Lumbar spinal stenosis (LSS) is a narrowing of the spinal canal in the lumbar region, in which the surrounding osseous and soft tissue structures lead to nerve compression [1] [2]. This condition is either congenital [3] or secondary to a degenerative process, trauma, infection, or surgery [4]. LSS commonly affects the aging population and has a slight predilection for males [1].

The clinical presentation, which is insidious, initially consists of backache but eventually progresses to include worsening pain, fatigue, weakness, and numbness of the leg(s) [1]. Specifically, patients describe symptoms such as tingling, burning, cramping, fatigue, and stiffness of the lower extremities. Moreover, the leg pain is most often bilateral and radiates distally, particularly with exercise [1].

As evident in the majority of cases, neurogenic intermittent claudication is the most predominant sign attributed to LSS [4] [5]. This manifestation is produced and worsened by walking or standing but alleviated with sitting or lying down on the side [1] [4]. Squatting and bicycle riding may also provide relief since flexion of the trunk leads to widening of the lumbar canal [1]. As the disease advances, the patient is likely to adopt a stooped posture [1].

LSS in the younger population [6] may cause radicular symptoms consisting of unilateral neurogenic claudication due to stenosis of the foraminal or lateral recess canal [4]. These patients experience severe leg pain that is worsened with lumbar extension [7].

Complications

Excruciating leg pain, paresthesia, and difficulty with ambulation are all likely sequelae in patients with LSS. Additionally, other possible complications include neurogenic bladder and/or abnormal bowel function [1] [8] and nocturnal leg cramps [9].

Physical exam

On visual inspection, the patient may have a stooped posture. Furthermore, examination of the lower back reveals limited extension [6]. Additionally, a neurological assessment may show absent or reduced ankle reflexes as well as sensory deficits [4].

• Nocturnal Leg Cramp

  Additionally, other possible complications include neurogenic bladder and/or abnormal bowel function and nocturnal leg cramps. Physical exam On visual inspection, the patient may have a stooped posture. [symptoma.com]

  Nocturnal leg cramps: a common complaint in patients with lumbar spinal canal stenosis. Spine. 2009 Mar 1;34(5):E189–94. [PubMed] [Google Scholar] 29. Inui Y, Doita M, Ouchi K, Tsukuda M, Fujita N, Kurosaka M. [ncbi.nlm.nih.gov]

  Patients with LSS also can report nocturnal leg cramps and neurogenic bladder symptoms. Symptoms can be unilateral or more commonly bilateral and symmetrical. [physio-pedia.com]

• Respiratory Distress

  distress, haematoma, stroke, risk of reoperation and death due to pulmonary oedema. [ncbi.nlm.nih.gov]

  distress, haematoma, stroke, risk of reoperation and death due to pulmonary oedema . [cochrane.org]

  distress, haematoma and death due to pulmonary oedema ( Zucherman 2004 ). [doi.org]

• Osteochondral Loose Body

  On review of the literature this is only the second case of osteochondral loose body as a cause for lumbar spinal stenosis and thus remains a rare phenomenon. [ncbi.nlm.nih.gov]

• Skeletal Dysplasia

  Introduction Achondroplasia is the most common form of skeletal dysplasia with micromelia, with an estimated prevalence is 1/16,000–25,000 live births1,2. [nature.com]

• Abnormal Gait

  Early symptoms are mostly abnormal sensations in the hands, abnormal gait – particularly in the dark –, and deficiencies in the fine motor skills of the hands. Disturbances in writing mostly occur at advanced stages. [doi.org]

Patients presenting with the above symptoms should be evaluated by their personal history, clinical picture, physical exam findings, and confirmatory studies. It is important to note that the severity of the clinical presentation does not usually correspond to the degree of stenosis [1].

Imaging

The American College of Physicians (ACP) recommends against routine imaging for low back pain unless there are risk factors for infection, malignancy, or other diseases [10] [11]. However, the traditional workup has included spinal radiography as the initial test. In patients with LSS, this modality is likely to reveal abnormalities such as degenerative changes in the disc or vertebrae, or other disease processes [1].

A spinal computed tomographic (CT) scan provides visualization of the canal and allows for accurate measurements of its diameter [1]. It may demonstrate narrowed canal with impingement by surrounding structures resulting in a "cloverleaf" or the pathognomonic "trefoil" appearance. To improve sensitivity, intrathecal contrast can be used but this is associated with risks.

Magnetic resonance imaging (MRI), the preferred study for diagnosis of LSS, is useful in the assessment of the spinal cord and associated soft tissue structures such as the cauda equina, epidural fat, intervertebral discs, etc. [1]. Additionally, this test helps rule out differential diagnoses. Specifically, LSS has characteristic appearances on T1 and T2-weighted images.

Other

Electromyelography is not required but is beneficial in diagnosing neuropathies secondary to demyelination and inflammation [1].

• Schmorl's Nodes

  Schmorl's nodes (SNs) are described as vertical herniation of the disc into the vertebral body through a weakened part of the end plate that can lead to disc degeneration. [ncbi.nlm.nih.gov]

  Classification of Schmorl’s nodes of the lumbar spine and association with disc degeneration: a large-scale population-based MRI study. Osteoarthr Cartil. 2016; S1063–4584(16)30059-0. [scoliosisjournal.biomedcentral.com]

• Lymphocytic Infiltrate

  Multinuclear giant cells and lymphocytes infiltrated some parts of the marginal layer of the cavity, and no obvious bony bridge had regenerated from autologous bone. [ncbi.nlm.nih.gov]

1. Alvarez JA, Hardy RH. Lumbar Spine Stenosis: A Common Cause of Back and Leg Pain. Am Fam Physician. 1998;57(8):1825-1834.
2. Machado GC, Ferreira PH, Harris IA, et al. Effectiveness of Surgery for Lumbar Spinal Stenosis: A Systematic Review and Meta-Analysis. Shamji M, ed. PLoS ONE. 2015;10(3):e0122800.
3. Ciricillo SF, Weinstein PR. Lumbar spinal stenosis. West J Med. 1993;158(2):171–7.
4. Genevay S, Atlas SJ. Lumbar Spinal Stenosis. Best Pract Res Clin Rheumatol. 2010;24(2):253-265.
5. Benoist M. The natural history of lumbar degenerative spinal stenosis. Joint Bone Spine. 2002;69(5):450–457.
6. Turner JA, Ersek M, Herron L, Deyo R. Surgery for lumbar spinal stenosis. Attempted meta-analysis of the literature. Spine. 1992;17(1):1–8.
7. Jenis LG, An HS. Spine update. Lumbar foraminal stenosis. Spine. 2000;25(3):389–94.
8. Inui Y, Doita M, Ouchi K, et al. Clinical and radiologic features of lumbar spinal stenosis and disc herniation with neuropathic bladder. Spine. 2004;29(8):869–73.
9. Matsumoto M, Watanabe K, Tsuji T, et al. Nocturnal leg cramps: a common complaint in patients with lumbar spinal canal stenosis. Spine. 2009;34(5):E189–94.
10. Chou R, Qaseem A, Owens DK, et al. Diagnostic imaging for low back pain: advice for high-value health care from the American College of Physicians. Ann Intern Med. 2011;154(3):181-9.
11. Chou R, Qaseem A, Snow V, et al. Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147(7):478-491.