Diagnosis of Cervical Vertebral Stenotic Myelopathy

Cervical vertebral malformation is one of the most common causes of neurologic disease in horses worldwide. The most important feature of this condition is a stenotic vertebral canal as a result of abnormal vertebral development resulting in compression of the spinal cord. Typically the narrowing is identified between the 3rd and 7th cervical vertebra. The disorder appears to be a multifactorial disease thought to be a developmental disorder that begins early in life, perhaps even in utero [10]. It is more prevalent in young male horses, especially among Thoroughbreds [2]. Vertebral canal stenosis may result from abnormal bone development, vertebral instability, degenerative changes or soft tissue hypertrophy within the vertebral canal leading to a narrowed canal and injury to the spinal cord. The pathogenesis of this syndrome may have a role of genetics predisposing the horse to a narrow spinal canal and the problem can then be aggravated by other environmental factors such as diet, rate of growth and gender. Trauma may speed up the onset of the clinical signs. Investigators have suggested osteochondrosis of the cervical vertebrae as contributing to or as the sole underlying problem in this disease process [4, 10-12]. Many factors have been suspected to play a role in the development of osteochondrosis in the appendicular and the axial skeleton of the horse. Included among these factors are genetic predisposition, endocrine dysfunction, dietary or nutritional imbalances, biomechanical stress and rate of growth. The underlying abnormalities associated with osteochondrosis result in abnormal bone metabolism as well as damage to cartilage. In a study designed to examine the frequency and severity of osteochondrosis in horses with cervical vertebral stenotic myelopathy Stewart et al identified a generalized narrowing of the vertebral canal of horses with cervical vertebral stenotic myelopathy compared to clinically normal horses […]