Overview
Tuberculous myelitis is a spinal cord damage formed by tubercle bacilli from other parts of the body (such as lungs, kidneys, bones, etc.) through blood circulation, or direct infiltration of spinal tuberculosis, most often involving the spinal membrane at the same time, so it is also known as tuberculous spondylomyelitis. It is most common in young adults, and may be preceded by a history of tuberculosis contact or tuberculosis. The disease usually starts slowly, with low-grade fever, poor appetite, lethargy and night sweats along with spinal cord symptoms.
Causes
The causative agent is Mycobacterium tuberculosis. Mycobacterium tuberculosis involves the spinal cord, spinal membrane and spinal blood vessels through bloodstream or direct invasion, forming tuberculous granuloma or tuberculous ball, causing spinal membrane, spinal arachnoiditis and spinal cord ischemia.
Symptoms
1. Most common in young adults, may have a history of tuberculosis contact or tuberculosis before the disease.
2. The disease usually starts slowly, and the spinal cord symptoms are accompanied by low-grade fever, poor appetite, emaciation, and night sweats.
3. Spinal cord damage is often incomplete, with paralysis of the limbs below the level of the lesion, sensory disturbances, and dysfunction of bowel and urinary functions.
4. When the lesion mainly involves damage to the spinal membranes and arachnoid membranes, radicular pain is the main manifestation, and scattered, asymmetric and segmental sensory disturbances occur, which is similar to arachnoiditis of the spinal cord.
Examination
1. Blood tests
Generally normal, peripheral blood white blood cell count is normal or mildly elevated; blood sedimentation is elevated.
2. Cerebrospinal fluid examination
The cell count of cerebrospinal fluid is mildly increased, with tens to hundreds of leukocytes, mostly of mixed type, with monocytes predominating in about 85%, protein content is mildly or moderately increased, and sodium chloride and glucose are mostly decreased. Cerebrospinal fluid dynamics may reveal a patent or partially obstructed spinal canal. Appearance can be hairy glass, placed for a few hours to see the formation of white fibrous film, the film antacid staining direct smear is easier to find tubercle bacilli.
3. The basis of pathogenesis
(1) CSF bacterial smear and bacterial culture detection rate is low.
(2) Skin tuberculin test.
(3) Early diagnosis: polymerase chain reaction (PCR) is often used to detect the DNA of M. tuberculosis in CSF.
Enzyme-linked immunosorbent assay (ELISA) can also be used to detect tuberculosis antibodies in CSF. Simultaneous application of the above two tests can improve the reliability of the diagnosis. However, the possibility of false positives and false negatives should be noted.
4. Other auxiliary examinations
(1) Chest radiography can show active or old tuberculosis foci. Some patients are combined with spinal tuberculosis or tuberculous paravertebral abscess, and the X-ray of the spine of these patients has more typical changes of spinal tuberculosis: destruction of the vertebral body, posterior protrusion and angular deformity of the spine, and formation of paravertebral cold abscesses.
(2) MRI of intraspinal tuberculosis shows swelling of the affected spinal cord, and the tuberculosis ball is an isosignal or low-signal lesion in T1, and a low, isosignal, or high-signal lesion in T2, and there is nodular enhancement of the edge of the lesion or within the lesion after injection of contrast medium. When spinal membrane and spinal arachnoid were involved, MRI showed thickening of lumbar segmental nerve roots, disappearance of subarachnoid space, and linear signal enhancement of nerve roots and spinal cord surface after injection of Gd-DTPA; and patchy signal enhancement of dura mater and arachnoid.
Diagnosis
According to the history of tuberculosis, chronic or subacute onset of symptoms of damage to the spinal cord and/or spinal membrane, specific cerebrospinal fluid changes, X-rays and MRI images of the spinal cord, the general diagnosis is not difficult.
Treatment
Regular anti-tuberculosis treatment should be carried out once the diagnosis is clear.
1. Isoniazid (INH), streptomycin, rifampicin.
2. Isoniazid (INH), streptomycin and para-aminosalicylic acid (PAS) should be used to consolidate the treatment.