Editorial: Deep brain stimulation in children

Abstract

We congratulate Dr. Air and colleagues for sharing their experience in treating various pediatric movement disorders with deep brain stimulation (DBS).1 This is a retrospective study of 31 pediatric patients spanning over 12 years at a high-volume surgical movement disorder program. A detailed methodology is presented and demonstrates the significant challenges of using DBS in pediatric patients. This population may be at increased risk of CSF leaks, wound breakdown, and hardware infection. The use of microelectrode recordings (MER) under local anesthesia was necessarily limited to 6 patients with normal cognition and without severe spontaneous hyperkinetic movement. The difficulties encountered in using MER under general anesthesia included the alteration of neuronal firing pattern and the inability to monitor the patients’ neurological status, both the occurrence of adverse neurologic events and potential clinical benefit during surgery. The heterogeneous results related the etiology of the movement disorders. Excellent outcomes were observed in 13 children with primary dystonia with a 77% improvement on the Burke-Fahn-Marsden Dystonia Rating Scale. The results largely mirror those that have appeared in the literature. In general, as with most open label studies, the results exceed those reported in trials where assessments are blinded. Variable benefit was noted in patients with secondary dystonia, particularly the patients with neurodegeneration with brain iron accumulation (previously known as Hallervorden-Spatz disease) where sometimes spectacular results have been reported in other centers. The modest and variable benefits with DBS as captured on the rating scales of patients with dystonia secondary to cerebral palsy and stroke are sometimes underestimates of the meaningful benefits reported by the patient’s caregivers and the patients themselves. It is quite clear from the field, and this paper in the pediatric population strengthens the idea, that primary dystonias respond better than secondary dystonias to DBS. This may be related to differences in the integrity of the neuroanatomical circuitry of the basal ganglia and the motor system, with the best results achieved in those without overt structural damage. Nevertheless, a large number of pediatric and adult patients with secondary dystonias including those with anoxic birth injury, other forms of cerebral palsy, and head injury can benefit. The challenge is to understand which of these patients are more likely to benefit from DBS and try to optimize and improve the results in this patient group. The authors are to be congratulated for their thorough and careful assessment of DBS for dystonia in pediatric patients.