Claudication

Claudication, literally 'limping' (Latin), is used as a medical term in various contexts. It is also used figuratively.

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Intermittent claudication

Intermittent claudication usually refers to cramplike pains in the legs (usually the calf muscles, but may be in the thigh muscles) caused by poor circulation of the blood to the leg muscles.

Symptoms and signs

The pain usually starts after walking a fixed distance on flat ground (called the claudication distance); this distance will get shorter if the patient walks uphill. Severity may be classed according to claudication distance: a claudication distance of 200m or more is Fontaine stage I, claudication occurring before 200m is Fontaine stage II. In the most severe cases, the patient may be forced to sleep with the affected leg dangling down off the bed because the blood supply is obliterated by placing the leg horizontal. The usual cause is peripheral vascular disease from atherosclerosis (most frequently caused by smoking, diabetes, or high cholesterol), and it is usual for one leg to be affected more than the other. Rare causes include diseases such as large vessel vasculitis (e.g., Takayasu arteritis).

When examining the patient with intermittent claudication, the doctor may find signs of vascular insufficiency (poor arterial blood supply). The pulses in the foot or knee may be weak or even missing; in severe cases there may be skin changes such as the loss of skin hair or ulcers. The leg, when lifted straight off the examination couch, may become drained of blood and turn white.

The ankle-brachial index is a simple, non-invasive test that can be used to assess patients with claudication symptoms. The ankle-brachial pressure index (ABI or ABPI), involves obtaining blood pressure measurements in both arms and both legs. The higher of the two arm pressures becomes the denominator, and the individual leg or ankle pressures serve as the numerator in calculating the ABI for each leg. Thus the ABI is a ratio which roughly compares the blood flow in the arms to that in the legs, and can help screen for arterial insufficiency as a source of the claudication symptoms. A normal ABI should be 1.0-1.3, whereas an ABI of less than 0.9 can indicate significant arterial insufficiency. An ABI of less than 0.5-0.6 correlates with threatened limb loss. An abnormal ABI in correspondence with claudication symptoms usually leads to a more sophisticated imaging work-up (usually an angiogram) to uncover the specific arterial blockages implied by the screening test.

The main differentials are spinal claudication (see below), spinal radiculopathy, arthritis of the joints, and Baker's cyst.

Treatment

The treatment of intermittent claudication is treatment of the vascular insufficiency (inadequate arterial blood supply). The most important step is to stop smoking, and many patients find an almost immediate relief of their symptoms with smoking cessation; exercise is another mainstay of treatment. Medical treatment is often insufficient to relieve symptoms, but does help to prevent the disease from getting worse: patients are usually prescribed medicine to lower risk from cardiovascular disease, such as low-dose aspirin, a statin and an antihypertensive (medication to lower the blood pressure). Surgical treatment is the mainstay for patients with severe disease.

Prognosis

Prognosis for patients with peripheral vascular disease due to atherosclerosis is poor. Patients with intermittent claudication due to atherosclerosis tend to die from cardiovascular disease (e.g., heart attacks), because the same disease that affects their legs is usually present also in the arteries of the heart.

Spinal claudication/ neurogenic claudication

Main article: Neurogenic claudication

Spinal claudication/ neurogenic claudication is not due to lack of blood supply, but is instead the pain felt on exertion by patients whose leg pain is caused by nerve root compression, usually from a degenerative spine. It may be differentiated from arterial claudication in that it is often only relieved by sitting down, whereas in arterial claudication standing at rest is usually sufficient to relieve the pain; weakness is also a prominent feature of spinal claudication that is not usually present in intermittent claudication.

Jaw claudication

Jaw claudication is pain in the jaw or ear while chewing. This is caused by insufficiency of the arteries supplying the jaw muscles. The most common cause is temporal arteritis.

See also

• Peripheral artery occlusive disease
• Intermittent claudication

External references

Intermittent claudication

• Roger W Simon, Andr Simon-Schulthess, Amann-Vesti BR (2007). "10-Minute consultation: Intermittent claudication". Br Med J 334: 746. doi:10.1136/bmj.39036.624306.68.
• Hiatt WR (2001). "Medical treatment of peripheral arterial disease and claudication". N Engl J Med 344: 1608–21.
• Patient information leaflet available from the Vascular Society of Great Britain and Ireland