[Efficacy of intravenous immunoglobulin for slowly progressive cerebellar atrophy]

In slowly progressive cerebellar atrophy, it has been difficult to suppress the progression of cerebellar symptoms because no effective therapeutic agents are available when the diagnosis of secondary cerebellar atrophy, such as drug-induced cerebellar atrophy or paraneoplastic syndrome, is denied. However, amongst the different forms of slowly progressive cerebellar atrophy, some may be associated with treatable immune abnormalities. Therefore, we investigated the therapeutic efficacy of intravenous immunoglobulin (IVIg) in 9 patients with slowly progressive cerebellar atrophy (4 sporadic atrophy; 5 hereditary atrophy). The results were as follows. With regard to the 4 cases of sporadic atrophy, gait ataxia and imbalance were markedly improved in 1 patient who had positive anti-GAD antibody. Moderate improvement was seen in 1 patient and slight improvement in 2. With regard to the 5 cases of hereditary atrophy, gait ataxia and imbalance were moderately improved in 2 patients with SCA3, although there were 3 non-responders. In conclusion, our study results suggested that not only patients with sporadic atrophy but also some with hereditary atrophy may respond to therapy. In cases of slowly progressive cerebellar atrophy in which the cause may be due to immune abnormality, we should consider instituting active immunotherapy when a pathological state caused by immune abnormality is suspected after extensive evaluations of autoantibodies, including anti-GAD, anti-thyroid and anti-gliadin antibody, malignancy, and so on.