Myelopathy describes any neurologic deficit related to the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...

. The most common form of myelopathy in humans, '' cervical spondylotic myelopathy (CSM)'', also called ''degenerative cervical myelopathy'', results from narrowing of the spinal canal (

spinal stenosis Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual i ...

) ultimately causing compression of the spinal cord. When due to

trauma Trauma most often refers to: * Major trauma, in physical medicine, severe physical injury caused by an external source * Psychological trauma, a type of damage to the psyche that occurs as a result of a severely distressing event *Traumatic i ...

, myelopathy is known as (acute)

spinal cord injury A spinal cord injury (SCI) is damage to the spinal cord that causes temporary or permanent changes in its function. Symptoms may include loss of muscle function, sensation, or autonomic function in the parts of the body served by the spinal cor ...

. When inflammatory, it is known as

myelitis Myelitis is inflammation of the spinal cord which can disrupt the normal responses from the brain to the rest of the body, and from the rest of the body to the brain. Inflammation in the spinal cord, can cause the myelin and axon to be damaged re ...

. 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 posterior longitudinal ligament is a ligament connecting the posterior surfaces of the vertebral bodies of all of the vertebrae. It weakly prevents hyperflexion of the vertebral column. It also prevents posterior spinal disc herniation, altho ...

Presentation

Clinical signs and symptoms depend on which spinal cord level (cervical, thoracic, or lumbar) is affected and the extent (anterior, posterior, or lateral) of the pathology, and may include: * Upper motor neuron signs—weakness, spasticity, clumsiness, altered tonus,

hyperreflexia Hyperreflexia is overactive or overresponsive bodily reflexes. Examples of this include twitching and spastic tendencies, which indicate upper disease of the upper motor neurons and the lessening or loss of control ordinarily exerted by higher ...

and pathological reflexes, including Hoffmann's sign and inverted

plantar reflex The plantar reflex is a reflex elicited when the sole of the foot is stimulated with a blunt instrument. The reflex can take one of two forms. In healthy adults, the plantar reflex causes a downward response of the hallux (flexion). An upward re ...

(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

Diagnosis of myelopathy

Myelopathy is primarily diagnosed by clinical exam findings. Because the term ''myelopathy'' describes a clinical syndrome that can be caused by many pathologies the differential diagnosis of myelopathy is extensive. In some cases the onset of myelopathy is rapid, in others, such as CSM, the course may be insidious with symptoms developing slowly over a period of months. As a consequence, the diagnosis of CSM is often delayed. As the disease is thought to be progressive, this may impact negatively on outcome.

Diagnosis of etiology

Once the clinical diagnosis ''myelopathy'' is established, the underlying cause must be investigated. Most commonly this involves medical imaging. The best way to visualize the spinal cord is magnetic resonance imaging (MRI). Apart from T1 and T2 MRI images, which are commonly used for routine diagnosis, more recently researchers are exploring quantitative MRI signals. Further imaging modalities used for evaluating myelopathy include plain

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

s 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 Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is perfor ...

is used to examine blood vessels in suspected cases of vascular myelopathy. The presence and severity of myelopathy can also be evaluated by means of

transcranial magnetic stimulation Transcranial magnetic stimulation (TMS) is a noninvasive form of brain stimulation in which a changing magnetic field is used to induce an electric current at a specific area of the brain through electromagnetic induction. An electric pulse gener ...

(TMS), 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. This measurement is called ''Central Conduction Time'' (''CCT''). TMS can aid physicians to: * Determine whether myelopathy exists * 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 * Follow-up the progression of myelopathy in time, for example before and after cervical spine surgery 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. Similarly, specific treatments exist for multiple sclerosis, which may also present with myelopathy. As outlined above, the most common form of myelopathy is secondary to degeneration of the cervical spine. Newer findings have challenged the existing controversy with respect to surgery for cervical spondylotic myelopathy by demonstrating that patients benefit from surgery.

References

External links

{{Spinal cord lesions Spinal cord disorders Orthopedic problems