Brown-Séquard syndrome

Brown-Séquard syndrome, also known as Brown-Séquard's hemiplegia and Brown-Séquard's paralysis, is a loss of motor function (paralysis and ataxia) and sensation caused by the lateral hemisection of the spinal cord. Other synonyms are crossed hemiplegia, hemiparaplegic syndrome, hemiplegia et hemiparaplegia spinalis and spinal hemiparaplegia.

Effects
The hemisection of the cord results in a lesion of each of the three main neural systems:
 * the principal upper motor neuron pathway of the corticospinal tract
 * one or both dorsal columns
 * the spinothalamic tract

As a result of the injury to these three main brain pathways the patient will present with three lesions.


 * The corticospinal lesion produces spastic paralysis on the same side of the body (the loss of moderation by the UMN).


 * The lesion to fasciculus gracilis or fasciculus cuneatus results in ipsilateral loss of vibration and proprioception (position sense).


 * The loss of the spinothalamic tract leads to pain and temperature sensation being lost from the contralateral side beginning one or two segments below the lesion. At the lesion site all sensory modalities are lost on the same side, and also an ipsilateral flaccid paralysis.

Causes
Brown-Séquard syndrome may be caused by a spinal cord tumor, trauma (such as a gunshot wound or puncture wound to the neck or back), ischemia (obstruction of a blood vessel), or infectious or inflammatory diseases such as tuberculosis, or multiple sclerosis.

History
It was first described in 1850 by the historically famous British neurologist Charles-Édouard Brown-Séquard (1817-1896), who studied the anatomy and physiology of the spinal cord. Brown-Séquard was quite a controversial and eccentric figure, and is also known for self-reporting "rejuvenated sexual prowess after eating extracts of monkey testis". The response is now thought to have been a placebo effect, but apparently this was "sufficient to set the field of endocrinology off and running."

Interestingly, many nations claim him as their own, he was the son of an American sea captain and a French woman, living in a British territory. He studied in the US, France, as well as the UK. He described this injury which resulted from caning knives trauma in Mauritius.