Teens, adults with congenital adrenal hyperplasia may have cognitive impairment
Patients with congenital adrenal hyperplasia (CAH), while having normal psychometric intelligence, appear to have impaired executive functions compared with population controls, a study has found. Poorer general cognitive capacity is associated with a null CAH genotype.
The observational study compared cognition between CAH patients (n=55) and controls from the general population (n=58), aged 16 to 33 years. Of the CAH patients, nine had been treated prenatally with dexamethasone. Standardized neuropsychological tests (Wechsler Scales and Stroop Interference Test) and questionnaires (Barkley Deficit in Executive Functioning Scale) were used in the assessments.
Compared with controls, patients with CAH performed poorly in tests measuring verbal working memory (p=0.024), visual-spatial working memory (p=0.005 and p=0.003) and inhibition (p=0.002). Males with CAH also performed worse than control males (p=0.033) in measures of fluid intelligence/nonverbal logical reasoning.
Performance of patients with salt-wasting CAH was similar to that of patients with simple virilising CAH.
However, patients with a null genotype had inferior performance compared with patients with a non-null genotype. In particular, performance was significantly worse on fluid intelligence/nonverbal logical reasoning (p=0.042).
Among prenatally-treated women, performance was worse on most cognitive measures compared with women with CAH not treated prenatally.
While the present data show that patients with CAH, who had normal general intelligence and learning and memory performance, performed poorly in tests of executive functions than controls, the impairments were not confirmed in self-ratings of executive difficulties in everyday life, researchers said.
“Chronic postnatal glucocorticoid exposure appears to be a likely explanation for the reduced test performance. Prenatal glucocorticoid insufficiency or the consequences of early salt-losing crises and hypoglycaemia are probable modifiers, since the null genotype group was more affected than patients with less severe genotypes,” they explained, adding that additional long-term studies are needed to identify whether prenatal dexamethasone have an additive effect.
Researchers highlighted the importance of assessing all patients with CAH to detect cognitive impairment at an early stage to be able to give individual support as such deficits may have a negative effect on learning and school outcomes.