[Microsurgical ventriculostomy of the third ventricle with access through a burrhole in the treatment of midly located deep-seated brain tumors]. / Mikrokhirurgicheskaya ventrikulostomiya III zheludochka s dostupom cherez frezevoe otverstie v lechenii sredinno raspolozhennykh glubinnykh opukholei golovnogo mozga.

BACKGROUND: Currently, endoscopic third ventriculostomy and simultaneous biopsy of deep midline brain tumors are a generally accepted option in neurooncology. Nevertheless, effectiveness of this surgery and diagnostic accuracy of biopsy are not without drawbacks. An alternative to endoscopic surgery may be simultaneous microsurgical third ventriculostomy and biopsy of deep midline tumors. OBJECTIVE: To evaluate effectiveness and safety of burr hole microsurgical third ventriculostomy in the treatment of deep midline brain tumors. MATERIAL AND METHODS: We used transcortical (25 cases) and transcallosal (8 cases) approaches for microsurgical third ventriculostomy. RESULTS: Initially scheduled biopsy was performed in 19 cases, partial resection in 6 cases, subtotal resection in 4 cases and total resection in 4 cases. All patients underwent microsurgical third ventriculostomy. In 12 cases, stenting of stoma was performed in addition to ventriculostomy. Biopsy was informative in all cases. Postoperative follow-up period ranged from 3 to 44 months (mean 29 months). There was no postoperative hydrocephalus and need for shunting procedure. CONCLUSION: Burr hole microsurgery may be an alternative to endoscopic surgery for the treatment of pineal, periaqueductal and third ventricular tumors.

[Astrocytoma with 1p19q codeletion]. / Astrotsitoma s kodeletsiei 1p19q.

Using the example of a recurrent tumor with a 10-year follow-up, the authors show that mutation of the IDH1/2 genes in astrocytomas is not always an early event in the pathogenesis of glioma, that in rare cases a 1p19q codeletion can be found in astrocytomas, and that IDH-mutant tumors can occur in childhood.

[«Burr hole¼ microsurgery for vestibular schwannoma]. / «Burr hole¼ mikrokhirurgiya vestibulyarnykh shvannom.

OBJECTIVE: To evaluate the efficacy and safety of minimally invasive «burr hole¼ microsurgery for vestibular schwannoma. MATERIAL AND METHODS: A retrospective analysis of postoperative outcomes in 50 consecutive patients with vestibular schwannoma was performed. All patients underwent burr hole microsurgery between 2016 and 2020. RESULTS: All patients satisfactorily tolerated surgical treatment. Total resection was carried out in 21 (42%) cases, almost total resection - in 21 (42%) patients (>95% of baseline volume). Subtotal resection was performed in 8 (16%) cases. Mean surgery time was 132 min (range 60-340). Postoperative deterioration of facial nerve function occurred in 20 (40%) patients. Severe dysfunction (House-Brackmann grade V-VI) was observed only in three patients. Other 17 patients had moderate dysfunction of the facial nerve (House-Brackmann grade III-IV). Useful hearing was preserved in 6 (50%) out of 12 patients with preoperative useful hearing. CONCLUSION: Minimally invasive burr hole microsurgery is an effective method for vestibular schwannoma. Moreover, the proposed technique reduces surgery time due to simpler craniotomy and wound closure.

[Neurophysiological aspects of multiple hippocampal transection in intractable temporal lobe epilepsy]. / Neirofiziologicheskie aspekty mnozhestvennoi transsektsii gippokampa pri visochnoi epilepsii.

OBJECTIVE: To search for correlations between intraoperative electrocorticographic data and seizure control after the multiple hippocampal transections (MHT) in patients with symptomatic pharmacoresistant medial temporal lobe epilepsy. MATERIAL AND METHODS: Six patients underwent MHT nearby the hippocampus. The left dominant hemisphere was affected in all cases. Patients had normal memory function. Follow up was 18 to 24 months. Scalp electroencephalogram (EEG) and electrocorticography (ECoG) were intaoperatively recorded. Transections of the hippocampus were performed until ECoG epileptiform discharges stopped. RESULTS: Seizure control was achieved in five patients. Synchronous epileptiform activity disappeared in the hippocampus in all patients after MHT. Complete disappearance of epileptiform activity in the hippocampus and basal cortex was demonstrated in 2 cases. The epileptiform activity remained in the basal cortex in 3 patients. CONCLUSIONS: Using the method of hippocampal transections it was possible to achieve the disappearance of synchronous epileptic activity in the hippocampus in all patients. It is correlated with good outcome in 5 out of 6 cases. Preservation and even arising of spiking in the basal temporal cortex are not a risk factor for maintaining seizures after complete resection of the epileptogenic substrate in the temporal lobe and hippocampal transections. A decrease in the background epileptiform activity on the scalp EEG was observed in 4 of 5 cases after the resection of the pathological substrate, uncus and amygdala.

[Retrograde degeneration of visual pathway]. / Retrogradnaya degeneratsiya zritel'nogo puti.

BACKGROUND: Optical coherence tomography (OCT) gives the opportunity to examine retrograde degeneration of visual pathway damaged at various levels. OBJECTIVE: To estimate OCT data on retrograde degeneration of visual pathway damaged at various levels. MATERIAL AND METHODS: Ganglion cell layer (GCL) thickness was measured by OCT in 79 patients with visual pathway damaged at various levels and known duration of visual disturbances. Twenty-One patients were diagnosed with traumatic lesions of the optic nerves and/or chiasma. Fifty-eight patients had retro-genicular visual pathway damage. Thirty-three patients were examined for postoperative homonymous hemianopia after surgery for drug-resistant temporal lobe epilepsy. Twenty-five patients were diagnosed with occipital lobe damage following stroke (12 patients), surgery for arteriovenous malformation (11 patients) and traumatic brain injury (2 patients). All patients underwent assessment of visual acuity, automatic static perimetry, MRI/CT of the brain. Retinal ganglion cell complex was analyzed during OCT. RESULTS: GCL thinning following anterior visual pathway damage was detected in 20 out of 21 patients after ≥22 days. In case of post-genicular visual pathway damage, GCL thinning was found in 25 out of 58 patients (9 out of 33 ones after surgery for temporal lobe epilepsy and 16 out of 25 patients with occipital lobe lesion). After surgery for temporal lobe epilepsy, minimum period until GCL thinning detection after previous visual pathway damage was 3 months, in case of occipital lobe lesion - 5 months. CONCLUSION: Retrograde visual pathway degeneration is followed by GCL thinning and depends on the level of visual pathway lesion.

[Surgical treatment of drug-resistant epilepsy following hippocampal sclerosis]. / Khirurgicheskoe lechenie farmakorezistentnoi epilepsii pri skleroze gippokampa.

Surgery is an effective approach for drug-resistant temporal lobe epilepsy following hippocampal sclerosis. There is still no clear and unanimous opinion about advantages and disadvantages of certain surgical technique. MATERIAL AND METHODS: There were 103 surgical interventions in 101 patients. Females prevailed (1.45:1). Age of patients ranged from 16 to 56 years (median 28). Anteromedial temporal lobectomy and selective amygdaloghippocampectomy were performed in 49 (47.6%) and 54 (52.4%) patients, respectively. In the latter group, 30 patients were operated via a 14-mm burr hole-subtemporal approach. Postoperative outcomes were assessed using the Engel grading system. The follow-up period ranged from 2 to 8 years (median 4 years). RESULTS: By the 2nd year, Engel class I was observed in 74 (72%) patients, Engel II, III and IV - in 20 (19.4%), 6 (5.8%) and 3 (2.9%) patients, respectively. Engel class I was achieved after anteromedial temporal lobectomy in 68% of cases, selective amygdaloghippocampectomy via standard approaches in 75% of cases, amygdaloghippocampectomy via subtemporal burr hole approach - in 80% of cases. Neurocognitive impairments after anteromedial lobectomy and selective amygdaloghippocampectomy were similar. At the same time, mental disorders de novo prevailed in the group of anteromedial lobectomy (p<0.05). There were no severe visual field disorders after subtemporal burr-hole access. In other cases, these disorders occurred in 36.2% of patients (p<0.05). There were 8 (7.8%) postoperative complications: 5 (10.2%) - after anterior temporal lobectomy, 3 (5.5%) - after selective surgeries via standard approaches. There were no complications after burr-hole surgery. CONCLUSION: Selective amygdaloghippocampectomy is not inferior to anteromedial lobectomy. Moreover, this procedure is associated with a lower risk of complications and adverse events.

[Visual field disorder after surgery of temporal lobe epilepsy associated to hippocampus sclerosis]. / Narushenie polia zreniia posle operatsii po povodu visochnoi épilepsii, obuslovlennoi sklerozom gippokampa.

OBJECTIVE: Assessment of frequency and severity of visual field disorders after neurosurgical operations at patients with pharmacoresistant form of epilepsy in hippocampus sclerosis. MATERIAL AND METHODS: The study included 48 patients having surgical operations for a pharmacoresistant form of temporal lobe epilepsy due to hippocampus sclerosis. Anterior lobectomy with amygdalohippocampectomy (LE + AHE) was performed in 25 patients; Selective amygdalohippocampectomy (SAHE) was performed in 23 patients. We evaluated both the frequency of cases of homonymous visual field disorders and their severity. RESULTS: After surgery the normal visual field was preserved at 7 (14.6%) patients. The appearance of visual field disorder by the type of homonymous hemianopsia was observed at 41 (85.4%) patients. When assessing the severity of visual field disorder, the smallest disorder was at patients who underwent sub-temporal access of SAHE: a statistically significant difference in the frequency of severe visual field disorder was revealed when comparing this group with patients having LE + AHE (p<0.02), as well as with patients having SAHE with access through sylvian gap (p<0.02). CONCLUSION: SAHE with sub-temporal access allows maintaining or minimally injuring the central optic neuron fibers, including the Meyer loop at patients operated for symptomatic temporal lobe epilepsy.

[microsurgery 'burr hole' for intracranial tumors and mesial temporal lobe epilepsy]. / Mikrokhirurgiia 'burr hole' pri intrakranial'nykh opukholiakh i medial'noi visochnoi épilepsii.

PURPOSE: In recent years, neurosurgery has been characterized by a clear tendency towards the development of minimally invasive and less traumatic surgical approaches. To minimize the degree of injury to the brain tissue, we have proposed burr hole-based microsurgical approaches. MATERIAL AND METHODS: In the period between February 2016 and February 2019, more than 500 microsurgical interventions were performed through a 14 mm burr hole using a technique that we called burr-hole microneurosurgery; to date, 200 of these have been analyzed. The age of patients varied from 16 to 79 years (median, 38 years). Female patients predominated - 1.6:1. Surgery for intracranial lesions with various locations was performed in 176 cases; in the remaining 24 cases, patients with hippocampal sclerosis underwent selective amygdalohippocampectomy. RESULTS: Various surgical approaches were used: transcortical approach in 81 (40.5%) cases; retro-sigmoid approach in 38 (19%); sub-temporal approach in 32 (16%); infratentorial supracerebellar approach in 25 (12.5%); interhemispheric approach in 17 (8.5%); telovelar approach in 5 (2.5%); trans-eyebrow approach in 2 cases. The resection degree was evaluated in 167 patients with planned maximum tumor resection. Resection was total and almost total in 145 (87%) patients, subtotal in 15 (9%), and partial in 7 (4%). The surgery duration varied from 35 to 300 min (mean, 80 min). The extubation time after surgery ranged from 5 min to 5 days (mean, 70 min). In 195 (97.5%) cases, patients were verticalized within the first 3 days after surgery. CONCLUSION: The proposed burr hole technique enables successful surgery in patients with various intracranial pathologies, using a smaller trepanation window compared to that in keyhole surgery. The proposed burr hole technique minimizes injury to the brain substance, significantly reduces patient's exposure to anesthesia, and decreases the entire duration of surgery.

[Surgical anatomy of the peri-insular association tracts. Part I.The superior longitudinal fascicle system]. / Khirurgicheskaya anatomiya periinsulyarnykh assotsiativnykh provodyashchikh putei. Chast' I. Sistema verkhnego prodol'nogo puchka.

AIM: To study the peri-insular association tract anatomy and define the permissible anatomical boundaries for resection of glial insular tumors with allowance for the surgical anatomy of the peri-insular association tracts. MATERIAL AND METHODS: In an anatomic study of the superior longitudinal fascicle system (SLF I, SLF II, SLF III, arcuate fascicle), we used 12 anatomical specimens (6 left and 6 right hemispheres) prepared according to the Klingler's fiber dissection technique. To confirm the dissection data, we used MR tractography (HARDI-CSD-tractography) of the conduction tracts, which was performed in two healthy volunteers. RESULTS: Except the SLF I (identified in 7 hemispheres by fiber dissection), all fascicles of the SLF system were found in all investigated hemispheres by both fiber dissection and MR tractography. The transcortical approach to the insula through the frontal and (or) parietal operculum is associated with a significant risk of transverse transection of the SLF III fibers passing in the frontal and parietal opercula. The most optimal area for the transcortical approach to the insula is the anterior third of the superior temporal gyrus that lacks important association tracts and, consequently, a risk of their injury. The superior peri-insular sulcus is an intraoperative landmark for the transsylvian approach, which enables identification of the SLF II and arcuate fascicle in the surgical wound. CONCLUSION: Detailed knowledge of the peri-insular association tract anatomy is the prerequisite for neurosurgery in the insular region. Our findings facilitate correct identification of both the site for cerebral operculum dissection upon the transcortical approach and the intraoperative landmarks for locating the association tracts in the surgical wound upon the transsylvian approach to the insula.