Brown-Séquard syndrome | |
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Brown-Séquard syndrome is bottom diagram | |
Classification and external resources | |
Specialty | Neurology |
ICD-10 | G83.8 |
ICD-9-CM | 344.89 |
DiseasesDB | 31117 |
eMedicine | emerg/70 pmr/17 |
MeSH | D018437 |
Brown-Séquard syndrome (also known as Brown-Séquard's hemiplegia, Brown-Séquard's paralysis, hemiparaplegic syndrome, hemiplegia et hemiparaplegia spinalis, or spinal hemiparaplegia) is caused by damage to one half of the spinal cord, resulting in paralysis and loss of proprioception on the same (or ipsilateral) side as the injury or lesion, and loss of pain and temperature sensation on the opposite (or contralateral) side as the lesion. It is named after physiologist Charles-Édouard Brown-Séquard, who first described the condition in 1850.
Any presentation of spinal injury that is an incomplete lesion (hemisection) can be called a partial Brown-Séquard or incomplete Brown-Séquard syndrome.
Brown-Séquard syndrome is characterized by loss of motor function (i.e. hemiparaplegia), loss of vibration sense and fine touch, loss of proprioception (position sense), loss of two-point discrimination, and signs of weakness on the ipsilateral (same side) of the spinal injury. This is a result of a lesion affecting the dorsal column-medial lemniscus tract, which carries fine (or light) touch fibers, conscious proprioception, vibration, pressure and 2-point discrimination, and the corticospinal tract, which carries motor fibers. On the contralateral (opposite side) of the lesion, there will be a loss of pain and temperature sensation and crude touch 1 or 2 segments below the level of the lesion via the Spinothalamic Tract of the Anterolateral System. Bilateral (both sides) ataxia may also occur if the ventral spinocerebellar tract and dorsal spinocerebellar tract are affected.
Crude touch, pain and temperature fibers are carried in the spinothalamic tract. These fibers decussate at the level of the spinal cord. Therefore, a hemi-section lesion to the spinal cord will demonstrate loss of these modalities on the contralateral side of the lesion, while preserving them on the ipsilateral side. Upon touching this side, the patient will not be able to localize where they were touched, only that they were touched. This is because fine touch fibers are carried in the dorsal column-medial lemniscus pathway. The fibers in this pathway decussate at the level of the medulla. Therefore, a hemi-section lesion of the spinal cord will demonstrate loss of both fine touch (preserved on the contralateral side) and crude touch (destruction of the decussated spinothalamic fibers from the contralateral side) on the ipsilateral side.