ABSTRACT
This chapter deals with two types of ‘muscle disorder': arthrogryposis, and muscular dystrophy. Distal arthrogryposis often manifests an autosomal dominant pattern of inheritance. Common deformities are ulnar deviation of the metacarpophalangeal joints, fixed flexion of the proximal interphalangeal joints and tightly adducted thumbs. The main consequence is the development of neuromuscular incoordination, dystonia, weakness and muscle spasticity. Spinal cord monitoring with neurophysiological tests is considered an essential part of any spinal surgery that includes deformity correction to ensure that no neurological damage occurs. Neurodiagnostic techniques comprising nerve conduction studies and needle electromyography have an important role in the investigation of peripheral nerve and muscle disorders. The sympathetic and parasympathetic systems are concerned with functions such as involuntary muscle contraction, sphincter control, peripheral blood flow and sweating. Electromyography is used to record the electrical discharge of motor units in a muscle: a needle electrode is inserted into the muscle and connected to an oscilloscopic screen and a loudspeaker.
