Spinal cord fibrocartilaginous embolization is caused by a small fragment of intervertebral disc material entering the spinal cord’s vascular system via the tissues attached to the intervertebral disc. Embolization is the sudden blocking of an artery by a clot of foreign material (an embolus). The tiny fragment of intervertebral disc material (embolus) results in varying degrees of damage depending on the portion of the cord supplied by the embolized blood vessel. Thus, the clinical signs are variable.

Fibrocartilaginous embolization of the spinal cord is the functional equivalent of a stroke to the spinal cord rather than to the brain. The events are acute, no progressive, and occur without any prior signs or warnings. Because emboli can occur in any portion of the cord, clinical signs can involve the rear limbs, all four limbs, one side of the body, or only one limb. The syndrome is not painful but can result in paralysis. After the initial spinal cord shock subsides, one side of the body frequently remains worse or is slower to show improvement.

In general, if deep pain perception is intact to the paralyzed limb's), recovery will begin in two to three weeks with most clinical function restored by four months. In most cases, once the diagnostentative diagnosis of a fibrocartilaginous embolism is made based on history and neurological examination. Radiographs (x-rays) are evaluated to ascertain the presence of degenerative discs and may outline other abnormalities in the spine including fractures and dislocations. A definitive diagnosis may require a myelogram (contrast dye study of the spine). Spinal cord swelling may be seen with a myelogram immediately after the embolus causes an infarction (a localized area of dead cells produced by occlusion of the arterial supply to that area). If several days have passed since the onset of clinical signs, the myelogram will be normal. Other findings with a myelogram may include intervertebral disc extrusions, tumours, fractures, haematomas, or haemorrhages and degree of clinical damage is ascertained, an accurate prognosis can be made.
Dogs experiencing an acute episode of fibrocartilaginous embolism are immediately treated once the diagnosis is confirmed. Intensive medical therapies are of value only during the first 24 to 48 hours after the spinal cord damage has occurred. Medications used include corticosteroids to relieve spinal cord swelling and to prevent collateral damage. Surgery is not indicated in the treatment of spinal cord infarction. After initial medical management, intensive nursing care and physical therapy are required. The goal is to maintain muscle tone while the spinal cord tissue heals.

The prognosis in cases of fibrocartilaginous embolization depends on many factors:

· The severity of neurological dysfunction

· The amount of disc material that has embolized

· The degree of accompanying spinal cord swelling

· The location of the spinal cord infarction

· The overall physical condition of the patient

In general, the ability to perceive deep pain in the affected limb's) and tail remain the major prognostic indicator. Even if paralysis is complete, the perception of deep pain remains the key to determining if permanent damage has occurred. This means that, even if paralysis has occurred, if the conscious perception of deep pain is intact a functional recovery is anticipated. The time required for recovery and the degree of neurological improvement are quite variable. Diligent physical therapy and good nursing care are important for recovery.

© 2004 Southern California Veterinary Referral Group