Historical Background John Fothergill 1773 Charles Bell 1829 - PowerPoint PPT Presentation

Historical Background  John Fothergill – 1773  Charles Bell – 1829  Walter Dandy –1934 Images from Prasad, et al.

Criteria for Diagnosis  Paroxsymal, usually unilateral attacks of facial pain in one or more trigeminal divisions lasting <1 sec – 2 min  At least one of the following: 1) Intense, sharp, superficial or stabbing quality, 2) Precipitation by “triggers” 3) Relative absence of symptoms between attacks  Stereotyped patterns of attacks within individual patients  No objective neurologic deficit  No other identified causes for facial pain The International Classification of Headache Disorders, 2 nd Ed.

Classification of Facial Pain Burcheil, KJ. “A New Classification for Facial Pain.” Neurosurgery . 2003

Treatment Options  Medication  Percutaneous Rhizotomy (Glycerol, Balloon, or RFA)  Stereotactic Radiosurgery (1951)  Microvascular Decompression

Gamma knife for Tic  Safe and effective  Non-invasive  Drawbacks: Durability and trigeminal dysfunction

MCG Patient Demographics  318 Patients treated, Mean follow up 16.25 months (3-120 mo)  33.6% Male/66.4% Female  81.4% Caucasian/15.1% African American  No Prior – 76.7%  MVD – 4.4%  GKRS – 0.6%  Other – 18.2%

Pain Characteristics  289 (90.9%) with TN1 or TN2  51.8% Right/47.1% Left/1.1% Bilateral

Treatment Protocol  80.7 Gy mean maximum dose to nerve (70-90Gy)  Single Shot (96.8%)  4mm collimator (100%)  82.7% Model B

Response to Gamma  Trigeminal Neuralgia Type 1 and Type 2  91.2% with good/excellent outcomes (Class I-III) 60.3% with pain-free outcomes  8.8% with little/no response to treatment (Class IV-V)  PFOM 36.3% PFWM 24% PWM 30.9% NR (IV/V) 8.8%

Neuropathy, MS, and Repeat GKRS Good/Excelle nt No Response Pain-Free n Neuralgia 91.2% 8.8% 60.3% 204 Neuropathy 57.1% 42.9% 21.4% 14 MS 77.8% 22.2% 66.7% 9 Repeat GKRS 91.7% 8.3% 37.5% 24

Subgroup Comparison Good/Excellent Pain Freedom p-value p-value Neuralgia vs Neuropathy <0.001 <0.005 Neuralgia vs MS NS NS Neuralgia vs Repeat GKRS NS <0.05 Age <65 vs >65 NS <0.01 Smoking NS NS  The neuropathy group was less likely to experience a Good/Excellent outcome, or experience a pain-free outcome than the neuralgia group The Repeat GKRS group was less likely to achieve a pain free outcome, but not  less likely to respond to therapy than patients undergoing initial treatment  Patients older than 65 were more likely to experience a pain free response than patients less than 65

Retreatment Response Good/Exc No ellent Pain-Free Response n Neuralgia 91.2 60.3 8.8 204 First Tx 94 48 6 50 Second Tx 91.7 37.5 8.3 24 Retreatment mean max dose 69.8 Gy   The retreatment group was less likely to achieve a pain free response than the initial treatment group on second treatment (p < 0.05)

Conclusions  Gamma knife radiosurgery is an effective option for the treatment of medically refractory trigeminal neuralgia  Durability is likely the greatest weakness of this treatment modality  Useful for patients with MS as well as Neuropathy, although efficacy may be decreased in these settings  Repeat GKRS is possible after initial treatment failure, but a pain free response may be less likely

Thank you  Special thanks to Christina Hamilton and Dr. Vender  Thank you for your attention