Biological rhythms in patients with lissencephaly (agyria-pachygyria)

Lissencephaly is a congenital malformation of the brain characterized by an extensive absence of cerebral gyral formation. Polysomnograms were recorded in 8 cases with lissencephaly (4 of agyria and 4 of pachygyria), and 24-h secretion of growth hormone, prolactin, luteinizing hormone, follicle-stimulating hormone and cortisol was examined in 6 of the 8 cases. The sleep-waking cycle and body temperature (BT) rhythm were studied in all 8 cases. The results were as follows: (i) the sleep-waking circadian rhythm was well preserved in 6 of the 8 cases; (ii) %REM (rapid eye movement) sleep decreased in 4 cases, but the ultradian rhythm of REM sleep was well observed in all cases except one; (iii) the secretion of GH and PRL showed normal or borderline increases with sleep; (iv) although these cases had not reached puberty, LH and FSH increased with sleep in 3 of 5 cases; (v) the circadian rhythm of cortisol secretion was preserved in all cases except one; (vi) BT showed a circadian rhythm after infancy. These findings suggest that the circadian rhythms function normally in lissencephaly, that the secretion of GH and PRL during sleep occurs almost normally, and that the cerebral cortex does not play a significant role in the regulation of these biological rhythms in lissencephaly.