MELBOURNE – Diabetic ketoacidosis was associated with swelling of white brain matter and shrinkage of gray matter, and the degree of change was associated with neurocognitive outcomes up to 6 months after the event, based on a study of children who were newly diagnosed with type 1 diabetes and did not have cerebral edema.
In a prospective cohort study of children newly diagnosed with type 1 diabetes, 36 patients presented with and 59 without diabetic ketoacidosis. Researchers performed magnetic resonance imaging (T1 weighted, diffusion tensor imaging, and fractional anisotropy) and a battery of psychometric tests at the time of diagnosis, then again at 1 week, 4 weeks, and 6 months after diagnosis in both groups.
Although there was no net change in brain volume, total gray matter volume was reduced and total cortical white matter volume was increased on day 1 in the diabetic ketoacidosis group.
Compared with those without ketoacidosis, children with ketoacidosis had lower levels of a marker of neuronal density, lower activity in the frontal gray matter and basal ganglia on day 1, and lower mental state scores on days 1 and 5.
"Swelling had resolved by the end of the first week but was associated with neurocognitive outcomes at 6 months. So even though the brain looked normal, [those with ketoacidosis at diagnosis] were still performing less well on neuropsychological testing, especially in terms of long-term memory," said Dr. Fergus Cameron, head of diabetes services at the Royal Children’s Hospital, Melbourne.
"Changes in white matter volume were associated with poorer divided attention, sustained attention, and long-term memory, while the changes in gray matter in the parietal lobe were associated with poorer sustained attention," Dr. Cameron said in an interview.
"The younger and more acidotic the patient, the more marked the morphologic brain changes," Dr. Cameron said.
The findings highlight a need for neuroprotective adjunct therapies that might reduce the degree of neuronal damage, he said. Also, given their cognitive state, children with ketoacidosis might be less able to process detailed information immediately after their diagnosis.
When trying to implement diabetic education with these children, it might be better to focus on survival skills in the first week or two after diagnosis, and then turn to more advanced diabetes education a few weeks later, he said at the World Diabetes Congress.
"We should also be aware of how these kids are functioning in the school room," he added. At 6 months after diagnosis, it might be good to measure progress with teachers.
The study was funded by the Juvenile Diabetes Research Foundation and the National Health and Medical Research Council. No other conflicts of interest were reported.