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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 «excellent» (intensity according to VAS decreased by 75% or more), in 1 (14.2%) - as «good» (intensity according to VAS decreased by 50-74%), in 1 (14.2%) - as «moderate» (VAS intensity decreased by 25-49% and in 2 (28.5%) as «unsatisfactory» (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.

Background: In recent years, prolonged states of impaired consciousness became widespread among patients with aneurysmal subarachnoid hemorrhage. Treatment and maintenance of vital functions in such patients represent a complex medical, economic and social problem. In this regard, searching for the causes of prolonged states of impaired consciousness and predicting the outcomes are important., Objective: To analyze available literature data on prevention and treatment of prolonged states of impaired consciousness after aneurysmal subarachnoid hemorrhage., Results: We reviewed the PubMed database using the keywords «unresponsive wakefulness syndrome», «persistent vegetative state2, «minimal consciousness state» and «outcome of subarachnoid hemorrhage». Only 4 reports devoted to the causes and treatment outcomes in patients with prolonged impairment of consciousness after aneurysmal subarachnoid hemorrhage were found. At the same time, patients with aneurysmal subarachnoid hemorrhage comprise up to 11% among all cases of prolonged states of impaired consciousness. Examination, management and treatment of patients with prolonged impairment of consciousness after aneurysmal subarachnoid hemorrhage are carried out according to general principles without taking into account specific etiological and pathogenetic factors., Conclusion: Increased number of patients with prolonged impairment of consciousness after aneurysmal subarachnoid hemorrhage necessitates analysis of etiopathogenesis and outcomes of these disorders based on modern clinical, instrumental and laboratory assessment of the brain.

Classification of pain syndromes is quite multifaceted. However, pathogenetic classification by which chronic pain syndromes are usually divided into nociceptive, neuropathic and psychogenic, is crucial in choosing treatment tactics. In modern classifications, psychogenic pain is distinguished from nociceptive pain (associated with direct tissue injury or damage) and neuropathic pain (in which lesion can only be determined morphologically). Mental disorders play a leading role in psychogenic pain. Here, somatic/neurological disorders, if any, are of no pathogenetic significance in the dynamics of pain syndrome. There are certain algorithms (though not yet fully developed) and even guidelines for diagnosing and treating nociceptive and neuropathic pain, whereas psychogenic pain has been and still is almost out of sight for a long time. Despite its considerable prevalence, attitude towards it is still uncertain. Until now, it has no single classification, nor any strategy with regards to diagnosis, treatment and prevention., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Statistics on open and closed states of the lipid pores was experimentally investigated in planar lipid bilayer membranes from dipalmitoylphosphatidylcholine at the phase transition temperature in LiCl solution (1 M). Polyethylene glycol of different molecular mass was added to the solution. Transmembrane current pulses were measured at voltage-clamp conditions (50 mV). The histograms of the pore lifetime and the pulse interval have no exponential shape but the pronounced maximum. It means that the pulse sequence of the transmembrane current measured in the phase conditions is dependent. The emergence of the new pulses depends on the emergence time of the previous pulses. The time of the pulse end depends on the time of the pulse start. The proposed Erlang model approximates the experimental histograms quite accurately. According to the model the lipid pore can have several open and closed states.