Treatment Options for Arachnoiditis
The management of arachnoiditis requires a combination of anti-inflammatory therapy, pain management, and in some cases surgical intervention, with corticosteroids being the first-line treatment for acute symptoms. 1, 2
Pathophysiology and Etiology
Arachnoiditis is a rare inflammatory condition affecting the pia mater of the spinal cord and nerve roots, which can lead to significant disability. Common causes include:
- Infections
- Oil-based myelographic dyes
- Blood in the intrathecal space
- Neurotoxic substances
- Spinal surgeries
- Intrathecal corticosteroids
- Trauma
- Epidural procedures (including blood patches)
- Antiseptic contamination during neuraxial anesthesia 2, 3
Clinical Presentation
Patients with arachnoiditis typically present with:
- Burning severe pain in the lower back and lower extremities
- Dysesthesia and numbness not following typical dermatome distribution
- Bladder, bowel and/or sexual dysfunction
- Progressive weakness of lower extremities
- Urinary symptoms (urgency, frequency, incontinence) in 23% of cases 2, 4
Diagnostic Approach
MRI with 3D volumetric sequencing is the most sensitive and specific diagnostic tool for arachnoiditis 1, 3. Look for:
- Clumped nerve roots
- Fibrosis
- Scarring
- Dural sac deformities
- Pachymeningitis
- Pseudomeningocele
- Syringomyelia 2
Treatment Options
1. Anti-inflammatory Therapy
- Corticosteroids: High-dose corticosteroids are recommended as first-line treatment for acute arachnoiditis to decrease brain edema and inflammation 1, 2
- IV methylprednisolone followed by oral prednisone taper has shown effectiveness 5
- NSAIDs: Should be considered early to prevent inflammatory response from evolving into proliferative phase 2
- Steroid-sparing agents: Methotrexate can be considered for patients requiring prolonged anti-inflammatory therapy 1
2. Pain Management
- Daily narcotic analgesics are often required for pain control 4
- Neuropathic pain medications (gabapentin, pregabalin)
- Antidepressants for pain modulation
3. Surgical Interventions
- Shunt surgery: Recommended for patients with hydrocephalus from arachnoiditis 1
- Surgical debulking: May benefit some patients over shunt surgery alone 1
- Minimally invasive procedures: When possible, neuroendoscopy is preferred for removal of cysticerci in cases of neurocysticercosis-related arachnoiditis 1
- Surgical removal: For cases with identifiable adhesions causing symptoms 6
4. Physical Rehabilitation
- Intensive rehabilitation is important but may not preserve independent mobility in severe cases 3
Prognosis
The long-term prognosis for arachnoiditis is guarded:
- Pain and functional disability tend to remain the same as at diagnosis, though severity fluctuates
- Increased neurologic deficits are more frequently due to surgical intervention than natural disease progression
- Most patients can walk and drive without limitation but have markedly limited ability to return to previous occupations
- Average lifespan may be shortened by approximately 12 years 4
Prevention
Prevention is critical since treatment results are often disappointing:
- Use 0.5% chlorhexidine in alcohol (rather than 2%) for skin antisepsis before central neuraxial blockade 1
- Avoid pouring antiseptic solutions into containers located on the same tray as equipment for central neuraxial blockade 1
- Use pre-soaked antiseptic sponge applicators to minimize contamination risk 1
- Avoid further spinal procedures in patients with suspected arachnoiditis 2
- Use absorbable, non-irritative contrast materials like Iohexol Parenteral for diagnostic procedures 6
Important Caveats
- Avoid repeated epidural blood patches in patients who develop symptoms of arachnoiditis
- Prompt administration of corticosteroids is crucial when symptoms first appear
- Further spinal procedures should be avoided in patients with established arachnoiditis
- Careful monitoring for suicide risk is warranted as there is an increased risk in this population 4