Arthrogryposis multiplex congenita (AMC) and obstetrical brachial plexus palsy (OBPP) are motor disorders with similar symptoms (contractures and the disturbance of upper limb function). Both conditions present as flaccid paresis but differ from each other in the pathogenesis: AMC is a congenital condition, while OBPP results from trauma during childbirth. Despite this difference, these diseases are identical in terms of their manifestations and treatment programmes. We compared the cognitive skills of children with AMC and OBPP diagnoses with those of healthy children; we also compared the motor skills of impaired children with those of healthy ones. The patients in both groups significantly differed from the healthy children with regard to psychological parameters, such as ‘visual memory capacity’ and ‘thinking’. Moreover, the two groups with children with AMC and OBPP significantly differed from each other in motor skill parameters, such as ‘delayed motor development’, ‘general motor development’, and the ‘level of paresis’. Upper limb motor function in the OBPP children was less impaired compared to that of the AMC children. However, we did not find any significant differences in cognitive deficits between the AMC children and the OBPP children. This may indicate that motor impairment is more significant than the underlying cause for the development of cognitive impairment; however, the factors causing this phenomenon require further study (e.g., social environment, treatment, and rehabilitation programme).

Cognitive function, arthrogryposis, obstetrics palsy, children, motor disorder

The purpose of the study was to investigate the effect of anodal trans-spinal direct current stimulation (tsDCS) applied at the level of cervical spinal cord enlargement (C7–Th1 segments) on corticospinal system excitability and motor skills. The study involved 54 healthy adults aged 21.19 ± 3.2 years. Our results showed that the application of an anodal tsDCS (11-minute, 1.5 mA) affected the first dorsal interosseous muscle of the index finger when measured by motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation of the primary motor cortex. The effect of tsDCS manifested as a decrease in MEP amplitude immediately following stimulation and an increase in amplitude 15 minutes after it. The statistical analysis demonstrated that the dynamics of MEP amplitudes differed between groups receiving anodal tsDCS and sham stimulation, although anodal tsDCS did not affect motor skills production. The ability of an individual after receiving anodal tsDCS to coordinate their fingers and manipulate objects effectively in the nine-hole peg test and pressing a key in response to visual stimulus in the serial reaction time task did not differ from the sham stimulation. We also found that the motor learning factor during stimulation did not affect the change in MEP amplitude.