Value Of Exercise Test In The Diagnosis Of Patients With Periodic Paralysis

Part 1. The reference range and influence factor of Electromyography Exercise Test'Background'The diagnosis of primary periodic paralysis is usually based on clinical impressions, the presence of a family history of the disease, changes in serum potassium level during attacks, and the response to treatment. However in some cases, the diagnosis remains in doubt. Electromyography Exercise Test has been reported to be useful in conforming the linicl suspicion. But there is still no study of the practice parameterand reference range on a large number of healthy subjects.'Objective'To explor the changes of ET in healthy subjects and determine the practice parameterand the reference range of ET. To identify the influence factors in ET.'Methods'100 healthy subjects which were spicially designed by age and gender were recruited in the study. Standardized protocols to ET were applied on them. The ulner nerve CMAP amplitude change rate were the study parameters. The refernce range was defined as the mean±a standard deviations. The subjects were grouped according to age, gender and test time. Statistical analysis compared the parameters between groups. The correlation between amplitude change rate and height and weight were analysised.'Results'ET induced a decrease of CMAP amplitude during 60 min after exercise. CMAP amplited decreased percentage was the test parameter. There was 8 outliers in data. Another 8 healthy volunteers were recruited in the study. The data was normal distribution (Kolmogorov-Smirnov test, P=0.614) and the reference range was 0-33%. There were no significantly diffirence between groups of age, gender and test time (P>0.05, ANOVA-LSD test) in CMAP amplited decreased percentage. There were no significant correlation between amplited decreased percentage and hight (r=-0.153, P=0.129, Pearson test) and weight(r=-0.152, P=0.131, Pearson test). 'Conclusion'CMAP amplited decreased percentage was determined to be the test parameter, and the reference range was 0-33%. Outside this range ,values were considered abnormal. There were no influence of age, gender, height, weight and test time on ET. There were some abnormal results of ET in healthy subjects and the rate was about 8%. Part 2. Electromyography Exercise Test and Clinical diagnostic study on primary periodic paralysis'Background'The diagnosis of primary periodic paralysis is usually based on clinical evidence, including clinical impressions, the presence of a family history of the disease, changes in serum potassium level during attacks, and the response to treatment. Electromyography Exercise Test has been reported to be useful in the identification of patients with periodic paralysis. But there is still no prospective diagnostic study tocompare the value of ET with clinical diagnosis.'Objective'To explore the sensitivity and the specificity of ET in the diagnosis of primaryperiodic paralysis. To compare with clinical diagnosis and determined the value of ET.' Methods'The patients were recruited at Peking Union Medical College Hospital from march 2006 to April 2008 which had those manifestations: (1) acute or episodic paralytic attack of the extremities; (2) paralytic attack lasting from hours to days; (3) complete recovery. All patients were screened according to a protocol consisting of a complete medical history, a full neurological examination, a serum potassium level test during attacks and asymptomatic phase, Standardized protocols to ET. The patients were divided into 4 groups, those were the PPs, the controls, the TPP and the Second-PP. To compare the sensitivity and the specificity of ET with clinical diagnosis in diagnosis of primary periodic paralysis.'Results'There were 155 patients in this study, 68 in PPs group and 72 in control group, 12 in TPP, 3 in Second-PP. The clinical diagnosis confirmed that 45 patients had been got the PPs, while ET confirmed 63 patients. The sensitivity of ET is 92.65% , higher than the clinical diagnosis whose is 66.18%. The clinical diagnosis had 16 false positive results more than ET. The specificity of ET is 91.67% and clinical diagnosis is 77.78%. Table 1 shows the results of clinical diagnosis and ET The CMAP amplitude decreased percentage of PPs group was significant larger than other groups(P=0.000, ANOVA-LTD检验). There were 12 patients in control group diagnosed PPs by clinical while they were anxiety disorder. All these patients had positive ET test results. There also were 6 patients had positive ET but had no clinical characters, the rate was 8.3%. It is probably the abnormal results of ET like those in healthy subject's tests.'Conclusion'ET had higher sensitivity and specificity than clinical diagnosis which we usually use.ET is useful in conforming the diagnosis of the primary periodic paralysis.ET can help to exclude the diagnosis of PPs especially to patients with anxiety disorder.ET had false positive result and the result of ET must be analysis with clinical characters. Part3. Electromyography Exercise Test and Genetics study on primary periodic paralysis'Background'The family periodic paralysis (FPP) is autosomal dominantly inherited. Molecular genetic testing identifies disease-causing mutations in CACNA1S or SCN4A in 80% of individuals meeting clinical diagnostic criteria. But most of the patients in clinical practice are Sporadical periodic paralyses (SPP). What is the mutation rate of thosepatients? Whether there are some conflicts between ET and genetic analysis.'Objective'To explore the mutation rate of sporadical PPs patients. To compare with moleculargenetic testing and determined the value of ET.'Methods'The patients were recruited at Peking Union Medical College Hospital from March 2006 to April 2008 which had those manifestations: (1) acute or episodic paralytic attack of the extremities; (2) paralytic attack lasting from hours to days; (3) complete recovery; (4) obtained the consent of genetic testing by blood. All patients were screened exons 11 and 30 of CACNA1S and exons 13 and 24 of SCN4A in order to find the Targeted mutation(R528H和R1239H , T704M, M1592V). All patients had the examination of ET. The patients were assigned to two groups, PPs and control. To compare the results of ET with genetic diagnosis in PPs. 5 patients had family history of PPs, some of the family members agreed to screen the mutations. We also screened mutations on the 8 healthy subjects who had abnormal ET results.' Results'There were 155 patients in this study, 70 patients agree to the genetic testing, 50 in PPs group and 20 in control group. We found 5 families and 24 individuals were screened the mutations. The molecular genetic testing only found 1 patient had the R528H mutation in CACNA1S gene. That patient had a positive family history. We found that other 5 patients in his family also had the same mutation, while other 5 healthy members found nothing. The result of ET in the two group was 48 positive (96%) in PPs and 18 negative (90%) in controls.'Conclusion'The molecular genetic testing had little uses in clinical diagnosis of PPs. The probably reason may be that the patients were mostly sporadic cases. ET is useful in clinical diagnosis of the primary periodic paralysis.