Timing variability in children with early-treated congenital hypothyroidism

• Published in: Acta psychologica 1997-06, Vol.96 (1), p.61-73
• Main Authors: Kooistra, Libbe, Snijders, Tom A.B., Schellekens, Jan M.H., Kalverboer, Alex F., Geuze, Reint H.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Case-Control Studies; Cerebellum; Children; Congenital Hypothyroidism; Endocrinopathies; Factors; Female; Humans; Hypothyroidism - complications; Infant, Newborn; Longitudinal Studies; Male; Medical sciences; Models, Psychological; Motor development; Motor performance; Motor timing; Movement Disorders - etiology; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Psychomotor Performance; Thyroid. Thyroid axis (diseases); Time Factors; Timing; Timing variability; Treatment
• ISSN: 0001-6918; 1873-6297
• DOI: 10.1016/S0001-6918(96)00047-9

This study reports on central and peripheral determinants of timing variability in self-paced tapping by children with early-treated congenital hypothyroidism (CH). A theoretical model of the timing of repetitive movements developed by Wing and Kristofferson was applied to estimate the central timekeeper (clock) and peripheral implementation (motor delay) variances from the variability in the response intervals. Before it is diagnosed and treated, CH is known to affect proper development of the cerebellum. If this would affect the time-keeper function of the cerebellum, it should be reflected by an increased central clock variability rather than by an increased peripheral motor-delay variability in terms of the Wing and Kristofferson model. Results of 46 children with early-treated CH, differing in severity (21 severe, 25 mild), and 34 normal controls are reported. A refinement of the Wing and Kristofferson model is applied to estimate central clock and peripheral motor delay timing variability more precisely than has been done before. Results show that for children with early-treated CH the estimate of the motor delay variance is four times higher than for the controls, while the estimate of the clock variance does not differ between the groups. It is concluded that motor problems in early-treated CH are associated with peripheral rather than with central timing deficiencies.