Transverse myelitis

Transverse myelitis (TM) is a rare neurological condition in which the spinal cord is inflamed. Transverse implies that the inflammation extends across the entire width of the spinal cord. Partial transverse myelitis and partial myelitis are terms used to define inflammation of the spinal cord that affects part of the width of the spinal cord. TM is characterized by weakness and numbness of the limbs, deficits in sensation and motor skills, dysfunctional urethral and anal sphincter activities, and dysfunction of the autonomic nervous system that can lead to episodes of high blood pressure. Signs and symptoms vary according to the affected level of the spinal cord. The underlying cause of TM is unknown. The spinal cord inflammation seen in TM has been associated with various infections, immune system disorders, or damage to nerve fibers, by loss of myelin. Decreased electrical conductivity in the nervous system can result. Transverse myelitis (TM) is a rare neurological condition in which the spinal cord is inflamed. Transverse implies that the inflammation extends across the entire width of the spinal cord. Partial transverse myelitis and partial myelitis are terms used to define inflammation of the spinal cord that affects part of the width of the spinal cord. TM is characterized by weakness and numbness of the limbs, deficits in sensation and motor skills, dysfunctional urethral and anal sphincter activities, and dysfunction of the autonomic nervous system that can lead to episodes of high blood pressure. Signs and symptoms vary according to the affected level of the spinal cord. The underlying cause of TM is unknown. The spinal cord inflammation seen in TM has been associated with various infections, immune system disorders, or damage to nerve fibers, by loss of myelin. Decreased electrical conductivity in the nervous system can result. Symptoms include weakness and numbness of the limbs, deficits in sensation and motor skills, dysfunctional urethral and anal sphincter activities, and dysfunction of the autonomic nervous system that can lead to episodes of high blood pressure. Symptoms typically develop over the course of hours to a few weeks. Sensory symptoms of TM may include a sensation of pins and needles traveling up from the feet. The degree and type of sensory loss will depend upon the extent of the involvement of the various sensory tracts, but there is often a 'sensory level' at the spinal ganglion of the segmental spinal nerve, below which sensation to pain or light touch is impaired. Motor weakness occurs due to involvement of the pyramidal tracts and mainly affects the muscles that flex the legs and extend the arms. Disturbances in sensory nerves and motor nerves and dysfunction of the autonomic nervous system at the level of the lesion or below, are noted. Therefore, the signs and symptoms depend on the area of spine involved. Back pain can occur at the level of any inflamed segment of the spinal cord. If the upper cervical segment of the spinal cord is involved, all four limbs may be affected and there is risk of respiratory failure – the phrenic nerve which is formed by the cervical spinal nerves C3, C4, and C5 innervates the main muscle of respiration, the diaphragm. Lesions of the lower cervical region (C5–T1) will cause a combination of upper and lower motor neuron signs in the upper limbs, and exclusively upper motor neuron signs in the lower limbs. Cervical lesions account for about 20% of cases. A lesion of the thoracic segment (T1–12) will produce upper motor neuron signs in the lower limbs, presenting as a spastic diplegia. This is the most common location of the lesion, and therefore most individuals will have weakness of the lower limbs. A lesion of the lumbar segment, the lower part of the spinal cord (L1–S5) often produces a combination of upper and lower motor neuron signs in the lower limbs. Lumbar lesions account for about 10% of cases. TM is a heterogeneous condition, that is, there are several identified causes. Sometimes the term Transverse myelitis spectrum disorders is used. In 60% of patients the cause is idiopathic. When it appears as a comorbid condition with neuromyelitis optica (NMO), it is considered to be caused by NMO-IgG autoimmunity, and when it appears in multiple sclerosis cases, it is considered to be produced by the same underlying condition that produces the MS plaques.