Arthrogryposis multiplex congenita (AMC) has recently drawn substantial attention from researchers and clinicians. New effective surgical and physiotherapeutic methods have been developed to improve the quality of life of patients with AMC. While it is clear that all these interventions should strongly rely on the plastic reorganization of the central nervous system, almost no studies have investigated this topic. The present study demonstrates the feasibility of using magnetoencephalography (MEG) to investigate brain activity in young AMC patients. We also outlined the general challenges and limitations of electrophysiological investigations on patients with arthrogryposis. We conducted MEG recordings using a 306-channel Elekta Neuromag VectorView system during a cued motor task performance in four patients with arthrogryposis, five normally developed children, and five control adults. Following the voice command of the experimenter, each subject was asked to bring their hand toward their mouth to imitate the self-feeding process. Two patients had latissimus dorsi transferred to the biceps brachii position, one patient had a pectoralis major transferred to the biceps brachii position, and one patient had no elbow flexion restoration surgery before the MEG investigation. Three patients who had undergone autotransplantation prior to the MEG investigation demonstrated activation in the sensorimotor area contralateral to the elbow flexion movement similar to the healthy controls. One patient who was recorded before the surgery demonstrated subjectively weak distributed bilateral activation during both left and right elbow flexion. Visual inspection of MEG data suggested that neural activity associated with motor performance was less pronounced and more widely distributed across the cortical areas of patients than of healthy control subjects. In general, our results could serve as a proof of principle in terms of the application of MEG in studies on cortical activity in patients with AMC. Reported trends might be consistent with the idea that prolonged motor deficits are associated with more difficult neuronal recruitment and the spatial heterogeneity of neuronal sources, most likely reflecting compensatory neuronal mechanisms. On the practical side, MEG could be a valuable technique for investigating the neurodynamics of patients with AMC as a function of postoperative abilitation.

Combined use of transcranial magnetic stimulation and electroencephalography (TMS-EEG) is a highly informative cutting edge technology which is relevant for fundamental, clinical and translational research. Unique capabilities of TMS-EEG approach allow to assess the functional state and connectivity of brain regions thus opening new prospects for the evaluation of the TMS effects in non-motor cortical areas. TMS-EEG responses have diagnostic and prognostic potential for many neurological and mental illnesses. Simultaneous co-registration of TMS with EEG remains a technically sophisticated procedure and requires specialized equipment in conjunction with application of complex data analysis techniques. This review describes the details of TMS-EEG technique, principles of the experiment design, the shape and the reproducibility of TMS-evoked responses and applications of this promising approach both in research and in clinics. Key words: transcranial magnetic stimulation with electroencephalography, functional state, connectivity of brain regions, non-motor cortical areas, evoked motor responseВведение Самый простой способ количественной оценки реактивности мозга в ответ на транскраниальную маг-нитную стимуляцию (ТМС) двигательной коры сегодня основан на оценке параметров вызванного моторного ответа (ВМО), регистрируемого с мышцы-мишени накожными электродами для электромиографии (ЭМГ). При стимуляции немоторных областей коры используются опрос испытуемого о возникающих ощу-щениях (например, при ТМС зрительной коры о нали-чии явления фосфенеза) и оценка поведенческих реак-ций (время реакции, ошибки при назывании слов и т. д.). В случае стимуляции моторной коры и регистра-ции ответа с мышцы-мишени порог ВМО можно ис-пользовать лишь для косвенной оценки состояния мозга, так как параметры ВМО зависят от всех уровней двигательной системы -от коры до мышцы. В связи с этим актуальны подходы совмещения ТМС с другими