Arachnoiditis - Causes, Symptoms, Disease Progression, and Management Strategies

What Is Arachnoiditis?

It is an inflammatory condition of the arachnoid membrane surrounding one’s spinal cord. The usually delicate arachnoid membrane undergoes thickening (fibrosis) after getting exposed to any physical or chemical assaults on the spinal column. And this causes severe stinging and burning sensations along the spine and legs coupled with certain other neurological issues. With the progression of the disease, the symptoms turn persistent and severe. With the unbearable pain and other disabilities, individuals lose their ability to work and lead a normal life. The pattern of symptoms, severity, and progression is unpredictable as it varies from person to person.

What Are the Causes of Arachnoiditis?

The arachnoid membrane is one of the three membranes covering and protecting the brain and spinal cord. Long-term assaults from injuries and irritants lead to scarring of this membrane. Additionally, the nerve roots and blood vessels tend to bind together. The most severe type of arachnoiditis is adhesive arachnoiditis, where the scar tissue will compress the nerve roots and block the blood supply and the flow of cerebrospinal fluid (CSF). Inflammation of the arachnoid membrane can be due to various reasons such as:

Those induced by physical assaults:

• Trauma to the spinal canal due to injuries involving the vertebral column.

• Damage caused by repeated surgical procedures.

• Long-term compression of the spinal cord.

• Bleeding in the subarachnoid region after repeated spinal tapping (lumbar puncture).

• Cancers in the area.

• Narrowing of the spinal column.

• Long-term wear and tear of the spine (degenerative disc diseases).

Those induced by chemical assaults:

• Exposure to contrasting agents. For instance, a myelography procedure performed with spine surgery often causes lumbosacral arachnoiditis.

• Repeated injections into the spinal cord (epidural and intrathecal injections), including steroids and anesthetic agents.

• Chemotherapy medications.

Those induced by infections:

• Tuberculosis.

• Syphilis.

• Viral or fungal meningitis.

What Are the Types of Arachnoiditis?

Different types of arachnoiditis include:

1. Adhesive Arachnoiditis: Adhesive Arachnoiditis is the most severe and progressive type, where spinal nerves stick together due to inflammation of the arachnoid.

2. Arachnoiditis Ossificans: This occurs when the arachnoid membrane hardens into bone.

3. Cerebral Arachnoiditis: This affects the membrane surrounding the brain and often leads to intense headaches.

4. Hereditary Arachnoiditis: A rare form caused by genetic defects in the meninges.

5. Neoplastic Arachnoiditis: Caused by cancer.

6. Optochiasmatic Arachnoiditis: This type occurs behind the optic nerve and can result in severe or complete vision loss.

What Is the Pathophysiology of Arachnoiditis?

When the subarachnoid or subdural space is inflamed due to an injury, collagen is deposited, and fibrosis begins to accumulate. The end product of this process is the formation of scar tissue, which reduces the flow of CSF (cerebral spinal fluid) and interferes with the neurons' ability to receive oxygen and nutrients, clearance of toxic metabolites, and circulation. In addition, consequences of fibrosis include nerve root encapsulation, compression, impairment, and eventual atrophy. Arachnoiditis commonly manifests as pain and may coincide with neurological impairments.

What Are the Symptoms of Arachnoiditis?

The most significant symptom of arachnoiditis is a long-lasting pain of neuropathic nature in the lower back and legs. Individuals may explain it as sciatic pain or deep muscular pain in the back and legs. Inflammation to the arachnoid membrane is the main reason for the initial symptoms. As the scarring and adhesions develop in the course of time, symptoms turn severe, and the condition progresses to the next level. In extreme cases of arachnoiditis, one suffers pain in the entire body. The typical symptoms involve:

1. Shooting, severe pain that feels like sending electric shocks up the spine, which worsens with activity and body movements.

2. Occasional dizziness.

3. Numbness and tingling on the legs, along with strange sensations such as an insect crawling or water trickling down the skin of the legs.

4. Pain in the joints.

5. Loss of sensation (dysesthesias).

6. Uncontrollable muscle twitches, spasms, and cramps.

7. In severe cases, weakness or paralysis can happen.

8. Losing bladder control and bowel control might sometimes be embarrassing to the affected. One might want to go to the toilet frequently.

9. Sexual dysfunction and reduced sex drive due to lack of sensations and having to endure pain.

10. Psychosocial problems and emotional stress.

11. The aging process seems to add to the severity of the existing symptoms.

12. Adhesive Arachnoiditis -As arachnoiditis advances, it can result in the development of scar tissue, causing the spinal nerves to adhere and malfunction, a condition known as chronic adhesive arachnoiditis. Chronic adhesive arachnoiditis has the potential to result in disability. A significant number of individuals with this condition may eventually require the use of a wheelchair due to paraparesis, which involves partial impairment of leg movement.

How Is Arachnoiditis Diagnosed?

Arachnoiditis has a significant chance of going undiagnosed as an extremely rare condition. Diagnosis is based on the evaluation of clinical symptoms and imaging studies, such as:

• Magnetic Resonance Imaging (MRI) And Computed Tomography (CT) - MRI and CT shows typical clumping of nerve roots. The nerves seem stuck to each other and to the adjacent structure, especially in the lower end of the spinal cord (cauda equina). Sometimes there will be calcifications in the area, as in conditions like arachnoiditis ossificans.

• Cerebrospinal Fluid (CSF) Analysis - It is performed to find out if there is a tumor or infection in the meninges (outer covering of the brain and spinal cord). The doctor may insert a needle into the lower back region of the spinal column and extract a sample of the cerebrospinal fluid. This procedure is called a lumbar puncture, and the CSF sample is evaluated for any abnormal findings.

• Electromyogram (EMG) - Where the pattern and strength of electrical impulses sent from the nerves to the muscle are studied to check for nerve function and ongoing nerve damage.

What Is the Treatment for Arachnoiditis?

This is an excruciatingly painful condition demanding treatment in an individualized manner. There is no exact cure for arachnoiditis. In the majority of individuals affected with arachnoiditis, the underlying cause for the condition stays unidentified or unapproachable for corrective treatment. Correctional surgeries rarely give fair outcomes. Moreover, the results are probably short-lived. After a period of short-term relief, the symptoms seem to recur. Hence the treatment is purely focused on alleviating the symptoms like any other chronic nerve pain condition.

One of the best among the identified treatments is:

• Spinal cord stimulation uses a stimulating device where one transmits electrical signals up the spine to relieve the pain.

• Administering anesthetic medications such as Lidocaine and Ketamine intravenously helps to reduce the pain and inflammation. Naltrexone is found to be helpful in reducing pain and inflammation as well as long-lasting arachnoiditis pain.

• Other medications that help with the pain and burning sensation are steroids, pain relievers, and anticonvulsants. Some of them can be injected directly into the spinal column to alleviate the symptoms.

• Providing psychotherapy and medications to help with the depression associated with the condition.

• Physical therapy and exercises help preserve the amount of functionality and restore mobility for the individual.

• Remedial measures like physical therapy, hydrotherapy, massages, and alternate heat and cold application help.

What Is the Prognosis for Arachnoiditis?

Arachnoiditis affects people differently. Some may have stable symptoms, while others see them get worse over time. Most people with arachnoiditis have about the same level of disability from when they are diagnosed, but their symptoms might go up and down.

For some, symptoms get worse gradually, leading to more pain and difficulty moving. Surgery often does not help and can sometimes make things worse. Arachnoiditis can cause permanent disability, but it is usually not deadly. However, severe cases can really affect a person's mental health. On average, it can shorten a person's life by about 12 years.

What Are the Possible Complications Associated With Arachnoiditis?

Complications of arachnoiditis may include chronic pain, debilitating neurologic deficits, syringomyelia, hydrocephalus, arachnoid cysts, sexual dysfunction, and loss of bladder and bowel control.

Conclusion:

One can try to prevent developing arachnoiditis by avoiding spinal injuries, as there is no known cure for this. Arachnoiditis can induce severe disability to an individual with the debilitating pain that worsens as the disease advances. It can be a reason for extreme mental stress as well. Doctors always encourage the affected individuals to join support groups for stress management. There are a number of therapeutic outlets one can try to relieve stress and improve the quality of life. Currently, the recommended management strategy involves pain management, exercises, physiotherapy, and psychotherapy. A qualified medical professional can guide the affected to suitable options for pain management.