Ultrasound characterization of medial gastrocnemius tissue composition in children with spastic cerebral palsy

Introduction: In this study we aimed to characterize muscle composition of the medial gastrocnemius in children with spastic cerebral palsy (SCP) using quantitative ultrasound. Methods: Forty children with SCP, aged 4–14 years, participated in this study. Children were grouped according to the gross motor function classification system (GMFCS I–V) and compared with a cohort of age‐ and gender‐matched, typically developing children (TD; n = 12). Ultrasound scans were taken of the medial gastrocnemius. Images were then characterized using grayscale statistics to determine mean echo intensity (EI) and the size and number of spatially connected homogeneous regions (i.e., blobs). Results: Significant differences in skeletal muscle composition were found between children with SCP and their TD peers. Children classified as GMFCS III consistently exhibited the highest EI and blob area. Conclusions: This study demonstrates altered tissue composition in children with SCP visualized using ultrasound. Further work is required to determine the pathophysiology contributing to these alterations in SCP. Muscle Nerve 52:397–403, 2015     

Induction intravenous cyclophosphamide followed by maintenance oral immunosuppression in refractory myasthenia gravis

Introduction: Myasthenia gravis (MG) can be refractory to conventional immunotherapy. We report on the efficacy and durability of intravenous (IV) remission‐induction cyclophosphamide (CYC) followed by oral immunosuppression in refractory MG. Methods: We identified 8 patients from our medical records with moderate or severe refractory MG who were treated with 6 cycles of IV CYC (0.75 g/m²) every 4 weeks followed by oral immunosuppression. Results: Six patients improved within 3 months of treatment. Four patients remained in clinical remission (mean follow‐up 31 months). Two patients responded partially, and 1 patient relapsed after 11 months. Two patients were non‐responders. CYC was well tolerated. Acetylcholine receptor antibody levels remained below pretreatment levels in patients in clinical remission. The leukocyte nadir was lower in CYC responders. Conclusions: Remission‐induction IV CYC followed by oral immunosuppression is a rapid, effective, and durable treatment for refractory MG. Adding a post‐CYC immunosuppressant may account for low relapse rates compared with other published series. Muscle Nerve 52 : 204–210, 2015     

Cyclical konzo epidemics and climate variability

Konzo epidemics have occurred during droughts in the Democratic Republic of Congo (DR Congo) for >70 years, but also in Mozambique, Tanzania, and the Central African Republic. The illness is attributed to exposure to cyanide from cassava foods, on which the population depends almost exclusively during droughts. Production of cassava, a drought‐resistant crop, has been shown to correlate with cyclical changes in precipitation in konzo‐affected countries. Here we review the epidemiology of konzo as well as models of its pathogenesis. A spectral analysis of precipitation and konzo is performed to determine whether konzo epidemics are cyclical and whether there is spectral coherence. Time series of environmental temperature, precipitation, and konzo show cyclical changes. Periodicities of dominant frequencies in the spectra of precipitation and konzo range from 3 to 6 years in DR Congo. There is coherence of the spectra of precipitation and konzo. The magnitude squared coherence of 0.9 indicates a strong relationship between variability of climate and konzo epidemics. Thus, it appears that low precipitation phases of climate variability reduce the yield of food crops except cassava, upon which the population depends for supply of calories during droughts. Presence of very high concentrations of thiocyanate (SCN^?), the major metabolite of cyanide, in the bodily fluids of konzo subjects is a consequence of dietary exposure to cyanide, which follows intake of poorly processed cassava roots. Because cyanogens and minor metabolites of cyanide have not induced konzo‐like illnesses, SCN^? remains the most likely neurotoxicant of konzo. Public health control of konzo will require food and water programs during droughts. [Correction added on 26 February 2015, after first online publication: abstract reformatted per journal style] Ann Neurol 2015;77:371–380