Gamma knife radiosurgery for torsion spasm. Report of two cases

The authors report on two patients who underwent radiosurgery for torsion spasm and evaluate the efficiency of gamma knife radiosurgery (GKS) as an alternative treatment. The first patient was a 33-year-old woman with severe right-sided lower-limb torsion dystonia. The second patient was a 20-year-old man with right-sided upper-limb torsion dystonia. The target was located at the anterior portion of the ventrolateral nucleus. The maximum doses were 150 Gy and 145 Gy, respectively. Double isocenters with a 4-mm collimator were used. Follow up lasted for 18 months and 8 months, respectively. Both patients had excellent clinical improvement 2 to 3 months after GKS, respectively. The authors believe that GKS may be a safe and efficient treatment for torsion spasm.