Cauda Equina Syndrome (CES)

Refers to the compression of spinal nerve roots in the lumbar spine, cutting off sensation and movement. Gitelman et al. described it as a rare condition which is a complex of symptoms and signs including low back pain, unilateral or bilateral sciatica, motor weakness of lower extremities, sensory loss disturbance in saddle area, and loss of visceral function resulting from compression of the cauda equina (Gitelman, et al., 2008). It is commonly caused by acute lumbar disc herniation (Balasubramania, Kalsi, Greenough, & Kuskoor, 2010). It can happen in anyone and it does not follow gender or race though it is more prevalent in adults than children (American Association of Neurological Surgeons, 2018). CES is a surgical emergency since delays in receiving treatment may result in permanent paralysis, impaired bladder and or bowel control, loss of sexual sensation and other problems.
Even with treatment, some patient may not recover full function. (Orthopedic Information, 2018). The following are some risk factors for CES:

• Spinal lesions and tumours
• Spinal infections or inflammation
• Violent injuries to the low back e.g. gunshots, falls and road traffic accidents
• Lumbar spinal stenosis
• Congenital defects
• Spinal arteriovenous malformations (AVMs)
• Spinal haemorrhage (Subarachnoid, subdural, epidural)
• Postoperative lumbar spine surgery complications
• Spinal anaesthesia

Diagnosing CES

Sensitivity of one symptom is not enough to diagnose CES. To increase sensitivity, use a cluster of signs and symptoms. The following are signs and symptoms which can be used together to increase diagnostic sensitivity:

• Saddle sensory deficits/ sacral sensory loss (Balasubramania, Kalsi, Greenough, & Kuskoor, 2010) and (Jalloh & Minhas, 2007).
• Bladder (incontinence or urinary retention), bowel and sexual dysfunction (Shi, et al., 2010).
• Sciatica (pain, numbness, weakness of legs) (Selz, Morard, Buchard, & Frochaux, 2010)
• Fast onset of symptoms within 24 hours
• History of back pain
• Loss of sphincter tone

Upper Lumbar Disc Herniation

Upper lumbar region comprises of L1, L2, L3 spinal segment. Herniations in this region are rare and symptoms are not specific. Positive femoral stretch test is relatively regarded as a good diagnostic test in about 80% to 94% of lumbar disc herniations. Conservative treatment outcome is often unfavourable (Duk-Sung, et al., 2010).

Lumbar Compression Fracture

A fracture is complete or partial interruption in the continuity of the bone. Injuries that change the shape of the lumbar spine will result in changes to the biomechanics of the spine. Compression fractures are caused by both traumatic and non-traumatic events such as osteoporosis, infection and spinal cancers. Compression fractures are common at the thoracolumbar junction. Osteoporosis results in the reduction of mineral bone density, making the bone more brittle. Suspect lumbar compression fracture in someone who is:

• Older than 70 years
• Having a history of trauma
• Having a history of corticosteroid use
These three points above have a high specificity when used together in diagnosing lumbar compression fractures. Vertebral compression fractures can be classified based on applied forces:
• Flexion compression with damage in posterior ligamentous structures
• Lateral compressions that can be the cause of scoliotic deformation
• Axial compression causing burst fractures
Based on the damage to the endplate, vertebral compression fractures can be subdivided into:
• Type A: both endplates are involved. Axial load ----- 16%
• Type B: Damage to the superior endplate. Axial load plus flexion is great than----62%
• Type C: Inferior endplate is damaged. Axial load plus flexion---6%
• Type D: Both endplates are intact. Axial load plus rotation---15%

Spinal cancer

Spinal cancer may also present with low back pain. The following should make you suspect spinal cancer in someone presenting with LBP:

Suspicion Factor	Sensitivity	Specificity
No improvement 1 month of treatment	31%	90%
No relief with bed rest	90%	46%
Duration more than 1 month	50%	81%
Age > 50, history of cancer, unexplained weight loss, failure with conservative treatment	100%	60%

To increase diagnostic accuracy, it is important to use a cluster of tests rather than one special test.

Predictors of Lumbar Discopathy /Radiculopathy

Presence of the following should make you suspect lumbar discopathy or radiculopathy:

• Dermatomal radiation [odds ratio (OR) 2.1]
• More pain on coughing, sneezing or straining (OR 2.4),
• Positive straight leg raising (OR 3.0)
• Ongoing denervation on EMG (OR 4.5)

These are significant predictors of radiological nerve root compression (Coster, de Bruijn, & Tavy, 2010). Increasing sciatica while raising the opposite (well leg), crossed leg raise sign is associated with herniated lumbar disc in about 97% of patients (Hudgins, 1979).
Note: Crossed Straight Leg Raise Test has a sensitivity of 29, a specificity of 88% and a positive likelihood ratio of 4.39. It is clear that SLR (Lasègue) has low sensitivity to rule out presence of pathology (Devillé, van der Windt, Dzaferagić, Bezemer, & Bouter, 2000). Femoral Nerve Stretch Test (FNST) has a range of specificity ranging from 88% to 100%, a positive likelihood ratio of 5.7 in detecting L3 nerve impingement. Patient history is the main component in the diagnosis of lumbar radiculopathy. (Vroomen, de Krom, Wilmink, Kester, & Knottnerus, 2002).

If you are suspecting disc involvement, look for:

• Leg pain greater than back pain: Odds Ratio: 5.5
• Dermatomal distribution: Odds Ratio 3.8
• Worse coughing/sneezing: OR 2.1
• Cold sensations leg: Odds Ratio 1.8
• Centralisation (Specificity between 70%-97%; Likelihood Ratio between + 2.1-9.4). Uses it to rule in disc involvement and as a predictor of a good outcome
Characteristics of disc involvement include:
• Directional preference
• Lateral shift
• Worse with lumbar flexion
• Worse by getting up from seated position
• Pain changes sides
• Midline pain that can refer to groin or leg
• Worse with axial loading, better supine
Clinical Note: In patients with lumbar radiculopathy that does not centralize, traction and a conditioning program can produce same long-term results in the absence of cauda equina syndrome symptoms (Saal, Saal, & Yurth, 1996).

Lumbar Spinal Stenosis

This is narrowing of the spinal or nerve root canal caused by degenerative arthritis in the facet joint or intervertebral discs. It is a degenerative condition that is common in the elderly. Compression on the vertebral venous plexus from multilevel stenosis that creates pooling and congestion. This leads to ischaemia which might result in fatigue and pain in the legs while walking. A cluster of five elements from patient history can be used to clinically predict presence of lumbar spinal stenosis. The elements include: Bilateral symptoms Leg pain more than back pain Pain during walking/standing Pain relief upon sitting Age greater than 48 years Pain, paraesthesia and cramping of the lower extremities while walking and relieved by sitting is called neurogenic claudication. Neurogenic claudication symptoms are aggravated based on the position of the spine at which lower extremity exertion is being done. In vascular claudication, symptoms are generally affected depending on the vascular demands and the level at which lower extremity exertion is being done. Differentials to this include vascular claudication, osteoarthritis of the knees and hips. Flexion based exercises are effective in the conservative management of spinal stenosis in older adults (Olson, 2009). Active exercise program in combination with manual therapy to the hip, lumbopelvic and the thoracic spine, together with progressive walking and unweighted treadmill walking give best results in people suffering from lumbar spinal stenosis (Whitman, et al., 2006). To differentiate neurogenic from vascular claudication, do a two-stage treadmill test (Fritz et al., 1997) i.e. walk on trademill on a level plane for 10 minutes then at 15 degrees inclined plane for 10 minutes. Walking on an inclined plane decreases lumbar lordosis while increasing cross-sectional area of the spinal canal. If the symptoms are easily reproduced or take time to settle with walking on a level plane, the test is positive. Note: 1 out of 5 positives above has sensitivity of 96% and likelihood ratio of -1.2 while 4 out of 5 positives have specificity of 98% and likelihood ratio of +4.6. Using this diagnostic criterion will reduce the need for radiographic imaging (Cook, et al., 2011).

Facet Joint Involvement

If facet joint is involved, the following may be present: Unilateral and localised pain Worse with pressure on facet joint or transverse processes No radicular signs Referred pain does not go beyond the knee Pain with extension, lateral flexion and or homolateral rotation Clinical Note: Kemp’s test (extension - rotation test of the trunk) can be used to test facet joint involvement though it has a limited evidence of diagnostic accuracy (sensitivity of 100% and specificity of 22% and a likelihood ratio of -0.0) (Stuber, Lerede, Kristmanson, Sajko, & Bruno, 2014)

Patient Suspected of Having Ankylosing Spondylitis (AS)

Clinical prediction for diagnosing AS:

Suspicion Factor	Sensitivity	Specificity
Pain that is not relieved by supine lying	80%	49%
Morning back stiffness 59% 64%	59%	64%
Pain duration great than 3 months	54%	71%
Onset age of less than 40	100%	7%
Improvement with exercise

The four points above plus improvement with exercise give a cluster of five things to look at while suspecting AS. 4 out of these 5 factors give a positive sensitivity of 23% and specificity of 82%.