What is Arachnoiditis?

Can be manifested as an acute, subacute or chronic course. Patients have varying degrees of fever and systemic symptoms.

Arachnoiditis

Arachnoiditis refers to a tissue reaction of the arachnoid of the brain or spinal cord under the action of certain causes. It is characterized by arachnoid thickening, adhesion and cyst formation. In essence, this is a pathological diagnosis, not a disease unit. It is more common in young and middle-aged people.

Arachnoid signs

Can be manifested as an acute, subacute or chronic course. Patients have varying degrees of fever and systemic symptoms.

Arachnoiditis As the main invasion sites of cerebral arachnoiditis are posterior cranial fossa, optic cross, and convex cerebral hemisphere, it has the following clinical characteristics:

1. Optic intersection arachnoiditis is the most common type of arachnoiditis at the base of the brain. Inflammation mainly invades the intracranial segment of the optic nerve and around the optic cross, forming a dense or fine network of connective tissue to surround it. The optic nerve is often pale, ischemic, and atrophic, and it is difficult to separate from the surrounding structure. It is also not uncommon to have arachnoid cysts that compress the nerves at the optic cross. Patients often have a history of paranasal sinusitis, and a few have a history of anterior cranial fossa fractures. Generally, the signs of increased intracranial pressure are not obvious. The earliest and major symptoms are chronic headaches and visual impairment. Headaches are mostly in the frontal, temporal or orbital areas. It is often accompanied by slow progressive vision loss on one side, which spreads to the contralateral side after a few months, and a few sides decrease simultaneously, and only one side of the optic nerve is affected. Most of the vision loss occurs early and develops rapidly, often with recurrence. It can be improved after treatment with anti-inflammatory drugs, etc., and gradually worsen after exertion, colds, paranasal sinusitis, excessive drinking, and more serious. 1 Blind within 2 weeks. In terms of visual defects, due to the different locations and degrees of adhesion damage to the optic nerve, the visual field can be diversified and atypically changed. It is characterized by early emergence of central dark spots or lateral central dark spots, and irregular peripheral visual fields. Atypical changes such as temporal hemianopia and narrowed nasal visual field. The fundus examination may be unchanged in the early stage, and primary or secondary optic nerve atrophy, optic discitis, and primary optic nerve atrophy on one side and optic disc edema on the other side gradually appear. More widespread arachnoiditis at the base of the brain can also show signs of ~ brain nerve damage. A small number of people with hypothalamic involvement may have symptoms such as diabetes insipidus, narcolepsy, obesity, and sexual decline.

2. Retrocranial arachnoiditis Arachnoid adhesions are common in this area. About one-third of all arachnoiditis and a ratio of 7: 1 to the tumor of the posterior cranial cavity. Posterior cranial arachnoiditis easily causes cerebrospinal fluid circulation disorders, causing symptoms of increased intracranial pressure. According to different parts of the lesion, it can be divided into three types:

(1) Midline type: most common in retrocranial depression. The main adhesion lesions are the median foramen, lateral foramen, occipital cisterna and occipital

Arachnoiditis Hole area. Most likely to cause symptoms of obstructive hydrocephalus and early intracranial hypertension. The patient had a significant headache at an early stage, followed by symptoms such as vomiting and vision loss. Except for the symptoms and signs of increased intracranial pressure such as optic disc edema or secondary atrophy, abducent nerve palsy, and cervical stiffness, the neurological examination is not conspicuous. However, the onset is rapid, the condition is severe, and there is little remission.

(2) Cerebellar convex type: the course of disease is relatively slow, usually about 1 to 3 years. Arachnoid cysts can compress cerebellar ataxia and nystagmus on one side of the cerebellar hemisphere, but they are not as significant as cerebellar tumors.

(3) Cerebellar pontine type: the main lesion is in the ventral area of the brainstem. There are often different degrees of cerebral nerve damage on one side, including incomplete paralysis of the trigeminal nerve, facial nerve, auditory nerve, and facial muscle spasm. Ipsilateral cerebellar ataxia and nystagmus are mild or absent, and symptoms of increased intracranial pressure appear later. When inflammatory adhesions spread to the foramen of the jugular vein, there may be signs of ipsilateral glossopharyngeal, vagus, and secondary nerve damage. This type of disease develops slowly, and symptoms can be relieved for a long period of time, and the course of the disease can last for several years.

3. Inflammatory lesions of the cerebral hemisphere convex arachnoiditis are often around the lateral cleft of the brain, a few are between the cerebral hemispheres, above the corpus callosum, or other parts of the brain surface. The earliest major symptoms are headaches, seizures, or mental symptoms. Headache is a persistent, dull, dull pain. Epilepsy is mostly localized. Symptoms such as hemiplegia, paresthesia, and aphasia rarely occur, even if they are present. Optic disc edema is rare. Generally, the disease course is long, the development is slow, and sometimes it is good and bad, and it can last for months to years. Increased intracranial pressure appears more slowly and is much lighter than the retrocranial depression.

Causes of arachnoiditis

(A) infection:

1. Central nervous system infection: can be secondary to various types of meningitis, encephalomyelitis, especially serous meningitis caused by infections such as viruses.

Arachnoiditis

2. Infections outside the central nervous system: Systemic infections such as colds, flu, rheumatism, pneumonia, tuberculosis, sepsis, and pelvic infections may all be the cause.

(2) Trauma:

Both craniocerebral trauma and spinal trauma can occur, the trauma can be mild, and the skull or spine can be changed without fractures.

(3) Foreign bodies enter the subarachnoid space:

Such as: subarachnoid hemorrhage, antibiotics, anesthetics, contrast agents, etc.

(IV) Primary lesions of the central nervous system:

Such as: tumors, syringomyelia, optic neuritis, multiple sclerosis, etc.

(5) Skull and spine lesions: such as skull base depression, spinal bone hyperplasia, intervertebral disc herniation, spinal stenosis, etc.

(6) Poisoning: such as lead poisoning, alcohol poisoning, etc.

(7) Unknown cause: It may be non-purulent meningitis with unclear clinical signs or unknown cause, especially caused by viral infection.

Arachnoiditis Pathophysiology

The main lesions are localized or multiple arachnoid and soft membrane thickening and adhesion, some brain tissue, cerebral blood vessels, ventricles

Arachnoiditis Tube membranes can be complicated by local arachnoiditis. Can be divided into three types:

1. The spotted arachnoid is simply thickened, cloudy, and has white spots or patterns. The arachnoid did not adhere to adjacent brain tissue, and the subarachnoid space was unobstructed. This type is common in arachnoiditis.

2. Adhesive arachnoids not only have irregular thickening, but also have string-like or sheet-like adhesions with adjacent pia mater, cerebrovascular, cerebral surface and cerebral nerves. Adhesions can be widespread or localized, making the subarachnoid space unobstructed or occluded.

3. Cystic arachnoid adhesions form cysts containing clear or yellow-green cystic fluid, sometimes forming intervals or gradually increasing, easily compressing brain tissue and brain nerves. These three types of common histological changes are: infiltration of small round cells and inflammatory cells, proliferation of arachnoid endothelial cells, fibrosis of the reticular layer, and damage to the normal structure of the arachnoid membrane.

Diagnosis of arachnoiditis

Diagnosis: Cerebral cobweb encephalitis is often caused by different affected sites, diverse etiology, different clinical manifestations, and atypical. It is not easy to diagnose based on clinical manifestations only. It is necessary to rely on auxiliary examination to make a clear diagnosis, but it also has its own characteristics and helps to diagnose.

1. Patients often have primary causes of arachnoiditis such as intracranial, extracranial infections, craniocerebral injury and surgery, subarachnoid hemorrhage, etc.

2. The onset can be acute, subacute, and gradually become chronic, or it is chronic at the beginning, with a long course of disease, which is often repetitive,

Arachnoiditis Relief can be induced by colds, infections, and fatigue.

3. The focal symptoms are mild or multifocal, and may also be diffuse, so the symptoms are variable.

Laboratory examination: The pressure can be normal in the early stage of lumbar puncture. The cerebrospinal fluid pressure of most patients has a slight increase, and the pressure of hydrocephalus is significantly higher in most patients. The number of cerebrospinal fluid cells in the acute phase increased slightly (below 50 × 106 / L), mainly lymphocytes, and the chronic phase was normal. Protein quantification can be slightly increased.

Other auxiliary checks:

1. X-ray of the skull can show the signs of chronic intracranial hypertension or normal.

2. CT scan can show local cystic low-density changes, and the ventricular system is shrinking, normal or enlarged uniformly. Scans can exclude other intracranial space-occupying lesions.

3.MRI scan showed more clearly on the skull base and posterior cranial fossa than CT. And can exclude other intracranial space-occupying lesions.

Identification of arachnoiditis

1. Midline arachnoiditis in the posterior cranial fossa must be distinguished from tumors in this area. Tumors in the midline of the posterior cranial fossa include cerebellar vermiform tumors and tumors in the fourth ventricle. They are more common in children and are often malignant medulloblastomas. , Serious condition, brain stem compression signs and

Arachnoiditis Bilateral cone tract sign.

2. Aponponemic horn arachnoiditis is distinguished from tumors in this area. Most tumors in this area are acoustic neuromas, in addition to meningiomas and epidermoid cysts. Such as acoustic neuromas and meningiomas, symptoms of auditory nerve damage may appear early, followed by symptoms of facial nerve, trigeminal nerve, and cerebellar damage. Epidermoid cysts often show symptoms of trigeminal neuralgia. Skull X-ray films, acoustic neuroma may show damage and enlargement of the inner auditory canal, meningiomas may have rock bone destruction and calcification. A CT or MRI scan can confirm the diagnosis.

3. Identification of arachnoiditis at the cross of the god and tumors in this area The most common tumors in this area are pituitary adenoma and craniopharyngioma. Most pituitary adenomas have endocrine disorders at an early stage, and the changes in the fundus and visual field are typical. Craniopharyngiomas are more common in children, and there can be calcification on plain X-ray saddles. There are also saddle nodular meningiomas in this area, which are manifested by chronic visual compression of the optic nerve and visual field disturbance, and primary optic nerve atrophy in the later stage. CT and MRI scans of these lesions can show their unique lesion manifestations, which can be used for identification and clear diagnosis.

4. Differentiating cerebral hemisphere convex arachnoiditis from superficial gliomas, hemangiomas, metastases, and tuberculosis of the cerebral hemisphere. Most of these lesions can be diagnosed by CT or MRI scans.

Arachnoid inflammation symptoms

The clinical symptoms vary depending on the location of the disease. Common are:

(A) Cerebral arachnoiditis.

Arachnoiditis

1. Posterior cranial arachnoiditis:

(1) Dorsal type: The clinical symptoms are mainly increased intracranial pressure, headache, vomiting, and papillary edema, etc., and can cause neck pain and neck stiffness due to chronic foramen magnum hernia.

(2) ventral type: dizziness, nystagmus, deafness on the side of the lesion, tinnitus, peripheral facial paralysis, decreased facial sensation, disappearance of corneal reflexes, and ataxia of limbs.

2. Cerebral convex arachnoiditis: The main symptoms are headache and seizures. Headaches can be localized or diffuse, generally mild, and sometimes worsened when the head position changes. Epilepsy is mostly limited. Local symptoms of neurological damage such as hemiplegia and aphasia are less frequent.

3 Optic arachnoiditis: headache and visual impairment.

(B) Spinal arachnoiditis.

The spinal cord and cervical spinal cord lesions are more common, and the symptoms of posterior root irritation often occur in the early stage, resulting in root pain in the affected area of the nerve root, which varies in severity and can be relieved after rest. It often lasts for several months and several years after the spinal cord appears. Compression symptoms.

(3) Cerebral spinal arachnoiditis.

There are lesions in the brain and spinal cord, both of which can occur at the same time, or caused by the spinal cord lesions gradually to the posterior cranial concave skull base, resulting in corresponding symptoms of spinal and cranial nerve damage.

Arachnoid examination

Cerebrospinal fluid protein and cell number increased.

Basic treatment for arachnoiditis

(1) Anti-infection treatment: In cases suspected or clearly caused by infection, antibiotics or antiviral preparations can be given. In some cases, even if there is not much evidence of tuberculosis, antituberculosis treatment can be given first. If there is effect in about two weeks, the treatment will continue according to tuberculosis.

(2) Adrenocortical hormone treatment: Hydrocortisone (100-200mg, once a day, 10 times a course of treatment can be intravenously administered; or intramuscular injection or oral prednisone, dexamethasone, etc .. Intrahormonal injection of hormones, Usually use 2 ~ 5mg of dexamethasone at a time, mix with cerebrospinal fluid and slowly inject it into the subarachnoid space, starting from a small amount, 2 ~ 3 times a week, 10 times as a course of treatment. Chymotrypsin (5mg) or trypsin ( 5 10mg) intramuscularly, once a day, can also be tried to soften adhesions, but the effect is not ideal.

(3) Dilation of blood vessels and improvement of blood circulation: Niacin, diabazole, 654-2, anisodamine injection, etc. can be used.

(D) Physiotherapy: If the retinal arachnoiditis can be tested by iodine iontophoresis through the eyeball.

(5) Radiation therapy: It is mostly used for spinal arachnoiditis and cerebral hemisphere convex arachnoiditis. The dosage should be small, which will help improve blood flow, but the effect is not clear.

(6) Surgical treatment: It is mainly used for cyst resection and surgical decompression. It is difficult to peel off the adhesion, and the effect is not clear. If it is difficult to identify the tumor, surgical exploration can also be considered.

In addition, spinal canal air therapy can also be used, injecting 10 ~ 15ml at one time as appropriate. Starting from a small amount, every 5ml of gas is injected to release the same amount of cerebrospinal fluid, once every 5 to 7 days, which may help to loosen adhesions and improve cerebrospinal fluid circulation in early cases. Those with increased intracranial pressure should use antihypertensive measures.

Arachnoiditis treatment options

1. Non-surgical treatment In general, early or acute cases should be treated comprehensively with various drugs or measures, the purpose of which is to control arachnoid inflammation, release inflammatory adhesions and reduce intracranial pressure, and treat the primary infection lesions .

(1) Antibiotics: It is not specific for non-specific arachnoiditis, but it can be effective in treating recessive or dominant bacterial infections that may exist in the skull or other parts of the body, especially during active periods of arachnoiditis. .

(2) Adrenocortical hormone: It has a good effect on the prevention and treatment of arachnoid adhesion and inflammation, and the initial application effect is better. Care should be taken during the administration of potassium chloride. If effective after a course of treatment, it can be reused if necessary.

(3) Reduce intracranial pressure: 20% mannitol, fructose (glycerol fructose), diuretics, etc. can be used.

(4) Other drugs: such as neurotrophic drugs and vasodilators.

2. Surgical treatment

(1) Posterior craniotomy: The arachnoid adhesions and cysts in the cerebellar hemispheres and pontine cerebellar horns can be stripped and resected to obtain a certain effect. Adhesions and cysts of the median foramen of the fourth ventricle and the cerebellar bulbar cistern can be stripped and resected, and the mesopores can be opened. If extensive occipital adhesions affect cerebrospinal fluid circulation and absorption, suboccipital decompression can be performed first, and later consider ventriculoperitoneal shunt.

(2) Optic intersection exploration: When vision loss and visual field defect of arachnoiditis in the visual intersection, if the symptomatic treatment does not improve or even worsens, adhesion and cyst separation and resection can be performed. According to the conventional pituitary surgical approach, it is best to carefully separate the arachnoid adhesions of the optic nerve and the optic nerve intersection under the operating microscope, remove the strangulated fiber bands and the oppressive arachnoid cysts, so that the optic nerve and the optic intersection can be relieved. However, they cannot be separated forcibly to avoid increasing damage. The general effective rate is about 30% to 40%, so various comprehensive treatments should be continued after surgery.

(3) On-the-scenes craniotomy: After long-term comprehensive treatment of cerebral convex arachnoiditis, the symptoms have not improved. On the contrary, there is a progressive increase in intracranial pressure and progressive vision loss. Those who are at risk of blindness can be opened cranially to separate adhesions and Removal of the cyst, application of bilateral decompression of the temporal muscle or decompression of the bone flap, can often relieve intracranial pressure and stabilize or improve vision.

(4) When atypical diffuse brain arachnoiditis has obvious obstructive or traffic hydrocephalus, the ventriculoperitoneal shunt can be performed first, and the aforementioned non-surgical treatment can be continued after the operation.

Arachnoiditis complications

Because arachnoiditis itself is an inflammatory response lesion, it is possible to perform an intracerebroventricular-peritoneal shunt operation. The infection may be a surgical infection, and it can also be infected after surgery. Most of the infections occur about 6 months after surgery, and a few can occur after 1 year. The infection may be retrograde infection in the distal abdominal cavity and chest, as well as blood-borne infections or the spread of inflammation in the brain. In short, once the infection occurs, the shunt tube must be temporarily removed for anti-inflammatory treatment. Take out the cerebrospinal fluid in the tube and send it for bacterial culture, drug sensitivity test, and centrifugation as a smear, as a basis for future treatment. The bacteria infected by shunt are mostly Staphylococcus, followed by Staphylococcus aureus, and others such as Gram-negative bacilli and Streptococcus. Prognosis and prevention (view content) Prognosis: There is a certain or significant effect regardless of comprehensive treatment or surgery, but there is no completely certain effect on certain arachnoiditis, so the patient's lesions cannot be completely resolved and may persist for a long time. Certain clinical symptoms remain.

Arachnoiditis prevention

Timely treatment and prevention of various primary diseases.

Controlling intracranial and extracranial infections, actively preventing and treating various craniocerebral injuries, and reducing intrathecal injections of drugs can help prevent cerebral arachnoiditis.

Arachnoiditis epidemiology

Cerebral arachnoiditis, the incidence of intracranial tumors is about 1/10. Occurs in young and middle-aged people, and there is no major difference in gender.