Exercise intolerance and collapse

Exercise intolerance, which may also be considered as activity-related weakness, occurs with walking or running and dissipates with rest. It is recognized as early fatigue with mild activity, although in some cases more vigorous or prolonged exercise may be needed to induce the problem. It may be associated with episodic muscle cramps. This chapter covers clinical signs, lesion localization, pathophysiology, differential diagnosis, neurodiagnostic investigation, peripheral neuropathies, disorders of neuromuscular transmission, myopathies.