The relationship of pineal calcification and melatonin secretion to the pathophysiology of tardive dyskinesia and tourette's syndrome

Abstract

Despite current intensive research, the pathophysiology of tardive dyskinesia (TD), a serious neurological side effect of neuroleptic treatment, is poorly understood. Prompted by the observation of an increased incidence and severity of abnormal perioral movements in neuroleptic-treated pinealectomized, as compared to intact rats, we suggested that the pineal gland exerts a protective effect which mitigates against the development of TD and, by inference, that reduced melatonin secretion may be related to the pathophysiology of TD. To investigate this proposition further, we studied the association of TD with pineal calcification (PC) on CT scan in chronic schizophrenic patients. Our findings revealed a significant association between TD and PC and suggest, furthermore, that PC may be a neuroradiological marker of TD. Since PC may reflect diminished secretory activity of the gland, these findings support the hypothesis that the pathophysiology of TD is linked to disturbances of melatonin secretion. The clinical and therapeutic implications of these novel findings are discussed. In the following communication, in which we introduce the hypothesis that disturbances of 5-HT and melatonin secretion are related to the pathophysiology of TD. Subsequently, we present a series of studies which relate to the association of TD with PC. We conclude by presenting the hypothesis that disturbances in melatonin secretion may also be relevant to the pathophysiology of Tourette's syndrome.

Effects of melatonin on orofacial movements in rats

“…In addition, both clinical and preclinical evidence provide further support to the notion that melatonin deficiency may be related to the pathophysiology of tardive dyskinesia. Indeed, while nocturnal plasma melatonin levels have been reported to be reduced in neuroleptic-treated schizophrenic patients (Ferrier et al 1982), a significant association between pineal calcification and the presence of tardive dyskinesia was found (Sandyk and Kay 1991). Furthermore, reduction in melatonin secretion has been suggested to be related to tardive dyskinesia associated with depression in bipolar patients (Sandyk 1990).…”

Regulation of antioxidant enzymes: a significant role for melatonin

“…Melatonin has a lengthy history of beneficial actions. For example, almost two decades ago it was reported as a protector against glucocorticoid damage [74, 75], against some degenerative neurological conditions [76], as an anticancer agent [31, 77–79], and also as an enhancer of immune function [32, 79]. Subsequently, the multiple antioxidant properties of melatonin were described [33, 34, 80, 81] and research on its protective effects against oxidative processes have now been identified under a very wide range of conditions in both experimental animals [82–84] and humans [85, 86].…”

Pineal Calcification, Melatonin Production, Aging, Associated Health Consequences and Rejuvenation of the Pineal Gland

“…Large amounts of evidence, however, also suggest that the pineal calcification was indeed associated with human pathological disorders and aging. Decades ago several studies pointed out the relationship between the pineal calcification and schizophrenia [ 73 , 166 , 167 , 168 ]. The highest pineal calcium content was detected in the pineal gland of patients who died of renal disease associated with hypertension among other diseases [ 169 ].…”