Spinal arachnoiditis is an aseptic or infectious inflammation of the arachnoid membrane of the spinal cord. It can be combined with cerebral arachnoiditis. Clinical manifestations vary according to the topic and prevalence of arachnoiditis, often have a picture of sciatica accompanied by a neurological deficit of segmental and conductive nature. The diagnosis of “spinal arachnoiditis” is made after myelography or MRI of the spinal cord. Treatment of acute and subacute forms is mainly conservative. Untreatable chronic spinal arachnoiditis is an indication for surgical dissection of adhesions and removal of cysts.
General information
Spinal arachnoiditis with myelographic confirmation was first described in 1929 . In the middle of the XX century, it was considered mainly as a complication spinal surgery. In the period from 1960 to 1980, there was a significant increase in the frequency of arachnoiditis associated with the use of iodophenylundecylates for contrast during myelography. Later it turned out that fat droplets of these contrast agents can persist for a long time in the subdural spinal space, grow fibrin and provoke an aseptic inflammatory process in the arachnoid membrane. The replacement of myelography with modern methods of neuroimaging of the spinal cord, as well as the technical improvement of surgical interventions on the spine, including through the use of microsurgery, have led to a significant reduction in morbidity. However, to this day spinal arachnoiditis remains an urgent problem of practical neurosurgery and neurology.
Causes
Among the trigger factors for the development of arachnoiditis of the spinal cord, a significant proportion belongs to spinal injuries. Injury to the spinal cord and its membranes can occur during surgical interventions on the spinal column, as a result of repeated epidural blockages and lumbar punctures. Secondary spinal arachnoiditis can occur against the background of spinal canal stenosis, degenerative diseases (spondylosis, osteochondrosis, spondyloarthrosis), spinal tumors, hematomyelia. Aseptic arachnoiditis can form due to the introduction of various chemicals into the spinal canal, for example, contrasts for myelography.
Infectious spinal arachnoiditis can be caused by a specific pathogen and be a consequence of syphilis, generalized tuberculosis or tuberculosis of the spine, brucellosis, rickettsiosis, systemic fungal infection in people with HIV or weakened patients, etc. Nonspecific infectious arachnoiditis in half of cases is caused by Staphylococcus aureus; the role of streptococcal infection, proteus, Escherichia is described. In 37% of cases of acute and subacute arachnoiditis, it is not possible to identify the pathogen.
Classification
According to the extent of the lesion, spinal arachnoiditis is classified into limited and diffuse. A limited variant usually occurs due to microtrauma, a diffuse one is caused by a spinal cord injury, an infectious and inflammatory lesion of the central nervous system or a systemic infectious process. According to the etiology, spinal arachnoiditis can be aseptic and infectious (specific and nonspecific).
Morphologically, spinal arachnoiditis is divided into adhesive (adhesive), cystic and mixed cystic-adhesive. The adhesive form is characterized by thickening of the arachnoid shell and the presence of its adhesions with the hard spinal membrane; sometimes ossification of the arachnoid shell is observed. The cystic form proceeds slowly with the gradual formation of arachnoid cysts, which can be extradural (including and not including nerve roots) and intradural. The most common is the cystic-adhesive form of arachnoiditis, which combines the formation of cysts along with the adhesive process.
In accordance with the clinical classification, there are 4 variants of arachnoiditis: root-sensitive, root-posterior lobe, motor-spinal, root-spinal. Spinal arachnoiditis can be acute, subacute and chronic in its course, although the time frame of these forms of course is not precisely established and is described differently in the neurological literature.
Symptoms
Clinical manifestations of arachnoiditis of the spinal cord depend on the localization and prevalence of inflammation along the arachnoid membrane. Limited arachnoiditis more often has a subclinical course and can be accidentally diagnosed during examination or autopsy. Acute and subacute diffuse spinal arachnoiditis manifests with high fever, shell symptoms, and inflammatory changes in the blood and cerebrospinal fluid. Often accompanied by cerebral arachnoiditis.
The first manifestations of arachnoiditis are often transient root pains and paresthesia. Then the pains become permanent, have the character of persistent sciatica. Segmental and conductive sensitivity disorders develop, motor disorders, tendon reflexes fall out, pelvic disorders appear. Chronic arachnoiditis has a slowly progressive course, accompanied by cerebrospinal fluid disorders. If cysts form, the manifestations of arachnoiditis include a symptom complex of compression myelopathy and are similar to the clinic of spinal tumors.
Diagnostics
Diagnostic search for arachnoiditis of the spinal cord consists of studying the anamnesis, examination by a neurologist, laboratory tests, lumbar puncture, myelography or tomography. Acute spinal arachnoiditis is reflected in the blood test by an increase in the level of leukocytes and C-reactive protein, an acceleration of ESR. Increased pressure of cerebrospinal fluid, its rapid outflow during lumbar puncture, indicates cerebrocirculatory disorders. In the study of cerebrospinal fluid, protein-cellular dissociation is observed, a slight increase in the concentration of proteins.
As a rule, it is not possible to unambiguously establish the diagnosis of arachnoiditis without the use of myelography or tomographic studies. A pathognomonic sign of arachnoiditis during contrast myelography is a delay in contrast in the form of individual drops. It became possible to visualize changes in the spinal arachnoid membrane after the introduction of spinal MRI into neurological practice. MRI also allows you to exclude tumors and other organic lesions of the spinal cord.
Differential diagnosis is carried out with meningomyelitis, myelitis, epidural abscess, posttraumatic hematoma, herniated intervertebral disc and other spinal pathology.
Treatment and prognosis
Pharmacotherapy of infectious arachnoiditis provides for the appointment of antibiotics, if necessary, anti—tuberculosis and anti-syphilitic drugs. Anti—inflammatory drugs are used, according to indications – corticosteroids. Decongestant therapy with diuretics (triamterene, hydrochlorothiazide, furosemide, spironolactone), vascular (nicotinic acid, pentoxifylline) and neurometabolic (vitamins B, neostigmine) treatment is carried out. For spastic paralysis, muscle relaxants (tolperizone hydrochloride) are used, for pelvic disorders — uroseptics (urotropin). The basis of rehabilitation therapy is adequate physical therapy, physiotherapy procedures (electrostimulation, reflexotherapy, electrophoresis, magnetotherapy, etc.), massage and hydrotherapy (radon, iodine-bromine, sodium chloride therapeutic baths).
The question of surgical treatment of arachnoiditis arises when conservative therapy is ineffective, mainly in the chronic course of the disease with the formation of cysts and adhesions. The decision on the expediency of the operation is discussed together with the neurosurgeon. The objective of the surgical intervention is the emptying of arachnoid cysts and dissection of adhesions. Surgical access is performed by laminectomy. However, open surgery often does not bring the expected results due to its traumatic nature, frequent complications in the form of the formation of repeated splices and activation of dormant infection. Minimally invasive surgical techniques involving the separation of adhesions using endoscope manipulators inserted into the space of the dural sac are more effective.
Acute spinal arachnoiditis has a relatively favorable prognosis. With adequate and timely conservative treatment, complete restoration of neurological functions is possible. The chronic form is less favorable, often leads to disability and does not respond well to therapy. The introduction of new operating techniques has somewhat improved the postoperative prognosis, and work in this direction continues.