Multimodal evoked potentials and electroretinography in limb girdle muscular dystrophy.

Evoked potentials (EP) were recorded as part of a complete systems evaluation in 20 strictly selected patients with limb girdle muscular dystrophy. Various abnormalities were detected in 68% (13/19) of patients: 21% (4/19) had visual EP abnormalities; 11% (2/19) had brainstem auditory EP abnormalities; 29% (5/17) and 31% (5/16) had somatosensory EP abnormalities of the median and posterior tibial nerves, respectively. An electroretinogram abnormality was detected in 12% (2/17) of patients. There was no consistent correlation between the number, type or severity of EP abnormality and the age, sex, disease duration or degree of muscle weakness. The significance and etiology of these EP abnormalities need to be established by pathologic studies.