facial nerve root exit zone and efficacy of interposition and transposition techniques of vascular decompression for hemifacial spasm., Material and Methods: Vascular compression was evaluated in 110 patients. Implant interposition between vessels and nerve was performed in 52 cases, transposition of arteries without contact between implants and nerve - in 58 patients., Results: Compressing vessels were anterior (44), posterior (61) inferior cerebellar, vertebral (28) arteries and veins (4). Multiple compressing vessels were found in 27 cases. Premeatal meningioma and jugular schwannoma were accompanied by vascular compression in 2 cases. Immediate regression of symptoms was observed in 104 patients, partial regression - in 6 patients. Transient facial paresis (4) and impaired hearing (5) were noted after implant interposition. Redo vascular decompression was performed in one case., Conclusion: The most common compressing vessels were cerebellar arteries, vertebral artery and veins. Transposition of arteries is highly effective technique with low incidence of VII-VII nerve dysfunction but relatively slow regression of symptoms.

Objective: To evaluate the correlation of neurological symptoms with anatomical relationships of cranial nerves, lesions and vessels in patients with epidermoids of the cerebellopontine angle., Material and Methods: We analyzed neurological symptoms, magnetic resonance data, intraoperative findings and postoperative functional outcomes in 25 patients (14 females and 11 males aged 22-77 years) with epidermoids of the cerebellopontine angle., Results: Cranial nerve dysfunctions were noted in 15 patients. Involvement of cochlear ( n =9) and trigeminal (9 cases including 4 ones with sensory impairment and 5 patients with neuralgia) nerves was the most common. There were 10 patients with ataxia, hemiparesis and seizures without cranial nerve dysfunction. In 15 patients, epidermoids spread to supratentorial space and contralateral cerebellopontine angle. Lesion-induced brainstem compression was found in 22 cases. Cranial nerves and cerebellar arteries were partially or completely enclosed by lesion in all cases. Severe compression and dislocation of the nerve root entry/exit zone were found in all cases. One patient with trigeminal neuralgia had vascular compression of trigeminal nerve caused by superior cerebellar artery. Total resection was achieved in 16 patients. Small capsule remnants were left on vessels, nerves or brainstem in 9 patients. Postoperative complete or partial restoration of cranial nerve functions was noted in 11 cases. Deterioration of preoperative neurological deficit in 4 patients and postoperative neurological symptoms de novo in 3 patients were temporary., Conclusion: Cranial nerve dysfunctions are caused by compression of the nerve root entry/exit zones by epidermoids of the cerebellopontine angle. Surgical intervention is effective in alleviating symptoms of cranial neuropathy and brainstem compression. Vascular decompression should be performed in patients with trigeminal neuralgia.

Background: The use of awake craniotomy for surgical treatment of epilepsy was applied in surgery of convexital tumors, arteriovenous malformations, some superficial aneurysms, and stereotactic neurosurgery. The aim of this study was to show the advantages of awake craniotomy without sedation, accompanied by intraoperative neurophysiological monitoring in patients with symptomatic epilepsy., Methods: This article describes the results of surgical treatment in 41 patients with various pathologies; 31 among them suffered from epilepsy., Results: Most frequently, the pathological foci were located in frontal and parietal lobes nearby eloquent brain areas. Irrespective of damage location, simple partial and complex partial seizures were seen almost with the same frequency. Intraoperative mapping of eloquent cortical areas and subcortical tracts without sedation resulted in total resection of pathological area in 75% of cases with low rate of permanent neurological deficit (two patients). Minor perioperative complications, including the decrease in blood pressure in six patients and intraoperative convulsions in two patients, were handled and did not led to operation termination or anesthesia conversion. Excellent seizures control (Engel 1) was achieved in 80% of patients with available catamnesis., Conclusion: Thus, the proposed method allows eliminating the complications associated with sedation and provides radical resection of pathological epileptogenic foci with low complication rate., Competing Interests: There are no conflicts of interest.

Background: The use of the anterior nucleus of thalamus (ANT) as a target for treatment of pharmacoresistant epilepsy is based on its crucial role in seizure propagation. We describe results of chronic bilateral ANT stimulation and bilateral ANT lesions in 31 patients with refractory epilepsy., Methods: ANT DBS was performed in 12 patients (group I) and bilateral stereotactic radiofrequency lesions of ANT were performed in 19 patients (group II). Targeting was based on stereotactic atlas information with correction of the final coordinates according to the location of anatomical landmarks and intraoperative microelectrode recording data., Results: Both groups were similar in age, gender, seizures frequency, and duration of disease. The median x, y , and z coordinates of ANT were found to be 2.9, 5, and 11 mm anterior, lateral, and superior to the mid-commissural point, respectively. Mean seizures reduction reached 80.3% in group of patients with ANT DBS with two nonresponders and 91.2% in group of patients with lesions. Five patients from group I and three patients from group II became seizure-free. The morbidity rate was low in both groups., Conclusions: Stereotactic anterior thalamotomy and chronic ANT stimulation are both effective for seizure control in epilepsy originated from frontal and temporal lobes. ANT lesions and stimulation were more effective for secondary-generalized seizures compared to simple partial seizures., Competing Interests: There are no conflicts of interest.

Background: Identification of the crucial role of the anterior thalamic nuclei (ATN) in the generalization of seizures led to increased interest in surgical interventions in this particular area in intractable epilepsy patients. Simulation of ATN destruction in animals demonstrated its high efficacy for both preventing the seizure development and reducing the seizure rate. However, bilateral radiofrequency destruction of the anterior thalamic nuclei in humans has not yet bee described., Aim: The study objective was to perform bilateral radiofrequency anterior thalamotomy in intractable epilepsy patients and to evaluate its, Material and Methods: We performed for the first time bilateral stereotactic radiofrequency thermocoagulation of ATN in 13 patients with long-term intractable epilepsy. Before surgery, we assessed the disease duration, age of seizure onset, localization of pathological activity sources, and types of seizures, morphological damages, and ongoing pharmacotherapy. All interventions were performed under local anesthesia and were accompanied by intraoperative microelectrode monitoring of the neuronal activity and by EEG., Results: Seven males and 6 females, aged 22 to 48 years, were operated on. All patients had epileptogenic foci in the frontal and/or temporal lobes. MRI revealed epileptogenic structural abnormalities in 3 patients. There were no postoperative complications. According to a postoperative examination, 5 patients were seizure-free; a decrease in the seizure rate was 70% in 6 patients and 50% in 1 patient; 1 patient had no response to the surgery. The resulting effect was manifested not only in a reduction in the frequency and severity of seizures but also in a decrease in the dose of administered anticonvulsants. EEG also showed a significant improvement in the majority of patients., Conclusion: Our experience demonstrates that bilateral radiofrequency anterior thalamotomy is a safe and effective technique to control seizures in humans. Further research will clarify, based on the clinical and EEG data, the patient selection criteria for surgical treatment.

Unlabelled: The mediobasal temporal region (MTR) is located near the brain stem and surrounded by the eloquent neurovascular structures. The supracerebellar transtentorial approach (STA) is safe access to the posterior MTR structures, however its use for resection of anterior MTR lesions still remains controversial. The article describes the technique and outcome of surgery for different MTR structures using STA., Material and Methods: The paramedian STA was used in 18 patients (13 females and 5 males) for 7 years. Ten patients presented with glial MTR tumors, 3 patients with cavernomas, 2 patients with arteriovenous malformations (AVMs), 2 patients with intraventricular meningiomas, and 1 patient with mesial temporal sclerosis. The patient age ranged from 19 to 57 years. In 10 cases, lesions were localized on the left. Epilepsy was the leading symptom in 14 cases. Patients underwent preoperative high-resolution MRI, electroencephalography video monitoring before and after surgery, intraoperative corticography (if necessary), and postoperative CT and MRI., Results: Lesions were located in the anterior third of MTR in 5 patients, in the anterior and middle thirds in 2 patients, in the middle third in 5 patients, in the middle and posterior thirds in 2 patients, in the posterior third in 1 patient, in the anterior, middle, and posterior thirds in 1 patient, and in the ventricular triangle area in 2 patients. In all patients with intraventricular tumors, AVMs, and cavernous malformations and in 8 patients with glial MTR tumors, the lesions were totally resected. Two patients with intracerebral tumors underwent subtotal resection. A patient with intractable epilepsy and mesial temporal sclerosis underwent resection of the anterior two-thirds of the hippocampus and parahippocampal gyrus and, partially, amygdala using intraoperative corticography. There was no surgical mortality; 2 patients developed a transient neurological deficit, and 1 patient had a cerebellar hematoma that was successfully removed during surgery., Conclusion: STA enables resection of lesions localized in all parts of the MTR, without damage to the surrounding nerve and vascular structures.

Background: The tortuous vertebrobasilar artery (TVBA) often causes neurovascular conflicts in patients with trigeminal neuralgia (TN) and hemifacial spasm (HFS). Implementation of microvascular decompression (MVD) in these circumstances is hindered due to stiffness of the enlarged and dilated arteries and is often accompanied by poor outcomes. The surgical strategy in cases of trigeminal neuralgia and hemifacial spasm associated with the TVBA should be clarified in order to achieve good outcomes., Material and Methods: MVD was performed in 268 TN patients and 71 HFS patients. The TVBA as a compressing vessel was identified in 30 cases (11 cases of TN, 18 cases of HFS, and 1 patient with painful tic convulsif). All patients underwent MVD and a retrospective analysis of clinical outcomes., Results: Compression caused by the vertebral artery was found in all HFS patients and 4 TN patients, and compression caused by the basilar artery was observed in 7 TN cases. Additional compression of the cranial nerve root entry/exit zone by cerebellar vessels was observed in 21 cases. The TVBA was mobilized by dissection of arachnoid adhesions between the vessel and the brainstem and retracted laterally. Then, the TVBA was retracted from the brainstem to the caudorostral direction. These manipulations resulted is "spontaneous" decompression of the cranial nerves without placing prostheses between the artery and the nerve root entry/exit zone. In all cases (except two), the displaced TVBA was fixed between the enlarged artery and brainstem using pieces of the patient's muscle and adipose tissues, followed by application of fibrin glue. A cylindrical silicone prosthesis was used in 1 case. In another case, the TVBA was retracted using a fascial loop fixed to the dura mater of the petrous pyramid by means of a suture. After application of MVD, TN and HFS symptoms completely regressed. There were several transient complications and 2 cases of permanent hearing loss. No clinical symptom recurrence was observed., Conclusion: MVD is the most effective surgical treatment of TN and HFS caused by the TVBA. The TVBA should be retracted from the brainstem without placing prostheses in the nerve root entry/exit zone.

Background: Hemifacial spasm is usually caused by compression of the facial nerve by ipsilateral blood vessels. Compression of the facial nerve root exit zone by a contralateral tortuous vertebral artery is very rare., Methods: This 68-year-old woman presented with left-sided hemifacial spasm and was found to have compression of the left facial nerve by the tortuous vertebrobasilar artery, as revealed by magnetic resonance imaging and magnetic resonance angiography. Retromastoid craniectomy demonstrated compression of the left facial nerve root exit zone by the distal portion of the right vertebral artery. The vertebrobasilar junction and both vertebral arteries were moved laterally from the facial nerve and a muscle implant was interposed between the brainstem and the right vertebral artery., Results: The patient has remained free of hemifacial spasm for a follow-up period of 27 months., Conclusions: Compression of the facial nerve by the contralateral tortuous vertebral artery may produce hemifacial spasm. A transposed large vessel can be secured by a sling technique or by interposing a soft implant between the brainstem and the vertebral artery.

Background: Contralateral trigeminal neuralgia as a false localizing sign in patients with posterior cranial fossa tumors is rare. Persistent contralateral trigeminal neuralgia after removal of the posterior fossa expanding lesion with microsurgical exploration of the affected trigeminal nerve root has been described in only a few reports. Displacement of the brainstem and the trigeminal nerve root, arachnoid adhesions, and vascular compression of the nerve root entry zone have been reported as causes of persistent contralateral trigeminal neuralgia., Methods: One patient developed transformation of the contralateral constant burning facial pain into trigeminal neuralgia after removal of a posterior fossa meningioma. A typical right-sided tic douloureux in our second patient did not disappear after removal of a left acoustic neurinoma. CT scan revealed brainstem displacement to the side of trigeminal neuralgia. Microsurgical exploration in both cases demonstrated the squeezed and distorted trigeminal nerve root and displaced brain stem with no vascular involvement. Both patients underwent partial trigeminal rhizotomy for pain control., Results: Complete disappearance of the trigeminal neuralgia was evident in both cases with postoperative facial sensory loss. The postoperative course in the first case was uneventful; the second patient died from purulent meningoencephalitis., Conclusion: Persistent contralateral trigeminal neuralgia after removal of a posterior fossa tumor is caused by distortion of the fifth nerve root by the displaced brainstem. Partial trigeminal rhizotomy can be performed for alleviation of facial neuralgic pain in cases without neurovascular compression.

The polyprojective microstereotopography of spinal canal structures at the cerebello-spinal, cervical, thoracic, lumbosacral and cauda equina levels on 20 fresh cadavers is presented using flexiscopes 3.7-3.9 mm diameter. This is possible due to the space between spinal cord-vertebral canal which is about 10 mm at all levels. This also allows one to insert the endoscopic tube by posterior or interradicular approach. The subdural and subarachnoid endoscopic examinations have been performed through small foraminotomic openings with resection of the base of the spinous process. The anterior and posterior roots, the spinal cord, dural root sleeves, cerebellar tonsils, orifice of the IV ventricle, vertebral artery and its lower branches can be visualised. On the stereotopographic basis the first operations in patients with severe spinal cord injury (detection of multilevel cord compression, removal of massive subarachnoid bleeding), syringomyelia and haemorrhage into the IV ventricle (clot removal by the ascending cervical route) were undertaken. More than 10 real and probable indications for operative spinal endofiberoscopy are discussed.

The case of trigeminal neuralgia and ipsilateral hemifacial spasm--painful tic convulsif--is presented. Microsurgical exploration revealed compression of the fifth and seventh cranial nerves by a tortuous contralateral vertebral artery. Neurovascular decompression of the roots entry/exit zone completely relieved preoperative facial pain and spasm.