Arachnoiditis — is a serous arachnoid mater inflammation of brain and spinal cord. Isolated inflammation lesion with arachnoiditis does not happen in the absence of her own vascular system. The infection passes from a solid or pia mater. In this connection, some authors consider more appropriate to treat the pathological process is not as arachnoiditis, as well as serous meningitis. However, a significant difference between clinical and flow arachnoiditis from inflammation of the meninges – meningitis can be considered correct selection of this form as an independent disease.
Causes of arachnoiditis
Arachnoiditis occurs as a result of the transferred acute and chronic infections, inflammatory diseases of the paranasal sinuses, chronic intoxication (alcohol, lead, arsenic), trauma (usually in the residual period). Arachnoiditis can occur as a result of reactive inflammation in slow-growing tumors, encephalitis. In many cases, the cause of arachnoiditis remains unclear. Morphologically with arachnoiditis determined turbidity and thickening of the arachnoid, which is accompanied in more severe cases, fibrinoid overlays. In the further course of arachnoiditis adhesions occur between the arachnoid and choroid, leading to impaired circulation of cerebrospinal fluid and the formation of cysts.
Arachnoiditis is divided into bottled and limited. Last extremely rare. In essence we are talking about more serious local changes against the background of diffuse process with arachnoiditis. Violation of the normal circulation of cerebrospinal fluid (CSF), leading to the emergence of hydrocephalus, is based on two mechanisms for arachnoiditis obstruction to the flow of fluid from the ventricular system (occlusive hydrocephalus) and malabsorption of fluid through the dura mater with spilled adhesive process (arezorbtive hydrocephalus).
Types of arachnoiditis
Brain membranes (cerebral) arachnoiditis
Cerebral arachnoiditis can be localized to the convex surface of the brain, its basis in posterior fossa. The clinical picture consists of the symptoms of arachnoiditis of the local effects of shell lesions on the brain and disorders of the liquor circulation. Frequent manifestation of cerebral arachnoiditis are hypertensive headaches or shell character.
Convexital cerebral arachnoiditis
Convexital cerebral arachnoiditis are more common in the anterior cerebral hemispheres, in the central gyrus. Due to the pressure on the motor and sensory centers of movement disorders may occur (mono-or hemiparesis) and sensitivity. Irritation, and in cases of cyst formation and compression of the crust and underlying brain with arachnoiditis cause focal seizures. In severe cases, may have generalized seizures until the development of status epilepticus. Essential to identify the localization of focal arachnoiditis have electroencephalography and pneumography.
Often observed arachnoiditis base of the brain. The most frequent localization - chiasmatic region, that is the reason for the relative frequency of opto-chiasmatic arachnoiditis. The importance of studying this form is determined by the involvement in the process of optic nerves and areas of overlap, which often leads to irreversible loss of vision. Among the etiological factors of opto-chiasmatic arachnoiditis are particularly important infection in the sinuses, sore throat, syphilis, malaria, and traumatic brain injury (brain concussion and contusion).
In the chiasm and the intracranial part of optic nerves with arachnoiditis produced multiple adhesions and cysts. In severe cases, scar creates a wrapper around the optic chiasm. Typically, opto-chiasmatic arachnoiditis is not strictly local: the less intense changes are detected in the distance from the main chamber. On the optic nerve affect mechanical factors (compression) and transfer to them of inflammation and circulatory disorders (ischemia).
Chiasmal arachnoiditis arachnoiditis usually develops slowly. First arachnoiditis captures one eye, then gradually (over several weeks or months) and the other involved. The slow and often one-sided development of opto-chiasmatic arachnoiditis helps to differentiate the process of retrobulbar neuritis. The degree of reduction in fiber-chiasmatic arachnoiditis may be different - from lowering to complete blindness. Often at the beginning of the disease in the opto-chiasmatic arachnoiditis have pain posterior to the eyeballs.
An important tool in the diagnosis of opto-chiasmatic arachnoiditis is the study of visual fields and fundus. Field of view changes depending on the preferential localization process. The most typical temporal hemianopsia (one-or two-sided), the presence of central scotoma (often bilateral), concentric narrowing of the visual field.
From the fundus in 60-65% of the cases determined by the atrophy of the optic nerves (primary or secondary, full or partial). In 10-13% of cases are detected stagnant nipples optic nerve. Manifestation of the hypothalamic region, as a rule, are absent. Snapshot sella also did not reveal pathology. In this form of arachnoiditis are the main foci of (visual) symptoms, hypertensive events (intracranial hypertension) is usually expressed in moderation.
Posterior cranial fossa arachnoiditis
Posterior cranial fossa arachnoiditis — the most common form among the cerebral arachnoiditis. The clinical picture of arachnoiditis posterior fossa tumors like this location and consists of cerebellar and brainstem symptoms. The damage of the cranial nerves (VIII, V and VII of the pairs) is observed mainly at the localization of arachnoiditis in the cerebellopontine angle. Cerebellar symptoms consist of ataxia, asynergy adiadohokineza. At this location arachnoiditis expressed frustration circulation of cerebrospinal fluid.
Symptoms of arachnoiditis posterior fossa depends on the nature of the process (adhesions, cysts), localization, and the combination of arachnoiditis with hydrocephalus. Increased intracranial pressure with arachnoiditis may be caused by closing holes ventricles (Lyushka, Magendie) due to adhesions, cysts, or as a result of irritation of the meninges with CSF hypersecretion (primarily as a result of increased activity plexus chorioideus) and the difficulty of its absorption. In the absence of a sharp rise in intracranial pressure arachnoiditis may last for years, with long-term remissions. Often it occurs in the form of arachnoiditis arahnoentsefalita due to concomitant inflammatory changes in the brain tissue and pressure adhesions, cysts on the brain.
The acute form of arachnoiditis is characterized mainly by symptoms of increased intracranial pressure (a sharp headache, mainly in the neck, nausea, vomiting, dizziness, often stagnant nipples optic nerves, and sometimes bradycardia), pyramidal and focal symptoms are often absent or weak and unstable.
When subacute neurologic the fore symptoms of posterior fossa (usually cerebellopontine space - the side of the tank bridge). Symptoms of increased intracranial pressure, although there are, but less pronounced, and occasionally almost never determined. Marked paresis cranial nerves (V, VI, VII, VIII, IX and X less, and even less III and IV), usually VIII pair, and vestibular disorders predominate feature in combination with cerebellar symptoms.
Along with the instability in the Romberg - a deviation or fall toward the affected ear, staggering gait, impaired index and the finger-nose test, adiadohokinezom, unstable spontaneous nystagmus (directed towards the ear of the patient, or bilateral) - noted frequent disharmony vestibular tests (eg loss caloric reaction when stored rotational). Sometimes there is a change of direction of nystagmus, positional nystagmus. Not all components of the vestibular-brain syndrome are constant and clearly defined. Gomolateralnye pyramidal signs are rare and even more rare extremity hemiparesis. The CSF changes are usually limited to high blood pressure, sometimes poorly marked. Rarely observed moderate pleocytosis or increased protein content.
Very rare arachnoiditis with other sites in the posterior fossa. It is isolated lesion preddvernoulitkovogo nerve in the inner ear canal, without the effects of hypertension, arachnoiditis and arachnoiditis predpontinny cerebellar hemispheres with impaired statics and scarce cerebellar symptoms, with the damage of the trigeminal nerve (predpontinnaya form) predmozzhechkovy arachnoiditis (the front surface of one of the lobes of the cerebellum) with partial cerebellar symptoms, labyrinth phenomena nonexcitability when caloric and low excitability during rotational sample laterobulbarny arachnoiditis with hypertension, cerebellar syndrome and damage IX, X, XI cranial nerves (homolateral), arachnoiditis rear ragged holes damage IX, X and XI cranial nerves.
When hydrocephalus otogenic posterior fossa predominate symptoms of increased intracranial pressure, with normal cerebrospinal fluid or "dilution" of his (poverty proteins) occlusion holes Lyushka Magendie and hypertension combined with mental disorders, vestibular disorders, sometimes epileptiform attacks.
With a total of hydrocephalus with the accumulation of large amounts of liquor intracranial pressure rises quickly, there are stagnant nipples optic nerves, decreased visual acuity. Such crises are gradually stabilized (despite the ventricular and lumbar punctures) and, if involved the medulla oblongata, the patient dies.
For the differential diagnosis of an abscess of the brain (cerebellum) brain tumor are important for clinical, research data liquor. All kinds pneumography in severe increased intracranial pressure are contraindicated.
If arachnoiditis posterior fossa rapidly evolving pattern of occlusive hydrocephalus, clinically manifested by headache, vomiting, dizziness. In the fundus stagnant nipples optic nerve. In the cerebrospinal fluid pattern of unstable protein-cell dissociation. On the X-ray of skull at posterior fossa arachnoiditis visible hypertensive effects.
Severe complication of arachnoiditis posterior fossa is the appearance of an attack of acute occlusion with wedging tonsils in foramen magnum, compressing the brain stem. Arachnoiditis posterior fossa may be responsible, and difficult to treat trigeminal neuralgia.
Spinal membranes (spinal) arachnoiditis
Spinal arachnoiditis, in addition to the above reasons, may occur when abrasions, purulent abscesses of different localization. The clinical picture of cystic limited spinal arachnoiditis is very similar to symptoms of extramedullary tumors. There radicular syndrome at the level of the pathological process and conductive disorders (motor and sensory). Arachnoiditis often located on the rear surface of the spinal cord at the thoracic, lumbar segments, as well as in the cauda equina. The process usually extends for a few roots, different variability of the lower limit of sensitivity disorders.
In the cerebrospinal fluid protein-cell dissociation. Cerebrospinal fluid (CSF) pleocytosis is uncommon. Characterized mielograficheskie data - a contrast agent is retained in the form of droplets in the arachnoid cysts. Less common diffuse spinal arachnoiditis involving the process of a large number of roots, but less clearly manifested conductor disorders. Spinal arachnoiditis is chronic.
Diagnosis of arachnoiditis
In the diagnosis of arachnoiditis, in addition to clinical and anamnestic data, and apply additional methods of research, ocobennosti contrast radiography. If arachnoiditis convex surface pneumoencephalography reveals how parts of subarachnoid space, not passable for air and liquid, and extended areas.
Magnetic resonance imaging (MRI) performed for suspected arachnoiditis arachnoid membrane of the brain.
At the same time on the affected side arachnoiditis occasionally observed smartness of the lateral ventricles to the cortex and, thus, the asymmetry and distortion of the ventricular system.
- If arachnoiditis base of the brain is of great importance craniography usual, allowing in many cases, install hypertensive manifestations (digital impressions, increased vascular pattern, change in shape of the Turkish saddle, etc.).
- Important to study the cerebrospinal fluid, which allows to specify the degree of hydrocephalus, as well as the existence of a block in the subarachnoid space. Inflammation (CSF pleocytosis), as a rule, are not expressed.
- Electroencephalography is important when locating the source on convex surface of the brain (in focal cystic process pattern of electroencephalogram (EEG) is similar to that in tumors, but more diffuse changes are recorded).
- It is difficult to overestimate the importance of research fundus and visual fields in optic-chiasmatic arachnoiditis and arachnoiditis posterior fossa.
- For the diagnosis of spinal arachnoiditis is important myelography. The greatest difficulty is the limited contrast arachnoiditis of the tumor.
- If arachnoiditis performed MRI of the brain or MRI of the spinal cord in myelography mode to refine the localization process and the degree of involvement of brain tissue and cranial and spinal nerves.
Necessary in the diagnosis of arachnoiditis take into account a history of acute and chronic infection, trauma, and occurring less frequently, less intensive changes in the fundus and the X-ray of skull during the process (continuous and remission). With tumors in the chiasm than in arachnoiditis, expressed gipofizarnomezhutochnye and other neurological symptoms. With tumors of the posterior fossa and spinal cord are more rude conductive disorders.
Treatment of arachnoiditis
In the treatment of arachnoiditis applied conservative and surgical treatment. Urgent surgical intervention is necessary for the progressive fall of (breaking and removal of adhesions and cysts in the optic chiasm), to eliminate the occlusion with arachnoiditis posterior fossa. Surgical treatment is also used with limited spinal arachnoiditis arachnoiditis and the convex surface of the brain.
Pneumoencephalography has in some cases not only diagnostic but also therapeutic. Injected air may break adhesions and thereby eliminate a number of symptoms (headache, focal epileptic seizures, myoclonus).
Conservative treatment consists of antibiotics (penicillin, streptomycin), hexamine, iodine preparations and other absorbable and anticonvulsants.
Radiation therapy is prescribed for diffuse arachnoiditis, and spinal arachnoiditis - physical, radon and hydrogen sulfide baths, mud applications.
Prognosis is favorable for life. With timely surgical treatment satisfactorily restored disorders caused by limited arachnoiditis. Worse still treatable diffuse arachnoiditis. Dangerous arachnoiditis posterior fossa pits which can cause an acute attack of occlusion.