• Clinical science

Incomplete spinal cord syndromes

Summary

Incomplete spinal cord syndromes are caused by lesions of the ascending or descending spinal tracts that result from trauma, spinal compression, or occlusion of spinal arteries. Central cord syndrome, anterior cord syndrome, posterior cord syndrome, and Brown-Séquard syndrome are the most common types of incomplete spinal cord syndromes. In contrast to a complete spinal cord injury, lesions only affect part of the cord and patients present with a dissociated sensory loss. A spine MRI is the diagnostic modality of choice to determine the etiology, level, and extent of the lesion. Treatment depends on the underlying etiology. In some cases, surgery may be necessary to treat the underlying cause and to improve the patient's outcome. Spinal compression is a medical emergency and requires urgent treatment with steroids and decompressive surgery.

Overview

Basic neuroanatomy and function

  1. Pyramidal tracts (lateral corticospinal tract and anterior corticospinal tract)
    • Descending tracts originate in the cerebral cortex and extend to the alpha (α) motor neuron in the ventral horn of the spinal cord.
    • About 90% of pyramidal neurons decussate as they pass through the medulla and descend further as the lateral corticospinal tract.
    • The remaining 10% continue as the anterior corticospinal tract and decussate at the segmental level.
    • Function: controls motor function
  2. Posterior column (posterior funiculus consisting of gracile and cuneate fasciculi)
  3. Spinothalamic tract (anterior spinothalamic tract and lateral spinothalamic tract)
    • Decussation only at segmental level or shortly above
    • Function: : conveys protopathic sensation (contralateral temperature, pain stimuli, and crude touch)

Types of incomplete spinal cord syndromes

Affected spinal tracts Etiology Clinical features
Central cord syndrome (most common)
  • Bilateral paresis: upper > lower extremities
Anterior cord syndrome
  • Corticospinal and spinothalamic tracts
Posterior cord syndrome
  • Ipsilateral loss of proprioception, vibration, and touch sensation below the level of the lesion
Brown-Séquard syndrome (hemisection syndrome)
  • Hemisection of the cord
  • Ipsilateral
  • Contralateral: loss of pain and temperature sensation one or two levels below lesion

References:[1][2][3][4][5][6][7][8][9][10]

Central cord syndrome

References:[11][12]

Anterior cord syndrome

Vibration and proprioception are typically spared because of an intact dorsal column!

References:[11][13][14][15][16][17][18]

Posterior cord syndrome

References:[19][20][21][22]

Brown-Séquard syndrome

Autonomic symptoms are generally absent in Brown-Séquard syndrome because of unilateral involvement of the descending autonomic fibers.

References:[11][4][23]