Changes in the BOLD signal of S1 and BA3 per finger/phalanx as a response to high-frequency vibratory stimulation.

PURPOSE AND METHOD: The purpose of this study was to determine the changes in the Blood Oxygen Level Dependent signal of Primary somatosensory area (S1) and Brodmann area 3 (BA3) per finger and phalanx in comparison to the activation voxel when 250 Hz vibratory stimulation with high sensitivity for the Pacinian corpuscle was given to the four fingers and three phalanges. RESULTS: The result of analyzing the activation voxel showed a significant difference for S1 per finger and phalanx, but for BA3, no significant difference was observed despite a similar trend to S1. In contrast, the activation intensity (BOLD) displayed a significant difference for S1 per finger and phalanx and for BA3, where the activation voxel had no significant variation. In addition, while the result of S1 did not indicate whether the index or the little fingers had the highest sensitivity based on the BOLD signal per finger, the result of BA3 marked the strongest BOLD signal for the little finger as a response to 250 Hz vibratory stimulation. The activation intensity per phalanx was the highest for the intermediate phalanx for S1 and BA3, which was in line with a previous study comparing the activation voxel. CONCLUSIONS: The method based on the intensity of the nerve activation is presumed to have high sensitivity as the signal intensity is monitored within a specific, defined area. Thus, for the extraction of brain activation patterns of micro-domains, such as BA3, monitoring the BOLD signal that reflects the nerve activation intensity more sensitively is likely to be advantageous.

Metatarsal sliding osteotomy is effective without altering plantar pressure in Morton's neuroma: Retrospective case series.

BACKGROUND: Various operative methods for the treatment of Morton's neuroma have been discussed, and osteotomy of the metatarsal bone has been reported recently. However, there has been no report of pedobarographic changes after metatarsal osteotomy. Pedobarographic changes of other metatarsal area after the surgery may cause transfer metatarsalgia, and thorough analysis of the pedobarographic data should be performed peri-operatively. The purpose of this study is to investigate the post-operative pedobarographic changes of sliding osteotomy of the 3rd metatarsal bone for treating Morton's neuroma. METHODS: Forty patients (45 feet) who underwent metatarsal sliding osteotomy of the 3rd metatarsal bone for treating Morton's neuroma from November 2013 to December 2021 were retrospectively reviewed. Proximal sliding osteotomy was performed at the proximal 3rd metatarsal bone through dorsal approach. Clinical outcomes were evaluated with American Orthopaedic Foot and Ankle Society Lesser Metatarsophalangeal Interphalangeal Scale (AOFAS LMIS), Foot Function Index (FFI), and Visual Analogue Scale (VAS). Plain radiograph and pedobarogram were performed to evaluate the radiologic and pedobarographic outcomes. RESULTS: AOFAS score was improved from 52.8 ± 9.0 (18-62) to 88.8 ± 9.8 (78-100) and FFI was improved from 61.8 ± 4.9 (50-70) to 32.2 ± 5.1 (23-42) on average. The 3rd metatarsal bone was shortened by 3.1 ± 0.8 mm and dorsally shifted by 1.5 ± 0.4 mm after the surgery. Plantar intermetatarsal distances between 2nd and 3rd and 3rd and 4th metatarsal heads were significantly increased post-operatively. Average forefoot pressure and maximum pressure of the 2nd to 4th metatarsal head were not significantly changed between pre-operatively and post-operatively. CONCLUSION: Proximal metatarsal sliding osteotomy of the 3rd metatarsal bone shows a satisfactory result in both clinical and pedobarographical evaluations. It could be an effective treatment of permanent indirect decompression of Morton's neuroma with avoiding recurred neuroma, adhesion of tissue, paresthesia, and transfer metatarsalgia.

Effects of inaudible binaural beats on visuospatial memory.

OBJECTIVES: Binaural beats are auditory beat stimulation that produces sounds and induces a specific state of brain wave based on the difference in the frequency of stimulation. This study aimed to investigate the effects of inaudible binaural beats on visuospatial memory at 18 000 Hz reference and 10 Hz difference frequencies. METHODS: Eighteen adult subjects in their twenties were enrolled, including 12 males (mean age: 23.8 ±â€…1.2) and 6 females (mean age: 22.8 ±â€…0.8). An auditory stimulator providing 10 Hz binaural beats stimulation via 18 000 Hz to the left and 18 010 Hz to the right ears was used. The experiment consisted of two 5-min phases, including a rest phase and a task phase involving task performance without (Task-only) and with binaural beats stimulation (Task+BB). A 3-back task was used to measure visuospatial memory. Cognitive ability measured by task performance (accuracy and reaction time) with and without binaural beats, as well as variations in alpha power across different brain domains, were compared using paired t-tests. RESULTS: Compared to the Task-only condition, the Task+BB condition had significantly higher accuracy and significantly shorter reaction time. The electroencephalogram analysis showed that the reduction level in alpha power for the task performance under the Task+BB condition was significantly lower in all brain areas except the frontal, compared to that under the Task-only condition. CONCLUSION: The significance of this study lies in having verified the independent effects of binaural beats stimulation without any auditory influence, based on visuospatial memory.

Study on the Cognitive Characteristics Induced by Changes in the Intensity, Frequency and Duration of Vibratory Stimuli.

The purpose of this study is to analyze the cognitive characteristics that can be induced by vibration stimuli at two intensities, three frequencies, and five presentation periods. The experiment was conducted on 20 right-handed adult males, and a subjective evaluation was performed using a questionnaire. Regression analysis was performed to observe the parameters affecting cognitive characteristics according to changes in intensity, frequency, and stimulation duration. The regression analysis results showed that the cognitive characteristics affected by changes in intensity, frequency, and stimulation duration were "heavy", "bold", "thick", and "light". The cognitive characteristics affected by two-variable combinations were "deep", "clear", "vibrating", "dense", "numb", "blunt", "shallow", "fuzzy", and "soft". Cognitive characteristics affected by either intensity, frequency, or stimulation duration were "fast", "pungent", "skinny", "thin", "slow", "ticklish", "tingling", "prickling", "tap", and "rugged". By observing the cognitive characteristics that can be induced by the combination of intensity, frequency, and stimulation duration, we confirmed that in addition to intensity and frequency, the stimulation duration is an important factor that influences the induction of various cognitive characteristics. The results presented in the study can be used to enhance the utility of haptic surfaces for extended reality applications.

Frequency-following response effect according to gender using a 10-Hz binaural beat stimulation.

BACKGROUND: Several studies have continuously investigated FFRs using binaural beat (BB) stimulations and their related effects. However, only a few studies have investigated the differences in BB stimulation effects according to basic demographic characteristics, such as gender and age. OBJECTIVE: This study aimed to determine the alpha wave activity after a 10-Hz BB stimulation and subsequently identify differences according to gender across all brain areas (frontal, central, parietal, temporal, and occipital areas). METHODS: A total of 23 healthy adults (11 male and 12 female), aged 20-29, participated in the study. For the 10-Hz BB stimulation, pure tone auditory stimuli of 250 and 260 Hz were given to the left and right ear, respectively. Through a power spectrum analysis of the phase-excluding BBs (non-BBs) and phase-including 10-Hz BBs (α-BBs), the alpha power at each brain area was estimated. These values were compared using a mixed-design ANOVA. RESULTS: With the exception of the temporal area, all other brain areas showed a significant increase in alpha power for α-BBs compared to those of non-BBs. However, the difference according to gender was not significant. CONCLUSION: The results indicated the lack of gender effects in alpha wave generation through a 10-Hz BB stimulation.

Preference for Fasciocutaneous Flap Over Musculocutaneous Flap as a First-Line Option for Ischial Pressure Wound Reconstruction: A Review of 64 Cases.

The ischial pressure wound usually comprises a large, extensive defect and involves the repair of more than a small opening. Most surgeons have used a musculocutaneous flap to fill the large dead space of an ischial pressure wound. However, sacrificing muscle tissue has a potential risk of postoperative bleeding. The transferred muscle ultimately loses function as a cushion to absorb pressure. Conservation of muscle structures may be beneficial for use in future recurrence, which is common with ischial pressure wound. We compared the difference in outcome between musculocutaneous and fasciocutaneous flaps and analyzed factors affecting complications with the flaps in ischial pressure wound reconstruction. This study reviewed the results of 64 flaps in 44 patients with ischial wounds. The wounds were reconstructed with 34 musculocutaneous flaps (53%) and 30 fasciocutaneous flaps (47%). Twenty-three cases (36%) had complete healing, and 41 (64%) had complications. There was no significant difference in outcomes between fasciocutaneous and musculocutaneous flap groups. Crude logistic regression analysis showed no significant risk factors for occurrence of major complications. When fasciocutaneous flaps were used, the neighboring perforators and muscle tissues could be conserved. With a perforator-based fasciocutaneous flap, a de-epithelized distal portion of the flap could be used to fill the dead space. Therefore, the fasciocutaneous flap may have priority over the musculocutaneous flap as a first-line option for ischial pressure wound reconstruction.

Effect of binaural beat in the inaudible band on EEG (STROBE).

This study aimed to determine the effects of the binaural beat (BB) on brainwave induction using an inaudible baseline frequency outside the audible frequency range. Experiments were conducted on 18 subjects (11 males [mean age: 25.7 ± 1.6 years] and 7 females [mean age: 24.0 ± 0.6 years]). A BB stimulation of 10 Hz was exerted by presenting frequencies of 18,000 Hz and 18,010 Hz to the left and right ears, respectively. A power spectrum analysis was performed to estimate the mean of the absolute power of the alpha frequency range (8-13 Hz). The variation in the mean alpha power during the rest and stimulation phases in each brain area was compared using the Wilcoxon signed-rank test. Compared to the rest phase, the stimulation phase with BB showed an increasing trend in the mean alpha power across all 5 brain areas. Notably, a significant increase was found in the frontal, central, and temporal areas. This is a significant study in that it determines the effects of only BB without the influence of auditory perception, which has been overlooked in previous studies.

A New Technique of Open Septal Reduction Using Polydioxanone Plates for Nasoseptal Fracture: Three-Dimensional Volumetric Analysis.

BACKGROUND: In this study, we designed a new technique for open septal reduction using a polydioxanone (PDS) plate and compared it with closed reduction (CR). METHODS: This study included 19 consecutive patients with nasoseptal fracture: 10 receiving open reduction with a PDS plate (PDS group) and 9 undergoing CR group. Open septal reduction was performed after CR for nasal bone fracture. A mucoperichondrial flap was unilaterally elevated, and the deviated septal cartilage was reduced. The PDS plate was inserted horizontally above the vomerine suture. Surgical outcome was analyzed with three-dimensional volumetry and with a quality-of-life scale for nasal obstruction (Nasal Obstruction Symptom Evaluation scale). RESULTS: Complications included 1 case of septal perforation in the CR group and 1 case of PDS exposure and septal hematoma in the PDS group. In the three-dimensional volumetric analysis of the PDS group, the median value of the nasal cavity change significantly differed between 1.14 mL (interquartile range; 0.46-2.4) at the preoperative computed tomography scan and 0.33 mL (interquartile range; -0.22 to 1.29) at the postoperative computed tomography scan (∗∗P = 0.0039). The Nasal Obstruction Symptom Evaluation scale revealed significant improvement in nasal obstruction postsurgically (median value, 42.5-7.5; ∗P = 0.0139) in the PDS group. CONCLUSIONS: Polydioxanone plates potentially present a new concept of open septal reduction in terms of septal reinforcement compared with the subtractive approach of open septal reduction.

Effective Connectivity Analysis of Brain Activated Regions during Distracted Driving.

This study aims to use functional magnetic resonance imaging (fMRI) to assess the effective connectivity between the regions of the brain activated when driving and performing a secondary task (addition task). The subjects used an MR-compatible driving simulator ㅊ to manipulate the driving wheel with both hands and control the pedals (accelerator and brake) with their right foot as if they were driving in an actual environment. Effective connectivity analysis was performed for three regions of the right and the left hemispheres with the highest z-scores, and six of the regions of the entire brain (right and left hemisphere) activated during driving by dynamic causal modeling (DCM). In the right hemisphere, a motor control pathway related to movement control for driving performance was discovered; in the left hemisphere, the pathways in the regions related to movement control for driving performance, starting with the region associated with the secondary task, were discovered. In the whole brain, connectivity was discovered in each of the right and left hemispheres. The motor network of declarative memory, which is the connectivity of the right thalamus, left lingual gyrus, and right precentral gyrus, was worth noting. These results seem meaningful, as they demonstrate the connectivity associated with the control of voluntary movement related to memory from human experience, although limited to driving tasks.

Outcome of distal lower leg reconstruction with the propeller perforator flap in diabetic patients.

In diabetic foot patients, wound coverage options are quite limited due to vascular abnormalities. However, even though significant atherosclerotic changes are found in major vessels of the lower leg in diabetic foot patients, perforating vessels, which are used as the vascular pedicle of propeller perforator flaps, are often spared from atherosclerosis. Therefore, the propeller perforator flap could be an alternative option for diabetic foot patients. The purpose of this study was to compare the outcome of the propeller perforator flap between diabetic and nondiabetic patients in reconstruction of the distal lower leg. We retrospectively included all patients who underwent reconstruction of the distal lower leg with a propeller flap between 2014 and 2018. Thirty-five propeller perforator flaps in 20 diabetic patients and 15 nondiabetic patients were included. Of the 35 patients, 21 showed complete healing, and 14 showed flap complications. The rate of complications in diabetic patients was approximately 85.7%. Sex (p = .002), diabetes (p = .007), chronic renal failure (p < .001), and diabetic neuropathy (p = .011) were associated with flap complications. Crude regression analysis showed that the female sex (p = .002), diabetes (p = .01), and diabetic neuropathy (p = .012) were significant risk factors for the occurrence of any complications, but the significance of diabetes and diabetic neuropathy was not maintained in the adjusted models. Therefore, the propeller perforator flap might not be effective for reconstructing diabetic foot ulcers.

Assessment of the efficacy of the far cortical locking technique in proximal humeral fractures: a comparison with the conventional bi-cortical locking technique.

BACKGROUND: Locking plate fixation is one of the treatment strategies for the management of proximal humeral fractures. However, stiffness after locking plate fixation is a clinical concern. The mechanical stiffness of the standard locking plate system may suppress the interfragmentary motion necessary to promote secondary bone healing by callus formation. The far cortical locking (FCL) technique was developed to address this limitation in 2005. FCL increases construct flexibility and promotes callus formation. Our study aimed to evaluate the clinical and radiological outcomes of the FCL technique when implemented in proximal humeral fracture management. Furthermore, we compared the surgical outcomes of FCL with those of the conventional bicortical locking (BCL) screw fixation technique. METHODS: Forty-five consecutive patients who had undergone locking fixation for proximal humeral fractures were included in this study. A proximal humeral locking plate (PHILOS) system with BCL screw fixation was used in the first 27 cases, and the periarticular proximal humeral locking plate with FCL screw fixation was used in the final 18 consecutive cases. Functional capacity was assessed using the constant score, American Shoulder and Elbow Surgeons (ASES) score, and range of motion. Radiographic outcomes were evaluated using the Paavolainen method of measuring the neck-shaft angle (NSA). RESULTS: No significant differences in clinical outcomes (ASES score, constant score, and range of motion) were found between the two groups. The union rate at 12 weeks was significantly higher in the FCL group (94.4%) than in the BCL group (66.7%, p = 0.006). No significant differences in NSA were found between the two treatment strategies. The complication rate was not significantly different between the two groups. CONCLUSIONS: When implemented in proximal humeral fractures, the FCL technique showed satisfactory clinical and radiological outcomes as compared with the conventional BCL technique. The bone union rate at 12 weeks after surgery was significantly higher in the FCL group than in the BCL group. However, no significant difference in the final bone union rate was found between the two groups.

Risk of necrosis in the adjacent toe after one-toe fillet flap in diabetic foot: Retrospective study of 107 cases over 5 years.

PURPOSE: Fillet flap is a "spare part" concept. This technique allows the defect to be covered without donor site morbidity. Over the past 5 years, there were 107 diabetic foot cases of one-toe fillet flap in our hospital. After the operation, in some patients, there was necrosis of the adjacent toe that required additional amputation. The aim of our study was to determine the cause of necrosis of the adjacent toe after fillet flap. METHODS: The patients were divided into two groups. One group had no necrosis of the adjacent toe (group A) after the operation, and the other group had necrosis of the adjacent toe that required additional amputation after the operation (group B). Then, to confirm the cause of the additional necrosis of the adjacent toe, χ2 tests, Fisher's tests, and logistic regression tests were performed. RESULTS: A total of 107 patients were included, and 48 patients needed additional amputation. The logistic regression test revealed that a fillet flap at the metatarsophalangeal joint (MTPJ), horizontal sutures, and a fillet flap at the second toe were significant risk factors for developing necrosis. CONCLUSIONS: If a fillet flap with a second toe, fillet flap on MTPJ level and horizontal closure after fillet flap is needed, the chance of developing necrosis of the adjacent toe and additional revisional surgery must be communicated preoperatively.

Clinical outcomes of arthroscopic lateral ulnar collateral ligament repair with or without intra-articular fracture.

BACKGROUND: The pathoanatomy and biomechanics of elbow instability have been previously reported; however, few researchers have dealt with the operative management and clinical consequence of recurrent elbow instability. Recent studies on arthroscopic lateral collateral ligament (LCL) complex repair have reported successful outcomes similar to those achieved by open repair. We aimed to determine the validity of arthroscopic repair of the LCL complex in elbows with unstable dislocation with or without intra-articular fracture. METHODS: Eighteen consecutive patients who had undergone arthroscopic repair of the LCL complex for unstable dislocation of the elbow with or without intra-articular fracture and who were followed for at least 12 months were included in the study. Ligament injury combined with coronoid and/or radial head fractures were treated with arthroscopic technique. Pain, range of motion, clinical outcomes based on the Mayo Elbow Performance Score (MEPS), and surgical complications were evaluated. RESULTS: At 12 months follow-up, all 18 patients demonstrated complete settlement of the instability and mean (and standard deviation) extension of 1.7 ± 3.8°, flexion of 138.3 ± 3.8°, supination of 88.6 ± 5.3°, and pronation of 88.2 ± 5.6°. The average MEPS was 97.7 ± 3.9 points and according to this validated outcome score. However, slight widening (2 mm) of the radiocapitellar joint space was accompanied in one patient, although the varus stress test and pivot shift test were not observed. One patient showed delayed union of the anteromedial facet fracture, and two patients showed pin site irritation, which was a complication of arthroscopic coronoid fracture fixation and was fully resolved after pin removal. CONCLUSION: In patients with unstable elbow dislocation, with or without an intra-articular fracture, arthroscopic repair of the LCL complex is an effective and alternative treatment option that can restore elbow stability and have satisfactory clinical and radiographic results.

Explosive Increase in Tramadol Use in Korea 2003-2013: Analysis of Patient Trends Based on the Korea National Health Insurance Database.

Our study assessed the trends and patterns of tramadol prescriptions and possible correlations of a person being prescribed tramadol using the Korean National Health Insurance Service Sample Cohort from 2003 to 2013. The study population consisted of patients who were prescribed tramadol, opioids, or nonsteroidal anti-inflammatory drugs (NSAIDs) in an outpatient setting. From 2003 to 2013, the number of tramadol users increased from 2,476 (19.9% of the study population in 2003) to 124,592 (33.3% of the 2013 study population). The absolute change in the proportion of study patients prescribed tramadol (%) was +13.4%, a relative change (%) of +67.3%. In contrast, absolute changes in the number of opioid and NSAID users were -4.78% and -8.65%, respectively, which were relative changes of -73.5% and -11.8%, respectively. Of the studied pain types, arthritis and back pain were the most prominent diagnoses in tramadol users. Notable correlations for tramadol prescriptions, when compared with NSAIDs, were rural area (adjusted odds ratio (aOR): 1.64; 95% CI 1.61-1.66), co-prescription of a benzodiazepine (aOR 2.01; 95% CI 1.97-2.05), and tertiary hospital (aOR: 3.08, 95% CI 3.00-3.17).

Coracoid clavicular tunnel angle is related with loss of reduction in a single-tunnel coracoclavicular fixation using a dog bone button in acute acromioclavicular joint dislocation.

PURPOSE: Despite the high failure rates of techniques used to maintain the reduction of single-tunnel coracoclavicular (CC) fixation, analyses of the etiology of loss of reduction related to surgical techniques are limited. Therefore, it was hypothesized that the initial coracoclavicular tunnel angle was related to loss of reduction in the single-tunnel technique for AC joint dislocation. This study aimed to evaluate the clinical and radiological outcomes of arthroscopic single-tunnel CC suture button fixation according to the initial coracoclavicular tunnel angle. METHODS: Thirty-two consecutive patients who underwent arthroscopic single-tunnel CC suture button fixation for AC joint dislocation from 2014 to 2018 were enrolled. The tunneling-first technique was used in the first 11 patients, while the reduction-first technique was used in the remaining 22 consecutive patients. For clinical assessments, the American Shoulder and Elbow Surgeons (ASES) score and Korean Shoulder Score (KSS) were recorded. For radiological evaluation, coracoclavicular distance ratio, coracoclavicular tunnel angle, coracoid, and clavicular tunnel widths were measured. RESULTS: The ASES score did not differ significantly between the two groups (n.s.). However, the KSS was significantly better in the reduction-first group (p = 0.031). No significant intergroup differences were observed in the pre- and postoperative coracoclavicular distance ratio. However, at the last follow-up, loss of coracoclavicular distance ratio was significantly smaller in the reduction-first group (p < 0.001). At the final follow-up, loss of the coracoclavicular distance ratio was positively correlated with the postoperative coracoclavicular tunnel angle (p < 0.001, Spearman's rho correlation coefficient = 0.602). The final follow-up clavicular tunnel width was also significantly smaller in the reduction-first group (p = 0.002). Finally, the last follow-up clavicular tunnel width was positively correlated with the postoperative coracoclavicular tunnel angle (p = 0.008, Spearman's rho correlation coefficient = 0.459). CONCLUSION: The reduction-first technique showed better clinical and radiological outcomes than the tunneling-first technique in single-tunnel CC fixation for AC joint dislocation. A large postoperative coracoclavicular tunnel angle was associated with loss of reduction and clavicular tunnel widening. Therefore, obtaining a straight coracoclavicular tunnel angle is crucial for achieving better outcomes and minimizing loss of reduction. LEVEL OF EVIDENCE: III.

A Highly Efficient Absorbent for Various Organic Solvents Using Hydrophobic Graphene-Sponge Composite.

We propose a hydrophobic graphene-sponge composite produced by embedding graphene flakes within polyurethane sponge as a selective absorbent for hydrophobic liquids from a contaminated water mixture. The self-aggregation nature of graphene flakes effectively allows higher graphene content to be added inside the polyurethane sponge with repeated dip-coating. High hydrophobicity due to the intrinsic nature graphene surface allows the selective absorption of liquid contaminants from a water mixture. Given the porous structure of the composite, absorption capability of 134-233 times its own weight towards various hydrophobic liquids is possible.

Ecoflex-Passivated Graphene-Yarn Composite for a Highly Conductive and Stretchable Strain Sensor.

We present a flexible strain sensor based on a graphene-yarn composite obtained by spray coating of graphene nanoplates. To improve the stretchability, graphene nanoplates were spray-coated instead of dip-coated on pre-stretched yarn. The spray-coating method yielded not only 3.68 times higher conductivity but also 2.1 times higher stretchability compared to the dip-coating method. The sensor spray-coated 400 times showed a high stretchability of 310%. Here, the relative resistance change (ΔR/R0) was 2.27 when a tensile strain of 50% was applied to the strain sensor. In addition, the fabricated sensor was coated with a protective layer of Ecoflex to minimize environmental effects. The passivated graphene-yarn composite sensor had a higher resistance than the unpassivated sensor because the Ecoflex film penetrated the conductive graphene nanoplates; however, the response to strains of up to 200% did not degrade after passivation. Furthermore, we demonstrated that our sensor can be used in wearable applications for monitoring individual finger movements and the wrist pulse.

Signal detection of benzodiazepine use and risk of dementia: sequence symmetry analysis using South Korean national healthcare database.

Background Benzodiazepine use can potentially cause confusion and delays in mental processes. These well-known side effects appear to be linked to an increased risk of being diagnosed with dementia. Objective To evaluate the possibility of an association between benzodiazepine and dementia. Setting Korean healthcare database from 2002 to 2013. Methods Sequence symmetry analysis was conducted to investigate whether benzodiazepine use increases the risk of dementia or not. We defined exposure as new benzodiazepine users and outcome as new diagnosis of dementia (ICD-10: F00-03, G30, and G318). Benzodiazepines were categorized into two groups (long-acting and short-acting) based on the duration of action. Antidepressants, opioid analgesic, and statin were used as active comparators to rule out any possible non-causal interpretations of our results. The time-trend adjusted sequence ratio (ASR) with 95% confidence intervals (CI) was measured to identify possible associations. Main outcome measure Adjusted sequence ratio. Results Benzodiazepine users were shown to be associated with dementia [benzodiazepine: 4212 pairs, ASR = 2.27 (95% CI 2.11-2.44)]. In addition, long-acting benzodiazepines had a higher ASR than that of short-acting benzodiazepines [long-acting: 3972 pairs, ASR = 2.22 (95% CI 2.06-2.39] and [short-acting: 5213 pairs, ASR = 1.88 (95% CI 1.77-2.00)]. However, our SSA found no duration-response relationship. Conclusion Our signal detection suggests that there is a possible association between benzodiazepines and dementia. Additionally, it proposes that persons receiving long-acting benzodiazepines are at a higher risk of developing dementia than those receiving short-acting benzodiazepines. Further studies are recommended to confirm whether this epidemiological association is a causal effect or not.