Differential Diagnosis in Neurology

4.3. Vertebral Column Bony Trauma

Mechanisms of Injury

• Sudden violent flexion (cervical vertebrae):
  • Anterior compression fracture of vertebral bodies
  • Unilateral or bilateral facet joint dislocation
  • Kinking and rupture of the longitudinal and interspinous ligaments
  • Extrusion of discs has also occurred while holding patients in flexion in preparation for an LP.
• Severe compression injures:
  • Affecting the thoracic lumbar area (ski injuries, falls)
  • Burst vertebral bodies (central area of compression with fracture lines radiating outwardly)
  • Bone splinters and disc material may extrude into the spinal canal and compress the spinal cord
  • Common in elderly osteoporotic women from minimal trauma (opening a window). Usually only local pain with no neurologic deficit (anterior wedge fracture of the thoracic vertebrae)
• Rotational injury:
  • Unilateral pars interarticularis fracture or facet injury
  • Rotary facet dislocation. Very difficult to see radiologically. Must be suspected from increased intraspinal distance at that level and persistent focal spine pain (rupture of an interspinal ligament).
• Jumped facets; the superior facets are displaced anteriorly
• Hyperextension injury:
  • Fracture of the posterior elements with evolving spondylolisthesis at the affected level.

Fracture and Dislocations

• Jefferson's fracture (fracture of the atlas)
• A ring fracture
• Vertebral body burst fracture
• Hangman's fracture (C2–C3 spondylolisthesis)
• Jumped and locked facet joints
• Bony canal fracture with cord compression
• Rotary facet subluxation
• Odontoid fracture:
  • Tip (distal 2–3 mm)
  • Base (ossification center)
  • Disruption of the cruciate, alar and lateral ligaments
• Post-surgical :
  • Severe neck deformity
  • Posterior displacement of a bone
  • Two level instability
  • Overgrowth of a lateral bone graft with stenosis of the canal
• Rotary injury: atlanto-occipital subluxation

Hyperflexion Injury

• Subluxation
• Facet joint dislocation
• Compression of the anterior portion of the vertebral body with fracture and bone fragments that compress the spinal cord

Parenchymatous Cord Trauma

• General considerations:
  • Incidence 30–40/1,000,000 population
  • Prevalence 900/1,000,000 population
  • 65% of patients are less than 35 years of age
  • Male to female ratio of 3:1
  • Second peak occurs between 55–59 years of age
  • Greatest during the summer months and on weekends
• Causes:
  • Motor vehicle accidents
    • Single and multiple vehicular accidents
    • Motorcycle
    • Injuries to pedestrians
    • Industrial accidents
    • Diving into shallow water
    • Sports injuries
    • Gunshot wounds
    • Stabbing
    • Non-industrial falls (elderly patients); cement stairs leading to the basement

Patterns of Spinal Cord Injury

• Cord concussion
• Spinal shock
• Complete cord transaction (rare)
• Incomplete cord transaction:
  • Brown-Sequard syndrome
  • Central cord syndrome
  • Anterior cord syndrome
  • Posterior cord syndrome
• Associated injuries:
  • Vertebral artery occlusion (cervical cord injury)
  • Cauda equina injury
  • Conus medullaris injury
  • Mixed epiconus, conus and cauda equina lesions
• Spinal cord concussion:
  • Transient neurological symptoms with full recovery in minutes to hours
  • Signs develop below the level of injury

Spinal Shock

• Clinical features:
  • Complete flaccid paralysis below the level of the lesion
  • Anesthesia below the level of the lesion
  • Incontinence of bowel and bladder
  • Areflexia below the level of the lesion
  • Babinski response plantar (muscles are paralyzed); maybe present or intermediate toes are seen (quivering extension/flexion movements); probably equivalent to a Babinski response.
  • Areflexic hypotonic state changes to hyperreflexia within six weeks (in general)
  • Complete transection of the cord:
    • Rare; they are most often caused by a high velocity missile, knife wound or vehicular accident
    • Most injuries are bruises that evolve their pathology (ovoid) and extend over time
    • Motor, sensory and autonomic dysfunction occurs below the level of the injury
    • In chronic patients:
      • Autonomic dysreflexia occurs if not treated with adrenergic blocking drugs. The syndrome consists of:
        • Severe hypertension 250–300 mmHg/200 mmHg
        • Hyperhidrosis
        • Severe headache that is vascular in nature
        • Seizures (during the headache phase)
        • Intracranial hemorrhage

Brown-Sequard Syndrome

• General considerations:
  • X-RT to the cord from the treatment of malignancy; usually Hodgkin's disease, Ewing's sarcoma, chordoma or non-Hodgkin's lymphoma. Usual dose is >3000 rads. There is little soft tissue in the neck to absorb radiation. Pathology is a proliferating endarteritis of the sulcal arteries
  • Rarely a knife, bullet or accidental cause has been described. If occurs with demyelinating disease, tumor and tuberculoma.
  • Vertical hemisection of the cord:
    • Ipsilateral paralysis below the level of the lesion
    • Ipsilateral loss of vibration proprioception, and light touch sensibility (partial)
    • Contralateral loss of pain and temperature sensibility
    • Bowel, bladder and sexual function is intact
    • Ipsilateral segmental loss of sensation or weakness at the appropriate level (destruction of the spinal grey matter at the level of injury)

Central Cord Syndrome

• General considerations:
  • Usually caused by a hyperextension injury of the neck (fall or automobile accident)
  • Clinical features:
    • Hands and arms are more affected than the legs due to lamination of the corticospinal tracts within the cord; brachial plexus traction injury may contribute to the arm weakness.
    • Sensory loss in the legs and arms is incomplete with sacral sparing. Pressure sensation may be lost in adductor muscles while pin prick and cold can be appreciated (lamination of the spinothalamic tract)
    • Acute urinary retention occurs in 50% of patients. Most patients regain bowel, bladder and sexual function
    • Visceral pain may be diminished due to its ventral position in the dorsal columns
    • Hyperactive reflexes and Babinski sign are present

Anterior Cervical Cord Syndrome

• General considerations:
  • Acutely ruptured disc with or without fracture
  • Abnormally prolonged and tight neck flexion (children or adults forcibly flexed during an LP)
  • Fracture dislocation of the cervical cord
• Clinical features:
  • Immediate paralysis
  • Loss of pain and temperature sensibility below the lesion
  • Preservation of proprioception and vibration sense below the lesion
  • Urinary retention

Posterior Cord Syndrome

• General considerations:
  • Differential diagnosis:
    • Demyelinating disease
    • Sjögren's syndrome
    • B12 deficiency
    • Trauma
    • Tabes dorsalis (most often a root entry zone lesion)
    • Tumor
• Clinical features:
  • Loss of vibration and proprioception. Often may best be determined by placing the tuning fork over the spinous processes.
  • Severe proprioceptive loss in the arms and legs; patients are unable to walk in the dark
  • Updrift of the arms with minimyoclonus of the fingers; a lateral drift occurs bilaterally
  • Dorsal column nuclear involvement causes wild movement of the arms
  • Trauma as a cause may have associated burning pain and paresthesia of the hands
  • Lhermitte's sign is noted with structured lesions irritating the posterior columns.

Associated Cervical Cord Traumatic Injuries

• General considerations:
  • Vertebral artery occlusion from injury in the transcervical canal
  • Dissection may occur at the C2 level
• Clinical features:
  • Rotary nystagmus is ipsilateral > contralateral
  • Involvement of cranial nerves IX, X, XI; XII is involved if the hypoglossal canal is injured at the foramen magnum
  • Pain in the side of the neck; rarely projects specifically to the lateral eyebrow
  • Ipsilateral peripheral or central Horner's syndrome; peripheral origin is from trauma to the carotid sheath or artery; sympathetics to the eye originate from C8–T1 and wrap around the carotid artery.
  • Ipsilateral Vth nerve involvement; VIth passes through the foramen magnum (upper division V_I)
  • Contralateral loss of pain and temperature below the clavicle
  • Ipsilateral ataxia; leg > arm; patients have lateral pulsion (feeling of being pushed) to the ipsilateral side
  • Nausea and vomiting; hoarseness; infarction of the nucleus ambiguous
  • Prolonged depressed level of consciousness

Epiconus Lesions

• General considerations:
  • Traumatic; sudden compression injuries of the thoracic spine; falls, ski and motor vehicular accidents
  • Metastatic tumor of the spinal cord
  • Embolic occlusion of the great radicular artery of Adamkiewicz (origin is T10–T12–L1–L2).
  • Aortic surgical procedures; iliac artery or ligature of the ilioinguinal branch that is the origin of the radicular artery of Adamkiewicz
  • T10–T12 is involved primarily
• Clinical features:
  • Bilateral symmetrical leg weakness
  • Sensory level at L1–L2
  • Bowel, bladder and sexual dysfunction
  • Babinski signs are present; the spinal cord ends at the spinal level of S5, but the vertebral level is L1–L2

Cauda Equina Level

• General considerations:
  • The differential diagnosis for lesions at this level is:
    • Disc protrusion
    • Spinal stenosis
    • Enlarged nerve roots (congenital peripheral neuropathies)
    • Metastatic tumors: colon, lung, breast, lymphoma, prostate are common
    • Vertebral fractures with posterior displacement of bone fragments into the spinal canal
• Clinical features:
  • Asymmetric motor and sensory loss
  • Severe pain (usually L5–S1 distribution)
  • Perineal sensory anesthesias ("saddle distribution")
  • Bowel and bladder dysfunction (obstipation and retention respectively)
  • Areflexic paralysis and sensory loss of the affected roots

Conus Medullaris Lesions

• General considerations:
  • Differential diagnosis of these lesions is:
    • Demyelinating disease in younger patients
    • Glioma and chordoma are the primary tumors; metastatic tumors similar to those for the cauda equina
    • Syrinx
    • Disc fragment
    • Lipoma
    • Liposarcoma
    • Glioma of the filum terminale
• Clinical features:
  • Symmetric if adjacent roots are involved
  • Painless
  • Bowel, bladder and sexual dysfunction are the earliest manifestation
  • Dissociated sexual dysfunction may occur. Patients may have erection without ejaculation or vice versa

Post Traumatic Syringomyelia

• General considerations:
  • A syrinx appears in a region of spinal cord injury due to phagocytosis of tissue debris; the cavities are surrounded by gliosis and have connective tissue in their walls (not seen in a congenital syrinx)
• Clinical features:
  • A syrinx cavity after injury may extend cephalad into previous uninjured tissue with the expected deficits

Arachnoiditis

• General considerations:
  • Arachnoiditis is a chronic inflammatory response of the spinal arachnoid and pial membrane
• Clinical features:
  • Burning patchy pain over several nerve root distributions
  • Motor power of the roots is relatively well maintained
  • Bladder and bowel may be involved
  • Reflexes are decreased or absent in a patchy distribution
• Pathology
  • The spinal cord and roots are encased by leptomeningeal fibrous tissue and loculated cysts. Rarely, the walls of arteries and veins are thickened (demonstrated by an autopsy series of arachnoiditis patients whose illness was caused by contaminated diluent in an anesthetic solution).
• Imaging evaluation:
  • MRI evaluation reveals clumped nerve roots in the center of the dural sac. Myelography with contrast demonstrates a featureless dural sac.