Use of Actigraphy for a Rat Behavioural Sleep Study.

Previous studies of animal behavioural sleep is mainly divided into two study types, observation by video recording or counts by sensor, both of which require a complex environment and procedure. An actigraph unit is a commercially available product which can provide non-invasive monitoring human rest/activity cycles. The goal of this study was to evaluate whether actigraphy can be applied for analysing behavioural sleep in rats, since no reports have described utilization of the actigraphy unit for monitoring sleep of small animals. The actigraph unit was held on the chest of eight male rats by a loose elastic belt. The rats spent two days in a normal condition, followed by two days of sleep deprivation. Total counts measured by the actigraph could be clearly divided into two phases, sleep phase and awake phase, when the rats were kept in the normal cage. Next, the rats were moved into the sleep-deviation cage, and the total counts were significantly higher during daytime, indicating the successful induction of sleep deprivation. These results showed that the actigraphy unit monitored rest/activity cycles of rats, which will contribute to making sleep behaviour experiments easier.

Two cases of exploding head syndrome documented by polysomnography that improved after treatment.

NONE: Exploding head syndrome is a rare sleep disorder, characterized by an explosive feeling in the head, that occurs during the sleep-wake transition. Usually the attacks are painless, but the fear caused by the attack can result in awakening and insomnia when it is generated frequently. It has been suspected that exploding head syndrome is related to emotional stress, because most patients report stressful life situations in periods when attacks are intense and frequent. The benign character and good prognosis of exploding head syndrome are the most likely reasons why it has not become a subject of more extensive neurologic research. Moreover, most of the articles reported symptomatic episodes but a lack of objective physiologic examinations, such as polysomnography, and effective treatment. Here, we report two cases of exploding head syndrome with the attacks documented by polysomnography and our trial treatment.

Normalization of breathing with adenotonsillectomy in Japanese pediatric OSA.

OBJECTIVE: Since reports on surgical results for pediatric obstructive sleep apnea (OSA) in Japan are insufficient for debate, this study aimed to evaluate the feature of Japanese OSA children and surgical result and document whether is obesity and affecting factor similar to non-Asian countries. METHODS: This is a retrospective study. A total of 242 children with OSA at the Department of Otolaryngology and the Good Sleep Center, Nagoya City University Hospital and the Toyohashi Mates Sleep Disorders Center were included in the study. All children underwent pre- and postsurgical polysomnography. OSA was defined as an apnea hypopnea index (AHI) 5 or greater. Pre- and postsurgical respiratory parameters were compared using paired T test. RESULTS: Normalization of breathing after surgery for OSA children was 40% with AHI < 2 and 85% with AHI < 5. Japanese OSA children are not as obese as OSA children in many non-Asian countries. However, the normalization of breathing as a result of surgery in Japanese OSA children does not differ much from non-Asian countries. CONCLUSION: Japanese pediatric OSA that is not normalized by surgery may be affected by factors other than obesity.

Sleep Disturbance and Hyperactivity Detected by Actigraphy in Rats with Allergic Rhinitis or Attention-Deficit Hyperactivity Disorder.

Actigraphy is an easy and noninvasive method used to monitor human ultradian cycles. However, to our knowledge, it has been not applied to experiments with rodents. Therefore, using actigraphy, we assessed the ultradian cycles and behavior of rats. Rats with or without allergic rhinitis wore an actigraphy device, and triaxial acceleration was recorded. The counts that represent physical activity were lower from 8:00 to 20:00 than those from 20:00 to 8:00 in control rats, suggesting that their sleep phase was from 8:00 to 20:00 and their awake phase from 20:00 to 8:00. The counts from 8:00 to 10:00 were significantly higher in allergic rhinitis rats than in control rats (p < 0.01), suggesting the presence of difficulty with sleep induction in rats with allergic rhinitis. The counts from 18:00 to 20:00 were also significantly higher in allergic rhinitis rats than in control rats (p < 0.05), suggesting the presence of early awakening in rats with allergic rhinitis. Moreover, the counts were significantly higher in allergic rhinitis rats than in control rats from 20:00 to 8:00. These results suggest that rats with allergic rhinitis experienced hyperactivity disorder during the daytime. Additionally, hyperreactivity and difficulty with sleep induction were observed in 6-hydroxydopamine-lesioned rats, an animal model of attention-deficit hyperactivity disorder. This study shows for the first time that actigraphy can be successfully used for behavioral analysis in rodents. These rat models could be useful for analyzing the mechanisms involved in sleep disturbances and hyperactivity disorder.

Relation between globus pharyngeus and OSA in patients examined simultaneously by PSG and pH monitor: A cross sectional study.

OBJECTIVE: This was a first cross-sectional single-center study to research the relation between globus pharyngeus, OSA and GERD. Since previous clinical studies have demonstrated a relationship between globus phayrngeus and GERD, however, no reported study on the relation between globus pharyngeus, sleep disorders including OSA, and GERD. METHODS: Seventeen patients underwent general and otorhinolaryngological examinations and responded to several questionnaires (ESS, PSQI, HADS, and Globus pharyngeus VAS score) at their first visit, and underwent a gastroesophageal test for 24-h pH monitoring and in-laboratory PSG one to two months later. RESULTS: No significant differences were seen in ESS, PSQI, or HADS scores between the groups. The acid exposure time was not significantly different among the groups. The percentage of esophageal reflux time was higher than the percentage of laryngopharyngeal reflux time through the total time as well as the supine period. This indicated that GERD occurred more frequently than laryngopharyngeal reflux. The entire results showed concurrent OSA in 10 cases (59%) and concurrent GERD in 7 cases (41%). The cases with OSA were treated by CPAP or oral appliance, and those treatments were effective for globus pharyngeus. CONCLUSION: Although the relation between OSA and globus phayngeus is still controversial, these findings suggest that OSA may be a previously undetected cause of globus pharyngeus. By improving OSA, it may offer an additional option of treatment for those globus pharyngeus cases combined with OSA.

A Pilot Study on the Efficacy of Continuous Positive Airway Pressure on the Manifestations of Ménière's Disease in Patients with Concomitant Obstructive Sleep Apnea Syndrome.

OBJECTIVES: To evaluate the effect of continuous positive airway pressure (CPAP) therapy on Ménière's disease patients with concomitant obstructive sleep apnea syndrome (OSAS), since recent reports suggest OSAS may cause dysfunction of the vestibular system. STUDY DESIGN: Prospective study using CPAP administered to patients diagnosed with "Definite Ménière's disease" according to the guidelines of the American Academy of Otolaryngology--Head and Neck Surgery and combined with OSAS. SETTING: University hospital. METHODS: Twenty consecutive patients, 14 male and 6 female with active, unilateral, cochleovestibular Ménière's disease refractory to medical management who also had concurrent OSAS as defined by International Classification of Sleep Disorders, Second Edition were selected to undergo solitary CPAP therapy. Audiometric testing, caloric testing, and DHI survey were conducted before and after CPAP therapy and compared to assess effectiveness of CPAP therapy as utilized for treatment of Ménière's disease. RESULTS: Although caloric testing did not show significant difference, audiometric testing and results of dizziness handicap inventory were significantly improved (p < 0.05) after CPAP therapy only, without standard treatment for Ménière's disease. CONCLUSION: Recent reports have suggested that OSAS may cause dysfunction of the vestibular system. We investigated whether standard therapy for OSAS would be of benefit in the management of vertigo and hearing loss in Ménière's disease patients. Our study cohort demonstrated significant improvement in both DHI and audiometric testing following solitary CPAP therapy for OSAS. Solitary CPAP therapy may become a new effective treatment strategy for Ménière's disease patients with OSAS, not just only for control of dizziness and vertigo but also for potential benefit of hearing.