Diagnostic Process In 53 Cases With Amyotrophic Lateral Sclerosis

Background: Amyotrophic lateral sclerosis(ALS), a progressive neuromuscular condition characterized by weakness, muscle wasting, fasciculations and hyperreflexia, was described in 1881 by the French neurologist Charcot and was the most common type of motor neuron diseases(MND). Although the underlying cause of ALS is unknown , the clinical picture is generally easy to be recognized when the disease is fully developed. The earlier a diagnosis can be made and the more effectively symptoms can be managed and care can be planned. In a disease as rapidly progressive as ALS, time is of the essence.Objective: The diagnostic process and misdiagnosed patterns of 53 patients with amyotrophic lateral sclerosis(ALS) were retrospectively reviewed in order to strengthen the recognition of the clinical characteristics of this disease, to analyze the cause and factor ofmisdiagnosis, minimize the misdiagnosis, and achieve the early diagnosis and treatment.Methods: The clinical data of admitted and patient follow-up of patients diagnosed as motor neuron disease during March 2001 to March 2007 in the Second Affiliated Hospital of Zhejiang University College of Medicine were reviewed. All of the patients were strictly diagnosed according to the China Diagnostic Criteria for ALS (draft). A total of 53 patients with definitely diagnosed ALS were enrolled as study objects. The age at onset, onset sites, diagnosis durations and the time when EMG was performed of these patients were recorded. The results of other examinations and misdiagnosis were also analyzed.Statistical analysis: Measurement data was expressed in mean±SD and analyzed with SPSS 13.0 Statistical Software. Independent samples T test was used to compare 2 groups of data; ANOVA was used to compare multi-groups of data; Pearson chi square test was used to compare numeration data; Spearman analysis was used to analyze the correlation between diagnosis durations and EMG durations. P values ≤ 0.05 were defined as statistical significance.Results: There were 30 "definite ALS" cases , 16 "probable ALS"cases and 7 "suspect ALS" cases very possible cases in all the 53 patients. Their mean onset age was (55.6±9.7) years old; mean diagnosis duration was (17.1±12.4) months; the time when EMG was performed was (14.1±12.5) months, the correlation between diagnosis durations and EMG durations was positive (r=0.721, P<0.01). The first occurred symptoms of these patients were in upper limb (n=17), lower limb (n=17), bulbar (n=9) and in other sites(n=10). Among these patients there were misdiagnosed 39 cases, not misdiagnosed 14 cases. The total misdiagnosis rate was 73.6%. There was very significant difference between the misdiagnosis rates in 30-39 years group and other years groups (P=0.003).In "definite ALS" and "suspect ALS" cases the misdiagnosis rates were 83.3% and 42.9% respectively, there was significant difference between them (P=0.03). In "nromal imaging result" group and "abnromal imaging result" group the misdiagnosis rates were 46.2% and 89.7% respectively , there was very significant difference between them (P=0.003).Most of misdiagnosed cases were 12 patients with cervical spondylopathy(30.8%), and 8 patients with cerebral vascular diseases(20.5%).Conclusion: The main causes of misdiagnosis in ALS were the infrequent clinical characteristics of the disease, insufficient knowledge of general practitioners to the disease and over depending on theimageology for clinic diagnosis. Thus it is important to improve doctors' understanding of ALS and that is the most effective and essential measure for reducing misdiagnosis rate of ALS.