The natural history of hereditary neuralgic amyotrophy in the Dutch population. Two distinct types?

Abstract

On investigation of 101 attacks in 24 patients with hereditary neuralgic amyotrophy (HNA) from nine different families, we found that HNA can run two distinct courses: a 'classic' relapsing-remitting and a chronic undulating type with exacerbations. Only one type occurred per family, suggesting genetic heterogeneity. This is supported by the finding that only in a family with 'classic type' HNA are data of linkage analysis compatible with linkage to the 17q24-q25 interval which harbours a locus for the disease. The average number of attacks per patient during a follow-up of 26 years was four in the classic form of HNA and five in the chronic undulating type. All patients suffered from residual symptoms on follow-up, with a median Rankin score of 2 in both groups, showing that long-term prognosis is less favourable than previously reported.