Opisthotonos - Definition, Position, Causes, Treatment
Opisthotonos is a type of an abnormality in the posture in which an afflicted patient assumes a bridging arch posture where the head, neck and spinal column go into a complete arch or a bridge position. It is characterized by an extreme Hyperextension and spasticity and is more apparent when the patient lies down on his back. The back of the head and the heel of the toes is what usually touch the flat surface when assuming a supine position. It is more common and defined in infant in relation to the underdeveloped nervous system. The abnormal posturing may also occur in adults although this is less common. Abnormal posturing is different from bad posture as the former is defined as a chronic abnormal position of the body and rigid body movements. Abnormal posturing is characterized by the inability of the muscle to provide resistance when a muscle contracts.
Opisthotonos is defined by extreme Hyperextension and spasticity. Hyperextension is an exaggerated backward bent of a body part. It can occur as a voluntary movement of the muscle and may also occur involuntary which may result from trauma, fall and other medical condition.
Spasticity results when there is an inability of the muscle to provide support when a muscle is contracting. The excessive contraction of the muscle will lead to over flexion of the joints or known as hyperreflexia. The incidence of spasticity, defined with an odd stiffness and pull of the muscle, is generally due to an imbalance in the inhibitory and excitatory contribution to the motor neurons that often resulted from the damages to the spinal cord or the central nervous system. The excitability in the muscles is increased due to the presence of imbalance in the transmission of signals between the muscles and the nervous system. The imbalance in the signal transmission is caused by an injury or damage to an area of the brain or the central nervous system that is responsible for controlling the voluntary movement of the muscles.
In Opisthotonos, the abnormal posture assumed by the patient is defined with Hyperextension on the back in an extreme arch similar to a bridge. The head and the neck are thrown backward, which is especially apparent in supine position. The back is arched with the torso and abdomen pushed upward. The legs are hyperextended with the heel of the toes giving the body support on a flat surface. The arms are bent toward the chest with fists that are tightly closed.
Opisthotonos can be easily recognized when a patient is placed in a supine position. The back of the head and the heels of the toes are the only body part that would touch the flat surface. The abnormal posturing is exaggerated by the extreme rigidity of the muscles as a result of muscle spasm. General spasm is notable in all parts of the body.
Opisthotonos occur when there is an imbalance in the signal transmission between the nervous system and the muscles. The imbalance that triggers the muscle to stiffen often resulted from any injury and damages directed into the central nervous system, particularly affecting the part of the brain that controls the voluntary movement of the muscles. This type of abnormal posturing is more common in infants and neonates and is often seen as a symptom of meningitis or tetanus. The incidence of Opisthotonos is often associated with medical conditions, injuries and damages affecting the brain, the nervous system and the central nervous system.
Tetanus is the most implicated in the incidence of Opisthotonos. Tetanus is an acute condition that involves the nervous system and is the result of toxins produced by bacteria called Clostridium tetani. It is also referred to as lockjaw and is characterized by an extended episode of muscle contraction. Tetanus usually arises from a skin wound contaminated by Clostridium tetani. Neonatal tetanus on the other hand occurs as a result of unsanitary conditions during delivery and usually contaminates the cut umbilical cord. Muscle spasm and stiffness of the neck, shoulders and the back are among the defining characteristic of tetanus.
Arnold-Chiari syndrome is a brain condition that causes severe spasms especially in children with hydrocephalus. The syndrome is described as a structural defect occurring in the back part of the brain of the child.
Meningitis is also among the cause of Opisthotonos in neonate. It is the inflammation of the meninges that surrounds the brain and the spinal cord. Meningitis is caused by a viral infection and stiffness of the neck is among its symptoms in a neonate including episode of seizure.
Opisthotonos may also occur in adults although this seldom happens. The onset in adults however may include the following:
- Severe head injury
- Severe electrolyte imbalance brought by another medical condition
- Bleeding in the brain or the so called subarachnoid hemorrhage
- Overdose of Adrenergic bronchodilatior
- Lithium intoxication
- Drowning victims can also be seen with Opisthotonos and is sometimes referred to as Opisthotonic Death Pose.
The treatment of Opisthotonos depends on the underlying medical condition that resulted in its onset. Tetanus causing Opisthotonos is rather treated towards the relief of symptoms as tetanus cannot be cured and the treatment is geared towards the prevention of infection from spreading to other parts of the body.
Meningitis causing Opisthotonos are given with an antibacterial medication to treat the infection while over-the-counter pain relievers can be given to relieve the symptom of pain.
Surgical procedure is indicated for Arnold-Chiari syndrome that is causing the incidence of Opisthotonos.
Opisthotonos is a medical emergency that it is necessary to seek immediate medical attention following the episode. The patient is usually treated and needs to be confined in the hospital until appropriate treatment has been applied and the condition of the patient has been stabilized. Supportive care is also necessary especially in providing patient with ample amount of oxygen. Treatment of the underlying conditions that triggered Opisthotonos usually follows after initial treatment has been given to stabilize the condition of the patient.