[Electrical dorsal root ganglion stimulation (DRGS) for the treatment of refractory postherpetic neuralgia]. / Elektricheskaya stimulyatsiya gangliya zadnikh koreshkov spinnogo mozga (DRGS) dlya lecheniya refrakternoi postgerpeticheskoi nevralgii.

Postherpetic neuralgia (PHN) is a rare complication of herpes zoster characterized by prolonged and excruciating pain. Traditional treatments for PHN, such as analgesics, anticonvulsants and antidepressants, do not always bring the desired result. One promising alternative that is attracting the attention of the scientific community is dorsal root ganglion stimulation (DRGS). This method focuses on targeted and precise targeting of the source of pain, providing a new level of effectiveness in the treatment of PHN. OBJECTIVE: A retrospective analysis of the technique and results of implantation of a permanent device for stimulating the spinal ganglia in patients with refractory PHN at the Burdenko Neurosurgical Center. MATERIAL AND METHODS: The study was conducted in 7 patients (5 men, 2 women) with refractory PHN in the period from 2018 to 2020. The age of the patients ranged from 57 to 84 years (average age 74±8.4). All patients were implanted with Boston systems (Precision or Spectra versions). Stimulation parameters: pulse width - 120-210 µs, frequency - 30-130 Hz, amplitude at the lower limit of the appearance of paresthesia with the possibility of increasing with increased pain up to 5 mA. The position of the electrode depended on the location of the pain. All systems were implanted under X-ray guidance. RESULTS: The duration of follow-up observation was more than 2.5 years. The average pain intensity one year after treatment was 3.42±2.45 points on the visual analogue scale (VAS) (a 62.3% decrease in intensity compared to baseline). In 3 (42.8%) patients, the result was characterized by us as «excellent¼ (intensity according to VAS decreased by 75% or more), in 1 (14.2%) - as «good¼ (intensity according to VAS decreased by 50-74%), in 1 (14.2%) - as «moderate¼ (VAS intensity decreased by 25-49% and in 2 (28.5%) as «unsatisfactory¼ (VAS intensity decreased by less than 25%, or postoperative complications occurred). CONCLUSION: Given the complicated nature of PHN, the use of dorsal ganglion stimulation appears to be a promising and innovative treatment approach. Further research is needed to introduce this technique into clinical practice for the treatment of patients suffering from PHN.

[Results of the Third Congress on Functional and Stereotactic Neurosurgery]. / Itogi Tret'ego kongressa po funktsional'noi i stereotaksicheskoi neirokhirurgii.

After several years of waiting due to the "covid quarantine" and subsequent restrictions, we finally met. Epidemiological restrictions prevented the planned interim congress in 2021. The Third Congress on Functional and Stereotactic Neurosurgery was held in Moscow on March 15-17, 2023. Despite the widespread use of the online conference format, the Congress was attended by almost everyone who is in one way or another associated with functional and stereotactic neurosurgery in our country. International participation was also present despite the existing sanctions restrictions.

[Methods and results of neurosurgical treatment of cerebral palsy]. / Metody i rezul'taty neirokhirurgicheskogo lecheniya detskogo tserebral'nogo paralicha.

Treatment of spastic syndrome and muscular dystonia in patients with cerebral palsy is a complex clinical problem. Effectiveness of conservative treatment is not high enough. Modern neurosurgical techniques for spastic syndrome and dystonia are divided into destructive interventions and surgical neuromodulation. Their effectiveness is different and depends on the form of disease, severity of motor disorders and age of patients. OBJECTIVE: To evaluate the effectiveness of various methods of neurosurgical treatment of spasticity and muscular dystonia in patients with cerebral palsy. MATERIAL AND METHODS: We To evaluate the effectiveness of various methods of neurosurgical treatment of spasticity and muscular dystonia in patients with cerebral palsy.analyzed literature data in the PubMed database using the keywords «cerebral palsy¼, «spasticity¼, «dystonia¼, «selective dorsal rhizotomy¼, «selective neurotomy¼, «intrathecal baclofen therapy¼, «spinal cord stimulation¼, «deep brain stimulation¼. RESULTS: Effectiveness of neurosurgery was higher for spastic forms of cerebral palsy compared to secondary muscular dystonia. Destructive procedures were the most effective among neurosurgical operations for spastic forms. Effectiveness of chronic intrathecal baclofen therapy decreases in follow-up due to secondary drug resistance. Destructive stereotaxic interventions and deep brain stimulation are used for secondary muscular dystonia. Effectiveness of these procedures is low. CONCLUSION: Neurosurgical methods can partially reduce severity of motor disorders and expand the possibilities of rehabilitation in patients with cerebral palsy.

[Treatment of sciatic posttraumatic neuropathy with chronic neuromodulation and endoscopic technics]. / Lechenie posttravmaticheskoi nevropatii sedalishchnogo nerva s ispol'zovaniem khronicheskoi neirostimulyatsii i endoskopicheskoi tekhniki.

OBJECTIVE: Sciatic nerve injury in the deep gluteal space is a major clinical problem due to microsurgical manipulations in this region are limited in scope. We offer new endoscopic approach to the sciatic nerve in the deep gluteal space which allows to perform microsurgical manipulations, neurophysiological mapping and electrode installation for the chronic nerve stimulation. MATERIAL AND METHOD: 3 patients with sciatic neuropathy have been operated. Before the operation they suffered from neuropathic pain in the the posterior thigh and calf, reaching 7-8 points on the visual analog scale (VAS). Paresis of triceps surae and biceps femur also was occurred. We performed endoscopic approach to the deep gluteal space through a small incision under the gluteal fold. Microsurgical external and internal decompression of sciatic nerve was performed under the endoscopic control. Next, intra-trunk nerve mapping was performed to visualize sensory fibers. Cylindrical electrodes for chronic neurostimulation were directly placed on the sensory fibers of sciatic nerve. RESULTS: Pain relief was obtained in all cases after activating the simulator, the patient noted a 50% reduction in pain. Muscle straight restoration was observed in all cases 2-3 months later. The clinical effect was stable in the follow up (6 months). CONCLUSION: This technique, combining minimal invasiveness and intraoperative neurophysiological control, makes it possible to optimally position the electrode, both to achieve positive analgesic effect and for potential restoration of nerve function.

[Spinal cord stimulation in the treatment of chronic pain]. / Khronicheskaya elektrostimulyatsiya spinnogo mozga u patsientov s khronicheskoi bol'yu.

Despite the numerous analgesic drugs, the prevalence of intractable neuropathic pain remains high making up about 5%. Intervention methods, including methods of chronic electrostimulation, are used to treat these patients. Spinal cord stimulation (SCS) is the most common surgical method worldwide that replaced destructive and ablation procedures. Currently, common tonic SCS, HF-10 stimulation and burst SCS are applied, and the choice of method is based on clinical and neurophysiological data. Also, the introduction of nanomaterial-enabled neural stimulation could significantly minimize surgery risk.

Intrathecal Baclofen Therapy in Russia: National Register, the Effect of One-Year Usage.

Patients with severe muscular spasticity still represent the most complex and resistant to therapy group of neuro-rehabilitation patients. In a few years, in Russia, intrathecal baclofen therapy has appeared to be the most effective method for such spasticity. For the first time the authors developed and implemented in clinical practice "Prospective register to treat spastic states using intrathecal baclofen therapy in Russian Federation" aimed at therapy classification of spastic patients: to reveal management characteristics, assess treatment outcomes and frequency of occurrence of adverse events that will finally help specify the need for the method employment in real clinical practice. The article presents the findings of a one-year usage of Register, which enabled to make a preliminary evaluation of intrathecal baclofen therapy in Russia.

[Complications of intrathecal baclofen therapy]. / Oslozhneniya intratekal'noi terapii baklofenom.

AIM: To analyze complications of intrathecal baclofen therapy and identify high-risk groups. MATERIAL AND METHODS: We implanted 52 pumps to spastic patients for chronic intrathecal baclofen infusion. Two groups of patients were distinguished: 23 patients with spinal spasticity (group 1) and 29 patients with cerebral spasticity (group 2). The mean patient age was 37.2±14.6 years in group 1 and 17.3±10.3 years in group 2. Surgery was performed according to a standard procedure. A Medstream (Codman) pump was implanted in 10 cases, and a Synchromed II (Medtronic) pump was implanted in the remaining 42 cases. RESULTS AND DISCUSSION: Complications developed in 12 (23%) patients. We divided complications into 3 groups: baclofen underdose, baclofen overdose, and others. Insufficiency of intrathecal therapy was observed in 7 cases, which was caused by catheter migration (5 cases) and pump dysfunction (2 cases). In one case, baclofen overdose was observed after air travel. Other complications included 4 cases of persistent peri-implant seroma and infectious complications. Groups with a high risk of complications were identified based on an analysis of the results. Patients with severe dystonia of the trunk muscles have an increased risk of spinal catheter migration. Pronounced communicating hydrocephalus is associated with the risk of cerebrospinal fluid leak through a catheter shaft channel. Weakness of the axial musculature can lead to progression of scoliotic deformity. CONCLUSION: In some cases, chronic intrathecal baclofen therapy can be accompanied by various complications. This technique should be carefully used in patients from high-risk groups.

[Long-term outcomes of SDR in various groups of cerebral palsy (CP) patients].

AIM: Long-term outcomes of selective dorsal rhizotomy (SDR) are not sufficiently summarized in the literature. The aim of this study was to systematize and evaluate long-term outcomes of SDR in various groups of cerebral palsy (CP) patients. MATERIAL AND METHODS: 47 patients with spastic CP were operated. In all cases, SDR of the L1-S1 roots was performed under EMG control. In all cases, laminoplasty was used as an approach. Outcomes of surgical treatment were estimated by the Ashworth scale and the GMFM 88 scale. The data were subjected to statistical analysis. The follow-up duration ranged from 12 months to 7 years. RESULTS: A significant reduction in spasticity from 4.34±0.53 points before surgery to 1.61±0.45 points after surgery (p<0.001) was observed in most cases. The dynamics of locomotor functions was maximal in the 3rd GMFM class: changing from 48±4% points before operation to 52±6% points 12 months after operation (p<0.042). The dynamics of locomotor functions amounted to 2% in the 4th GMFM class and 1% in the 5th GMFM class. The best functional outcomes were obtained in children under 10 years of age. A positive correlation only between the percentage of cut roots and a decrease in spasticity (r= 0.85) was found. No correlation between the amount of cut roots and the dynamics of locomotor functions was observed. No spinal cord deformities were observed during the follow-up period. CONCLUSION: A reduction in spasticity due to SDR depends on the amount of cut roots. The functional result of SDR is affected not only by a decrease in spasticity but also by the functional status and age of the patient at the time of surgery. In all cases, laminoplasty should be performed to prevent spinal cord deformities.

[Results of motor cortex stimulation in the treatment of chronic pain syndromes].

AIM: The article is aimed to demonstrate our experience in motor cortex stimulation (MCS) in patients with chronic neuropathic pain syndromes, assess the clinical efficacy of the technique in short-term and long-term follow-up, and analyze potential predictors of the MCS efficacy. MATERIAL AND METHODS: Twenty patients were implanted with MCS electrodes at the Burdenko Neurosurgical Institute in the period between 2004 and 2014. The mean age of patients was 52 years (26 to 74 years). The patients suffered from neuropathic pain syndromes of different genesis (post-stroke, multiple sclerosis, atypical facial pain, phantom limb pain, brachial plexus injury, spinal cord injury, complex regional pain syndrome I). All patients underwent neurological examination with verification of neuropathic pain (DN4, Pain Detect, LANSS). The pain intensity and its effect on quality of life were assessed before operation and during follow-up according to 10-point visual-analog scales (modified Brief Pain Inventory). Before surgery, all patients underwent several repetitive transcranial magnetic stimulation (rTMS) sessions. After implantation of epidural electrodes, test MCS was performed. RESULTS: Test stimulation was positive in 19 (95%) patients. All these patients were implanted with a chronic MCS system. The mean follow-up was 49.3 months (from 3 to 96 months). In short-term follow-up (fist 6 months), a positive result of MCS was observed in 17 patients, and a reduction in the pain intensity ranged from 37.5% to 90%. In long-term follow up (from 12 to 96 months), 14 patients had positive MCS RESULTS: and a reduction in the pain intensity amounted to 25% to 60%. All patients with positive MCS results received significantly decreased doses of opioids and tramadol. Two patients developed infectious complications, but there was no neurological deficit. Analysis of the factors affecting the efficacy of motor cortex stimulation did not reveal a statistically significant effect of rTMS and the presence and intensity of motor deficit. CONCLUSION: Chronic epidural MCS is an effective and safety method for the treatment of some chronic neurogenic medically-refractory pain syndromes. Further research is necessary to specify the patient selection criteria and the MCS efficacy predictors.