Neck injury of the whiplash type may lead to the cranial symptoms of the Barre-Lieou syndrome. Forty patients with this syndrome and 40 without it were investigated by a variety of imaging techniques. There was a clear correlation between root sleeve defects at C3/4 shown by special oblique myelographic views and cranial symptoms. Good results were obtained by anterior cervical discectomy and fusion at C3/4 in 21 cases. It is suggested that the syndrome may result from irritation of the sympathetic nervous supply at this level.