Acute myelitis is a non-specific inflammatory lesion of the spinal cord that occurs after infection. The inflammation often involves the gray and white matter of several medullary segments and their surrounding spinal membranes, with the thoracic medulla being the most susceptible to transverse spinal cord damage. In some patients, the level of paralysis and sensory impairment rises, eventually reaching the upper cervical medulla and causing tetraplegia and respiratory muscle paralysis, and may be accompanied by high fever, endangering the patient’s life, called ascending myelitis.
Acute myelitis is a non-specific inflammatory lesion of the spinal cord that occurs after infection. The inflammation often involves the gray and white matter of several medullary segments and the surrounding spinal membrane, with the thoracic medulla being the most susceptible and producing symptoms of transverse spinal cord damage. In some patients, the level of paralysis and sensory impairment rises, eventually reaching the upper cervical medulla and causing tetraplegia and respiratory muscle paralysis, and may be accompanied by high fever, endangering the patient’s life.
The cause of acute myelitis is not known, but it may be due to some viral infections or an autoimmune reaction of the body after infection, and some occur after vaccination.
How is acute myelitis diagnosed?
Most young adults with symptoms of upper respiratory infection within two weeks before the onset of the disease, or a history of vaccination. There is a history of cold, overexertion, trauma and other triggers for the onset of the disease. The first symptoms are numbness and weakness of both lower extremities, back pain and girdling sensation in the corresponding part of the lesion, urinary retention and fecal incontinence.
There are manifestations of transverse spinal cord damage.
The early stage of spinal cord shock is characterized by bradykinetic paralysis, and after the shock period (3-4 weeks), the limbs below the lesion site show upper motor neuron paralysis.
2. Loss of superficial and deep sensation below the lesion plane, and some of them may have sensory hypersensitivity zones in the lesion plane.
3.Vegetational disorders: manifested as urinary retention, large amount of residual urine and filling incontinence, fecal incontinence. After the shock period, it presents reflex bladder, stool constipation and abnormal penile erection.
Auxiliary tests
1, Peripheral blood leukocyte count is normal or slightly high in the acute phase.
2, cerebrospinal fluid pressure is normal, some patients have mildly increased leukocytes and protein, and the sugar and chloride content is normal.
3. MRI of the spinal cord showed thickening of the spinal cord at the site of lesion and abnormal signal.
Based on the acute onset of the disease, the history of infection before the disease, the symptoms of transverse spinal cord damage and the cerebrospinal fluid, the diagnosis is not difficult but needs to be differentiated from the following diseases.
1. Acute infectious polyneuritis.
The limbs are flaccid paralysis, which may or may not be accompanied by distal limb set sensory disorders, craniosynostosis is often damaged, there is usually no urinary or fecal disorders, and the cerebrospinal fluid often has protein a cell separation phenomenon ten days after the onset of the disease.
2.Spinal cord compression disorder.
Spinal cord tumors generally have a slow onset and gradually develop into transverse spinal cord damage symptoms, often with a history of neurogenic pain and obstruction of the spinal canal. Epidural abscesses have a rapid onset, but there are often localized foci of purulent infection, more obvious symptoms of systemic toxicity, pain and percussion pain at the site of the abscess, the plane of paralysis often rises rapidly, and the spinal canal is obstructed. If necessary, myelography and magnetic resonance imaging can be used to confirm the diagnosis, and it is generally not difficult to distinguish.
3, acute spinal vascular disease.
Acute onset of anterior spinal artery thrombosis, severe radicular pain, paralysis of the limbs below the damage plane and loss of pain and temperature sensation, but normal deep sensation. Spinal cord vascular malformation can be asymptomatic, or can be manifested as slowly progressive spinal cord symptoms, some can also be manifested as recurrent limb paralysis and radicular pain, and symptoms often fluctuate, some in the corresponding segment of the skin can be seen in the hemangioma or in the blood guest malformation site at the spine hear vascular murmur, must be confirmed by myelography and selective spinal angiography.
4. Optic neuromyelitis optica.
Acute or subacute onset, with symptoms of both myelitis and optic neuritis, easily diagnosed if both appear simultaneously or shortly apart. The disease often has relapsing remission, and there is a mild increase in pleural spinal fluid leukocyte count and protein amount.