Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Feb;129(2):473-486.
doi: 10.1016/j.clinph.2017.11.017. Epub 2017 Nov 24.

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

Affiliations
Free PMC article

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

Verity M McClelland et al. Clin Neurophysiol. .
Free PMC article

Abstract

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.

Keywords: Central Motor Conduction Time; Children; Deep Brain Stimulation; Dystonia; Dystonic cerebral palsy; Secondary; Somatosensory Evoked Potentials.

Figures

Fig. 1
Fig. 1
Example traces. (A) Normal upper limb SEPs from a 13 year-old child with isolated genetic (DYT1) dystonia. (B) Upper limb SEPs from a 5 year old child with Dyskinetic Cerebral Palsy secondary to term HIE showing absent cortical response despite normal cervical responses. (C) Normal lower limb SEPs from same patient as A. (D) Lower limb SEPs from a 12 year old child with Dyskinetic Cerebral palsy secondary to prematurity (25 weeks) showing low-amplitude, poorly formed cortical waveform despite adequate peripheral and spinal responses.
Fig. 2
Fig. 2
(A) Distribution of abnormal neurophysiology results across aetiological groups. Bars show percentage of children in each aetiological group with one or more abnormal cortical SEP (grey) or CMCT result (red). Note different denominators: CMCT abnormal in 0/14 Genetic/Idiopathic Isolated, 3/19 Idiopathic Complex, 14/68 Acquired perinatal CP, 1/11 Acquired metabolic, 8/24 Acquired non-degenerative “Other” and 2/10 Acquired degenerative. SEP abnormal in 1/8 Genetic/Idiopathic Isolated, 4/13 Idiopathic Complex, 28/50 Acquired perinatal CP, 2/7 Acquired metabolic, 9/18 Acquired non-degenerative “Other” and 3/4 Acquired degenerative patients. (B) Distribution of abnormal neurophysiology results across Clinical MRI Diagnostic Categories. Bars show percentage of children in each imaging group with one or more abnormal cortical SEP (grey) or CMCT result (red). Imaging abnormality in PVWM = Periventricular white matter, BG-GP = basal ganglia including globus pallidus, BG+Post WM = basal ganglia and posterior white matter. Misc. (BG or Thal) = miscellaneous minor imaging abnormalities involving thalamus or basal ganglia other than globus pallidus. Misc (non-BG/Thal) = miscellaneous minor imaging abnormalities not involving the basal ganglia or thalamus. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
Fig. 3
Fig. 3
Flow charts showing numbers of children attending for each test (A = CMCT, B = SEP) and numbers proceeding to DBS.
Fig. 4
Fig. 4
Box and Whisker plots showing outcome from DBS measured as percentage change in BFMDRS-motor score at 1 year after surgery in relation to CMCT result. (A) Results for the whole group (B–E) sub-group analyses for (B) Idiopathic/Genetic dystonia, (C) Acquired dystonia, (D) Normal cranial MRI, (E) Abnormal cranial MRI. The p-values are calculated using Mann-Whitney tests. Note different scales for C and E as improvements are generally smaller in these groups.
Fig. 5
Fig. 5
Box and Whisker plots showing outcome from DBS measured as percentage change in BFMDRS-motor score at 1 year after surgery in relation to SEP result. (A) Results for the whole group (B–E) sub-group analyses for (B) Idiopathic/genetic dystonia, (C) Acquired dystonia, (D) Normal cranial MRI, (E) Abnormal cranial MRI. The p-values are calculated using Mann-Whitney tests. Note different scales for C and E as improvements are generally smaller in these groups.
Fig. 6
Fig. 6
Box and Whisker plots showing outcome from DBS measured as percentage change in BFMDRS-motor score at 1 year after surgery in relation to Neurophysiology score. (A) Results for the whole group (B–E) sub-group analyses for (B) Idiopathic/Genetic dystonia, (C) Acquired dystonia, (D) Normal cranial MRI, (E) Abnormal cranial MRI. Kruskal Wallis test shows significant difference across groups for A (p = 0.002), C (p = 0.018) and E (p = 0.022). The p-values shown on the figures are calculated using Mann-Whitney tests. Note different scales for C and E as improvements are generally smaller in these groups.

Comment in

Similar articles

See all similar articles

Cited by 2 articles

References

    1. Abbruzzese G., Berardelli A. Sensorimotor integration in movement disorders. Mov Disord. 2003;18:231–240. - PubMed
    1. Abbruzzese G., Marchese R., Buccolieri A., Gasparetto B., Trompetto C. Abnormalities of sensorimotor integration in focal dystonia: a transcranial magnetic stimulation study. Brain. 2001;124:537–545. - PubMed
    1. Air E.L., Ostrem J.L., Sanger T.D., Starr P.A. Deep brain stimulation in children: experience and technical pearls. J Neurosurg Pediatr. 2011;8:566–574. - PubMed
    1. Albanese A., Bhatia K., Bressman S.B., Delong M.R., Fahn S., Fung V.S. Phenomenology and classification of dystonia: a consensus update. Mov Disord. 2013;28:863–873. - PMC - PubMed
    1. Alterman R.L., Snyder B.J. Deep brain stimulation for torsion dystonia. Acta Neurochir Suppl. 2007;97:191–199. - PubMed

Publication types

Feedback