Correlation among subcortical white matter lesions, intelligence and CTG repeat expansion in classic myotonic dystrophy type 1.
OBJECTIVE
To analyze the correlation among intelligence, brain magnetic resonance images (MRI) and genotype in classic myotonic dystrophy type 1 (DM1) patients.


METHODS
Seventeen patients with classic DM1 were administered intelligence and neuropsychological tests and brain MRI focusing on a semi-quantitative rating scale of subcortical white matter lesions (WMLs). Statistical analysis was measured to evaluate the correlation among clinical manifestations, intelligence, brain MRI abnormalities, and CTG repeat expansion.


RESULTS
There were statistically significant correlations between intelligence test and insular WMLs for all DM1 patients and between intelligence quotient and temporal WMLs for those patients with less than 400 of the CTG repeat size. We also documented that temporal WMLs were related to the disease course, and frontal WMLs were correlated with aging in all DM1 patients. However, a poor correlation was found among CTG repeat size and clinical pictures, neuropsychological impairments, and brain MRI abnormalities in all DM1 patients.


CONCLUSIONS
These results suggest that subcortical WMLs are correlated with focal dementia in classic DM1 patients. Temporal and insular WMLs may be responsible for the global intellectual dysfunction of adult DM1 patients.
Kuo
H-C
HC
Department of Neurology, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taipei, Taiwan.
Hsieh
Y-C
YC
Wang
H-M
HM
Chuang
W-L
WL
Huang
C-C
CC
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D065636:Myotonin-Protein Kinase; D009457:Neuroglia / Q000473:pathology*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D018709:Statistics, Nonparametric; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*
C585517:DMPK protein, human; D065636:Myotonin-Protein Kinase; D017346:Protein Serine-Threonine Kinases