Background. Paediatric-onset MS (POMS) has a unique clinical profile compared to the more prevalent adult-onset MS. For this study, we aimed to determine the demographic and clinical characteristics of POMS in Poland as well as addressing some of its epidemiological aspects. Methods. A retrospective study was conducted based on the Polish Multiple Sclerosis Registry, considering a population of children and adolescents with MS (age ≤ 18 years). Data were collected by all 13 centres across Poland specializing in diagnosing and treating POMS. The actual course of the disease and its clinical properties were compared between child (≤12 years) and juvenile (>12 years) patients. MS onset and its prevalence were assessed at the end of 2019, stratified by age range. Results. A total of 329 paediatric or juvenile patients (228 girls, 101 boys) with a clinically definite diagnosis of MS, in conformity with the 2017 McDonald Criteria, were enrolled. For 71 children (21.6%), the first symptoms appeared before the age of 12. The female: male ratio increased with age, amounting to 1:1 in the ≤12 years group and to 2.9:1 in the >12 years group. In most cases, the disease had multi-symptomatic onset (31.3%), and its course was mostly of a relapsing–remitting character (95.7%). The initial Expanded Disability Status Score for both groups was 1.63 ± 1.1, whereas the annual relapse rate was 0.84 during the first 2 years. The time between the onset of symptoms and diagnosis was longer in the younger patients (8.2 ± 4.2 vs. 4.6 ± 3.6 months; p < 0.005). On 31 December 2019, the age-adjusted prevalence standardized to the European standard population was 5.19/100,000 (95% CI, 4.64–5.78). Significantly higher prevalence was noted in the 13–18 years group (7.12; 95% CI, 6.64–7.86) than in the 9–12 years group (3.41; 95% CI, 2.98–3.86) and the <9 years group (0.56; 95% CI, 0.46–0.64; p < 0.001). Conclusion. POMS commencing at the age of ≤12 years is rare, differing significantly from the juvenile-onset and adult MS in terms of clinical characteristics, course, and incidence, as stratified by gender.

Objectives: The recovery of arm function after macroreplantation is influenced by various factors. The aim of this study was to present the results of functional rehabilitation outcome after replantation of an upper extremity. Moreover, we assessed nerve conduction validity in the process of monitoring the return of manual functions. Methods: The study was performed in a group of seven patients after upper extremity macroreplantation and rehabilitation. Assessments included measuring hand/arm function loss using Swanson’s method, range of motion, muscle strength, sensation, and manipulation dexterity through the NHPT (Nine-Hole Peg Test). The nerve conduction study measured response amplitude, conduction speed, and distal latency. Results: The average loss of function of the hand diminished from 63.6% to 49.18%. Significant improvement in global pressure was achieved. In the functional capacity test (NHPT), the average time of the test was improved. The final nerve conduction study demonstrated improvements in motor and sensory conduction parameters. A correlation between improvement in conduction parameters in sensory fibers and sensation in the two-point discrimination test was found. Increased potential amplitude in motor fibers of the examined nerves correlated with a decrease in loss of function of the arm. Conclusions: Functional assessment and tailored rehabilitation strategies would maximize recovery potential after macroreplantation. Nerve conduction remains a crucial tool in monitoring the progress of manual skills after months of rehabilitation. Our findings highlight the importance of long-term follow-up of these patients.