Sleep Electroencephalograms and Sleep Stages in Hypoparathyroidism

2 patients with hypoparathyroidism, one idiopathic and the other pseudoform, were studied by overnight polygraphic recording of the sleep EEG and related activities before and after start of treatment to investigate their sleep EEG patterns and states, with the results as follows. (1) Conspicuous abnormalities were noted in the sleep record, namely, disappearance of humps, spindles and hill waves, emergence of the mitten pattern and rather monotonous delta rhythm bursts. The EEGs, both awake and asleep, showed findings suggestive of a possible disorder of the desynchronizing mechanism of the brain stem. Normal sleep EEG patterns were restored after the serum calcium level had returned to the normal range. (2) In the course of overnight sleep, disturbance in the cyclic changes of sleep EEG pattern and absence of REM sleep were observed. Restoration to the normal course of sleep was achieved following the normalization of serum calcium level. Divalent calcium ion is considered to have intimate bearing upon the mechanism whereby synaptic chemical transmitters are activated. When viewed with reference to the monoamine hypothesis of Jouvet, the disturbance in the course of sleep observed in the present cases, especially the absence of or disturbed REM sleep, is inferred to be related to the hypocalcemia.