Pachymeningitis is an inflammation of the dura mater, which is provoked by bacterial, mycotic or viral infection. The pathognomonic sign of the disease is meningeal syndrome, severe headaches, fever and other symptoms of intoxication are also bothering. Verification of the diagnosis requires neuroimaging, lumbar puncture, followed by examination of the cerebrospinal fluid. Etiotropic therapy is selected in accordance with the identified pathogen, pathogenetic treatment includes dehydration, neuroprotection, the fight against shock and hypoxia.
General information
Pachymeningitis is a rarer pathology compared to leptomeningitis. Basically, it begins with the transition of the inflammatory process from the soft and arachnoid meninges or from the bone tissue. The frequency of occurrence is about 3-5 cases per 100 thousand population, but despite the low prevalence, pachymeningitis does not lose its relevance in modern neurology. It is characterized by a polymorphic clinical picture, a high probability of complications, a large percentage of deaths (up to 30%, depending on the etiological factor).
Causes
Pachymeningitis belongs to the group of neuroinfections, that is, it is caused by infection of the meninges with various pathogens. The etiological factor is crucial because it determines the severity of the course, the nature of treatment, and the prognosis for the patient. Although the variability of pathogens is typical for the disease, typical groups of infections can be distinguished:
- Bacterial. Among the top three pathogens of pachymeningitis are N. meningitidis, S. pneumonie, H. influenzae. Up to 1% of pathologies are caused by Mycobacterium tuberculosis. More rare causes include staphylococci, streptococci A and B, enterobacteria, listeria.
- Fungal. Severe forms of pachymeningeal inflammation occur when infected with Candida fungi, mycoses caused by Cryptococcus neoformans, Aspergillus.
- Viral. The disease is associated with infection with enteroviruses, mumps virus (more often in children), herpesviruses. Less often, the causative agents are tick-borne encephalitis virus, rubella.
Risk factors
The main predisposing factor for the development of pachymeningitis are infections in the cavities and channels of the cranial bones: purulent otitis media, cholesteatoma, chronic sinusitis. The risk of getting sick increases in patients with suppurated head wounds, bacterial lesions of soft tissues (carbuncle, phlegmon). Usually, the inflammatory process manifests itself during a period of a decrease in the overall resistance of the body.
Pathogenesis
The spread of infection to the dura mater occurs in various ways. A hematogenic variant is more often observed — the introduction of bacteria with blood flow, and the penetration of pathogens through the perineural spaces is also possible. Contact infection from the bones of the skull is described, lymphogenic — with tuberculosis, liquorogenic — with primary spinal lesion.
Often cerebral pachymeningitis has a limited character by the type of intradural abscess, however, diffuse spread of the process is also possible. The severity of the patients’ condition is due to impaired cerebrospinal fluid metabolism, the development of hypertension-hydrocephalus syndrome, damage to cerebral tissue, hypoxia of neurons. These pathological changes lead to a serious neurological deficit.
Symptoms
The main sign of the disease is a sudden severe headache. It has a pressing, pulsating or bursting character, diffusely spreads throughout the skull. When tapping with your fingers, you can identify the zone of maximum soreness corresponding to the lesion zone in the dura mater. The pain increases under the influence of loud sounds, bright light, head movements.
Another characteristic symptom of inflammation of the meninges is hyperthermia up to 39-40 ° C, although with tuberculous pachymeningitis, fever, as a rule, does not reach such figures. Patients also experience excruciating repeated vomiting of central genesis, which is not associated with eating, does not bring relief, appears suddenly without typical precursors.
Fundamental in the diagnosis of pachymeningitis is meningeal syndrome caused by irritation of the meninges. It is manifested by the forced pose of a “cop dog” (“cocked trigger): head thrown back, legs bent and brought to the stomach, lying on the side. When trying to bend the head to the chest, there is a sharp resistance (muscle rigidity), the patient experiences severe pain.
Complications
With purulent pachymeningitis, cases of inflammation transition to the walls of venous sinuses with the development of phlebitis, sinus-phlebitis, thrombosis of transverse or sigmoid sinuses are not uncommon. With an unfavorable course, infectious pathogens spread to all parts of the meninges, enter the systemic circulation, which results in sepsis, multiple organ failure, and a high risk of death.
Acute complications of the disease include cerebral edema, accompanied by the insertion of the brain stem, critical disorders of vital functions, frequent death of patients. Brain lesions can also manifest themselves in the form of ventriculitis, cerebral infarction, and epileptic status. Blood clotting disorders often occur, DIC syndrome is formed.
Even with a successful initial phase of treatment, pachymeningitis often causes a persistent neurological deficit that persists for a long time or for life. Disorders are represented by a decrease in intellectual functions, psychoemotional instability, cerebrogenic asthenia. Taking into account the localization of the lesion, it is possible to develop sensorineural hearing loss, optic nerve atrophy, and speech disorders.
Diagnostics
The examination of the patient is within the competence of a neurologist, an emergency doctor, and the staff of the intensive care unit. It is possible to suspect pachymeningitis by characteristic physical signs: positive symptoms of Kernig, Brudzinsky (upper, middle, lower), Mondonesi and Bekhterev. To confirm the diagnosis, the patient is assigned an extended examination using laboratory and instrumental methods:
- CT scan of the brain. Computed tomography is the most informative for studying the pathologies of the dura mater. It demonstrates structural disorders, reveals possible complications (edema, abscess). MRI is recommended to detect a rare complication of the disease — thrombophlebitis of the sagittal sinus.
- Lumbar puncture. During the study, the leakage of the cerebrospinal fluid under pressure is determined. Cytological diagnostics of cerebrospinal fluid shows neutrophilic pleiocytosis in bacterial process, lymphocytic — in viral process. There is also protein-cellular dissociation, a decrease in the level of glucose and chlorides in the liquor.
- Microbiological methods. In order to identify the pathogen, a back-up of the liquor is carried out on nutrient media, PCR of cerebrospinal fluid, blood culture before the start of antibiotic therapy. For the express diagnosis of some pathogens, latex agglutination tests are performed.
Treatment
Conservative therapy
The basis of the treatment of pachymeningitis is the rational selection of etiotropic agents. In the case of purulent inflammation, empirical antibiotic therapy is carried out, which is corrected after receiving the result of sowing. Meningitis caused by Koch’s bacillus requires the appointment of anti-tuberculosis drugs. Antimycotics are used in fungal processes. Pathogenetic therapy includes several directions:
- Dehydration. With intracranial hypertension, swelling of the brain, osmodiuretics (mannitol), saluretics (furosemide), solutions of glycerin and oncodegirators are recommended.
- Elimination of hypoxia. With an uncomplicated form of the disease, inhalation of moistened oxygen is necessary. Cerebral edema is an indication for transferring a patient to a ventilator in the mode of moderate hyperventilation.
- Anti-shock measures. In bacterial pachymeningitis accompanied by toxic shock, adequate infusion therapy is carried out in combination with corticosteroids, dopamine, anticoagulants.
- Neuroprotection. B vitamins, ascorbic acid, vitamin E are used to relieve oxidative stress and replenish the energy deficiency of brain tissue. Antiplatelet agents and neurometabolic agents are also prescribed.
Rehabilitation
To speed up the recovery of neurological functions, nootropics, vitamin and mineral complexes, drugs that normalize the rheological properties of blood are recommended. Adaptogens, actoprotectors give a good effect. As the patient’s well-being improves, the rehabilitation program is enhanced by methods of physiotherapy, physical therapy, massage.
Prognosis and prevention
The best results are observed with viral pachymeningitis: 99% of patients recover without severe neurological complications. Bacterial processes have a less favorable course, mortality is up to 20%. With tuberculosis etiology of inflammation — more than 30% of fatal cases, up to 40% of patients have severe residual phenomena. A negative prognosis is established with fungal lesions on the background of weakened immunity.
Specific prevention of pachymeningitis involves planned or optional vaccination against typical pathogens: pneumococcus, meningococcus, tuberculosis and hemophilic infection. In close contact with sufferers of purulent meningitis, post-exposure chemoprophylaxis with antibiotics may be prescribed. Non-specific measures include individual protection during contacts with patients with acute respiratory viral infections, sanitary and educational work among the population.