C França Marcondes, D'abreu Anelyssa, Nucci Anamarli, Cendes Fernando, Lopes-Cendes Iscia
Department of Neurology, University of Campinas, Campinas, São Paulo, Brazil.
Muscle Nerve. 2009 Dec;40(6):1012-8. doi: 10.1002/mus.21396.
Peripheral neuropathy (PN) has long been recognized in Machado-Joseph disease (MJD), but its natural history is an unsettled issue. Therefore, we prospectively assessed 40 with MJD for 13 months with nerve conduction (NC) studies and the revised total neuropathy score (TNSr) to study the progression of PN. There was no significant change in the TNSr score over the follow-up period. In contrast, the average sural sensory nerve action potential (SNAP) amplitude decreased significantly over the same interval from a mean of 13.2 muV to 9.8 muV (P < 0.001). There was an inverse correlation between the change in the sural SNAP amplitude and the length of the CAG triplet repeat expansion (r = 0.574, P < 0.001). The reduction in the mean sural SNAP amplitude also correlated with progression of ataxia. This indicates that PN progresses faster in individuals with larger (CAG)(n) expansions, and nerve conduction studies may be useful to study disease progression in MJD.
周围神经病变（PN）在马查多-约瑟夫病（MJD）中早已被认识到，但其自然病史仍是一个未解决的问题。因此，我们对40例MJD患者进行了为期13个月的前瞻性评估，采用神经传导（NC）研究和修订后的总神经病变评分（TNSr）来研究PN的进展情况。随访期间TNSr评分无显著变化。相比之下，在相同时间段内，腓肠感觉神经动作电位（SNAP）平均波幅从13.2 μV显著下降至9.8 μV（P < 0.001）。腓肠SNAP波幅的变化与CAG三联体重复扩增的长度呈负相关（r = 0.574，P < 0.001）。腓肠SNAP平均波幅的降低也与共济失调的进展相关。这表明在（CAG）n扩增较大的个体中PN进展更快，神经传导研究可能有助于研究MJD的疾病进展。
