6.4. Thoracic Root Disease
Disc Disease
- General Features:
- Trauma:
- Severe trauma (high speed motor vehicle accidents, heavy lifting, direct spinal injury)
- Radicular lancinating pain
- Intercostal or abdominal radiation
- Exacerbated by specific movements
- If associated myelopathy:
- Weakness of the legs
- Babinski's signs
- Hyperactive reflexes
- Bladder, bowel, sexual dysfunction
- Sensory level, two segments below the injury
- Clinical features:
- Radicular lancinating pain
- Intercostal or abdominal radiations
- Exacerbated by specific movements (torsional or compressive)
- Weakness of the legs
- Babinski signs
- Hyperactive reflexes
- Bladder, bowel, sexual dysfunction with acute spinal cord compression
Traumatic radicular disease
- General Features:
- Jumped facet joint:
- Overriding of the inferior over the superior facet joint
- Traction or direct injury of the segmental root
- Rotary subluxation of the facet joint:
- Facet joint twisted; synovial interfacet joint breached
- Missed by conventional X-ray; CT for diagnosis
- Segmental radiculopathy; pain most prominent symptom
- Burst fracture of vertebral body:
- Vertebral body star fracture
- Bilateral radicular pain
- Fractured bone fragment often displaced into the spinal canal or foraminal exit area
- Concomitant spinal cord injury
- Lateral vertebral body translocation:
- Severe trauma (high speed MVA)
- Bilateral radicular pain
- Associated severe spinal cord injury
- Anterior vertebral body compression fracture:
- Middle aged and elderly women with metabolic bone disease
- Minimal trauma (opening a window, fall or hug)
- Severe lancinating radicular pain at the segmental level
Rarer Causes of Thoracic Root Disease
- Syrinx
- Atrophy at the segmental level
- Early hyperhidrosis followed by anhidrosis of the affected segment
- Dissociated sensory loss at the segmental level
- Long tract motor and sensory signs below the syrinx
- Post traumatic syrinx:
- Further cystic degeneration of the spinal cord that occurs months after injury
- Usually 2–3 segment loss of function above and below the level of injury
- Bilateral root involvement at the segment levels
- Chest surgery
- Open heart surgery
- Lung surgery
- Retraction (neuropraxic or direct radicular injury)
- Prolonged neuropathic pain of the involved roots or intercostal nerve
Thoracic Nerve Root Involvement from Systemic Disease
- Diabetes mellitus:
- Infarction and ischemia of the thoracic roots (vaso vasorum)
- Elderly type II diabetes
- Associated with weight loss
- Abrupt onset
- Much more frequent in lower extremities
- Diabetic dying back neuropathy:
- Shield chest sensory loss
- Associated with distal dying back neuropathy of the hands and legs
- Single or multiple dermatomal involvement of the chest or abdomen
- Distributions of the ventral or dorsal rami of the spinal nerves; branches of these rami or various combinations of these distributions
- Amyloid neuropathy:
- Associated with primary amyloid neuropathy
- FOLMA; amyloid with meningeal involvement
- Denervation of the segmental disc; radicular pain due to root compression
- Ochronosis:
- AR; homogentisic acid synthetase deficiency
- Homogentisic aciduria (dark urine)
- Calcification and degeneration of multiple thoracic discs
- Rugger–Jersey X-ray findings (calcification of discs)
- May be asymptomatic
- Ankylosing spondylitis
- Hyperparathyroidism
- AIP
- Toxins
- Immune mediated processes:
- AIDP (acute GBS)
- GM1, Gd1b, Gal-NAc-GD1a antibodies
- CIDP
- Sjögren's Disease
- Dorsal root ganglion involvement
- Involvement of dorsal primary division and its medial and lateral branches (thoracic roots)
- SICCA complex:
- Dry eyes, mouth, serous membranes
- Segmental and regional anhidrosis
- Segmental and regional sensory loss
- Radiculopathy with increased sed rate:
- Usually lumbosacral roots involved
- Idiopathic (occasionally noted with increased sed rate)
- Cancer and Benign Tumors:
- Leukemia
- Hodgkin's and non-Hodgkin's lymphoma
- Carcinomatosis of the meninges
- Tumor:
- Anterior mediastinal tumors (rarely involve thoracic roots)
- Thymoma
- Thymic carcinoma
- Thymic carcinoid (associated with MEN-1)
- Thymolipoma
- Hodgkin's and non-Hodgkin's lymphoma (NHL)
- Primary mediastinal germ cell tumor
- Mature teratoma
- Seminoma
- Nonseminomatous germ cell tumor
- Posterior mediastinal tumors:
- Peripheral nervous system benign and malignant neoplasms are more frequent in the posterior mediastinum
- Develop from peripheral nerves, sympathetic and parasympathetic ganglia and neural tube embryonic remnants:
- Schwannoma
- Neurofibroma
- Melanotic schwannoma
- Ganglioneuroma
- Granular cell tumor
- Malignant melanocytic nerve sheath tumor
- Neuroblastoma
- Ganglioneuroblastoma
- Neurofibrosarcoma (Von Recklinghausen's disease)
- Metastatic disease (similar to cervical root):
- Anhidrosis or hyperhidrosis if sympathetic chain involved (T2-sympathetic innervation of the arm)
- Multiple myeloma
- Osteoclastic myeloma
- Plasmacytoma
- Paget's (sarcoma)
- Multiple myeloma
- Osteoclastic myeloma
- Plasmacytoma
- Paget's Disease (degenerate to sarcoma)
- Multiple myeloma (vertebral fractures with secondary radicular involvement)
- GI cancer (sacral bone involvement; lumbar and sacral roots > thoracic)
- Giant articular bone cyst (vertebral fracture)
- Osteoid osteoma:
- Refractory to narcotics; respond to prostaglandin inhibitors
- Involve posterior elements of the vertebral body (pedicles and facets)
- Radicular symptoms
- Vertebral body sarcoma
- Chondrosarcoma
- Enchondroma:
- Involves the nerve root exit foramina
- Chordoma:
- Brown bone cyst
- Hemangioma of vertebral body:
- Most often incidental (MRI T2 weighted image)
- May weaken vertebral body
- Bloody
- May compress exiting nerve root
- May have concomitant spinal cord compression due to hemorrhage
- Thoracic meningoma in women:
- Extremely rare in men
- Possible association with growth in pregnancy and with breast cancer
- Schwannoma:
- Typical enlargement of foraminal nerve root exit canal
- Scalloping of affected vertebral body
- Dumbbell tumor
- Intradural extramedullary location; meniscus sign on myelography
- Neurofibroma
Infection Involving the Thoracic Root
- HZ (Herpes Zoster):
- Thoracic dermatomes most commonly involved
- Clinical symptomatology (also see cervical dermatomes):
- Grouped vesicular eruption in a dermatomal distribution
- Sensory loss in dermatomal pattern to all modalities (early)
- Atrophy, weakness, sensory loss in involved myotome
- May have dermatomal sensory loss weeks to occasionally months prior to vesicular eruption (herpes sine herpete); often burning pain in the dermatomal distribution
- Post herpetic neuralgia:
- Spontaneous lancinating pain
- Deep continuous ache with lancinating exacerbations in involved dermatome
- Decreased sensory threshold to pinprick, touch or temperature of the dermatome
- Allodynia to both static and dynamic mechano and thermal stimuli
- Hyperalgesia of the involved dermatome
- Neuroma in continuity along the root of the affected dermatome may be cause of post herpetic neuralgia
- Dorsal root ganglionitis; pain of burning nature may occur prior to vesicular eruption
- Rarely hemorrhagic spinal cord infarction associated (paraparesis; most often at T4–T6)
- HIV:
- Usually cervical cord involvement
- Vacuolar degeneration of the cord
- Rare radicular complaints
- Staphylococcus aureus:
- Young IV drug abusers; endarteries to the disc
- Disc space infected:
- Enhancement of disc space on MRI
- Bone spared; pre and post vertebral ligament inflammation
- Lancinating radicular pain; minimal movement initiates pain (touching patient's bed)
- Spinal cord involvement from direct spread or by venous infarction
- Gram negative disc space infection following surgery:
- Involvement may be delayed for up to six weeks
- Pain, swelling, erythema, and edema at the operative site
- High sed rate
- Exquisitely sensitive to mechanical perturbation of the root
- Tuberculosis:
- T4–T6; T11–T12; L1–L2 usual location of the infection
- Infection more common in cervical regions in Asian patients
- Disc space infection > bone; bony sclerosis of the vertebral body end plate
- Pott's disease (thoracic cord):
- Occurs with compression and loss of disc integrity
- May cause spastic paraparesis
- Cold abscess along the iliopsoas muscle; T10–L1 root involvement; blurring of the psoas stripe of X-ray
- Actinomycosis:
- Extension into thoracic vertebrae from active lesions of the lung
- Abscess with radicular symptoms
- Sulfur granules
- Rural population
- Nocardia:
- Immunocompromised patients
- Venous (epidural vein involvement)
- Often noted in lung abscess
- Associated with osteomyelitis
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