title: Predictors of long-term success after microvascular decompression for trigeminal neuralgia.
abstract: OBJECTIVE
  Microvascular decompression (MVD) is an effective treatment for trigeminal neuralgia (TN). However, many patients do not experience complete pain relief, and relapse can occur even after an initial excellent result. This study was designed to identify characteristics associated with improved long-term outcome after MVD.
  
  
  METHODS
  One hundred seventy-nine consecutive patients who had undergone MVD for TN at the authors' institution were contacted, and 95 were enrolled in the study. Patients provided information about preoperative pain characteristics including preponderance of shock-like (Type 1 TN) or constant (Type 2 TN) pain, preoperative duration, trigger points, anticonvulsant therapy response, memorable onset, and pain-free intervals. Three groups were defined based on outcome: 1) excellent, pain relief without medication; 2) good, mild or intermittent pain controlled with low-dose medication; and 3) poor, severe persistent pain or need for additional surgical treatment. Results Type of TN pain (Type 1 TN vs Type 2 TN) was the only significant predictor of outcome after MVD.
  
  
  RESULTS
  were excellent, good, and poor for Type 1 TN versus Type 2 TN patients in 60 versus 25%, 24 versus 39%, and 16 versus 36%, respectively. Among patients with each TN type, there was a significant trend toward better outcome with greater proportional contribution of Type 1 TN (lancinating) symptoms (p < 0.05).
  
  
  CONCLUSIONS
  Pain relief after MVD is strongly correlated with the lancinating pain component, and therefore type of TN pain is the best predictor of long-term outcome after MVD. Application of this information should be helpful in the selection of TN patients likely to benefit from MVD.
authors.affiliation: Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Miller
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Magill
authors.forename: Feridun
authors.initials: F
authors.lastname: Acar
authors.forename: Kim J
authors.initials: KJ
authors.lastname: Burchiel
mesh_terms: D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008866:Microsurgery / Q000379:methods; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000145:classification / Q000503:physiopathology / Q000601:surgery*