Computed tomography study of pineal calcification in schizophrenia

Prevalence and Clinical Significance of Incidental Findings in the Maxillofacial Complex of Adolescent Orthodontic Patients: A Retrospective Cone Beam Computed Tomography Analysis

OBJECTIVES

The aim of this study was to determine the prevalence and severity of incidental findings in the maxillofacial complex of orthodontic patients imaged with cone beam computed tomography (CBCT) and assign those findings an appropriate clinical significance.

METHODOLOGY

Incidental findings (IF) were identified in 250 CBCT scans of adolescent orthodontic patients (aged 13-18 years) with a large field-of-view and categorized based on their anatomic location and placed into one of six subgroups based on anatomic region: i) sino-nasal, ii) dentoalveolar, iii) nasooropharyngeal airway, iv) temporomandibular joint, v) neck, vi) calcifications, and vi) miscellaneous findings. Additionally, findings were assigned a clinical significance score based on severity on a scale of mild, moderate and severe. Mild IF was defined as an IF that does not require any further investigation or referral. Moderate IF was defined as an IF that has the tendency to become clinically significant and should be observed periodically. IFs that warrant further investigation and/or intervention were designated as severe.

RESULTS

The percentage of IFs in sino-nasal and dento-alveolar regions were 44.7% and 19.1% respectively. The percentage of IFs with mild, moderate, and severe clinical significance were 27%, 72%, and 1%, respectively. Out of the IFs involving calcifications, 80.8% were stylohyoid calcifications and <1% were cranial cavity IFs such as petroclinoid calcifications and falx cerebri calcifications. Among the sino-nasal findings, 1.2% were identified as severe.

CONCLUSION

The sino-nasal region had the highest frequency of IFs. Understanding the prevalence of incidental findings and its clinical relevance is important for clinicians to allow for appropriate monitoring and timely treatment of patients.

Physiological and pharmacological perspectives of melatonin

The pineal gland is a interface between light-dark cycle and shows neuro-endocrine functions. Melatonin is the primary hormone of pineal gland, secreted at night. The night-time melatonin peak regulates the physiological functions at dark. Melatonin has several unique features as it synchronises internal rhythm with daily and seasonal variations, regulates circadian rhythm and sleep-wake cycle. Physiologically melatonin involves in detoxification of free radicals, immune functions, neuro-protection, oncostatic effects, cardiovascular functions, reproduction, and foetal development. The precise functions of melatonin are exhibited by specific receptors. In relation to pathophysiology, impaired melatonin secretion promotes sleep disorder, cancer progression, type-2 diabetes, and neurodegenerative diseases. Several reports have highlighted the therapeutic benefits of melatonin specially related to cancer protection, sleep disorder, psychiatric disorders, and jet lag problems. This review will touch the most of the area of melatonin-oriented health impacts and its therapeutic aspects.

Pineal gland and schizophrenia: A systematic review and meta-analysis

Melatonin (MLT), the main hormone of the pineal gland (PG), is assumed to support initiation and maintenance of sleep, and a stable sleep-wake cycle, exerting antioxidative and neuroprotective actions. Evidence demonstrates that sleep and circadian rhythm abnormalities are very common in schizophrenia patients. Some imaging studies suggest structural abnormalities of the PG in these patients as well. We aimed to critically appraise the literature on PG imaging and melatonin secretion in schizophrenia patients, in comparison to matched healthy controls, and to review placebo-controlled trials of add-on exogenous MLT treatment in schizophrenia patients. In this systematic review, twenty-nine studies were included. Meta-analytical evaluation of data was possible only for MLT secretion finding that midnight plasma levels were significantly reduced in individuals with schizophrenia as compared to healthy controls (Hedge`s g = 1.32, p < 0.01). Imaging studies demonstrated greater prevalence of enlarged calcifications (>1 cm) of the PG (2 out of 2 computed tomography studies) and smaller PG volume (2 out of 3 magnetic resonance studies) compared with healthy controls. Anatomic and functional abnormalities of the PG were not associated with duration of illness or with treatment factors, maybe suggesting them to be primary characteristics of the disease and genetically based. Add-on MLT treatment leads to a modest improvement of objective and subjective sleep quality, of metabolic adverse effects of antipsychotics, and of tardive dyskinesia symptoms in schizophrenia patients. It remains to be established whether MLT treatment in prodromal phases of the disease could prevent neurostructural abnormalities.

Pineal gland calcification under hypoxic conditions

The pineal gland (glandula pinealis) is neuroendocrine gland located at the epithalamus of the brain secreting melatonin. The aim of this study was to explore effects of prenatal hypoxia in rats at the age of 33 weeks on the occurrence of pineal gland calcification. Distribution and chemical composition of calcerous material by light, scanning and transmission electron microscopy was investigated. Melatonin concentrations in blood plasma by direct radioimmunoassay were measured. Rats were exposed to prenatal hypoxia for 12 h at day 20 of development and second group to prenatal hypoxia for 2x8 h at days 19 and 20 of development. Vacuoles of intracellular edema in the pineal samples after 12 h hypoxia were found. Their size ranges up to 30 µm. Some of them were filled with the flocculent and fibrous material. Samples of pineal glands after 2 x 8 h hypoxia revealed the pericellular edema of pinealocytes. The amount of calcium rich particles in 2 x 8 h hypoxia group was lower than in 12 h hypoxia group. Plasma melatonin levels did not differ between control and both hypoxia groups. We concluded that calcification is a process induced by osteoblasts and osteocytes with melatonin as a promotor and it is favored under hypoxic conditions.

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

The pineal gland is a unique organ that synthesizes melatonin as the signaling molecule of natural photoperiodic environment and as a potent neuronal protective antioxidant. An intact and functional pineal gland is necessary for preserving optimal human health. Unfortunately, this gland has the highest calcification rate among all organs and tissues of the human body. Pineal calcification jeopardizes melatonin's synthetic capacity and is associated with a variety of neuronal diseases. In the current review, we summarized the potential mechanisms of how this process may occur under pathological conditions or during aging. We hypothesized that pineal calcification is an active process and resembles in some respects of bone formation. The mesenchymal stem cells and melatonin participate in this process. Finally, we suggest that preservation of pineal health can be achieved by retarding its premature calcification or even rejuvenating the calcified gland.

Prevalence of pineal gland calcification as an incidental finding in patients referred for implant dental therapy

PURPOSE

Pineal gland calcification has been proposed to play a role in the pathogenesis of Alzheimer disease. This study evaluated the prevalence and extent of pineal gland calcification in cone-beam computed tomography (CBCT) scans of patients referred for dental implant therapy who could possibly be a vulnerable group for this condition.

MATERIALS AND METHODS

A retrospective evaluation of 500 CBCT scans was conducted. Scans that showed the area where the pineal gland was located were included. The scans were initially screened by a single observer to record the prevalence and extent of calcification. Six weeks following the completion of the study, another investigator randomly reviewed and selected 50 scans to investigate inter-observer variation, which was evaluated using reliability analysis statistics. The prevalence and measurements of the calcifications were reported using descriptive statistics. The chi-square test was used to compare the prevalence between males and females.

RESULTS

The prevalence of pineal gland calcification was 58.8%. There was no statistically significant correlation between age and the extent of the calcification. The prevalence of calcification was 58.6% in females and 59.0% in males. The average anteroposterior measurement was 3.73±1.63 mm, while the average mediolateral measurement was 3.47±1.31 mm. The average total calcified area was 9.79±7.59 mm².

CONCLUSION

The prevalence of pineal gland calcification was high in patients undergoing implant therapy. While not all pineal gland calcifications lead to neurodegenerative disorders, they should be strongly considered in the presence of any symptoms as a reason to initiate further investigations.

Pineal Gland Calcification in Kurdistan: A Cross-Sectional Study of 480 Roentgenograms

Objective

The goal of this study was to compare the incidence of Pineal Gland Calcification (PGC) by age group and gender among the populations living in the Kurdistan Region-Iraq.

Methods

This prospective study examined skull X-rays of 480 patients between the ages of 3 and 89 years who sought care at a large teaching public hospital in Duhok, Iraq from June 2014 to November 2014. Descriptive statistics and a binary logistic regression were used for analysis.

Results

The overall incidence rate of PGC among the study population was 26.9% with the 51–60 age group and males having the highest incidence. PGC incidence increased after the first decade and remained steady until the age of 60. Thereafter the incidence began to decrease. Logistic regression analysis revealed that both age and gender significantly affected the risk of PGC. After adjusting for age, males were 1.94 (95% CI, 1.26–2.99) times more likely to have PGC compared to females. In addition, a one year increase in age increases the odds of developing PGC by 1.02 (95% CI, 1.01–1.03) units after controlling for the effects of gender.

Conclusion

Our analysis demonstrated a close relationship between PGC and age and gender, supporting a link between the development of PGC and these factors. This study provides a basis for future researchers to further investigate the nature and mechanisms underlying pineal gland calcification.

Assessment of Pineal Gland Volume and Calcification in Healthy Subjects: Is it Related to Aging?

Purpose:

The human pineal gland is a small neuroendocrine organ which produces melatonin. The main goal of this study was to provide a reference range for pineal volume in all age groups and to determine calcified and noncalcified tissue and their proportions, which may be a reflection of melatonin production in all age groups, by using very thin computerized tomography (CT) slices.

Materials and methods:

A total of 167 outpatients had undergone cranial CT. Each of the subject’s total pineal volume (TPV), calcified pineal volume (CPV) and noncalcified pineal volume (NPV) according to age groups were calculated in cubic millimeters. Also, proportion of calcification (POC) was noted.

Results:

The median values were 88.5 mm³ (12.3 mm³–411mm³) for TPV, 74.3 mm³ (12.3 mm³–298 mm³) for NPV, and 3.9 mm³ (0 mm³–141 mm³) for CPV. POC showed a gradual increase from 0–49 years. In the ≥70 group, when compared with the 60–69 age group, CPV and POC values were significantly lower (P: 0.036, P: 0.034, respectively).

Conclusion:

This study brings a radiological point of view to the distribution of pineal calcification according to age that has a link with melatonin secretion.

Prevalence of brain calcifications in a Brazilian cohort: A retrospective study in radiology services

Brain calcifications may be present in a wide range of neuropsychiatric, infectious traumatic, neoplastic and endocrine conditions, associated with motor and cognitive symptoms. They are often considered "physiologic" or pathologic.

OBJECTIVE

To determine the prevalence of brain calcifications in a Brazilian cohort.

METHODS

1898 consecutive patients underwent skull CTs, comprising 836 men and 1062 women.

RESULTS

Among all 1898 patients, 333 (197 women and 136 men) presented with brain calcifications, representing an overall prevalence of 17.54%. The prevalence in the female group was 18.54% versus 16.26% in the male group.

CONCLUSIONS

A growth in incidental findings on CT scans are likely as these exams become more widely available. However, a current debate between radiologists and regulators is set to redefine the CT usage, especially in the United States and the United Kingdom, considering new norms for use and radiation dosage per exam.

Age-related changes in the incidence of pineal gland calcification in Turkey: A prospective multicenter CT study

The goal of this cross-sectional observational study was to determine the incidence of pineal gland calcification (PGC), to investigate the interaction of PGC and aging, and to compare the incidence of PGC among the populations living in Turkey. In a prospective study the rate of PGC on CT scans of 1376 individuals in six referral centers from different regions of Turkey was investigated, with emphasis on effects of climatological parameters and aging on PGC. It was found that the incidence of PGC increased rapidly after first decade and the increase remains gradual thereafter, higher in males than in females for all age groups. There was a significant difference for incidence and degree of PGC between different clinics and between both sexes (p<0.001). In addition, there was a significant difference for the degree of PGC between the clinics in low altitude group and those in high altitude group (p<0.001 for each). Logistic regression analysis revealed that age, sex, altitude and intensity of sunlight exposure significantly affected the risk of PGC (odds ratios (OR) 1.335, 95% confidence intervals (CI) 1.261-1.414, p<0.001; OR 1.900, 95% CI 1.486-2.428, p<0.001; OR 0.715, 95% CI 0.517-0.990, p<0.05; OR 0.997, 95% CI 0.994-0.999, p<0.01, respectively). Furthermore, by multiple linear regression analysis, high altitude and increased intensity of sunlight exposure were found to affect the degree of PGC (beta=0.003, p<0.001). It is concluded that there is a close relationship between PGC and the aforementioned parameters, supporting a link between the development of PGC and these. This study provides some reference data for new clinical studies on the putative role of pineal gland in future.

Identification and treatment of a pineal region tumor in an adolescent with prodromal psychotic symptoms

An adolescent male patient originally presented to a prodromal clinical research program with severe obsessive-compulsive behaviors and subthreshold symptoms of psychosis, which eventually developed into first-rank psychotic symptoms. The patient was followed over a 2-year period. His symptoms did not respond to psychotherapy or pharmacotherapy. However, when a pineal region tumor was discovered and treated with chemotherapy and autologous stem cell rescue, both psychotic symptoms and psychosocial functioning reverted toward baseline. Although subcortical brain structures have been implicated in the pathophysiology of idiopathic psychosis, reports of psychiatric sequelae of treatment of subcortical tumors are rare. Etiological pathways that may have played a role in symptom development are of particular interest, as understanding these mechanisms may shed light on the pathophysiology of psychotic disorders more generally.

Role of the central cholinergic system in the therapeutics of schizophrenia

The therapeutic agents currently used to treat schizophrenia effectively improve psychotic symptoms; however, they are limited by adverse effects and poor efficacy when negative symptoms of the illness and cognitive dysfunction are considered. While optimal pharmacotherapy would directly target the neuropathology of schizophrenia neither the underlying neurobiological substrates of the behavioral symptoms nor the cognitive deficits have been clearly established. Abnormalities in the neurotransmitters dopamine, serotonin, glutamate, and GABA are commonly implicated in schizophrenia; however, it is not uncommon for alterations in the brain cholinergic system (e.g., choline acetyltransferase, nicotinic and muscarinic acetylcholine receptors) to also be reported. Further, there is now considerable evidence in the animal literature to suggest that both first and second generation antipsychotics (when administered chronically) can alter the levels of several cholinergic markers in the brain as well as impair memory-related task performance. Given the well-established importance of central cholinergic neurons to information processing and cognition, it is important that cholinergic function in schizophrenia be further elucidated and that the mechanisms of the chronic effects of antipsychotic drugs on this important neurotransmitter system be identified. A better understanding of these mechanisms would be expected to facilitate optimal treatment strategies for schizophrenia as well as the identification of novel therapeutic targets. In this review, the following topics are discussed: 1) the central cholinergic system in schizophrenia 2) effects of antipsychotic drugs on central cholinergic neurons 3) important neurotrophins in schizophrenia, especially those that support central cholinergic neurons; 4) novel strategies to optimize the therapeutics of schizophrenia via the use of cholinergic compounds as primary (i.e., antipsychotic) treatments as well as adjunctive, pro-cognitive agents.

Impaired cognitive performance in rats after complete epithalamus lesions, but not after pinealectomy alone

In the midbrain, the epithalamus comprises the habenular nuclei and the pineal gland. Based on evidence including imaging studies in schizophrenia patients, several investigators have postulated that dysfunction of this structure is causally involved in symptoms of schizophrenia. Recently, we showed that bilateral habenula lesions in the rat induced some schizophrenia-like behavioural changes, namely memory and attention impairments, but unaltered social interaction in a brief encounter and prepulse inhibition (PPI) of the startle reflex. Here, the possible involvement of the pineal gland in the same behaviours was assessed, by examining them in two series of experiments. In the first, these behaviours were examined in pinealectomized rats compared to sham-operated controls. In the second, they were examined in rats with combined lesion of habenula plus pinealectomy compared to sham-operated controls, to examine whether pinealectomy induced further deficits when combined with habenula damage. Lesions of habenula were confirmed histologically and neurochemically by reduction of choline acetyltransferase in the interpeduncular nucleus. Pinealectomy was confirmed post mortem by careful visual inspection. Pinealectomy induced no deficits in any test, while combined lesions led to the same pattern of deficits as previously observed after habenula lesion, i.e. marked memory impairment in the Morris water maze without affecting the amount of social interaction or PPI of the startle reflex. Thus, loss of pineal function causes no deficits in these behaviours and does not alter the qualitative pattern of deficits resulting from habenula damage.

Habenula lesions cause impaired cognitive performance in rats: implications for schizophrenia

Cognitive impairment is a prominent feature of schizophrenia. Currently there is no well-accepted explanation of the aetiology of this disorder, but recent evidence indicates that dysfunction of the habenula may be involved. We therefore examined whether habenula lesions in Sprague-Dawley rats cause behavioural changes resembling those of schizophrenia. Rats received either habenula lesions, a sham operation or a small lesion of the overlying dorsal hippocampus as a check that effects observed were not due to incidental damage to this structure. As there are alterations of social behaviour, sensorimotor gating and cognition in schizophrenia, we examined comparable behaviours. Social interaction time was measured during a 5-min encounter with a novel juvenile conspecific. Prepulse inhibition of an acoustic startle response, as an index of sensorimotor gating, was measured with prepulses of various amplitudes, and spatial cognitive performance was assessed in the Morris water maze task. Histological analysis showed that habenula lesions substantially damaged both medial and lateral habenula bilaterally while largely sparing neighbouring structures. Assay of choline acetyltransferase (ChAT) in the interpeduncular nucleus terminal region of the habenulo-interpeduncular tract, showed marked reduction (by 80%) in habenula-lesioned animals. Habenula-lesioned rats, but not the control group with small dorsal hippocampus lesions, showed marked impairment of Morris maze performance compared to the sham-operated control group. Social interaction time and prepulse inhibition were not significantly altered in either lesion group. The results are consistent with a role of the habenula in cognition, and with the view that pathology of the habenula may contribute to the cognitive impairments of schizophrenia.

Reduced pineal volume in male patients with schizophrenia: no relationship to clinical features of the illness

Several investigations have suggested pineal gland abnormalities in the pathogenesis of schizophrenia. The pineal volume on brain magnetic resonance imaging scans was calculated in 15 male schizophrenic inpatients and in 16 matched control subjects. The statistical comparison found a significant difference of pineal gland volume between schizophrenics and controls (P = 0.022), with a smaller pineal volume in the schizophrenics. These results do not confirm the previous data of Schizophrenia Res. 14 (1995) 253, showing no significant pineal volumetric differences between schizophrenics and normal controls. Since the present study is based on a smaller but more homogeneous sample of patients, this could reduce the heterogeneity features of the schizophrenic disease. No correlation was found between pineal volume and clinical and psychopathological features of the schizophrenic subjects. Volume reduction in schizophrenia could be at least partially included in the wider brain developmental abnormalities of the illness or in the late effects of previous neuroleptic treatments.