Neurogenic claudication, also called pseudoclaudication, is a common symptom of lumbar spinal stenosis due to causing impingement or inflammation of the spinal nerves
Claudication refers to an impairment in walking or pain, discomfort, numbness, or tiredness in the legs that occurs during walking or standing and is relieved by rest.
The word claudication comes from the Latin claudicare meaning ‘to limp’. Thus, it is a form of claudication due to neurogenic causes.
The feeling is typically described as a painful cramping or weakness or heaviness in the legs after a certain distance has been walked [few hundred meters or even less in severe cases].
Typically the distance that a patient may walk without symptoms of claudication gets reduced over the time.
Claudication is most commonly is due to vascular causes and that is what the word “claudication” refers mostly to. To differentiate it from the vascular claudication, the term neurogenic is used along with claudication.
Risk Factors for Neurogenic Claudication
Neurogenic claudication is usually caused by spinal stenosis (narrowing of the spinal canal) in the lumbar spine (lower back). The narrowing of the spinal canal is generally degenerative changes, disc herniations.
The risk factors for narrowing of spinal canal [spinal stenosis] and thus neurogenic claudication are-
Age
It is something which we cannot avoid. As we grow older, arthritic changes [bone spurs or osteophytes] and degenerative disc disease [disc buldges] occur leading to a narrowing of the canal.
Obesity
A greater weight puts a greater load on the spine and hence increases the degenerative changes
Previous Spinal Deformities
Previous trauma or congenital abnormalities may lead to a reduction of canal space and hence neurogenic claudication. Many arthropathies or calcium deposition diseases can contribute to the reduction of space.
[ Read more on spinal stenosis ]
The pain is usually worse when standing and can often be temporarily relieved by sitting down or flexing forward.
Pathophysiology of Neurogenic Claudication
In the setting of decreased canal space, the symptoms of spinal stenosis become prominent when a further reduction of the space leads to compression of the neural structures. Erect position leads to the extension of the spine causing overlapping of laminar edges of adjacent vertebral bodies, with resultant relaxation and inward buckling of the ligamental flavum. There is also the movement of the superior facets in the anterior direction.
The claudication occurs because of increased metabolic demands of compressed nerve roots because of the ischemia resulted from compression [Oxygen demands of the spinal nerve roots may exceed the available blood flow].
Pain is relieved when the patient flexes the spine leaning forward, stooping, sitting] because flexion of the canal increases canal size by stretching the protruding ligamentum flavum, reduction of the overriding laminae and facets, and enlargement of the foramina.
This relieves the pressure on the exiting nerve roots and, thus, decreases the pain.
Clinical Presentation
Neurogenic claudication may present in one or both legs. It usually presents as some combination of discomfort, pain, numbness and weakness in the calves, buttocks, and/or thighs.
Patients are typically in their 50s and report intermittent, crampy, diffuse radiating thigh or leg pain with associated paresthesias.
It is often precipitated by walking and prolonged standing. The pain is classically relieved by a change in position or flexion of the waist.
The patients typically have a lesser disability in climbing steps, pushing carts and cycling where the lumbar spine is flexed and the vertebral foramen widens.
Downhill ambulation worsens the pain as lumbar spine is kept in extension.
[Lumbar spinal canal and lateral recess cross-sectional area increases with spinal flexion and decreases with extension.]
Patients may compensate for symptoms by flexing forward, slowing their gait, leaning onto objects (eg, over a shopping cart) and limiting the distance that a patient could walk.
Differentiation Between Vascular and Neurogenic Claudication
Distinguishing between neurogenic and vascular claudication is important because the treatments, as well as the implications, are quite different.
Vascular claudication is a manifestation of peripheral vascular disease and arteriosclerosis. Other vessels, including the coronary, vertebral, and carotid, are also often affected.
In some patients, neurogenic and vascular claudication may occur together and it is important to identify them both
Vascular claudication may be accompanied by changes in skin color, turgor, and temperature. The distal lower extremity pulses or arterial bruits may be absent.
Classic five Ps of vascular claudication are
- Pulselessness
- Paralysis
- Paresthesia
- Pallor
- Pain
A patient with vascular claudication also complains of cramping pain in the buttocks, thighs, which stops quickly with rest, even in the standing position.
But the pain of neurogenic claudication is not relieved by standing alone but with postures that cause flexion of the spine. Thus pain in neurogenic claudication may continue for as long as you remain standing. Bending forward or sitting down usually relieves the pain, but even then it does not stop as quickly as pain resulting from insufficient blood flow.
If the patient is able to differentiate, vascular claudication pain starts in their feet or calves and radiates up toward their back and buttock.
Neurogenic claudication often starts in their back and buttock and radiates down toward their feet.
Neurogenic pain is increased with walking, walking downhill/downstairs, and extension of the back whereas relieved with walking flexed with a cart, and sitting/lying.
Vascular claudication increases with walking, walking both up or downhill, and both with extension and flexion of the back. It is not relieved with walking flexed with a cart.
Diagnosis and Treatment of Neurogenic Claudication
Neurogenic claudication is a symptom in itself and leads to the disease causing it. The most common cause is spinal stenosis.
The workup includes clinical examination and imaging for spinal stenosis.
Treatment of neurogenic claudication involves the treatment of the condition causing the narrowing of the canal. the narrowed space generally needs to be decompressed
Read more on spinal stenosis for different treatment approaches.
Prevention of Neurogenic Claudication
While we cannot absolutely stop this from happening, maintaining a healthy lifestyle helps.
There are various lifestyle choices that one could choose and follow to stay with the healthy spine and reduce the pace of stenosis.
These include
- Maintain healthy weight
- Flexibility exercises
- Quitting smoking
- Smoking reduces oxygen availability to the disc and surrounding tissues.
- Maintaining good posture
