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Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal narrows and compresses the spinal cord and nerves at the level of the lumbar vertebra. This is usually due to the common occurrence of spinal degeneration that occurs with aging. It can also sometimes be caused by spinal disc herniation, osteoporosis or a tumor. In the cervical (neck) and lumbar (low back) region it can be a congenital condition to varying degrees. It is also a common symptom for those who suffer from various skeletal dysplasias such as with pseudoachondroplasia and achondroplasia at an early age. Spinal stenosis may affect the cervical or thoracic region in which case it is known as cervical spinal stenosis or thoracic spinal stenosis. In some cases, it may be present in all three places in the same patient. Lumbar spinal stenosis results in low back pain as well as pain or abnormal sensations in the legs, thighs, feet or buttocks, or loss of bladder and bowel control. ==Signs and symptoms== Understanding the meaning of signs and symptoms for the clinical syndrome of lumbar stenosis requires an understanding of what the syndrome is, and the prevalence of the condition. A recent review on lumbar stenosis in the Journal of the American Medical Association's "Rational Clinical Examination Series" emphasized that the syndrome can be considered when lower extremity pain occurs in combination with back pain. This syndrome occurs in 12% of older community dwelling men and up to 21% of those in retirement communities. The leg symptoms in lumbar spinal stenosis (LSS) are similar to those found with vascular claudication, giving rise to the term pseudoclaudication. These symptoms include pain, weakness, and tingling of the legs,〔 which may radiate down the leg to the feet.〔 Additional symptoms in the legs may be fatigue, heaviness, weakness, a sensation of tingling, pricking, or numbness and leg cramps, as well as bladder symptoms.〔 Symptoms are most commonly bilateral and symmetrical, but they may be unilateral; leg pain is usually more troubling than back pain.〔 Pseudoclaudication, now referred to as neurogenic claudication, typically worsen with standing or walking and improve with sitting. The occurrence is often related to posture and lumbar extension. Lying on the side is often more comfortable than lying flat, since it permits greater lumbar flexion. Vascular claudication can resemble spinal stenosis, and some individuals experience unilateral or bilateral symptoms radiating down the legs rather than true claudication.〔 The first symptoms of stenosis include bouts of low back or neck pain. After a few months or years, this may progress to claudication. The pain may be radicular, following the classic neurologic pathways. This occurs as the spinal nerves or spinal cord become increasingly trapped in a smaller space within the canal. It can be difficult to determine whether pain in the elderly is caused by lack of blood supply or stenosis; testing can usually differentiate between them but patients can have both vascular disease in the legs and spinal stenosis. Among people with lower extremity pain in combination with back pain, lumbar stenosis as the cause is two times more likely in those older than 70 years of age while those younger than 60 years it is 0.40 as likely. The character of the pain is also useful. When the discomfort does not occur while seated, the likelihood of LSS increases considerably around 7.4 times. Other features increasing the likelihood of lumbar stenosis are improvement in symptoms on bending forward 6.4 times, pain that occurs in both buttocks or legs 6.3 times, and the presence of neurogenic claudication 3.7 times.〔 Alternately, the absence of neurogenic claudication makes lumbar stenosis much less likely as the explanation for the pain. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「lumbar spinal stenosis」の詳細全文を読む スポンサード リンク
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