Diagnosis of muscle atrophy

Diagnostics of different types of muscle atrophy currently does not present much difficulty in communication with the introduction into a clinical study of methods of electromyography and biopsy of the affected muscles.
When electromyographic study of simple A. M. revealed frequent disritmia electrical activity without separate peaks (Fig. 1), A. M. neurogenic type - isolated peaks of high amplitude (spike), grouped in the clear "rhythms of the fence" (Fig. 2). Biopsy revealed certain differences between the scattered location of atrophied muscle fibers in simple muscular atrophy (Fig. 3) and "line" of their location when neurogenic (Fig. 4). Diagnostic importance is the study of creatine metabolism, which is muddy indicator of the degree of atrophic process in muscles and often changes in parallel with the clinical picture of the disease. In normal conditions the process of angellove creatine is more or less fully, and therefore in the urine creatine not. Only in early childhood in healthy in the urine may be a small amount of creatine. The presence of creatinuria (see) in adults is characteristic of primary (myopathy) atrophy. In secondary A. M. creatinuria relatively minor, as together with the affected muscles are saved and properly functioning.
The differential diagnosis should be borne in mind dermatomyositis, which different from muscle atrophy acute onset, the presence of pain, skin rashes and changes in muscle inflammatory nature, found in the biopsy. Difficult differential diagnosis from progressive forms of tick-borne encephalitis, beginning not acute. The availability of epidemiological history and a positive result of serological reactions to the virus of tick-borne encephalitis help diagnosis.
There are a large number of individual clinical variants of both simple and neurogenic amyotrophy, which is of independent nosological forms. There are forms that are mixed certain features of neurogenic and simple amyotrophy, such as shoulder-perenially amyotrophy described S. N. Davydenkova, and other more rare variants.

Fig. 1. Electromyogram with a simple disease. Arbitrary reduction of atrophied flexor brush. Visible frequent disritmia electrical activity.
Fig. 2. Electromyogram when neural disease. Arbitrary reduction of atrophied flexor brush. Visible almost right rhythm isolated "spikes".
Fig. 3. The scattered location of atrophied saved and exaggerated muscle fibers with a simple disease.
Fig. 4. "Beam" atrophy of the muscle fibers with neurogenic disease.