A disorder with variable symptoms, etiology, and treatments.
Myelopathy describes any neurologic deficit related to the spinal cord.
Its most common form is cervical spondylotic myelopathy (CSM), also called degenerative cervical myelopathy.
It results from narrowing of the spinal canal (spinal stenosis) ultimately causing compression of the spinal cord.
When due to trauma, myelopathy is known as an acute spinal cord injury.
When inflammatory, it is known as myelitis.
Disease that is vascular in nature is known as vascular myelopathy.
In Asian populations, spinal cord compression often occurs due to a different, inflammatory process affecting the posterior longitudinal ligament.
The clinical findings and symptoms depend on which spinal cord level-cervical, thoracic, or lumbar, is affected and the extent of anterior, posterior, or lateral position of the pathology.
Diagnosis is suggested by spinal cord dysfunction signs and symptoms.
The spinal cord is a continuation of the brain and extends from the cranial-cervical junction to the lumbar spine.
It ends at the conus medullaris, most frequently at the L1-2 interspace disc level.
It is a segment of structure with pairs of dorsal and ventral nerve rootlets entering and exiting at each level.
The dorsal nerve rootlets bring sensory information to the dorsal horn, whereas ventral nerve rootlets exit from the ventral horn containing motor nerve fibers.
The spinal rootless join at the intravertebral foramen to form the spinal nerves, eight cervical, 12 thoracic, five lumbar, five sacral, and one coccygeal nerve.
The gray matter containing neurons are centrally located, surrounded by ascnding and descending white matter tracts.
The majority of neurons in the spinal cord or interneurons, integrating with afferent and efferent signals.
There are several white matter tracts in the spinal cord, three major tracts are associated with major functional impairment.
Findings of myelopathy:
Upper motor neuron signs—weakness, spasticity, clumsiness, altered tonus, hyperreflexia and pathological reflexes, including Hoffmann’s sign and inverted plantar reflex a positive Babinski sign.
Lower motor neuron signs—weakness, clumsiness in the muscle group innervated at the level of spinal cord compromise, muscle atrophy, hyporeflexia, muscle hypotonicity or flaccidity, fasciculations
Sensory deficits
Bowel/bladder symptoms and sexual dysfunction
Diagnosis of myelopathy:
Myelopathy is primarily diagnosed by clinical exam findings.
Myelopathy describes a clinical syndrome that can be caused by many pathologies the differential diagnosis of myelopathy is extensive.
The onset of myelopathy may be rapid, or as in cervical myelopathy the course may be insidious with symptoms developing slowly over a period of months.
Diagnosis of etiology involves medical imaging.
The best way to visualize the spinal cord is magnetic resonance imaging (MRI).
T1 and T2 MRI images are commonly used for routine diagnosis.
Other imaging modalities used for evaluating myelopathy include plain X-rays for detecting arthritic changes of the bones, and Computer Tomography, which is often used for pre-operative planning of surgical interventions for cervical spondylotic myelopathy.
Angiography is used to examine blood vessels in suspected cases of vascular myelopathy.
Myelopathy’s presence and severity can also be evaluated by means of transcranial magnetic stimulation (TMS).
TMS is a neurophysiological method that allows the measurement of the time required for a neural impulse to cross the pyramidal tracts, starting from the cerebral cortex and ending at the anterior horn cells of the cervical, thoracic or lumbar spinal cord: Central Conduction Time (CCT).
TMS can determine whether myelopathy exists and can identify the level of the spinal cord where myelopathy is located.
This is especially useful in cases where more than two lesions may be responsible for the clinical symptoms and signs, such as in patients with two or more cervical disc hernias.
TMS can also help in the differential diagnosis of different causes of pyramidal tract damage.
Treatment:
The treatment and prognosis of myelopathy depends on the underlying cause.
Myelopathy caused by infection requires medical treatment with pathogen specific antibiotics.
Specific treatments exist for multiple sclerosis associated with myelopathy.
The most common form of myelopathy is secondary to degeneration of the cervical spine, and patients benefit from surgery.