TY - JOUR
T1 - Insomnia cycling with a 42-day infradian period
T2 - Evidence for two uncoupled circadian oscillators?
AU - Vignatelli, Luca
AU - Masetti, Simone
AU - Amore, Mario
AU - Laterza, Caterina
AU - Mattarozzi, Katia
AU - Pierangeli, Giulia
AU - Cortelli, Pietro
AU - Vandi, Stefano
AU - Vetrugno, Roberto
AU - Plazzi, Giuseppe
AU - Montagna, Pasquale
PY - 2010/4
Y1 - 2010/4
N2 - Objective: To describe the unique case of a middle-aged woman with severe insomnia recurring with a regular infradian period without any other significant clinical condition. To infer the existence of a circadian dysfunction modeled according to the physical phenomenon of the ″beats.″ Patient/Methods: A two-year prospective observation by means of a sleep log was performed during the patient's normal life. She underwent one month of motor activity recording and also polysomnography, circadian rhythm of body core temperature and psychiatric evaluation during periods with and without insomnia. Results: Visual inspection of the 293-day plot of the sleep log disclosed a regular 42-day rhythm of insomnia recurrence confirmed by a Discrete Fourier Transform. During the periods of insomnia, lasting 5-7. days, only moderate mood symptoms (depressive overlapping hypomaniac symptoms) were present. Treatment with sodium valproate was effective in curtailing insomnia. Conclusion: The wax and wane infradian modulation of the sleep length suggested the presence of a basic mechanism similar to the physical phenomenon of the ″ beats,″ i.e., a long period modulation of the amplitude of an oscillating system due to the interference of two uncoupled oscillators with a slightly different oscillation frequency. Hypothesizing a dysfunction of the circadian component of sleep, namely two uncoupled circadian cycles, a simple mathematical model estimated the difference of their periods of oscillation |34. ±. 2. min| and reproduced the sleep-log data of the drug-free period of observation.
AB - Objective: To describe the unique case of a middle-aged woman with severe insomnia recurring with a regular infradian period without any other significant clinical condition. To infer the existence of a circadian dysfunction modeled according to the physical phenomenon of the ″beats.″ Patient/Methods: A two-year prospective observation by means of a sleep log was performed during the patient's normal life. She underwent one month of motor activity recording and also polysomnography, circadian rhythm of body core temperature and psychiatric evaluation during periods with and without insomnia. Results: Visual inspection of the 293-day plot of the sleep log disclosed a regular 42-day rhythm of insomnia recurrence confirmed by a Discrete Fourier Transform. During the periods of insomnia, lasting 5-7. days, only moderate mood symptoms (depressive overlapping hypomaniac symptoms) were present. Treatment with sodium valproate was effective in curtailing insomnia. Conclusion: The wax and wane infradian modulation of the sleep length suggested the presence of a basic mechanism similar to the physical phenomenon of the ″ beats,″ i.e., a long period modulation of the amplitude of an oscillating system due to the interference of two uncoupled oscillators with a slightly different oscillation frequency. Hypothesizing a dysfunction of the circadian component of sleep, namely two uncoupled circadian cycles, a simple mathematical model estimated the difference of their periods of oscillation |34. ±. 2. min| and reproduced the sleep-log data of the drug-free period of observation.
KW - Bipolar disorder
KW - Chronobiology disorders
KW - Circadian rhythm
KW - Sleep initiation and maintenance disorders
KW - Suprachiasmatic nucleus
KW - Theoretical models
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U2 - 10.1016/j.sleep.2009.09.006
DO - 10.1016/j.sleep.2009.09.006
M3 - Article
C2 - 20133194
AN - SCOPUS:77949913166
VL - 11
SP - 343
EP - 350
JO - Sleep Medicine
JF - Sleep Medicine
SN - 1389-9457
IS - 4
ER -