Aside from the obvious primary disability associated with cerebrovascular accidents, there is secondary morbidity/disability which often can go undiagnosed or undetected. Awareness of the epidemiological association between stroke and other conditions will hopefully allow earlier diagnosis and effective treatment, or possibly could lead to preventive measures.

Some of the associated conditions are relatively unique to the CVA population. Much has been written about the shoulder and the stroke patient. There are three conditions affecting the shoulder which may exist in a continuum. In the acute stroke patient, during the flaccid stage, it is common to find shoulder subluxation. The inferior displacement of the head of the humerus is the result of dysfunction of the supraspinatus muscle, the muscle primarily responsible for maintaining glenohumeral integrity. Lack of adequate tone predisposes to subluxation, especially in positions where gravity is active. If the shoulder is left unsupported, this may lead to excessive traction forces on the upper trunk of the brachial plexus. It is, therefore, not uncommon for stroke patients with prolonged hypotonus of the upper extremity to present with brachial plexus dysfunction.

This presentation is often similar to those patients with a true Erb’s palsy. The patients present with weakness of the shoulder girdle, biceps, forearm flexion and supination, and wrist extension. This presentation may be more subtle in a patient with incomplete neurological return in the upper extremity. Thomas Twitchell, MD, described the normal expected patterns of neurological recovery after cerebrovascular accident, in a large population almost four decades ago. He described the return of proximal tone before distal tone and predominance of flexor tone over extensor tone in the upper extremity. When distal return (hand and finger function) and extensor tone predominate, one must wonder whether there is a superimposed brachial plexus injury.

It has been proposed that partial or sustained brachial plexus dysfunction may be the precipitating factor in shoulder-hand syndrome. A form of reflex sympathetic dystrophy (sympathetically maintained pain), shoulder-hand syndrome occurs in as many as 30 or 40 percent of stroke patients and can be terribly disabling in these patients. At times, the pain and dysfunction associated with the shoulder-hand syndrome can overshadow the neurological dysfunction associated with the primary neurological deficit. At times, however, the patient may present primarily with a "frozen shoulder" without the full blown clinical picture of shoulder-hand syndrome.

Another condition in the disabled population, which is somewhat unique to the stroke population, is knee instability and/or degenerative osteoarthritis. This may be the result of genu recurvatum. In patients with incomplete neurological return in the lower extremity, often gait is accomplished through pelvic control and the leg is "snapped" into extension for stability. Many years of genu recurvatum may lead to weakening of ligaments with consequent instability or the one development of degenerative osteoarthritis. Attenion to better control of the patient’s gait through additional physical therapy, bracing, and assistive devices may prevent or reduce the likelihood of development of these conditions.

In patients confined to a wheelchair for prolonged periods of time, a number of other conditions may develop. These are not unique to the stroke population; they are seen in the disabled population in general with increased frequency. Patients with improper seating, especially the elderly, may accelerate the development of osteoporosis. This is especially true if the patient is completely nonambulatory. However, even those patients who might be ambulatory on a household level, but do not stand for long periods of time, are predisposed to the development of early osteoporosis.