Diffusion tensor imaging identifies deficits in white matter microstructure in subjects with type 1 diabetes that correlate with reduced neurocognitive function.
OBJECTIVE
Long-standing type 1 diabetes is associated with deficits on neurocognitive testing that suggest central white matter dysfunction. This study investigated whether diffusion tensor imaging (DTI), a type of magnetic resonance imaging that measures white matter integrity quantitatively, could identify white matter microstructural deficits in patients with long-standing type 1 diabetes and whether these differences would be associated with deficits found by neurocognitive tests.


METHODS
Twenty-five subjects with type 1 diabetes for at least 15 years and 25 age- and sex-matched control subjects completed DTI on a 3.0 Tesla scanner and a battery of neurocognitive tests. Fractional anisotropy was calculated for the major white matter tracts of the brain.


RESULTS
Diabetic subjects had significantly lower mean fractional anisotropy than control subjects in the posterior corona radiata and the optic radiation (P < 0.002). In type 1 diabetic subjects, reduced fractional anisotropy correlated with poorer performance on the copy portion of the Rey-Osterreith Complex Figure Drawing Test and the Grooved Peg Board Test, both of which are believed to assess white matter function. Reduced fractional anisotropy also correlated with duration of diabetes and increased A1C. A history of severe hypoglycemia did not correlate with fractional anisotropy.


CONCLUSIONS
DTI can detect white matter microstructural deficits in subjects with long-standing type 1 diabetes. These deficits correlate with poorer performance on selected neurocognitive tests of white matter function.
Kodl
Christopher T
CT
Departmentof Medicine, Division of Endocrinology, Diabetes, and Metabolism, University Of Minnesota, Minneapolis, Minnesota, USA.
Franc
Daniel T
DT
Rao
Jyothi P
JP
Anderson
Fiona S
FS
Thomas
William
W
Mueller
Bryon A
BA
Lim
Kelvin O
KO
Seaquist
Elizabeth R
ER
D000328:Adult; D000367:Age Factors; D016880:Anisotropy; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D003071:Cognition / Q000502:physiology*; D003922:Diabetes Mellitus, Type 1 / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests