Clonidine has a paradoxical effect on cyclic arousal and sleep bruxism during NREM sleep

Study Objective:

Clonidine disrupts the NREM/REM sleep cycle and reduces the incidence of rhythmic masticatory muscle activity (RMMA) characteristic of sleep bruxism (SB). RMMA/SB is associated with brief and transient sleep arousals. This study investigates the effect of clonidine on the cyclic alternating pattern (CAP) in order to explore the role of cyclic arousal fluctuation in RMMA/SB.

Design:

Polysomnographic recordings from a pharmacological study.

Setting:

University sleep research laboratory.

Participants and Interventions:

Sixteen SB subjects received a single dose of clonidine or placebo at bedtime in a crossover design.

Measurements and Results:

Sleep variables and RMMA/SB index were evaluated. CAP was scored to assess arousal instability between sleep-maintaining processes (phase A1) and stronger arousal processes (phases A2 and A3). Paired t-tests, ANOVAs, and cross-correlations were performed. Under clonidine, CAP time, and particularly the number of A3 phases, increased (P ≤ 0.01). RMMA/SB onset was time correlated with phases A2 and A3 for both placebo and clonidine nights (P ≤ 0.004). However, under clonidine, this positive correlation began up to 40 min before the RMMA/SB episode.

Conclusions:

CAP phase A3 frequency increased under clonidine, but paradoxically, RMMA/SB decreased. RMMA/SB was associated with and facilitated in CAP phase A2 and A3 rhythms. However, SB generation could be influenced by other factors besides sleep arousal pressure. NREM/REM ultradian cyclic arousal fluctuations may be required for RMMA/SB onset.

Citation:

Carra MC; Macaluso GM; Rompré PH; Huynh N; Parrino L; Terzano MG; Lavigne GJ. Clonidine has a paradoxical effect on cyclic arousal and sleep bruxism during NREM sleep. SLEEP 2010;33(12):1711-1716.     

Temporal association between sleep apnea–hypopnea and sleep bruxism events

There is some evidence suggesting that obstructive sleep apnea–hypopnea syndrome is concomitant with sleep bruxism. The aim of this study was to investigate the temporal association between sleep apnea–hypopnea events and sleep bruxism events. In an open observational study, data were gathered from 10 male subjects with confirmed obstructive sleep apnea–hypopnea syndrome and concomitant sleep bruxism. Polysomnography and audio‐video recordings were performed for 1 night in a sleep laboratory. Breathing, brain, heart and masticatory muscle activity signals were analysed to quantify sleep and sleep stage duration, and number and temporal distribution of apnea–hypopnea events and sleep bruxism events. Apnea–hypopnea events were collected within a 5‐min time window before and after sleep bruxism events, with the sleep bruxism events as the pivotal reference point. Two temporal patterns were analysed: (i) the interval between apnea–hypopnea events termination and sleep bruxism events onset, called T1; and (ii) the interval between sleep bruxism events termination and apnea–hypopnea events onset, called T2. Of the intervals between sleep bruxism events and the nearest apnea–hypopnea event, 80.5% were scored within 5 min. Most intervals were distributed within a period of <30 s, with peak at 0–10 s. The T1 interval had a mean length of 33.4 s and was significantly shorter than the T2 interval (64.0 s; P < 0.05). Significantly more sleep bruxism events were scored in association with the T1 than the T2 pattern (P < 0.05). Thus, in patients with concomitant obstructive sleep apnea–hypopnea syndrome and sleep bruxism, most sleep bruxism events occurred after sleep apnea–hypopnea events, suggesting that sleep bruxism events occurring close to sleep apnea–hypopnea events is a secondary form of sleep bruxism.     

Comparison of rhythmic masticatory muscle activity during non‐rapid eye movement sleep in guinea pigs and humans

Rhythmic masticatory muscle activity can be a normal variant of oromotor activity, which can be exaggerated in patients with sleep bruxism. However, few studies have tested the possibility in naturally sleeping animals to study the neurophysiological mechanisms of rhythmic masticatory muscle activity. This study aimed to investigate the similarity of cortical, cardiac and electromyographic manifestations of rhythmic masticatory muscle activity occurring during non‐rapid eye movement sleep between guinea pigs and human subjects. Polysomnographic recordings were made in 30 freely moving guinea pigs and in eight healthy human subjects. Burst cycle length, duration and activity of rhythmic masticatory muscle activity were compared with those for chewing. The time between R‐waves in the electrocardiogram (RR interval) and electroencephalogram power spectrum were calculated to assess time‐course changes in cardiac and cortical activities in relation to rhythmic masticatory muscle activity. In animals, in comparison with chewing, rhythmic masticatory muscle activity had a lower burst activity, longer burst duration and longer cycle length (P < 0.05), and greater variabilities were observed (P < 0.05). Rhythmic masticatory muscle activity occurring during non‐rapid eye movement sleep [median (interquartile range): 5.2 (2.6–8.9) times per h] was preceded by a transient decrease in RR intervals, and was accompanied by a transient decrease in delta elelctroencephalogram power. In humans, masseter bursts of rhythmic masticatory muscle activity were characterized by a lower activity, longer duration and longer cycle length than those of chewing (P < 0.05). Rhythmic masticatory muscle activity during non‐rapid eye movement sleep [1.4 (1.18–2.11) times per h] was preceded by a transient decrease in RR intervals and an increase in cortical activity. Rhythmic masticatory muscle activity in animals had common physiological components representing transient arousal‐related rhythmic jaw motor activation in comparison to human subjects.     

A two‐part,double‐blind,placebo‐controlled trial of exogenous melatonin in REM sleep behaviour disorder

Rapid eye movement (REM) sleep behaviour disorder (RBD) has been suggested to predict the development of neurodegenerative disorders. Patients with RBD are acting out dream behaviour associated with loss of normal muscle atonia of REM sleep. The aim of the present study was to confirm that exogenous melatonin improves RBD. Eight consecutively recruited males (mean age 54 years) with a polysomnographically (PSG) confirmed diagnosis of RBD were included in a two‐part, randomized, double‐blind, placebo‐controlled cross‐over study. Patients received placebo and 3 mg of melatonin daily in a cross‐over design, administered between 22:00 h and 23:00 h over a period of 4 weeks. PSG recordings were performed in all patients at baseline, at the end of Part I of the trial and at the end of Part II of the trial. Compared to baseline, melatonin significantly reduced the number of 30‐s REM sleep epochs without muscle atonia (39% versus 27%; P = 0.012), and led to a significant improvement in clinical global impression (CGI: 6.1 versus 4.6; P = 0.024). Interestingly, the number of REM sleep epochs without muscle atonia remained lower in patients who took placebo during Part II after having received melatonin in Part I (–16% compared to baseline; P = 0.043). In contrast, patients who took placebo during Part I showed improvements in REM sleep muscle atonia only during Part II (i.e. during melatonin treatment). The data suggest that melatonin might be a second useful agent besides clonazepam in the treatment of RBD.     

Association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism

The aim of this study was to investigate the association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism. A total of 35 university students and staff members participated in this study after providing informed consent. All participants were divided into either a sleep bruxism group (n = 21) or a control group (n = 14), based on the following clinical diagnostic criteria: (1) reports of tooth‐grinding sounds for at least two nights a week during the preceding 6 months by their sleep partner; (2) presence of tooth attrition with exposed dentin; (3) reports of morning masticatory muscle fatigue or tenderness; and (4) presence of masseter muscle hypertrophy. Video‐polysomnography was performed in the sleep laboratory for two nights. Sleep bruxism episodes were measured using masseter electromyography, visually inspected and then categorized into phasic or tonic episodes. Phasic episodes were categorized further into episodes with or without grinding sounds as evaluated by audio signals. Sleep bruxism subjects with reported grinding sounds had a significantly higher total number of phasic episodes with grinding sounds than subjects without reported grinding sounds or controls (Kruskal–Wallis/Steel–Dwass tests; P < 0.05). Similarly, sleep bruxism subjects with tooth attrition exhibited significantly longer phasic burst durations than those without or controls (Kruskal–Wallis/Steel–Dwass tests; P < 0.05). Furthermore, sleep bruxism subjects with morning masticatory muscle fatigue or tenderness exhibited significantly longer tonic burst durations than those without or controls (Kruskal–Wallis/Steel–Dwass tests; P < 0.05). These results suggest that each clinical sign and symptom of sleep bruxism represents different aspects of jaw motor activity during sleep.     

Modafinil in the treatment of idiopathic hypersomnia without long sleep time—a randomized,double‐blind,placebo‐controlled study

In 2010 the European Medicines Agency withdrew the indication of modafinil for the treatment of obstructive sleep apnea, shift work sleep disorder and for idiopathic hypersomnia (IH). In uncontrolled studies, modafinil has been reported to be efficacious in the treatment of sleep disorders. We therefore performed a randomized, placebo‐controlled study with the aim of proving the efficacy of modafinil treatment in these patients. Drug‐free IH patients without long sleep according to ICSD2 criteria, age >18 years and disease duration >2 years were included. After a washout phase, patients at baseline received placebo or 100 mg modafinil in the morning and at noon over 3 weeks, followed by 1 week without medication. At each visit the Epworth Sleepiness Scale (ESS) and Clinical Global Impression (CGI) rating scale were performed. At baseline and on days 8 and 21 four Maintenance of Wakefulness Tests (MWTs)/day or per day were performed. Patients kept a sleep–wake diary throughout the study. Between 2009 and 2011 three sleep centres recruited 33 participants. Compared to placebo, modafinil decreased sleepiness significantly and improved mean sleep latency in the MWT non‐significantly. The CGI improved significantly from baseline to the last visit on treatment. The most frequent adverse events were headaches and gastrointestinal disorders; skin and psychiatric reactions were not reported. The number of reported naps and duration of daytime sleepiness decreased significantly. Total sleep time of nocturnal sleep was slightly reduced. The sleep diaries showed increases in feeling refreshed in the morning; the diurnal diaries showed significant improvement of performance and of exhaustion. Modafinil is an effective and safe medication in the treatment of IH. Adverse events are mild to moderate.     

Japanese sake yeast supplementation improves the quality of sleep: a double‐blind randomised controlled clinical trial

Activation of adenosine A_2a receptors in cerebral neurons induces sleep in various mammals. It was previously found that Japanese sake yeast enriched in adenosine analogues activates A_2a receptors in vitro and induces sleep in mice. Here it is reported that sake yeast activated A_2a receptors in a cultured human cell line and improved human sleep quality in a clinical trial. Sake yeast activated A_2a receptors in HEK cells in a dose‐dependent manner with an EC₅₀ of 40 μg mL^?1, and the activation was attenuated almost completely by the A_2a receptor antagonist ZM241385 with an IC₅₀ of 73 nm . In a double‐blind placebo‐controlled crossover clinical study, 68 healthy participants ingested tablets containing either 500 mg of sake yeast powder or a placebo (cellulose) 1 h before sleep for 4 days. Electroencephalograms were recorded during sleep at home with a portable device for 4 week days. Electroencephalogram analyses revealed that sake yeast supplementation significantly (P = 0.03) increased delta power during the first cycle of slow‐wave sleep by 110%, without changing other sleep parameters. Sake yeast supplementation also significantly increased growth hormone secretion in the urine on awakening by 137% from 3.17 ± 0.41 (placebo) to 4.33 ± 0.62 (sake yeast) pg mg^?1 creatinine (P = 0.03). Subjective sleepiness (P = 0.02) and fatigue (P = 0.06) in the morning were improved by sake yeast. Given these benefits and the absence of adverse effects during the study period, it was concluded that sake yeast supplementation is an effective and safe way to support daily high‐quality, deep sleep.     

Nasal steroids in snorers can decrease snoring frequency: a randomized placebo‐controlled crossover trial

Although it is anecdotally known that nasal obstruction is associated with snoring, it remains unknown whether the application of nasal steroids could decrease oral/oro‐nasal breathing and increase nasal breathing, and subsequently decrease snoring indices. This study evaluated the effect of nasal budesonide on breathing route pattern and snoring. Twenty‐four snorers were enrolled in a randomized, double‐blind, crossover trial of 1‐week treatment with nasal budesonide compared with 1‐week intervention with nasal placebo. At the start and end of each treatment period, patients underwent nasal resistance measurement and overnight polysomnography with concomitant measurement of breathing route pattern and snoring. Twelve patients were randomly assigned to a 1‐week treatment with nasal budesonide, followed by 2‐week washout period and a 1‐week intervention with the nasal placebo; and 12 patients were randomly assigned to a 1‐week intervention with nasal placebo, followed by 2‐week washout period and a 1‐week treatment with nasal budesonide. Nasal budesonide was associated with a decrease in oral/oro‐nasal breathing epochs and concomitant increase in nasal breathing epochs, decrease of snoring frequency by [median (interquartile range)] 15.8% (11.2–18.8%), and an increase of rapid eye movement sleep; snoring intensity decreased only in patients with increased baseline nasal resistance by 10.6% (6.8–14.3%). The change in nasal breathing epochs was inversely related to the change in snoring frequency (R_s = 0.503; P < 0.001). Nasal budesonide in snorers can increase nasal breathing epochs, modestly decrease snoring frequency and increase rapid eye movement sleep.     

Maize food allergy: a double‐blind placebo‐controlled study

Background Maize allergy is not very common especially in Europe. The number of studies that address IgE mediated maize allergy is all too few. Objective Evaluate subjects with a history of maize allergy by double‐blind, placebo‐controlled food challenge; identify the spectrum of symptoms manifested during challenge; determine the lowest provocation dose (PD) during challenge; determine the performance characteristics of maize skin prick test and specific IgE. Methods Twenty‐seven patients with a history of maize allergy were enrolled to be evaluated by skin test, specific IgE and double‐blind placebo‐controlled maize challenge. Results Forty‐eight percent of the patients were challenge positive. PD range was 0.1–25 g. Fifty‐four percent of the maize allergic subjects had a PD that was 2.5 g; two subjects reacted to 100 mg of maize. Comparison of maize specific IgE levels and skin test results to the challenge results revealed the following (specific IgE level/skin testing): sensitivity 1.00/0.846, specificity 0.077/0.384, positive predictive value 0.520/0.579, and negative predictive value 1.00/0.714. Conclusion Maize is a cause of IgE‐mediated allergic reactions to foods in adults and children. Nearly half of the subjects recruited were confirmed by challenge to be allergic to maize. Twenty‐three percent of the positive challenge patients manifested symptoms that involved two organ systems, thus fulfilling the criteria for maize induced anaphylaxis. Maize is allergenic and can pose a risk for symptomatic food allergy at a dose of 100 mg.     

The effects of testosterone on ventilatory responses in men with obstructive sleep apnea: a randomised,placebo‐controlled trial

We recently showed that testosterone therapy worsens sleep‐disordered breathing at 6–7 weeks, but not after 18 weeks, in men with obstructive sleep apnea. Changes in ventilatory chemoreflexes may be responsible. The effect of testosterone on ventilatory chemoreflexes in men with obstructive sleep apnea has not been systematically studied before. Twenty‐one obese men with obstructive sleep apnea, a subgroup of our recent report, were randomised in an 18‐week, randomised, double‐blind, placebo‐controlled, parallel group trial to three intramuscular injections (0, 6, 12 weeks) of either 1000 mg testosterone undecanoate (n = 10) or placebo (n = 11). Awake ventilatory chemoreflex testing was performed before (week 0), during (week 6) and at the end of treatment (week 18) to determine the ventilatory carbon dioxide recruitment threshold and chemosensitivity. Sleep and breathing was assessed by overnight polysomnography at 0, 7 and 18 weeks. Serum hormones levels were measured at every visit. A significant increase in blood testosterone levels (5.65 nmol L^?1, 0.51–10.8 nmol L^?1, P = 0.03) and lean muscle mass (2.36 kg, 0.8–3.9 kg, P = 0.007) between the two groups was observed as expected. No significant differences were seen in ventilatory chemoreflexes between the two groups at 6 weeks or at 18 weeks. However, positive correlations were observed between changes in serum testosterone and hyperoxic ventilatory recruitment threshold (r = 0.55, P = 0.03), and between changes in hyperoxic ventilatory recruitment threshold and time spent with oxygen saturations during sleep <90% (r = 0.57, P = 0.03) at 6–7 weeks, but not at 18 weeks. Time‐dependent alterations in ventilatory recruitment threshold may therefore mediate the time‐dependent changes in sleep breathing observed with testosterone.     

Respiratory safety of lemborexant in healthy adult and elderly subjects with mild obstructive sleep apnea: A randomized,double‐blind,placebo‐controlled,crossover study

Lemborexant is a dual orexin receptor antagonist indicated for the treatment of adult and elderly individuals with insomnia. Some current pharmacologic treatments for insomnia cause respiratory depression, a serious safety concern, particularly for individuals with obstructive sleep apnea (OSA). This phase 1, randomized, double‐blind, placebo‐controlled, two‐period crossover study examined respiratory safety parameters in individuals with mild OSA following treatment with lemborexant. Participants (n = 39) were randomized to one of two treatment sequences, including placebo and lemborexant 10 mg. Each treatment period lasted 8 days and was separated by a washout of at least 14 days. Following single or multiple doses, there were no significant differences in mean apnea–hypopnea index for lemborexant 10 mg versus placebo (least squares mean [LSM] difference [95% confidence interval {CI}]: day 1, ?0.03 [?2.22, 2.17]; day 8, ?0.06 [?1.95, 1.83]) or peripheral capillary oxygen saturation during sleep (LSM difference [95% CI]: day 1, 0.07 [?0.31, 0.46]; day 8, 0.25 [?0.11, 0.61]). There were no significant differences versus placebo for the percentage of total sleep time during which peripheral capillary oxygen saturation was <80% (LSM difference [95% CI]: day 1, 0.002 [?0.019, 0.023]; day 8, 0.006 [?0.015, 0.026]), <85% (LSM difference [95% CI]: day 1, 0.067 [?0.124, 0.258]; day 8, 0.056 [?0.117, 0.228]) or <90% (LSM difference [95% CI]: day 1, 0.312 [?0.558, 1.181]; day 8, 0.088 [?0.431, 0.607]). The incidence of treatment‐emergent adverse events was low and similar for lemborexant and placebo. Lemborexant demonstrated respiratory safety in this study population and was well tolerated.     

Blackcurrant seed oil for prevention of atopic dermatitis in newborns: a randomized,double‐blind,placebo‐controlled trial

Background The present increased incidence of atopic diseases has been associated with an altered intake of essential fatty acids (EFAs). The composition of blackcurrant seed oil (BCSO) corresponds to the recommended dietary intake of EFAs, and as a dietary supplement could, in small doses, modify the imbalance of EFAs in an efficient way. Objective To assess the effect of dietary supplementation with BCSO on the prevalence of atopy at 12 months of age. Methods Three hundred and thirteen pregnant mothers were randomly assigned to receive BCSO (151) or olive oil as placebo (162). The first doses were administered at 8th–16th weeks of pregnancy and were continued until the cessation of breastfeeding, followed by supplementation to the infants until the age of 2 years. Atopic dermatitis and its severity (SCORAD index) were evaluated, serum total IgE was measured and skin tests were performed at the age of 3, 12 and 24 months. Results Parental atopy was common (81.7%) among study subjects, making them infants with increased atopy risk. There was a significantly lower prevalence of atopic dermatitis in the BCSO group than in the olive oil group at the age of 12 months (33.0% vs. 47.3%, P=0.035). SCORAD was also lower in the BCSO group than in the olive oil group at 12 months of age (P=0.035). No significant differences in the prevalence of atopic dermatitis were observed between the groups at the age of 24 months (P=0.18). Conclusion Dietary supplementation with BCSO was well tolerated and it transiently reduced the prevalence of atopic dermatitis. It could therefore be one potential tool in the prevention of atopic symptoms when used at an early stage of life. (Registration number SRCTN14869647, http://www.controlled‐trials.com ) Cite this as: P. Linnamaa, J. Savolainen, L. Koulu, S. Tuomasjukka, H. Kallio, B. Yang, T. Vahlberg and R. Tahvonen, Clinical & Experimental Allergy, 2010 (40) 1247–1255.     

A randomized,double‐blind,placebo‐controlled,dose‐finding trial with Lolium perenne peptide immunotherapy

Background

A novel subcutaneous allergen immunotherapy formulation (gpASIT+?) containing Lolium perenne peptides (LPP) and having a short up‐dosing phase has been developed to treat grass pollen–induced seasonal allergic rhinoconjunctivitis. We investigated peptide immunotherapy containing the hydrolysate from perennial ryegrass allergens for the optimum dose in terms of clinical efficacy, immunogenicity and safety.

Methods

This prospective, double‐blind, placebo‐controlled, phase IIb, parallel, four‐arm, dose‐finding study randomized 198 grass pollen–allergic adults to receive placebo or cumulative doses of 70, 170 or 370 μg LPP. All patients received weekly subcutaneous injections, with the active treatment groups reaching assigned doses within 2, 3 and 4 weeks, respectively. Efficacy was assessed by comparing conjunctival provocation test (CPT) reactions at baseline, after 4 weeks and after completion. Grass pollen–specific immunoglobulins were analysed before and after treatment.

Results

Conjunctival provocation test (CPT) response thresholds improved from baseline to V7 by at least one concentration step in 51.2% (170 μg; P = .023), 46.3% (370 μg), and 38.6% (70 μg) of patients receiving LPP vs 25.6% of patients receiving placebo (modified per‐protocol set). Also, 39% of patients in the 170‐μg group became nonreactive to CPT vs 18% in the placebo group. Facilitated allergen‐binding assays revealed a highly significant (P < .001) dose‐dependent reduction in IgE allergen binding across all treatment groups (70 μg: 17.1%; 170 μg: 18.8%; 370 μg: 26.4%). Specific IgG₄ levels increased to 1.6‐fold (70 μg), 3.1‐fold (170 μg) and 3.9‐fold (370 μg) (mPP).

Conclusion

Three‐week immunotherapy with 170 μg LPP reduced CPT reactivity significantly and increased protective specific antibodies.

     

Preoperative methylprednisolone increases plasma Pentraxin 3 early after total knee arthroplasty: a randomized,double‐blind,placebo‐controlled trial

Preoperative glucocorticoid administration reduces the systemic inflammatory response. Pentraxin 3 (PTX3) is a novel inflammatory marker belonging to the humoral arm of innate immunity exerting a potentially protective host response. This study evaluated PTX3 and other complement marker changes after preoperative methylprednisolone (MP) early after total knee arthroplasty (TKA). Seventy patients were randomized (1 : 1) to preoperative intravenous (i.v.) MP 125 mg (group MP) or isotonic saline i.v. (group C). The outcomes included change in plasma PTX3, mannose‐binding lectin (MBL), ficolins (ficolin‐1, ?2 and ?3), complement components (C4 and C3), terminal complement complex (TCC) and C‐reactive protein (CRP) concentrations. Blood samples were analysed at baseline and 2, 6, 24 and 48 h after surgery with complete sampling from 63 patients for analyses. MP resulted in an increase in circulating PTX3 compared to saline from baseline to 24 h postoperatively (P < 0·001), while MP reduced the systemic inflammatory response (CRP) 24 and 48 h postoperatively (P < 0·001). However, the small postoperative changes in MBL, ficolin‐1, ?2 and ?3, C4, C3 and TCC concentrations did not differ between groups (P > 0·05). In conclusion, preoperative MP 125 mg increased circulating PTX3 and reduced the general inflammatory response (CRP) early after TKA, but did not affect other complement markers.     

Gabapentin acutely increases the apnea–hypopnea index in older men: data from a randomized,double‐blind,placebo‐controlled study

Although drugs with sedative properties may increase the risk of airway collapse during sleep, their acute effects on the apnea–hypopnea index in older adults are under‐reported. We investigated the acute effects of gabapentin (GABA) on sleep breathing in older men without sleep apnea. A double‐blind, randomized, placebo‐controlled cross‐over pilot study using a bedtime dose of gabapentin 300 mg was conducted in eight non‐obese older men. Polysomnography measured the effects of the intervention. The apnea–hypopnea index was higher in the gabapentin arm than in the placebo arm (22.4 ± 6.1 versus 12.2 ± 4.3, P ≤ 0.05, d: 0.67), as was the oxygen desaturation index (20.6 ± 5.8 versus 10.8 ± 3.9, P ≤ 0.05, d: 0.68). The number needed to harm was four. A subset analysis demonstrated that differences in sleep respiratory parameters were present only during non‐rapid eye movement sleep, as well as only in the supine position. No adverse events were reported. Hence, gabapentin worsened sleep breathing acutely compared with placebo. Long‐term clinical trials are warranted to elucidate the clinical relevance of these findings for the safety profile of GABAergic agents.     

Efficacy and safety of D. pteronyssinus immunotherapy in local allergic rhinitis: a double‐blind placebo‐controlled clinical trial

The effects of allergen immunotherapy (AIT) on local allergic rhinitis (LAR) are largely unknown. We conducted the first randomized, double‐blind, placebo‐controlled (DBPC), phase II trial of D. pteronyssinus (DP) subcutaneous AIT (DP‐AIT) on LAR (clinicaltrials.gov identifier: NCT02123316). Thirty‐six LAR patients received Pangramin PLUS DP or placebo for 24 months. The primary endpoints were symptoms, medication scores, and medication‐free days. The secondary included skin test, serum specific IgE and IgG4, nasal allergen provocation test (NAPT), and adverse events. AIT‐DP produced significant improvements in both primary and secondary endpoints vs placebo. After 12 months of AIT‐DP, we detected a significant and marked increase in allergen tolerance with negative NAPT in 50% of patients, and significant increases of serum sIgG4. Immunotherapy was well tolerated; no systemic reactions were reported. This study demonstrated that AIT‐DP is a safe and clinically effective treatment for LAR, confirming that LAR is a new indication for AIT.     

A randomised,open‐label,crossover study of the dopamine agonist,pramipexole, in patients with sleep bruxism

Sleep bruxism bears several similarities to restless legs syndrome, and a link to changes in central dopamine activity has been considered in both conditions. The dopamine agonist pramipexole is currently indicated for the symptomatic treatment of restless legs. The effect of pramipexole on sleep bruxism was investigated in subjects with ‘probable bruxism’ recruited at the Orofacial Pain Clinic. Thirteen patients underwent polysomnographic recordings, including bilateral masseter electromyographic activity. Following habituation to the recording equipment, a baseline registration was used to confirm bruxism [total episodes per hour, mean 11.3 (6.3)]. Following randomisation, subjects received no treatment or pramipexole titrated from 0.09 to 0.54 mg, o.d., for 3 weeks according to a crossover procedure. A polysomnographic‐electromyographic registration was performed at the end of each period. Pramipexole was associated with more frequent awakenings and a reduction in rapid eye movement sleep (both P ≤ 0.02). Sleep apnea decreased marginally after pramipexole (apnea–hypopnea index 17.1 compared with control 21.5, P ≤ 0.05). The number of bruxism episodes, phasic, tonic and mixed per hour, remained unchanged after pramipexole [total episodes per hour 12.7 (8.5) and 9.8 (5.2) during pramipexole and control conditions, respectively]. It is concluded, from this pilot study, that sleep bruxism is not affected by the dopaminergic agent, pramipexole.