[Intraoperative visual evoked potential recording in occipital tumor surgery]. / Udalenie opukholei zatylochnoi doli s primeneniem intraoperatsionnoi registratsii korkovykh zritel'nykh vyzvannykh potentsialov.

Currently, visual field defects are considered as an inevitable consequence of occipital lobe surgery. However, recent advances in neuroimaging techniques, such as diffusion tensor tractography allowing better visualization of optic radiation and its relationship with occipital lobe tumors, as well as intraoperative monitoring of cortical visual evoked potentials (cVEPs) can contribute to correct planning of surgery and minimizing the risk of visual field defects after surgery. OBJECTIVE: To evaluate the effectiveness of intraoperative monitoring of cVEP in patients with occipital lobe tumors. MATERIAL AND METHODS: Ten patients with occipital lobe tumors have undergone surgery with neurophysiological monitoring since 2020. Mean age of patients was 57 years. There were 6 women and 4 men. In 7 patients, neoplasms were located in the right hemisphere, in 3 patients - in the left hemisphere. According to preoperative automatic perimetry data, 7 patients had various visual field defects, and other ones had intact visual fields. All patients underwent pre- and postoperative MRI for visualization of optic radiation, its relationship with tumor and control of resection quality. Intraoperative monitoring of cVEPs was performed in all patients. RESULTS: Biopsy verified glioblastoma in 5 cases, metastasis of adenocarcinoma - 2 cases, diffuse glioma - 1 case, ganglioglioma - 1 case, CNS lymphoma - 1 case. Postoperative MRI confirmed total or subtotal resection of tumor in all cases. Enlargement of visual fields occurred in 3 patients after surgery. Two ones had deterioration and/or new homonymous defect. No changes of visual fields was observed in other cases. Analysis of visual field defects after surgery found no correlation with functional state of visual tract according to fractional anisotropy before and after surgery. CONCLUSION: MR tractography of optic radiation and intraoperative monitoring of cVEP allow choosing the safest approach for resection of occipital tumor and minimizing the risk of damage to visual cortex and optic radiation fibers. In most cases, postoperative visual functions do not worsen after intraoperative mapping of visual cortex and determining the safest trajectory for resection of occipital lobe tumors. Moreover, improvement is observed in some cases.

[Use of optical coherence tomography in diagnosis of retinal lymphomas]. / Vozmozhnosti opticheskoi kogerentnoi tomografii v diagnostike retinal'nykh limfom.

Primary intraocular lymphomas (PIOL) affecting the vitreoretinal complex is a rare nosology, and because of that PIOLs often cause diagnostic difficulties and/or lead to misdiagnosis. In the event of retinal lesions, in addition to routine ophthalmoscopy, optical coherence tomography (OCT) of the retina plays an important role in the diagnosis of the disease. PURPOSE: Evaluation of the characteristic features of retinal lymphomas using OCT. MATERIAL AND METHODS: The study included 6 patients (10 eyes) with retinal lymphomas associated with brain lesions of diffuse large B-cell lymphoma (DLBCL) who were treated at the N.N. Burdenko National Medical Research Center of Neurosurgery from 2017 to 2020; they were examined with OCT. RESULTS: All patients with retinal lymphomas showed typical OCT signs in the form of hyperreflective subretinal infiltrates. CONCLUSION: OCT is a modern non-invasive method that allows diagnosing retinal lymphomas based on clinical and instrumental signs with a high degree of reliability.

[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.

[Occipital gliomas. Case report and literature review]. / Intraoperatsionnaya registratsiya korkovykh zritel'nykh vyzvannykh potentsialov pri udalenii gliomy zatylochnoi doli. Klinicheskoe nablyudenie i obzor literatury.

The authors report intraoperative mapping with cortical visual evoked potentials during occipital tumor resection. This approach was valuable to reduce the risk of visual cortex and visual pathways damage and, accordingly, the likelihood of postoperative visual impairment. The peculiarity of this case is registration of clear cortical visual evoked potentials in various positions before and after tumor resection. Intraoperative monitoring was valuable to avoid damage to visual cortex and visual pathways during tumor resection. There was no postoperative visual deterioration. Moreover, we observed partial recovery of visual fields after resection of occipital malignant tumor.

[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.

[Neurosarcoidosis of the anterior visual pathway (a case report and literature review)]. / Neirosarkoidoz perednego zritel'nogo puti (klinicheskie nabliudeniia i obzor literatury).

Sarcoidosis is a multisystem granulomatous disorder of unknown nature. Patients often present with pulmonary, skin, eye, and orbital lesions. Involvement of the central nervous system (CNS) is accompanied by granulomatous leptomeningitis and damage to the basal brain structures with formation of granulomas near the cranial nerves, hypothalamus, pituitary gland, cavernous sinuses, optic chiasm, and intracranial optic nerves. The optic nerves can be affected independently of the other CNS regions, which may be the first manifestation of the disease. The article presents two clinical cases of sarcoidosis affecting the anterior visual pathway. Diagnosis of the disease was associated with certain difficulties. A biopsy revealed a sarcoidosis lesion.

[The trans-eyebrow supraorbital approach for removal of anterior cranial fossa and suprasellar meningiomas]. / Supraorbital'nyi chrezbrovnyi dostup dlia udaleniia meningiom perednei cherepnoi iamki i supraselliarnoi oblasti.

Over the past two decades, improvements in surgical tools, navigation systems, and endoscopic techniques have resulted in the widespread use of keyhole surgery for a wide range of skull base tumors. Currently, the trans-eyebrow supraorbital approach is being increasingly used in surgery for anterior cranial fossa and parasellar tumors. MATERIAL AND METHODS: The study included 7 patients who underwent surgery for meningioma using the trans-eyebrow supraorbital approach at the Burdenko Neurosurgical Institute in the period between 2013 and 2017. The age of patients ranged from 51 to 75 years (median, 60 years); there were 5 females and 2 males. The maximum diameter of resected tumors ranged from 20 to 60 mm (median 40 mm). RESULTS: Total resection of the tumor was achieved in all 7 cases, which was confirmed by postoperative MRI control. All 7 patients had a good cosmetic result. In 1 case, there was postoperative cerebrospinal fluid rhinorrhea due to incomplete closure of the frontal sinus, which required the patient to be re-operated. None of 7 cases was associated with injury to the main vessels or cavernous sinus. CONCLUSION: Supraorbital trans-eyebrow craniotomy provides a minimally invasive approach for removing most anterior cranial fossa base and suprasellar tumors. The advantages of keyhole surgery, in comparison with traditional craniotomies, are minimal complications associated with the approach.

[Chiasm and optic nerve glioma manifested as hemorrhage (two clinical cases and a literature review)]. / Glioma khiazmy i zritel'nykh nervov, proiavivshaiasia krovoizliianiem (dva klinicheskikh nabliudeniia i obzor literatury).

The article presents two rare clinical cases of low-grade (WHO grade I-II) glioma of the anterior visual pathway structures, the chiasm and optic nerves, in adults. The feature of these cases was the benign nature of a chiasm and optic nerve glioma in adults as well as its presentation in the form of hemorrhage to the tumor and parenchymal and subarachnoid space, which to some extent complicated making the correct diagnosis. Removal of an intracerebral hematoma and open tumor biopsy were performed in one case, and removal of a hematoma and partial tumor resection followed by radiotherapy were performed in the other case.

[Supracerebellar transtentorial approach to tumors of the posterior portions of the medial temporal region].

OBJECTIVE: Despite the advances in microsurgery, the choice of the most adequate approach to the posterior part of the medial temporal region (MTR) remains a very controversial issue. The supracerebellar transtentorial approach (STA) is considered as the most preferable one, since it provides the optimal balance between retraction, incision, and resection of the brain tissue. Here, we present our consecutive series of 20 patients who underwent STA surgery. MATERIAL AND METHODS: Twenty patients with glial tumors affecting the posterior MTR underwent STA surgery between 2006 and 2014. The mean age of the patients was 20 years. Benign tumors were predominant (18 out of 20 cases). RESULTS: Resection of the posterior and middle MTRs was conducted in 16 cases. The anterior MTR was accessed through STA in 1 patient only; in 2 patients, STA was combined with the infraoccipital approach. Cerebellar edema occurred in 4 patients, with hemiparesis persisting in one of the cases for 1 year after surgery. Of 8 patients with drug resistant epilepsy, the Engel class 1 or 2 outcome was achieved in 6 cases within 1 year after surgery. CONCLUSION: STA provides an excellent surgical route to the posterior and middle MTR portions; however, the anterior MTR portions cannot be reached safely. The operative risks of STA increase as the surgeon proceeds with resection of the anterior MTR portions. Anterior MTR structures can be removed using a combination of the supracerebellar and infraoccipital transtentorial approaches or two-stage resection.

[Multiple echinococcosis of brain, heart and kidneys].

The authors report a rare case of multiple echinococcosis (brain, heart and kidneys). Neuronavigation, intraoperative ultrasound scanning have allowed to plan exact and non-traumatic access to the cysts. Microsurgical technique and intraoperative neurophysiological monitoring provided removal of seven cysts without their rupture from the left parietooccipital and right parietal area with good postoperative functional result. Serologic analysis of antibodies with antigens of echinococci and histological research confirmed the diagnosis of cystic echinococcosis.

[Papilledemas: clinical features in space-occupying lesions of the brain].

Neuroophthalmological symptoms were analyzed in 513 patients with papilledemas in space-occupying lesions of the brain. The ophthalmoscopic features of papilledemas, the pattern of visual impairments and the developmental pattern of papilledemas were considered. Several determinants of the clinical course of papilledemas, such as their stage, the grade of malignancy, and the site of a space-occupying lesion, and a patient's age, were identified. The ability to diminish visual functions generates a need for early detection of papilledemas in patients with space-occupying lesions of the brain and for timely neurosurgical treatment in order to normalize intracranial pressure.

[Confocal scanning laser retinal tomography in study of 3-D topography of the optic disk in patients with papilledema].

Confocal scanning laser tomography (CSLT) giver the opportunity to describe stereometric parameters of the optic disk in patients with different stages of papilledema. CSLT of the optic disk (Heidelberg Retina Tomograph II) was performed in 20 healthy volunteers (40 eyes) and in 85 patients with papilledema caused by cerebral tumors (8 eyes without papilledema, 52 eyes with early, 38 with moderate and 56 with severe stage of papilledema, and 9 with chronic papilledema and optic atrophy). Rim volume (RV) and disk area (DA) were measured. CSLT was performed during postoperative follow-up in 40 patients. The difference in RV (p < 0.01) and DA (p < 0.01) between normal optic disk and optic disk with early and moderate edema, and optic disk with severe edema, was significant. Stereometric parameters of optic disks measured by CSLT provide objective quantitative assessment of papilledema in patients with cerebral tumors. CSLT is especially valuable in monitoring of papilledema.

[Neuroophthalmological aspects of benign intracranial hypertension].

Benign intracranial hypertension (BICH) is characterized by elevated spinal fluid pressure in the absence of space-occupying lesion in the skull, dilated cerebral ventricles, significant neurological disorders, and altered spinal fluid composition. Forty-nine patients with a female predominance were examined. Their age ranged from 4 to 52 years (median 39 years). The most common predictors of BICH were overweight, endocrine disorders, and cerebral sinus thrombosis. Ophthalmoscopically, the patients were found to have early, moderate, and significant papilledema, and secondary optic atrophy. Examination of visual functions revealed these or those disturbances of visual acuity and/or field of vision in 43 of the 49 patients. The incidence and degree of visual disturbances depended on the stage of papilledema. Timely diagnosis and treatment in patients with BICH allows the development of visual disturbances to be prevented in them.

[Congestive optic disks in the brain massive lesions].

To study the specific features of development of papilledema (PE) in brain space-occupying lesions, the authors made a statistical analysis of neuroophthalmologic symptoms in 962 patients with brain tumors, colloid cysts of the third ventricle and cholesteatomas, who had been examined at the Research Institute of Neurosurgery during a calendar year. PE was identified in 30.8% of the patients. The frequency of PE was ascertained to depend on histological pattern, space-occupying lesion site, and age. Visual disturbances in PE were observed in more than a third of patients and manifested themselves as both diminished visual acuity and defects in the field of vision. The frequency and degree of visual deficit depended on the stage of PE.

[Ultrasound study of optic nerves in intracranial hypertension].

Ultrasonography was used to measure the standing of the optic disk (OD) and the diameter of the orbital segment of the optic nerve together with its tunics in a control group of the examinees, in patients with different stages of optic disk disease (ODD) and with clinical signs of intracranial hypertension in the absence of the ophthalmoscopic pattern of ODD. Eleven healthy volunteers and 168 patients with intracranial hypertension induced by brain tumors, hydrocephalus, and benign intracranial hypertension were examined. Ultrasonography revealed that there was a great difference in the standing of OD into the vitreous body in different stages of ODD, as evidenced by their comparison with that in the control group (healthy individuals), and a significant increase in the diameter of the optic nerve subtunicary space in patients with intracranial hypertension as compared with the controls. Intracranial hypertension regression as demonstrated by ultrasonography leads to a concurrent reduction in the previously increased diameter of the optic nerve subtunicary space and the standing of OD into the vitreous body.

[A role of laser retinal tomography in the study of patients with congestive optical disks].

A Heidelberg retina tomograph II was used to examine 35 (55 eyes) patients with intracranial hypertension caused by brain tumors. Ophthalmoscopy revealed no changes in the optic disk in 6 eyes, mild, moderate, and severe congestive optic disks (COD) in 6, 14, and 29 eyes, respectively. The volume of the neuroretinal rim (V) and the area of the Optic disk (S) were measured. There was a significant difference in V (p < 0.01) and S (p < or = 0.02) with the intact optic disk, in mild, moderate, and severe COD. One-week-to-one-month follow-ups after tumor removal showed that in 12 patients the positive or negative changes, as evidenced by the readings of a retina tomograph, corresponded to those in the ophthalmoscopic pattern. Laser retinal tomography is an objective and accurate study of the stereometric parameters of COD in patients with intracranial hypertension, which permits a follow-up of COD.

[Delayed radiation-induced optic neuropathy in patients with tumors in the chiasmal-sellar area after radiation therapy]. / Otsrochennaia radiatsionnaia opticheskaia neiropatiia u bol'nykh s opukholiami kiazmal'no-selliarnoi oblasti posle luchevoi terapii.

Six clinical observations of a rare condition, delayed radiation-induced optic neuropathy (RON) are presented. RON developed in patients with brain tumors treated by radiotherapy and radiosurgery; in the majority of patients the condition developed during exposure to therapeutic doses; its incidence was 0.5% of the total number of patients treated by radiotherapy during this period. Asymmetrical chiasmal syndrome developed rapidly in all the patients. Clinical diagnosis of RON was confirmed by magnetic resonance tomography in all cases, and in one case by morphological analysis. Conservative therapy including hyperbaric oxygenation just stabilized the visual function. Remote period of observation was 42 months.