Spinal shock in humans

In neurology, spinal or spinal shock is defined as a clinical syndrome arising from an initial neurological response to traumatic spinal cord injury - with a reversible loss or reduction of all of its functions below the level of the injury. [1]

According to ICD-10, its code is R57.8 (in the section on general symptoms and signs), but the actual spinal cord injury (the main diagnosis) has the code S14.109A.

Epidemiology

Since it can be difficult for doctors to distinguish between symptoms arising directly from spinal cord injury and manifestations of spinal shock, the clinical statistics of this syndrome are extremely difficult.

Globally, according to WHO estimates, every year 250-500 thousand people receive spinal cord injury (on average, 10-12 cases per 100 thousand population).

Traffic accidents are associated with 38-46% of cases of spinal shock, almost 35% of cases are due to domestic spinal injuries (and every fourth victim had a fall with such an injury), and 10-15% of patients had sports injuries.

Causes spinal shock

Acute  spinal cord injuries  at the level of the cervical (CI-CVII), thoracic (ThI-ThXII) or lumbar (LI-LV) spine are common causes or etiological factors in the development of spinal shock. Although there is an opinion that this clinical syndrome is observed only in spinal cord injury localized up to the sixth thoracic vertebra (ThVI).[2]

In addition  to spinal cord injury  with its intersection (violation of integrity), crushing or distraction (stretching) of the nerves, spinal shock can occur in acute  spinal cord injury syndrome .

Risk factors

Risk factors for the development of spinal shock are  trauma to the thoracic and lumbar vertebrae  - with dislocation and / or fracture of their bodies, severe bruises (with spinal cord concussion),  compression comminuted fractures of the cervical vertebrae  , etc.

These injuries can be obtained during a road traffic accident, industrial accident, sports activities, as a result of domestic accidents, due to a fall from a height or with a gunshot wound. [3]

Pathogenesis

Explaining the pathogenesis of the immediate temporary suppression of all the main functions of the spinal cord in its segments below the level of damage that occurs in spinal shock, experts put forward several versions that are sufficiently substantiated from the anguish of neurophysiology.

The main mechanism of spinal shock is a sharp interruption of the descending pyramidal and extrapyramidal, as well as the vestibulospinal and reticulospinal tracts (pathways) of the spinal cord. Such manifestations of this syndrome, as loss of tone and suppression of reflexes, are associated both with a violation of corticospinal connections and a decrease in the excitability of motor neurons (motor neurons) of the spinal cord, and with a decrease in the sensitivity of stretch receptors and contraction of the muscles of the neuromuscular spindle. The process can be aggravated by presynaptic inhibition and blocking of autonomic reflex arcs - pathways for nerve signals to secondary ganglion neurons outside the spinal cord.

In addition, a sharp neurological reaction to damage to the spinal cord may be due to increased polarization of its motor neurons and / or an increase in the concentration of aminoacetic acid (glycine), a neurotransmitter that inhibits nerve conduction.

Read also -  The structure of the nervous system

Symptoms spinal shock

In spinal shock, the first signs are manifested by complete or partial loss of spinal reflexes - hyporeflexia, as well as a short-term increase in blood pressure and a slowdown in the pulse, which is quickly replaced by neurogenic arterial hypotension with cardiac arrhythmia in the form of bradycardia. At the same time, some polysynaptic reflexes (plantar, bulbocavernous) are restored several days after the injury.[4]

There are also symptoms of spinal shock such as:

• hypothermia  and pallor of the skin;
• violation of sweating  in the form of hypohidrosis or anhidrosis;
• lack of sensory response - loss of sensitivity (numbness) below the level of injury;
• violation of muscle tone  and flaccid paralysis with varying degrees of immobility;
• spasticity of skeletal muscles with hyperreflexia (increased manifestation of deep tendon reflexes).

The clinical picture may vary depending on the location and severity of the spinal cord injury. The duration of spinal shock also varies: from several hours to several weeks (on average, this syndrome is observed within one to three months from the moment of injury).

Complications and consequences

In cases of spinal shock, patients may have complications and consequences in the form of impaired function of the detrusor (the muscle of the bladder that provides the urinary process), which causes urinary retention, and if the bladder overflows, urinary incontinence occurs, that is, symptoms of the so-called  neurogenic urinary bubble . In some cases, the lack of autonomic tone leads to intestinal obstruction.

Complications may include:  lower spastic paraparesis (paraplegia) of  skeletal muscles or lack of mobility of all limbs - tetraparesis (tetraplegia); contractures, weight loss, muscle atrophy and pressure sores; muscle or joint pain; swelling of the lower extremities with the threat of deep vein thrombosis and pulmonary embolism; orthostatic hypotension; breathing problems with an increased risk of pneumonia; depression.[5]

Diagnostics spinal shock

When receiving a spinal cord injury, the diagnosis of spinal shock requires a full examination of the patient, first of all, an assessment of his condition and the study of reflexes (tendon, extensor-flexion, skin). [6]

Instrumental diagnostics is used for visualization:

• X-ray of the spine and spinal cord ;
• computed tomography of the spine ;
• MRI of the spine .

Do blood tests: general, for clotting, for levels of  lactic acid (lactate) in the blood  and arterial blood gases.

Differential diagnosis

Differential diagnosis should be carried out with degenerative diseases of the central nervous system, malignant neoplasms or infectious lesions of the spinal cord, spinal amyotrophy,  spinal cord infarction , Brown-Séquard syndrome, myelopathic or myasthenic syndromes. Also, neurogenic shock must be distinguished from spinal shock - a sudden loss of autonomic tone due to damage to the spinal cord, but not below the level of injury, but above it.

Treatment spinal shock

Patients with spinal cord injuries and spinal shock are treated in the intensive care unit. [7]

As a rule, therapeutic measures consist of immobilization of the spine (which is carried out even during the provision of emergency care), ensuring respiratory function, and controlling blood circulation. In  infusion therapy  , a hypertonic solution is used with the addition of Atropine (with bradycardia),  Dopamine , Norepinephrine. That is, treatment focuses on the spinal cord injury in general.

The first task of the  neurotraumatologist  is to relieve the patient of the symptoms caused by spinal shock. The use of corticosteroids for spinal cord injury, in particular methylprednisolone, is not supported by all specialists, since its side effects often outweigh the expected therapeutic effect. Although for young patients, this drug is prescribed on the first day after injury.[8]

At the same time, as practice shows, more than half of the patients need to stabilize the spine with the help of surgical intervention.

Spinal shock and spinal cord injury require a variety of treatments, including exercise therapy to strengthen muscles and  therapeutic massage ; physiotherapy activating nerve conduction; rational nutrition to maintain a healthy body weight; prevention of pressure sores  , etc.

All patients need rehabilitation to restore spinal cord function. [9]

Prevention

Prevention of the development of spinal shock can be considered to reduce the risk of injury to the spine and spinal cord: wear a seat belt in a car and follow traffic rules; do not dive into the water in unfamiliar places and shallow pools; take precautions when playing sports, etc.[10]

Forecast

The most favorable prognosis is with minor damage to the spinal cord, when the most complete restoration of its functions is possible. [11]But many patients, especially those with a spinal fracture, have to move in a wheelchair.