Brown-Séquard syndrome (BSS) is a type of incomplete spinal cord lesion with a particular clinical pattern, which is characterized by the paralysis and loss of proprioception on the body side of the injury (ipsilateral) and loss of pain and temperature sensation on the opposite one.
The onset of the clinical manifestations is generally acute and progressive in nature. As previously said, complete hemisection is very rare. Incomplete hemisection, instead, is much more common and implies the appearance of signs and symptoms of other forms of spinal cord injury.
Pure BSS is generally characterized by the interruption of the lateral corticospinal tracts, the interruption of the posterior white column, and that of lateral spinothalamic tracts. Partial forms instead, are usually characterized by asymmetrical paresis with marked hypalgesia on the less paretic side.
At the level of the lesion it is possible to observe a total ipsilateral loss of position, light touch and vibration sensation. As previously said, controlateral loss of pain and temperature can be seen a few segments below the lesion, due to the particular architecture of spinothalamic tracts in the spinal cord. This is usually associated with ipsilateral spastic paraparesis with the loss of vibration and joint-position sense due to the damage of ipsilateral dorsal column fibres underneath the lesion.
The signs of the incomplete forms of BSS are usually the result of vascular impairment due to spinal cord compression or inflammatory lesions such as multiple sclerosis. Other conditions and syndromes which show similar clinical signs to those of BSS include spinal cord compression, stroke, multiple sclerosis, and spinal tumors.
Physical examination is the key procedure to diagnose BSS, although laboratory studies might be useful to confirm the results, especially in the cases of nontraumatic epidoses like infections and tumors. Imaging studies might also be important, although not necessary, especially when additional injuries are suspected, like for example intraabdominal injuries or those resulting from bone fractures which are frequently neglected during physical examination. In particular, MRI might help understand the structure of the point damaged or identify nontraumatic transformations like tumors. CT scanning, instead, might be very useful to identify the injury on nerve tissue around the damaged point of the spinal cord  . Other imaging studies include angiography, to identify vascular malformations, and nuclear medicine scans, to identify infections or inflamed states responsible for the episode of BSS. Lumbar puncture is used only for specific etiologies, like multiple sclerosis, tumor, or tuberculosis, where it is usually coupled with the laboratory analysis of cerebral spinal fluid.
Emergency care of BSS is performed through a thorough physical examination of the injury, which should be followed by a cervical spine/dorsal spine immobilization, with the exception of neck, before the beginning of physical therapy. It is essential to perform a complete and detailed physical examination, with the aid of imaging studies, because the sensory loss might make the identifications of the injury(ies) much more difficult.
The goals of physical therapy is to maintain strength in the intact muscles and assure proper movement in the joints. Furthermore, patients should be positioned in an appropriate way in order to avoid subsequent skin breakdown, improve respiratory function and achieve early mobilization to increase upright position tolerance. Recovery of functional movement has to be performed with a progressive and gradual manner, starting from bed mobility and going on with wheelchair mobility and prostheses-aided ambulation. As neurologic recovery continues even after discharge, therapy should be performed in an outpatient setting as well, coupled with home exercise programs to maintain patient’s strength, flexibility, and balance.
Many studies have demonstrated better clinical outcomes with patients undergoing corticosteroid administration, drugs which are well known for their anti-inflammatory properties based on their capability of modifying the immune response to external stimuli. Other drugs used to manage the signs and symptoms of BSS include antibiotics, antispasmodics and pain medications.
The prognosis is relatively good, with many severe cases showing significant motor recovery. This is very fast in the first two months, but slows down and continues for at least one year, even though there are cases in which it might even take up to two years. The classical healing pattern shows first of all the recovery of the ipsilateral proximal extensor muscles and distal flexor muscles, then the recovery from the weakness in the extremity affected by sensory loss, and recovery of voluntary motor strength within 1 to 6 months.
The potential long-term complications of BSS are very similar to those seen in other types of spinal cord injuries, especially problems related to the lower extremities causing difficult ambulation, although the final clinical outcome appears to be much better .
The most common cause of BSS is a violent trauma  with a penetrating mechanism, which results in the injury of just one side of the spinal cord. Classical example of events causing a damage like this include stab and gunshot wounds, or fractures resulted from a violent accident  . Very frequent are also the assaults with a pen and injuries from blowgun darts .
The nontraumatic causes include frequent events and conditions such as tumor, disk herniation , multiple sclerosis, ligamentum flavum ossification , meningitis, and infection by some viruses like herpes zoster and herpes simplex. Rarer, but not less effective as etiological factor, is also chiropractic manipulation  .
In the US there is no database which records cases of Brown-Séquard syndrome due to traumatic and nontraumatic events and its incidence is still unknown. To have a raw approximation, it might be useful to know that the incidence of spinal cord trauma in USA is around 12,000 cases per year, 2-4% of which are supposed to result in BSS. No data about the international incidence of spinal cord trauma are available.
Spinal cord trauma events appear to be more frequent in the white population than in the other ethnic groups. The same tendency can be seen in males, where the frequency of spinal cord events is much higher than in females. In any case, these data represent the traumatic injuries and might have no relation with nontraumatic ones. The average age of individuals affected by BSS is around 40 years .
The lesion created after an accidental event might affect the upper motor neuron pathway of the corticolspinal tract, the dorsal columns, and the spinothalamic tract. The clinical consequences depend on the neuronal system that has been damaged.
The main clinical sign resulting from a damage of the upper motor neuron pathway is spastic paralysis on the ipsilateral side, which is coupled with a flaccid paralysis of the muscles at the level of the lesion itself. Ipsilateral loss of vibration and proprioception are the main clinical signs of the damage of the two dorsal columns, fasciculus gracilis or fasciculus cuneatus. Loss of pain and temperature sensation to the other side of the lesion, instead, are the classical clinical signs of the damage to the spinothalamic tracts. These usually occur a few segments below the lesion, because spinothalamic tracts enter the cord and travel ipsilaterally a few segments before passing to the other side of the cord itself.
Since the etiology is mainly made of accidental events, no prevention plan can be provided.
Brown-Séquard syndrome (BSS) is also known as Brown-Séquard's hemiplegia, Brown-Séquard's paralysis, hemiparaplegic syndrome, hemiplegia et hemiparaplegia spinalis, and spinal hemiparaplegia. BSS was first described during the 1840s by Dr Charles-Édouard Brown-Séquard, whose name then became the name of the condition itself. The ipsilateral hemiplegia with controlateral pain and temperature sensation is the result of the criss-cross pattern of the nerve fibers in the spinal cord.
Being an incomplete lesion, the clinical presentation shows a variety of neurological signs whose severity ranges from mild to severe. The appearance of a pure form of BSS, characterized by a perfect hemisection of the cord, is rarely seen. More common, instead, are the less pure forms with a clinical picture characterized by some signs and symptoms of BSS, plus additional ones which are not specific of this injury. This form of BSS is called Brown-Séquard–plus syndrome .
Brown-Séquard syndrome (BSS) is a type of incomplete spinal cord lesion, which is characterized by the paralysis and loss of proprioception on the body side of the injury and loss of pain and temperature sensation on the opposite one. Being an incomplete lesion, BSS shows a variety of neurological signs whose severity ranges from mild to severe.
The most common cause is a violent trauma with a penetrating mechanism which results in the injury of just one side of the spinal cord. Classical example of events causing a damage like this include stab and gunshot wounds, or fractures resulted from a violent accident. Very frequent are also the assaults with a pen and injury from a blowgun dart. The nontraumatic causes include conditions such as tumor, disk herniation, multiple sclerosis, ligamentum flavum ossification, meningitis, and infection by some viruses like herpes zoster and herpes simplex.
The prognosis of BSS is relatively good, with many severe cases showing significant recovery. The potential long-term complications are very similar to those seen in other types of spinal cord injuries, especially problems related to the lower extremities causing difficult ambulation, although the final clinical outcome appears to be much better.
Treatment is performed through a thorough physical examination of the injury, which should be followed by a cervical spine/dorsal spine immobilization, with the exception of neck, before the beginning of the physical therapy. Many studies have demonstrated better outcomes with patients undergoing corticosteroids administration, a group of drugs which are well known for their anti-inflammatory properties based on their capability of modifying the immune response to external stimuli. Other drugs used to manage the signs and symptoms of BCC include antibiotics, antispasmodics and pain medications.