Case #19 Weakness

A cauda equina syndrome - key symptoms and signs include lower back pain, reduced anal tone, leg weakness and altered sensation, urinary retention.

Cauda Equina compression is a medical emergency as if there is a compressive lesion pressing on the cauda, and this might be treatable and this can enable the patient to regain function. Early decompression may save neurology. Cauda equina syndrome is a severe, rare and complex condition. The longer it goes untreated, the greater the chance it will lead to permanent paralysis and incontinence for the patient.

The cauda is a bundle of lower nerve roots that have left the spinal cord and have yet to exit through the spinal foramina. They carry motor to the legs and sensory from lower lumbar and sacral nerve roots back to the brain, and they also supply urinary and rectal sphincters.

• Muscles are weak and Tone is reduced
• Reflexes are reduced or absent
• Plantar response is down or absent
• Develops fasciculations and wasting with time

Below L1 there will be no UMN signs - NO hyperreflexia, No upgoing plantars and no brisk reflexes. If you find these, you will need to review your findings and diagnosis. Such signs in both legs suggest a cord lesion above L1.

If you remember, the spinal cord ends at L1. So remaining in the canal are the roots for L2, L3, L4, L5, S1, S2, S3. S4. S5, which exit at their corresponding foramina. The lower the lesion in the lumbar spine, the more distal the damage. Answer

The sole of the foot for s1 and then the back of the legs and buttocks and perianal region and the genitals. This is called the saddle area. Numbness here is a possible sign of root compression above S2/3 in the lumbar canal. With time the genitals and buttocks become numb and at risk of pressure damage.

There may be a weakness of the legs, which can be asymmetrical, and the sphincters will also be flaccid. This means faecal and urinary incontinence and loss of control. Urinary retention may also occur as patients cannot sense that the bladder is full and so do not micturate. This can also apply to bowel movements.

Red flags for Cauda Equina syndrome are

• Bilateral sciatica.
• Severe or progressive bilateral neurological deficit of the legs, such as major motor weakness with knee extension, ankle eversion, or foot dorsiflexion.
• Difficulty initiating micturition or impaired sensation of urinary flow, if untreated this may lead to irreversible.
• Urinary retention with overflow urinary incontinence.
• Loss of sensation of rectal fullness, if untreated this may lead to irreversible.
• Faecal incontinence.
• Perianal, perineal or genital sensory loss (saddle anaesthesia or paraesthesia).
• Laxity of the anal sphincter. Assess anal tone

There are several

• Infection (such as discitis, vertebral osteomyelitis, or spinal epidural abscess). Red flags include:
• Fever
• Tuberculosis, or recent urinary tract infection.
• Diabetes.
• History of intravenous drug use.
• HIV infection, use of immunosuppressants, or the person is otherwise immunocompromised.

There are several

• The person is 50 years of age or more.
• Gradual onset of symptoms.
• Severe unremitting pain that remains when the person is supine, aching night pain that prevents or disturbs sleep, pain aggravated by straining (for example, at stool, or when coughing or sneezing), and thoracic pain.
• Localised spinal tenderness.
• No symptomatic improvement after four to six weeks of conservative low back pain therapy.
• Unexplained weight loss.
• Past history of cancer — breast, lung, gastrointestinal, prostate, renal, and thyroid cancers are more likely to metastasize to the spine.

There are several

• Sudden onset of severe central spinal pain, which is relieved by lying down.
• There may be a history of major trauma (such as a road traffic collision or fall from a height), minor trauma, or even just strenuous lifting in people with osteoporosis or those who use corticosteroids.
• Structural deformity of the spine (such as a step from one vertebra to an adjacent vertebra) may be present.
• There may be point tenderness over a vertebral body.

The imaging of choice would be MRI. For those who cannot have MRI then CT would be appropriate.

There are several

• Haematoma (anticoagulation is a risk factor) so if found then reverse anticoagulation and take a neurosurgical opinion
• SOL – malignancy, infection/abscess
• Traumatic – central disc herniation, spinal fracture

• ABC and full trauma assessment were indicated to ensure no injuries were missed. Ensure analgesia.
• Depending on local pathways, these patients need urgent referral to neurosurgical or spinal teams to consider urgent decompression of the nerve roots. Generally, care will involve regular turning to prevent pressure lesions, sphincter management and good nursing care and post-op neurorehabilitation. Patients may have other injuries needing attention.