Regina Lopes Schimitt

We evaluated the correlation between chronobiological variables and characteristics of juvenile myoclonic epilepsy. Sample: 17 individuals epileptic outpatients and respective controls. Instruments: The Social Rhythm Metric for social zeitgebers, lux meter, and an ACT10^® thermistor for activity–rest rhythm, light exposure, and peripheral body temperature. Regularity scores showed an inverse correlation with age at disease onset (r = −0.5; p < 0.05), but not with disease duration or stabilization time. A significant intergroup difference was recorded for mean diurnal peripheral temperature (p < 0.01) and activity amplitude (= 0.06). There was a correlation between activity and temperature means in both groups. These results underscore the relationship between epilepsy and the biological clock on a physiological level. Epilepsy, in turn, is influenced by the circadian rhythm, indicating the potential involvement of the body’s internal clock in the development of the disease or the seizure recurrence pattern.

Background: Circadian theories for major depressive disorder have suggested that the rhythm of the circadian pacemaker is misaligned. Stable phase relationships between internal rhythms, such as temperature and rest/activity, and the external day-night cycle, are considered to be crucial for adapting to life in the external environmental. Therefore, the relationship and possible alterations among (i) light exposure, (ii) activity rhythm, and (iii) temperature rhythm could be important factors in clinical depression. This study aimed to investigate the rhythmic alterations in depression and evaluate the ability of chronobiological parameters to discriminate between healthy subjects and depressed patients. Methods: Thirty female subjects, including healthy subjects, depressed patients in the first episode, and major recurrent depression patients. Symptoms were assessed using Hamilton Depression Scale, Beck Depression Inventory and Montgomery-Äsberg Scale. Motor activity, temperature, and light values were determined for 7 days by actigraph, and circadian rhythms were calculated. Results: Depressed groups showed a lower amplitude in the circadian rhythm of activity and light exposure, but a higher amplitude in the rhythm of peripheral temperature. The correlation between temperature and activity values was different in the day and night among the control and depressed groups. For the same level of activity, depressed patients had lowest temperature values during the day. The amplitudes of temperature and activity were the highest discriminant parameters. Conclusions: These results indicate that the study of rhythms is useful for diagnosis and therapy for depressive mood disorders.

O presente estudo tem como objetivo descrever o conceito de ritmo social e suas formas de mensuração descritas na literatura dentro de uma perspectiva histórica. Ritmo social não é um ritmo biológico, mas interfere na sincronização de ritmos biológicos e caracteriza-se pela regularidade da vida diária determinada pelas relações sociais, ou seja, exposição regular aos zeitgebers sociais, estes definidos como agentes sincronizadores externos inseridos em um determinado contexto social. O estudo do ritmo social pode trazer reflexões sobre a organização temporal da sociedade, revelando os efeitos perniciosos da incompatibilidade entre demandas sociais e ritmos biológicos no campo do trabalho, esclarecendo de que maneira o estabelecimento das relações pode ter impacto na qualidade de vida e possibilitando que as pessoas possam repensar sua organização.