Introduction: CP dystonia dominates referral to our Service. We assessed the clinical, neurophysiological and functional imaging characteristics to provide greater personalised prognostic information regarding suitability for DBS.

Methods: Data from 108 CP patients were analysed. CMCT and SEP were obtained using standard methodology. 106/108 FDG-PET-CT brain scans were quantitatively analysed using Statistical Parametric Mapping (SPM12), applying a visualization threshold of p=0.001.

Results: The cohort included 15(14%) cases of Kernicterus, 41(38%) pre-term and 52(48%) term births. The mean baseline dystonia severity score using the Burke-Fahn-Marsden Dystonia Rating Scale-motor (BFMDRS-M) was 87.4/120 (SD=19.9). DBS was performed in 54 (50%) cases. A 1-year follow-up (N=44) modest BFMDRS-M improvement trend was observed (Z=1.81, p=0.071). The kernicterus group had the least favourable DBS outcome and the pre-terms the most favourable (absolute change in mean BFMDRS-M=4.81, p=0.015). 14/77 (18%) cases had abnormal CMCT and 30/65 (46%) had abnormal SEP. SEP/CMCT did not relate significantly to outcome in this small group. PET imaging revealed a significant hypometabolism within the posterior putamen extending to the posterior globus pallidus of the CP-term patients, when compared to the other two CP groups. When compared to DYT1 cases (N=7), both term and pre-term CP cases had relative bilateral thalamic hypometabolism.

Discussion: CP is a common aetiology of dystonia. A significant proportion of children show neurophysiological abnormalities, particularly of sensory pathways. FDG-PET abnormalities imply an underlying functional defect, which may offer further insight into various distinct CP pathophysiologies. Multi-modal assessment may help with patient selection and prognostic counselling.