Metabolic diseases in children

A family physician is likely to be the person presented with the responsibility of diagnosing a child with a metabolic disease. Such diseases can have very varied clinical presentations. This article presents a framework of laboratory tests which should be used to diagnose children presenting with acute metabolic diseases. Some specific diseases likely to be encountered are discussed and put into the overall perspective of a family practice.

The laboratory approach to thyroid disease

The author reviews thyroid-function tests from the viewpoint of clinical use of the more modern tests of basic thyroid function. Particular attention is paid to the changing use of the TSH assay, with the advent of the "sensitive" TSH tests. Following an overview of relevant physiology, the tests and their current indications are assessed. Finally, the newer strategies of measuring thyroid function are discussed by means of an example recommended by many authors, and a recommendation is made for adoption of such a strategy in the reader's laboratory.

Electromyography and nerve conduction studies

Electromyography and nerve-conduction studies are very useful tools in the evaluation of disease of peripheral nerve and muscle. They should be thought of as extensions of the physical examination. The tests should be used to answer specific questions and to help arbitrate diagnostic dilemmas. The tests, however, have very definite limitations. There are significant false-negative rates, and unexpected positive results can be misleading. The tests rely heavily on careful clinical-electrophysiological correlation.