Effects of a violet-excitation light-emitting diode on melatonin secretion and sleepiness: preliminary findings from a randomized controlled trial.

STUDY OBJECTIVES: A new type of lighting using violet-excitation light-emitting diodes (LEDs) with an action spectrum centered at approximately 405 nm was developed. Although violet-excitation LEDs can reduce melatonin suppression compared with blue-excitation LEDs, no studies have compared the effects of violet-excitation LEDs with those of blue-excitation LEDs on melatonin suppression. This study was designed to compare the effects of violet-excitation LEDs with those of blue-excitation LEDs on melatonin suppression, psychomotor vigilance, and sleepiness. METHODS: Sixteen healthy Japanese males aged 20-39 years were exposed to violet- and blue-excitation LEDs for 3 hours in a crossover randomized manner. The primary outcome was changes in salivary melatonin levels compared with the baseline levels. The secondary outcomes were changes in psychomotor vigilance and the Karolinska Sleepiness Scale. Melatonin suppression was calculated from the difference in the area under the curves between the baseline and intervention. RESULTS: Of the 16 participants, 15 completed the measurements. The baseline characteristics did not differ significantly between the 2 groups. After adjusting for age, a difference of 16.28 pg/mL in mean melatonin suppression was observed between the violet- and blue-excitation LED groups (-2.15 pg/mL vs -18.43 pg/mL; P = .006). The overall melatonin suppression by violet-excitation LEDs was 48.6% smaller than that by blue-excitation LEDs. No significant differences in psychomotor vigilance and sleepiness were observed between the 2 groups. CONCLUSIONS: Melatonin suppression in healthy Japanese males exposed to violet-excitation LEDs was significantly smaller than that in those exposed to blue-excitation LEDs. Our preliminary findings indicate that violet-excitation LEDs may have the potential to reduce the magnitude of blue-excitation LED-induced melatonin suppression. CITATION: Mitsui K, Saeki K, Sun M, Yamagami Y, Tai Y, Obayashi K. Effects of a violet-excitation light-emitting diode on melatonin secretion and sleepiness: preliminary findings from a randomized controlled trial. J Clin Sleep Med. 2024;20(1):101-109.

Short-wavelength light exposure at night and sleep disturbances accompanied by decreased melatonin secretion in real-life settings: a cross-sectional study of the HEIJO-KYO cohort.

OBJECTIVES: To determine the association between short-wavelength light exposure at night (LAN) power and sleep quality or melatonin levels in real-life settings. METHODS: In this cross-sectional study of 580 older adults (mean age, 71.0 years), we measured short-wavelength LAN power at cornea level using an originally developed light loggers over two nights. Sleep quality and physiological melatonin levels were measured using the Pittsburgh sleep quality index (PSQI) questionnaire and overnight urinary 6-sulfatoxymelatonin excretion (UME), respectively. RESULTS: The first and second tertile short-wavelength LAN power values obtained were 0.77 × 10-2 µW/cm2 and 7.0 × 10-2 µW/cm2, respectively, and the overall prevalence of sleep disturbances was 34.7%. The mean UME was 1.88 ± 0.70 log µg. The mean global PSQI score and the prevalence of sleep disturbances significantly increased (P = 0.004 and 0.006, respectively) with increasing tertile groups of short-wavelength LAN power. In multivariable analysis adjusted for potential confounders, the odds ratio (OR) for sleep disturbances was significantly higher in the highest tertile group of short-wavelength LAN power compared with that in the lowest tertile group (adjusted OR, 1.90; 95% confidence interval [CI]: 1.20, 3.00; P = 0.006). In addition, UME was significantly lower in the highest tertile group of short-wavelength LAN power than that in the lowest tertile group (adjusted mean difference, -0.14 log µg; 95% CI: -0.28, -0.007; P = 0.039). CONCLUSIONS: Although short-wavelength LAN power measured at cornea level in real-life settings seemed to be significantly low, our findings suggest that short-wavelength LAN power is significantly associated with both melatonin levels and sleep disturbance.

Subacute hemorrhagic cyst of the ligamentum flavum occurred in the lumbosacral transitional vertebra presenting as progressive lumbar nerve root compression: a case report.

The lumbosacral transitional vertebrae (LSVT) has been reported to be a cause of lumbar disc herniation as a result of mechanical stress, however there were no reports about relationship between LSTV and hemorrhagic intervertebral cystic lesion. We report a rare case of a hemorrhagic intravertebral cystic lesion that occurred in the LSVT of a 42-year-old man and had a subacute course of lumbar nerve root compression. He presented our hospital with complain of increasing left leg pain for one week. Contrast-enhanced MRI (Gd-T1WI) showed a heterogenous contrast-enhanced effect on the nodule at the entrance of the left pedicle root of L6. The LSTV was classified as Type IIIA using the Castellvi's classification, and the nodule was found on the ipsilateral of the lumbarization. From the imaging findings, disc cysts, ganglion cysts, synovial cysts, disc sequestration and Schwannomas were differentials of the intravertebral canal cystic lesions; however, it was suspected to be a hemorrhagic cystic lesion because of their acute progression of his symptoms, his relatively young age and imaging findings. His symptoms improved shortly after the resection of the cyst and he was diagnosed as intracystic hemorrhage of a ganglion in the ligamentum flavum. There were no features suggestive of recurrence of the cystic lesion in the follow-up MRI on 6 months after the surgery. It was speculated that in the LSTV, twisting movements act on the upper part adjacent to the transitional vertebra, causing microtrauma around the facet joint that leads to the forming a hemorrhagic cyst following damage around the joint capsule. It is difficult to make a diagnosis of hemorrhagic cyst from imaging alone. It must be suspected from the aspect of age (relatively young), gender (male), clinical course (acute to subacute) and MR imaging (various signal intensity patterns on T2WI and contrast effect on Gd enhancement).

An increase in the risk of excessive femoral anteversion for relatively younger age and types of femoral morphology in total hip arthroplasty with direct anterior approach.

BACKGROUND: Direct anterior approach (DAA) is known to diminish a dislocation risk and widely used for total hip arthroplasty (THA). On the other hand, anterior dislocation due to increasing stem anteversion and cup anteversion is an important complication. METHODS: A retrospective analysis of 140 (male/female: 10/130) consecutive patients with 149 hips who had undergone primary THA in the period between 2011 and 2015 was conducted. Factors including age, gender, body mass index (BMI), and primary diagnosis were examined. Radiographic parameters including the Dorr proximal femoral types, cortical thickness index (CTI), canal flare index (CFI), and canal to calcar index were measured. To investigate relationships of combined anteversion (CA) with other factors, a stepwise regression analysis was performed. RESULTS: The mean age, BMI, and the follow-up period were 69.5 ± 10.3 years old, 23.4 ± 3.4 kg/m2, and 48.2 ± 13.6 months, respectively. The proximal femurs of the 149 hips were categorized as Dorr type A ( n = 33), type B ( n = 110), and type C ( n = 6). The mean CTI, CFI, and canal to calcar index were 0.56 ± 0.08, 4.15 ± 0.83, and 0.46 ± 0.09, respectively. The mean stem varus angle, radiographic inclination, and radiographic anteversion of the cup were 0.19 ± 1.63, 40.9 ± 6.0°, and 12.7 ± 3.5°, respectively. Stem anteversion measured by computed tomography (CT) axial image was 17.7 ± 12.0°. The mean radiographic inclination, radiographic anteversion (CTRA), and anatomical anteversion analyzed by Kyocera 3-D template were 40.8 ± 7.2°, 19.8 ± 6.6°, and 28.8 ± 10.0°, respectively. Mean CA defined as the sum of stem anteversion and CTRA was 37.5 ± 14.5°. To investigate relationships of CA with other factors, a stepwise regression analysis was performed and resulted in a model with age ( p < 0.001). In the same way, stem anteversion and CTRA were analyzed; only for the stem anteversion, the stepwise selection process resulted in a model with age ( p < 0.001) and the Dorr types ( p = 0.047). CONCLUSION: The risk of excessive femoral anteversion increases for relatively younger age and for types of femoral morphology according to the Dorr classification, moreover with an increase of CA in DAA-THA with cementless tapered-wedge stem.

Tarsal Tunnel Syndrome Caused by a Schwannoma of the Posterior Tibial Nerve.

Schwannoma is the most common tumor of the peripheral nerve sheath. However, there have been few reports on schwannoma of the posterior tibial nerve causing tarsal tunnel syndrome. We report on a 60-year-old man with tarsal tunnel syndrome caused by a schwannoma of the posterior tibial nerve, which was first diagnosed as a ganglion cyst. After enucleation of this tumor, the patient was asymptomatic and had no related sequelae except for minor numbness in the plantar aspects of his digits. Although schwannoma of the posterior tibial nerve is rare, it should be considered even if a ganglion is clinically suspected.

Successful Closed Reduction of a Lateral Elbow Dislocation.

In this report, we present a case of lateral elbow dislocation treated with closed reduction. Lateral elbow dislocation is rare, and a closed reduction is reported with even less frequency. The reduction can be hindered by swelling and soft tissue interposition, and we describe the use of a nonoperative reduction technique performed under mild sedation with early physiotherapy to avoid joint stiffness. No additional complication was observed, and the normal range of elbow movement and function was obtained by early physiotherapy.

Characteristics of L3 nerve root radiculopathy.

BACKGROUND: In degenerative lumbar spinal disease with nerve root compression, the L5 and S1 nerve roots are the most often affected and the L3 nerve root is involved infrequently. The purpose of this study was to investigate the characteristics of L3 nerve root radiculopathy. METHODS: Seventeen consecutive patients with L3 radiculopathy were treated. The symptomatic nerve roots were determined by the pain distribution, the neurologic findings, and selective nerve root injection. The clinical characteristics and outcomes of these patients were assessed retrospectively. RESULTS: The average age was 76 years. The spinal diseases that were associated with L3 radiculopathy were lumbar canal stenosis in 6 patients, lumbar extraforaminal stenosis and lumbar disk herniation in 5 each, and lumbar canal stenosis with degenerative scoliosis in 1. The patients' symptoms were thigh pain in 12 patients, and hip or knee pain in 5. Four patients were nonambulatory because of severe pain. Although a sensory disturbance was reported in 9 patients, motor weakness was present in 2. Selective nerve root injection was completely effective in 10 patients. Six had decompressive surgery and/or fusion followed by a favorable outcome. Four patients were misdiagnosed and received conservative treatment for hip and/or knee joint diseases. CONCLUSIONS: L3 radiculopathy was characterized by various lower limb pain and neurologic deficit. Selective nerve root injection was effective for most patients. In elderly patients who do not respond to treatment for hip and/or knee joint diseases, L3 nerve root radiculopathy should be considered as the cause of lower limb pain.