[Clinical aspects of the narrow spinal canal]

Not infrequently the lumbosacral root-compression syndrome is due to stenosis of the lumbal spinal canal. The clinical symptoms, usually emerging in the middle-aged, may be characterized by either simple radicular pain with or without neurological deficit or by exercise-dependent transient functional disturbance of the cauda equina, namely, the so-called neurogenic intermittent claudication (NIC). In most cases, NIC is due to mechanical compression of the cauda fibers as a result of extension of the patient's lumbar spine. In some patients, exercise-induced ischemic radiculopathy is assumed to be the main factor. Differential diagnosis must take into account true intermittent claudication, certain rare myopathies (if the exercise-dependent pain is the main feature), and certain transient disturbances in spinal cord function (if a motor and/or sensory deficit arises during the NIC attack).