Potential multisystem degeneration in Asidan patients

Objective To evaluate a potential multisystem involvement of neurodegeneration in Asidan, in addition to cerebellar ataxia and signs of motor neuron disease. Methods We compared the new Asidan patients and those identified in previous studies with Parkinson's disease (PD, n = 21), and progressive supranuclear palsy (PSP, n = 13) patients using ¹²³I-2β-Carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (¹²³I-FP-CIT) dopamine transporter single photon emission computed tomography (DAT-SPECT) and ¹²³I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy (Asidan, DAT: n = 10; MIBG: n = 15). Results Both the PD and PSP groups served as positive controls for DAT decline. The PD and PSP groups served as a positive and negative control, respectively, of MIBG decline in the early phase H/M ratio. Of the Asidan patients, 60.0% showed DAT decline without evident parkinsonian features and 6.7% showed impaired MIBG in only the delayed phase H/M ratio. Combined with a normal range of the early phase H/M ratio, this phenotype was newly named Declined DAT Without Evident Parkinsonism (DWEP). Interpretation The results of present study including DWEP suggest a wider spectrum of neurodegeneration for extrapyramidal and autonomic systems in Asidan patients than expected, involving cerebellar, motor system and cognitive functioning.