title: Does egress of cerebrospinal fluid during percutaneous retrogasserian glycerol rhizotomy influence long term pain relief?
abstract: OBJECTIVE
  To examine the effect of cerebrospinal fluid (CSF) flow during percutaneous retrogasserian glycerol rhizotomy (PRGR) on long term pain relief in patients with trigeminal neuralgia.
  
  
  METHODS
  Eighty-nine patients with trigeminal neuralgia underwent 102 PRGR procedures. PRGR was conducted under fluoroscopy. After the egress of CSF, anhydrous glycerol (0.3-0.4 cc) was injected in the sitting position. In the absence of CSF flow, 0.25 mL 2% lidocaine was injected to elicit hypesthesia in the affected side. Once hypesthesia was elicited glycerol was injected. Patients were grouped as A (CSF flow present) or B (CSF flow absent), according to the egress of CSF at the time of needle placement. Patients were followed up for the recurrence of pain (average duration of follow up, 62 months).
  
  
  RESULTS
  CSF flow was present in 54 patients (60.6%) and absent in 35 patients (39.4%). Thirty patients (56.6%) of group A had excellent pain relief, 18 patients (33.3%) had good pain relief, and 6 patients (11.1%) had no pain relief. However, in the absence of CSF flow, 14 patients (40%) each had excellent and good pain relief, and 7 patients (20%) were treatment failures. The pain relief was comparable between the groups. The median time to recurrence of pain needing further injection was 66 months in group A and 63 months in group B (not significant).
  
  
  CONCLUSIONS
  Presence of CSF flow during needle placement does not influence the success rate and duration of pain relief following PRGR.
authors.affiliation: Department of Neuroanaesthesiology, Neurosciences Centre, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Mihir Prakash
authors.initials: MP
authors.lastname: Pandia
authors.forename: Hari Har
authors.initials: HH
authors.lastname: Dash
authors.forename: Parmod Kumar
authors.initials: PK
authors.lastname: Bithal
authors.forename: Rajendra Singh
authors.initials: RS
authors.lastname: Chouhan
authors.forename: Virendra
authors.initials: V
authors.lastname: Jain
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002555:Cerebrospinal Fluid / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005990:Glycerol; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011446:Prospective Studies; D019233:Retreatment; D019051:Rhizotomy / Q000379:methods*; D055502:Secondary Prevention; D012997:Solvents; D013126:Spinal Nerve Roots / Q000187:drug effects*; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000628:therapy*
chemical_list: D012997:Solvents; D005990:Glycerol