title: Trochlear nerve palsy after repeated percutaneous balloon compression for recurrent trigeminal neuralgia: case report and pathogenic considerations.
abstract: OBJECTIVE
  Repeated percutaneous balloon compression for the treatment of idiopathic trigeminal neuralgia is infrequent. When a second procedure is performed, the outcome is unknown. A patient developed an isolated trochlear nerve palsy after undergoing percutaneous trigeminal ganglion balloon compression for a second time. The mechanism of diplopia and the complications associated with this technique were studied.
  
  
  METHODS
  The patient was a 67-year-old woman with a history of medically refractory idiopathic trigeminal neuralgia involving all three divisions of the right trigeminal nerve.
  
  
  METHODS
  Percutaneous balloon compression was performed. Despite initial total relief from pain without complications, the patient again displayed manifestations of trigeminal neuralgia 3 months after the procedure. The pain disappeared after she underwent a second balloon compression procedure, but she developed an isolated trochlear nerve palsy, which spontaneously resolved in 2 months.
  
  
  CONCLUSIONS
  Isolated trochlear nerve palsy is a rare and reversible complication after percutaneous balloon compression for trigeminal neuralgia. This case illustrates that the mechanism of injury to the fourth nerve is the result of an erroneous technique: excessive penetration of the Fogarty catheter in Meckel's cave beyond the porus trigemini and compression of the cisternal segment of the trochlear nerve when the inflated balloon is pushed against the tentorium.
authors.affiliation: Department of Neurosurgery, Hospital Donostia, Paseo del Dr. Begiristain s/n, 20014 San Sebastian, Spain. erculo@chdo.osakidetza.net
authors.forename: Enrique
authors.initials: E
authors.lastname: Urculo
authors.forename: Roger
authors.initials: R
authors.lastname: Alfaro
authors.forename: Mariano
authors.initials: M
authors.lastname: Arrazola
authors.forename: Edgar
authors.initials: E
authors.lastname: Astudillo
authors.forename: Guillermo
authors.initials: G
authors.lastname: Rejas
mesh_terms: D000368:Aged; D002404:Catheterization / Q000009:adverse effects*; D005260:Female; D006801:Humans; D012008:Recurrence; D019233:Retreatment / Q000009:adverse effects; D014277:Trigeminal Neuralgia / Q000628:therapy*; D020432:Trochlear Nerve Diseases / Q000209:etiology* / Q000473:pathology