Radiculopathy

Radiculopathy, or nerve root involvement, presents with segmental radicular symptoms (pain or paresthesia distributed across the dermatome and weakness of the muscles innervated by the root). Neuroimaging, EMG, or physical examination may be required to establish the diagnosis. Treatment of radiculopathy depends on the cause but includes symptomatic therapy with NSAIDs and other analgesics).

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Causes radiculopathies

Chronic pressure on a nerve root within or near the spinal canal causes nerve root damage (radiculopathy). The most common cause of radiculopathy is a herniated disc. Bone changes in rheumatoid arthritis or osteoarthritis, especially in the cervical and lumbar regions, can also put pressure on nerve roots. Less commonly, a carcinomatous process leads to multiple mosaic radicular dysfunction.

Spinal cord lesions (e.g., epidural abscesses and tumors, spinal meningiomas, neurofibromas) may present with radicular symptoms rather than with normal spinal cord dysfunction. Radiculopathy may occur in diabetes. Nerve root involvement may occur in fungal (e.g., histoplasmosis) and spirochetal (e.g., Lyme disease, syphilis) infections. Herpes infection typically causes painful radiculopathy with dermatomal numbness and a characteristic rash, but motor radiculopathy with myotome muscle weakness and reflex loss may also occur.

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Symptoms radiculopathies

Nerve root lesions cause characteristic radicular pain syndromes and segmental neurological deficits depending on the level.

Characteristic symptoms of radiculopathy at different levels of the spinal cord

C (cervical spine)	Pain in the trapezius muscle and shoulder, often radiating to the thumb, paresthesia and sensory disturbances, weakness of the biceps and decreased bicipital and brachioradialis reflexes
Th (thoracic region)	Pain in the shoulder and armpit area, radiating to the middle finger, triceps weakness, decreased triceps reflex. Girdle dysesthesia in the chest area.
L (lumbar)	Pain in the buttocks, posterior lateral thigh, calves and foot with weakness of the anterior and posterior tibialis and peroneal muscles, loss of sensation in the lower leg and dorsum of the foot
S (sacral region)	Pain in the back of the leg and buttock, weakness of the medial head of the gastrocnemius muscle with impaired plantar flexion, loss of the Achilles reflex and loss of sensation on the lateral surface of the calf and foot

The muscles innervated by the affected root become weak and atrophy; fasciculations may occur. Damage to sensory nerve roots causes sensory disturbances along the dermatomes. The corresponding segmental deep tendon reflexes may be weakened or absent.

The pain increases with movements that put pressure on the root through the subarachnoid space (e.g., spinal movement, coughing, sneezing, Valsalva maneuver). Cauda equina lesions involving multiple lumbar and sacral roots cause radicular symptoms in both legs and may lead to sexual dysfunction and sphincter dysfunction.

Signs of spinal cord compression may include a level of sensory impairment (a sharp change in sensitivity below the level of compression), flaccid paraparesis or tetraparesis, changes in reflexes below the level of compression, hyporeflexia in the initial stages, then hyperreflexia and sphincter dysfunction.

Diagnostics radiculopathies

In case of radicular symptoms, it is necessary to perform CT and MRI of the affected area. In case of multiple levels of damage, myelography is sometimes used. The area of examination is determined by complaints and clinical signs; if the level of damage is unclear, EMG should be performed to clarify the localization, but it will not allow to clarify the cause of the damage.

If neuroimaging does not reveal structural pathology, CSF analysis is taken to exclude an infectious or inflammatory cause, and a fasting blood sugar test is taken to detect diabetes.

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Treatment radiculopathies

Some of the causes suggest etiotropic and pathogenetic treatment of radiculopathy. For acute pain, analgesics are prescribed (e.g., NSAIDs, sometimes opioids). Taking tricyclic antidepressants in low doses before bedtime may help. Muscle relaxants, sedatives, and local therapy occasionally provide additional benefit. Chronic pain is difficult to treat, NSAIDs are only partially effective, and opioids are fraught with a high risk of addiction.

A patient with radiculopathy is consulted by a psychiatrist, tricyclic antidepressants, anticonvulsants, and physical therapy are tried. Alternative treatment for radiculopathy (e.g., transcutaneous electrical nerve stimulation, manual therapy, acupuncture, herbal medicine) is occasionally helpful.