Evaluation of the child with muscular weakness

The child with muscle weakness may present in the neonatal period as a hypotonic infant or as a child with hip dislocations or contractures of various muscles. In the toddler age group, the patient with a neuromuscular disease presents with a history of delay in the development of motor milestones. In later childhood the child my suffer from a loss of previously attained motor ability. In each of these three age groups, certain disorders are more likely to appear than in the other age groups. The authors listed a number of neuromuscular diseases according to the portion of the motor unit involved, and some indication is given of the age at which such diseases may be expected to present. This list is by no means exhaustive, nor should the age distribution be regarded as absolute. The problem of evaluation is to be discussed at three levels. Level 1 deals with the issue as it confronts the primary physician, with emphasis on a specific method of history taking, a modification of the clinical examination designed to detect the weakness, and a discussion of certain laboratory procedures that will indicate the need for further investigation. Level 2 briefly outlines the information to be gained from pulmonary function tests, muscle histochemical examination, and electrophysiological studies. Although these studies are becoming more widely available, they are still in general limited to specialty clinics. Level 3 examines some new techniques for more specific diagnosis and for more exact evaluation of function. Such techniques are being employed at centers with a major research interest in neuromuscular disorders.