Surgical Treatment of Facial Pain Nicholas M. Barbaro, MD University of California at San Francisco Classification of Facial Pain Trigeminal neuralgia Atypical trigeminal neuralgia Neuropathic facial pain Migraine with facial component Typical trigeminal neuralgia Paroxysmal lancinating pain Triggers Pain-free intervals Remissions Responds to medications Atypical trigeminal neuralgia TN with additional features Burning or aching component Lack of response to typical medications? Related to dental work Causes of trigeminal neuralgia Idiopathic Vascular compression Other Multiple sclerosis Tumors Meningiomas Other Genetic
Trigeminal Neuralgia: medications Carbamazepine (Tegretol ) Oxcarbazepine (Trileptal ) Gabapentin (Neurontin ) Phenytoin (Dilantin ) Baclofen (Lioresal ) Other anticonvulsants Topamax Keppra Lamictal New drugs Lyrica Cymbalta Medically-refractory pain Break-through pain Toxicity Sedation Ataxia Memory disturbance Low white blood cell count Bone marrow suppression Liver Neuropathic facial pain Pain in trigeminal distribution typically caused by nerve injury Dental or other surgical trauma Head/skull trauma Herpes zoster/post-herpetic neuralgia Typically constant burning, aching May have paroxysms including shocks Sensory deficit Allodynia, hyperpathia Medications for neuropathic pain Neurontin Tricyclics (nortriptyline, others) Lyrica All other anticonvulsants All other antidepressants
Intervention Endovascular coil embolization was done with obliteration of the dural arteriovenous fistula and resolution of facial pain but with decreased sensation in the face Pre-embolization Post-embolization Surgical techniques Open surgery Microvascular decompression (MVD, Jannetta procedure) Open rhizotomy Percutaneous procedures Radiofrequency lesion (RFL) Chemical lesion (glycerol) Balloon compression Radiosurgery Gamma Knife Cyberknife Considerations in choice of surgery Cause of trigeminal neuralgia Severity of pain General medical condition Age Patient preference Goals Risk aversion General guidelines Treat the cause of pain Tumors require open surgery or radiosurgery Patients with MS will not likely have vascular compression Less invasive approaches for older or medically ill patients Microvascular Decompression Jannetta Treats the most common cause of TN Most invasive Least damage to trigeminal nerve Longest pain-free, medication-free periods Success rate 80% MVD + rhizotomy success rate 90% 3
MVD Risks Typical surgical risks Infection (%) Bleeding (Transfusion) Risks of anesthesia Serious neurological injury Hearing (neuromonitoring) Direct injury Vascular injury stroke Death Radiofrequency lesion (RFL) Best for severe pain in high risk patient MS Excellent early relief (90%) Relatively high recurrence rate (50%) Can be selective (trigeminal divisions) Easily repeated 4
Risks of radiofrequency lesion General surgical risks Infection Bleeding Excessive nerve injury Dysesthesias (Unpleasant numbness) Corneal numbness Anesthesia dolorosa Intracranial hemorrhage Radiosurgical treatment of TN Least invasive Little or no anesthesia Outpatient Very good relief (80+%) Primary treatment Treat recurrence or failure of other treatment Short follow-up Slow response 4-6 weeks initial 3-6 months for full effect MRI (claustrophobia) 5
Dose considerations Early studies recommended 70-90 Gy Mayo Clinic data Unacceptable sensory deficits with 90 Gy UCSF preliminary results Similar results with 70 and 75 Gy Faster response with 80 Gy 85% excellent response 40% pain-free with lower dose meds 6
Retreatment No Yes p-value Age at Treatment (years) 65. 69. 0.868 Duration of symptoms (months) 93.9 04. 0.78 Female (%) 67.5 59.40% 0.376 Duration of follow-up (months) 5.9.9 0.000 Initial Treatment MVD RF RS p-value Age at Treatment (years) 58. 7.8 7.7 0.000 Duration of Symptoms (months) 95.6 40.6 0.40 Female (%) 63. 77.7 68. 0.586 Duration of follow-up (months) 70. 86. 50.6 0.33 RS % patients not requiring retreatment MVD RF MVD w/ PR Time after first procedure (months) 7
Multiple Sclerosis Associated Trigeminal Neuralgia Small percentage (<5%) of patients presenting with TN Small percentage (~5%) of patients with MS Response to surgical therapy worse than for idiopathic TN Likelihood of having vascular compression small Least invasive approach advisable for this group of patients Results: overall management Pain-free no meds Pain-free meds Pain-free then recurrence Partial improvement No improvement Total st Rx 4 5 3 5 70Gy 0 6 80Gy 3 4 0 9 80Gy + Re-Rx 6 0 9 All pts all Rx 7 3 5 Lessons from multi-modality treatment Importance of disease-based, rather than technique-based approach Majority of patients can have single treatment All currently accepted treatments are good For many patients, TN requires nearly lifelong treatment Is there a perfect procedure for TN? NO All procedures work most of the time Balance goals with risks Lifelong management of pain Reasonable doses of medications Avoid repeated nerve damaging procedures Surgery for non-tn pain Much lower success rates May make pain worse Increase sensory disturbance Increase burning Recent experience with Gamma Knife Surgery for non-tn pain Motor cortex stimulation Experimental Sub-threshold stimulation Used for various neuropathic pains Best for facial neuropathic pain 8
Motor Cortex Stimulation Emerging technique Few patients studied Offers hope for potentially untreatable patients Preliminary efficacy reported in three disorders: Thalamic pain syndrome Spinal cord injury pain Facial deafferentation pain Chronic Motor Cortex Stimulation for the Treatment of Central Pain T Tsubukowa, Y Katayama, T Yamamoto, T Hirayama S Koyama. Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan Acta Neurochirurgica, Suppl. 5, 37-39 (99) fmri Localization Direct stimulation of motor cortex Epidural placement of permanent electrode 9
Connection to extension lead/ipg Conclusions MCS is an emerging technique with potential for treating a variety of neuropathic pain conditions Most promising area is with facial pains Preclinical and preliminary clinical data support more extensive study Pilot/definitive trials are planned 0