Spine syndromes and back pain

Radicular disorder syndromes are characterized by segmental radicular symptoms (pain or paresthesia in the dermatome, muscle weakness in the root innervation zone). Diagnosis may require neuroimaging, electromyography, and a systemic examination to identify the underlying disorder. Treatment depends on the cause, but includes symptomatic treatment of pain with NSAIDs and other analgesics.

Radicular syndromes (radiculopathies) occur when nerve roots are compressed within or near the spinal column. The most common cause is a herniated disc. Bone changes that occur in rheumatoid arthritis or osteoarthritis, especially in the cervical and lumbar regions, may also compress individual nerve roots. Less commonly, carcinomatous meningitis causes "patchy" radicular symptoms. Rarely, space-occupying lesions (eg, epidural abscess and tumor, spinal meningiomas, neurofibromas) may present with radicular symptoms instead of spinal symptoms. Diabetes frequently causes painful thoracic or extremity radiculopathy. Infectious diseases such as fungal (eg, histioplasmosis) and spirochetal infections (eg, Lyme disease, syphilis) occasionally affect nerve roots. Herpes zoster usually causes painful radiculopathy with sensory disturbances in the dermatome and a characteristic rash, but can also cause motor radiculopathy with weakness in the myotome and decreased reflexes.

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Symptoms of radicular syndromes

Radicular syndrome consists of pain and segmental neurological deficits determined by the level of damage. Muscles innervated by the affected root become weak and undergo atrophy; they may also become flaccid. Damage to the sensory portion of the root causes sensory disturbances in the lermatome. Tendon reflexes corresponding to the affected root may decrease or disappear.

Spinal roots and the main muscles they innervate

Root	Muscle	Action
C5	Deltoid	Shoulder abduction
C5	Infraspinatus	External rotator of the shoulder (test: the patient's ability to externally rotate the shoulder with the arm pressed to the body and flexed at the elbow)
C5, C6	Biceps brachii	Forearm flexion and supination
C6	Extensors of the wrist radialis and ulnaris	Wrist extension
C7	Extensor digitorum Triceps brachii	Finger extension Extension of the forearm at the elbow joint
C8, T1	Interosseous and vermiform	Adduction and abduction of fingers (test: the patient's ability to spread fingers individually and together against resistance)
L2, L3, L4	Quadriceps femoris, iliopsoas muscle. Adductor group	Knee extension, hip flexion Hip adduction
L5	Anterior tibialis and extensor hallucis	Extension (dorsiflexion) of the foot and big toe (test: patient's ability to walk on heels)
S1	Calf	Flexion (plantar flexion) of the foot (test: patient's ability to walk on tiptoes)

Four basic reflexes

Reflex	Roots that implement the reflex	Muscles that perform the reflex
Ankle flexion (Achilles reflex)	S1	Calf
Knee extension (knee jerk)	L2, L3, L4	Quadriceps femoris
Biceps Brachii Reflex	C5, C6	Biceps brachii
Triceps reflex	C7, C8	Triceps brachii

Pain may be aggravated by movements that transmit pressure to the root through the subarachnoid space (eg, spinal movements, coughing, sneezing, Valsalva maneuver). Cauda equina lesions cause radicular symptoms in both lower extremities and may be accompanied by sphincter and sexual dysfunction. Signs of spinal cord compression include the presence of a sensory level (sudden change in sensitivity below a horizontal level drawn through the spinal cord), flaccid paraparesis or tetraparesis, reflex impairment below the level of compression, early hyporeflexia followed by hyperreflexia, and sphincter impairment.

Diagnosis and treatment of radicular syndromes

Radicular symptoms require CT or MRI of the affected level. Myelography is rarely used in cases of multiple levels of damage. The level of examination depends on the symptoms; if the level of damage is unclear, electromyography may be used, which helps to localize the affected root but does not allow to establish the cause.

Damage to individual peripheral nerves is characterized by sensitivity disorders in the corresponding areas, as well as other associated symptoms.

Characteristic distinctive features of damage to various nerves

Nerve	Symptoms
Median Elbow	Thumb and thenar eminence Little finger and hypothenar
Ray	Falling brush
Femoral	Absence of knee reflex, weakness of hip flexion and leg extension
Peroneal	Drop foot (steppage)
Sciatic	Pain along the outer surface of the thigh and shin with the absence of the Achilles reflex.

If neuroimaging does not reveal anatomical abnormalities, cerebrospinal fluid analysis should be performed to exclude infectious and inflammatory causes and urgent blood glucose measurement should be performed to exclude diabetes.

Specific causes of radicular syndromes are treated according to their etiology. Acute pain requires analgesics (eg, NSAIDs, sometimes opioids). Low-dose antidepressants and bed rest may be helpful. Muscle relaxants, sedatives, and topical treatments are sometimes helpful.

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