Sleep bruxism frequency and platelet serotonin transporter activities in young adult subjects.

PURPOSE: To evaluate correlations between serotonin transporter (SERT) uptake ability in human peripheral platelets and sleep bruxism (SB) frequency. METHODS: Subjects were consecutively recruited from sixth-year students at Okayama University Dental School. Subjects were excluded if they (1) were receiving orthodontic treatment, (2) had a dermatological disease, (3) had taken an antidepressant within 6 months, or (4) had used an oral appliance within 6 months. SB frequency was determined as the summary score of three consecutive night assessments using a self-contained electromyography detector/analyzer in their home. Fasting peripheral venous blood samples were collected in the morning following the final SB assessment. SERT amount and platelet number were quantified via an ELISA assay and flow cytometry, respectively. Functional SERT characterization, 5-hydroxytryptamine (5-HT) uptake, maximum velocity (V max), and an affinity constant (K m ) were assessed with a [(3)H] 5-HT uptake assay. The correlations between these variables and SB level were evaluated. RESULTS: Among 50 eligible subjects (26 males, mean age 25.4 ± 2.41 years), 7 were excluded because of venipuncture failure, smoking, and alcohol intake during the experimental period. A small but significant negative correlation between SB level and [(3)H] 5-HT uptake was observed (Spearman's correlation R (2) = 0.063, p = 0.04). However, there were no significant correlations between SB level and total platelet amount, SERT, V max, and K m values (p = 0.08, 0.12, 0.71, and 0.68, respectively). CONCLUSIONS: Platelet serotonin uptake is significantly associated with SB frequency, yet only explains a small amount of SB variability.

Prevalence of hypertension in patients with trigeminal neuralgia.

It is unclear whether hypertension (HTN) is a predisposing factor for the development of trigeminal neuralgia (TN). The purpose of this study was to determine the prevalence of HTN in TN patients and controls at the USC Orofacial Pain and Oral Medicine Center. A retrospective chart review was conducted from a database of over 3,000 patient records from 2003 to 2007. We identified patients diagnosed with TN with or without HTN. A total of 84 patients (54 females; 30 males) between the ages of 33 and 93 years were diagnosed with TN; 37% had TN with HTN and 32% of controls had HTN. The increased prevalence of HTN in the TN patients was not statistically significant (P = 0.50). Since, both TN and HTN are seen in the elderly, it is likely that HTN is simply a co-existing condition in patients with TN and not a risk factor for its development.