Brown-Sequard Syndrome

Among the numerous neurological diseases, the Brown-Séquard syndrome stands out, which is also called hemiparaplegic syndrome or Brown-Séquard hemiplegia (from the Greek hemi - half). It occurs as a result of unilateral damage to the spinal cord, particularly in the cervical spine. [1]

The disease belongs to paralytic syndromes, and in the ICD-10 its code is G83.81.

Epidemiology

This syndrome is classified as a rare neurological condition, and its share in the total statistics of spinal cord injuries recorded by the WHO accounts for no more than 4%. [2], [3]

Causes brown-Séquard syndrome

The syndrome of the defeat of the half of the spinal cord can be caused by various causes, and most often its damage is associated with:

• blunt or penetrating  spinal cord injury , vertebral fracture in the neck or back;
• prolonged compression -  compression of the spinal cord ;
• herniated disc , as well as cervical spondylosis (C1-C8);
• protrusion of the disc of the  spinal column in the same section; [4]
• spinal neoplasm, including  angioma  and intramedullary tumor;
• arachnoid or ganglionic  cyst of the spine ;
• intradural spinal hernia;
• epidural hematoma of the spinal cord at the level of the thoracic spine (Th1-Th12);
• demyelination of the nerve roots in the cervical spine, including in patients with  multiple sclerosis .

Tuberculosis of the spine also belongs to diseases that damage a part of the spinal cord. And the development of the syndrome due to the dissection of the vertebral artery, in which the blood flow in the spinal vessels with ischemic damage -  spinal cord infarction , decreases, is considered an extremely rare case. [5],  [6],  [7], [8]

Risk factors

Based on the main causes of hemiparaplegic syndrome, the risk factors for its development are:

• injuries from gunshot or stab wounds to the neck or back, falling from a height or car accidents;
• pathological changes in the structures of the spine of a degenerative nature, as well as its lateral curvature (kyphosis);
• spinal cord tumors (primary or metastatic);
• inflammatory processes in the spine;
• spinal cord hemorrhage caused by vascular damage;
• bacterial or viral infections with the development of tuberculosis, neurosyphilis (tabes dorsalis), meningitis, shingles, etc.;
• manual and radiation therapy, long-term use of anticoagulants.

Pathogenesis

The pathogenesis of spinal hemiparaplegia is caused by  impaired neuromuscular transmission  due to damage to one side of the spinal cord with destruction of the fibers of the lateral nerve tracts: corticospinal (pyramidal), spinothalamic (extrapyramidal), as well as the medial lemniscus pathway of the dorsal columns.

The fibers of the conducting nerve pathways, consisting of motor and sensory neurons and their processes - axons, do not go straight, but repeatedly intersect with the transition to the opposite side. This means that unilateral damage to the spinal cord, provoking the development of Brown-Séquard syndrome, leads to its manifestations both from the same side as the alteration of nerve fibers - ipsilateral, and from the opposite, that is, the contralateral side of the body.

In the absence of transmission of nerve signals along the lateral corticospinal tract, motor function is lost. And the result of a violation of neurosensory conduction along the lateral spinothalamic and middle lemniscal tracts is the loss of nociception (sensations of pain) - with persistent hypalgia, proprioception (mechanosensory sensation of body position and movement) and tactile (tactile) sensations, including temperature - with pronounced thermanesthesia.

More information in the materials:

• Pathways of the brain and spinal cord
• The structure of the nervous system

Symptoms brown-Séquard syndrome

Depending on the localization of the spinal cord injury, such types of Brown-Séquard syndrome are distinguished as right-sided and left-sided. And according to the clinical manifestation - complete (inverted) and incomplete (partial); most patients have an incomplete form.

The first signs of this syndrome: loss of sensations of pain, temperature, light touch, vibration and position of the leg joints - below the spinal cord alteration zone (on the same side of the body).

The main clinical symptoms reflect hemisectional damage to the spinal cord and are manifested as:

• loss of motor function - flaccid (spastic) paraparesis or  hemiparesis (hemiplegia)  with weakening of the ipsilateral lower limb;
• contralateral loss (below the affected area) of pain sensation, plantar response, and temperature sensitivity;
• violations of the coordination of movements - ataxia;
• loss of bladder and bowel control.

Complications and consequences

Possible complications are associated with loss of sensitivity (in which the risk of cuts and burns increases) and weakening - hypotonia of muscles, which in conditions of limited mobility can lead to muscle atrophy.

The most severe consequences are noted when the syndrome progresses to complete paralysis.

Diagnostics brown-Séquard syndrome

In the prevention of the irreversible consequences of hemiparaplegic syndrome, its early diagnosis plays an important role.

Neuropathologists examine the patient with the  study of reflexes  - deep and superficial, as well as assess the degree of functional and neurological disorders.

Laboratory tests - biochemical and immunological tests of blood, as well as cerebrospinal fluid - may be required in difficult cases (non-traumatic origin of the syndrome) and to clarify the diagnosis.

The key diagnostic method is instrumental diagnostics:  X-ray of the spine and spinal cord , computed tomography and  MRI of the spine ,  electroneuromyography , CT myelography.

Differential diagnosis

Differential diagnosis includes diseases of motor neurons (primarily amyotrophic lateral sclerosis), progressive atrophy of the spinal muscles, hereditary motor-sensory polyneuropathies and spinocerebellar ataxias, Mills and Horner syndromes, multiple sclerosis,  [9]almost all alternating syndromes associated with the spinal cord  , as well as... [10]

Treatment brown-Séquard syndrome

Standard treatment for Brown-Séquard hemiplegia focuses on its underlying cause - when it is well established. Drugs may be used to relieve or reduce the intensity of some symptoms.

Although high-dose corticosteroids are used, their effectiveness remains a matter of debate.

In Brown-Séquard syndrome, etiologically associated with multiple sclerosis, an immune stimulator is used -  B-immunoferon 1a .

With Brown-Séquard syndrome, caused by a herniated cervical intervertebral disc, they resort to surgical treatment: discectomy, spinal fusion,  laminectomy .

And the treatment of an epidural hematoma of the spinal cord is carried out by its surgical drainage. Decompression surgery is recommended for patients with trauma, tumor, or abscess causing spinal cord compression. [11], [12]

All patients with Brown-Séquard syndrome require comprehensive rehabilitation, which can help partially restore motor skills (thanks to the preserved functions of the descending motor axons of the nerve pathways). To do this, various physiotherapy procedures are used, as well as locomotor therapy using a robotic treadmill with body weight support.

Prevention

There are no special preventive measures to prevent unilateral spinal cord injury with the development of hemiparaplegic syndrome.

Forecast

In Brown-Séquard syndrome, the prognosis varies depending on its etiology and the degree of clinical manifestation, and it cannot be called good in terms of functional improvements. More than half of patients with BSS recover well, and most post-traumatic patients recover motor function. Recovery slows down within three to six months, and permanent neurological recovery can take up to two years.  [13] If the deficiency is at the level at which it affects the intestines and bladder, patients can recover their function in 90% of cases. Most patients recover some strength in the lower limbs, and most recover functional ability to walk. When loss of motor function is present, recovery is faster on the opposite side and slower on the ipsilateral side.