Abstract
The network model of dystonia reconciles many of the neuroanatomical and electrophysiological abnormalities identified as potential pathophysiological factors. Recent [18F]fluorodeoxyglucose (FDG)-PET brain imaging findings support this concept, revealing distinct patterns of abnormal brain metabolism in specific dystonia aetiologies. However, it is unclear how changes in specific neural pathways alter brain glucose metabolism. This observational study investigates patterns of brain metabolism found using [18F]FDG-PET imaging in children with dystonia, awake-resting during the uptake period, in relation to measures of brain function using standard neurophysiological tests of motor and sensory pathway integrity.
Central motor conduction times (CMCT), somatosensory evoked potentials (SEP) and [18F]FDG-PET scans were obtained in children with dystonia or dystonic-dyskinetic cerebral palsy undergoing standard clinical assessment for bilateral pallidal deep brain stimulation (DBS) between 2007 and 2018 in Evelina London Children’s Hospital (ELCH). Data from 109 children aged 2.8-18.8 years were analysed retrospectively. Patients were divided into groups based on their neurophysiology results as follows: both tests normal (NN; 67), both abnormal (AA; 11), normal CMCT/abnormal SEP (NA; 20), abnormal CMCT/normal SEP (AN; 11). Groups were compared with a control group comprising [18F]FDG-PET scans from thirty-nine healthy adults using Statistical Parametric Mapping (SPM12) with age and groupwise global means as covariates.
Taking into account groupwise global uptake, all four groups shared relative hypermetabolism in parietal areas, postcentral and precentral gyri.
In addition, mild peri-insular hypometabolism was seen in the NN group. The NA group showed marked regional hypometabolism bilaterally in the thalami, globi pallidi, putamina, heads of the caudate nuclei and areas of peri-sylvian cortex. The AN group had hypometabolism in the thalami and posterior globi pallidi, the posterior putamina, and areas of peri-sylvian cortex. The AA group also exhibited hypometabolism in the medial thalami and some areas of frontal and peri-insular cortex.
Across the whole cohort, abnormal SEPs were strongly associated with thalamic hypometabolism, with no marked differences for abnormal CMCTs.
Brain metabolism patterns in dystonia relate to neurophysiological abnormalities in our study. Relative parietal hypermetabolism is more common than recognised previously, while thalamic hypometabolism is prominent in those with abnormal sensory pathway function. The findings support the network model of dystonia and emphasise the importance of multi-modal assessment in providing detailed phenotyping, which could inform individualised management strategies.
Central motor conduction times (CMCT), somatosensory evoked potentials (SEP) and [18F]FDG-PET scans were obtained in children with dystonia or dystonic-dyskinetic cerebral palsy undergoing standard clinical assessment for bilateral pallidal deep brain stimulation (DBS) between 2007 and 2018 in Evelina London Children’s Hospital (ELCH). Data from 109 children aged 2.8-18.8 years were analysed retrospectively. Patients were divided into groups based on their neurophysiology results as follows: both tests normal (NN; 67), both abnormal (AA; 11), normal CMCT/abnormal SEP (NA; 20), abnormal CMCT/normal SEP (AN; 11). Groups were compared with a control group comprising [18F]FDG-PET scans from thirty-nine healthy adults using Statistical Parametric Mapping (SPM12) with age and groupwise global means as covariates.
Taking into account groupwise global uptake, all four groups shared relative hypermetabolism in parietal areas, postcentral and precentral gyri.
In addition, mild peri-insular hypometabolism was seen in the NN group. The NA group showed marked regional hypometabolism bilaterally in the thalami, globi pallidi, putamina, heads of the caudate nuclei and areas of peri-sylvian cortex. The AN group had hypometabolism in the thalami and posterior globi pallidi, the posterior putamina, and areas of peri-sylvian cortex. The AA group also exhibited hypometabolism in the medial thalami and some areas of frontal and peri-insular cortex.
Across the whole cohort, abnormal SEPs were strongly associated with thalamic hypometabolism, with no marked differences for abnormal CMCTs.
Brain metabolism patterns in dystonia relate to neurophysiological abnormalities in our study. Relative parietal hypermetabolism is more common than recognised previously, while thalamic hypometabolism is prominent in those with abnormal sensory pathway function. The findings support the network model of dystonia and emphasise the importance of multi-modal assessment in providing detailed phenotyping, which could inform individualised management strategies.
| Original language | English |
|---|---|
| Journal | Brain Communications |
| Publication status | Accepted/In press - 15 Apr 2025 |
Keywords
- Paediatric neurology, dystonia, dystonic-dyskinetic cerebral palsy, PET functional imaging, Motor Evoked Potentials, Somatosensory Evoked Potentials