Richard D. Ball

Increased muscle tone during etretinate therapy

A 40-year-old man with severe psoriasis developed painless muscle stiffness coinciding with four successive courses of etretinate therapy. Peripheral nerve block extinguished the increased muscle tone. Our patients symptoms resembled those of the stiff-man syndrome. Increased muscle tone is a potential side effect of etretinate treatment and must be distinguished from the common musculoskeletal symptoms observed in patients taking retinoid therapy.

1. Anatomy and physiology

Abstract The purpose of this self-directed learning module is to describe the anatomy and physiology of the nerve, neuromuscular junction, and muscle as they relate to rehabilitation of diseases affecting these structures. It is a section of the chapter on rehabilitation in nerve and muscle disorders for the Self-Directed Medical Knowledge Program Study guide for practitioners and trainees in physical medicine and rehabilitation. The major clinically important structural features and relationships of the spinal cord segment, spinal roots, peripheral nerve, motor unit, and muscle fiber are outlined with structure-function correlations. Metabolic features of neuronal physiology, including axonal transport, blood-nerve barriers, and synaptic function, are reviewed as they relate to commonly encountered neurologic diseases. Lastly, skeletal muscle cell biochemistry and physiology are discussed as they relate to force generation and force maintenance.

3. Specific diseases

Abstract This self-directed learning module provides review and references for basic concepts of, and highlights new advances in, the area of specific diseases affecting nerve and muscle. It is a section of the chapter on rehabilitation in nerve and muscle disorders for the Self-Directed Medical Knowledge Program Study Guide for practitioners and trainees in physical medicine and rehabilitation. This section deals with 1) focal neuropathies, 2) generalized neuropathies, 3) myopathies, and 4) diseases of the neuromuscular junction. The emphasis is on physiology, on concepts for evaluation and diagnosis, and on specific treatments when these are available.