Study on relationship between the muscular pathology and prognosis in the motor neuron disease

In order to investigate the mode of progression in motor neuron disease (MND), and find if there is any correlation between the muscular pathology and prognosis of the disease, activity index (ACT), atrophy factor of type I muscle fibers (A1), and type II (A2), hypertrophy factor of type I muscle fibers (H1), and type II (H2) and grouping factors were analyzed. Thirty-five patients with MND were evaluated whether there were any factors correlated to the severity of ACT. Among various factors, A1 showed the most significant change to the severity of ACT. Therefore, it was suggested that A1 was best correlated with the rate of prognosis of the disease process. Probably involvement of the motor neuron innervating type I muscle fibers takes place in the earlier stage than that of the neurons of type II, or there might be some difference of innervation ratio between type I and type II fibers. Further investigation is necessary to evaluate the relationship between the actual prognosis of these patients and their ACT by follow up study.