Somatosensory Evoked Potentials and Central Motor Conduction Times in children with dystonia and their correlation with outcomes from Deep Brain Stimulation of the Globus pallidus internus.
Clin Neurophysiol 2017;
129:473-486. [PMID:
29254860 PMCID:
PMC5786451 DOI:
10.1016/j.clinph.2017.11.017]
[Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/14/2017] [Accepted: 11/17/2017] [Indexed: 12/13/2022]
Abstract
A high proportion (47%) of children with dystonia have evidence of abnormal sensory pathway function.
Central motor conduction times (CMCTs) and somatosensory evoked potentials (SEPs) show a significant relationship with deep brain stimulation (DBS) outcome, independent of aetiology or cranial MRI.
CMCTs and SEPs can guide patient selection and help counsel families about potential benefit of DBS.
Objectives
To report Somatosensory Evoked Potentials (SEPs) and Central Motor Conduction Times (CMCT) in children with dystonia and to test the hypothesis that these parameters predict outcome from Deep Brain Stimulation (DBS).
Methods
180 children with dystonia underwent assessment for Globus pallidus internus (GPi) DBS, mean age 10 years (range 2.5–19). CMCT to each limb was calculated using Transcranial Magnetic Stimulation. Median and posterior tibial nerve SEPs were recorded over contralateral and midline centro-parietal scalp. Structural abnormalities were assessed with cranial MRI. One-year outcome from DBS was assessed as percentage improvement in Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS-m).
Results
Abnormal CMCTs and SEPs were found in 19% and 47% of children respectively and were observed more frequently in secondary than primary dystonia. Of children proceeding to DBS, better outcome was seen in those with normal (n = 78/89) versus abnormal CMCT (n = 11/89) (p = 0.002) and those with normal (n = 35/51) versus abnormal SEPs (n = 16/51) (p = 0.001). These relationships were independent of dystonia aetiology and cranial MRI findings.
Conclusions
CMCTs and SEPs provide objective evidence of motor and sensory pathway dysfunction in children with dystonia and relate to DBS outcome.
Significance
CMCTs and SEPs can contribute to patient selection and counselling of families about potential benefit from neuromodulation for dystonia.
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