On the pharmacotherapy of sleep bruxism: placebo-controlled polysomnographic and psychometric studies with clonazepam.
OBJECTIVE
Sleep bruxism (SB) is a parasomnia defined as a stereotyped movement disorder characterized by grinding or clenching of the teeth during sleep. Pathophysiologically, SB is the result of biological and psychosocial influences. Treatment comprises behavioral, orthodontic and pharmacological interventions. While benzodiazepines and muscle relaxants have been reported by clinicians to reduce bruxism-related motor activity, placebo-controlled studies are lacking. Thus, the aim of the present study was to investigate the acute effects of clonazepam (Rivotril) as compared with placebo, utilizing polysomnography and psychometry.


METHODS
Ten drug-free outpatients (6 females, 4 males), aged 46.5 +/- 13.1 years, suffering from SB (ICD-10: F45.8; ICSD: 306.8) and having been treated by bite splints were included in the trial. Comorbidity was high: 7 patients presented nonorganic insomnia related to adjustment or anxiety disorders (5 patients) or depression (2 patients); all patients had a concomitant movement disorder (6 restless legs syndrome, 4 periodic leg movement disorder). After one adaptation night, patients received placebo and 1 mg clonazepam 1/2 hour before lights out in a single-blind, nonrandomized study design. Objective sleep quality was determined by polysomnography, subjective sleep and awakening quality by rating scales, objective awakening quality by psychometric tests. Clinical evaluation was based on the Pittsburgh Sleep Quality Index (PSQI), the Zung Depression (SDS) and Anxiety (SAS) Scales, the Quality of Life Index, the Epworth Sleepiness Scale and the International Restless Legs Syndrome Study Group (IRLSSG) Scale.


RESULTS
On admission, SB patients exhibited deteriorated PSQI, SAS, SDS and IRLSSG measures. As compared with placebo, 1 mg clonazepam significantly improved the mean bruxism index from 9.3 to 6.3/h of sleep. Furthermore, it significantly improved the total sleep period, total sleep time, sleep efficiency, sleep latency and time awake during the total sleep period, and increased stage 2 sleep and movement time. Periodic leg movements decreased significantly, while the apnea index and apnea-hypopnea index increased marginally, but remained within normal limits. Subjective sleep quality improved as well, while in mood, performance and psychophysiology no changes were observed.


CONCLUSIONS
Acute clonazepam therapy significantly improved not only the bruxism index but also objective and subjective sleep quality, with unchanged mood, performance and psychophysiological measures upon awakening, suggesting good tolerability of the drug.
Saletu
Alexander
A
Department of Dental Medicine, Medical University of Vienna, Währinger Strasse 25a, AT-1090 Vienna, Austria. alexander.saletu@meduniwien.ac.at
Parapatics
Silvia
S
Saletu
Bernd
B
Anderer
Peter
P
Prause
Wolfgang
W
Putz
Hanna
H
Adelbauer
Josef
J
Saletu-Zyhlarz
Gerda Maria
GM
D000328:Adult; D000704:Analysis of Variance; D000927:Anticonvulsants / Q000627:therapeutic use*; D001288:Attention / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002998:Clonazepam / Q000627:therapeutic use*; D015897:Comorbidity; D018592:Cross-Over Studies; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000187:drug effects / Q000503:physiopathology; D010919:Placebos; D017286:Polysomnography / Q000187:drug effects*; D011594:Psychometrics; D011597:Psychomotor Performance / Q000187:drug effects; D011602:Psychophysiologic Disorders / Q000188:drug therapy* / Q000453:epidemiology; D011930:Reaction Time / Q000187:drug effects; D016037:Single-Blind Method; D012890:Sleep / Q000187:drug effects; D020186:Sleep Bruxism / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology*; D016896:Treatment Outcome; D014851:Wakefulness / Q000187:drug effects
D000927:Anticonvulsants; D010919:Placebos; D002998:Clonazepam