[Comparison of clinical characteristics of patients with riboflavin responsive lipid storage myopathy versus polymyositis].
OBJECTIVE
To compare the clinical characteristics of riboflavin responsive lipid storage myopathy (RR-LSM) versus polymyositis (PM).


METHODS
The clinical data were collected and analyzed for 26 RR-LSM and 15 PM patients from 2003 to 2011 at Peking University First Hospital .


RESULTS
The mean onset ages of RR-LSM and PM were (29 ± 10) and (43 ± 15) years while the durations before definite diagnosis were (8.2 ± 8.0) and (2.6 ± 3.7) years respectively. There were significant inter-group differences in onset age (P = 0.001) and duration before definite diagnosis (P = 0.003). No significant inter-group difference existed in the frequency of limb weakness, dysphagia, neck weakness, dyspnea or myalgia. Dysmasesia occurred in 65.38% of RR-LSM and 26.67% of PM patients and significant inter-group difference existed (P = 0.017). All RR-LSM patients had exercise intolerance with a fluctuating course. Both groups had extra-muscular symptoms and it was more obvious in PM. Mean creatine kinase (CK) level was (1475 ± 1796) U/L in RR-LSM and (4062 ± 3448) U/L in PM patients with significant inter-group difference (P = 0.017).


CONCLUSIONS
Comparing with PM patients, RR-LSM patients tend to have an earlier onset, a longer diagnosis delay time, fluctuating weakness, a higher frequency of dysmasesia. But there are fewer extra-muscular symptoms and a smaller elevation of CK level.
Department of Neurology, Peking University First Hospital, Beijing 100034, China.
Yun
Y
Wang
Xiao
X
Liu
Email: drwangzx@163.com.
Zhaoxia
Z
Wang
Wei
W
Zhang
He
H
Lü
Wenli
W
Hu
Yun
Y
Yuan
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008052:Lipid Metabolism, Inborn Errors / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009136:Muscular Dystrophies / Q000175:diagnosis*; D017285:Polymyositis / Q000175:diagnosis*; D012256:Riboflavin; D055815:Young Adult
D012256:Riboflavin