The role of fat indices as factors leading to sarcopenia in older adults residing in underpopulated areas.

Simplifying the diagnostic criteria for sarcopenia is key to establishing effective interventions. Herein, we aimed to clarify novel diagnostic factors. We calculated novel fat indices [total fat index (TFI) and limb fat index (LFI)] and clarified factors leading to pre-sarcopenia and sarcopenia in 594 enrolled older adults. Physical measurements [height, weight, body mass index (BMI), gait speed, grip strength, and skeletal muscle mass] were performed. Sarcopenia was determined using established diagnostic criteria (pre-sarcopenia, n = 102; sarcopenia, n = 42). Age was associated with sarcopenia status. BMI, TFI, and LFI were lower in patients with pre-sarcopenia and sarcopenia. Logistic regression analysis showed the following odds ratios (ORs) for pre-sarcopenia: BMI [OR: 0.787, 95% confidence interval (CI): 0.7-0.885], LFI (OR: 0.589, 95% CI: 0.402-0.863), and age (OR: 1.06, 95% CI: 1.02-1.1). ORs for sarcopenia (vs pre-sarcopenia) were as follows: LFI (OR: 50.6, 95% CI: 10.2-250.0), age (OR: 1.1, 95% CI: 1.0-1.2), and BMI (OR: 0.418, 95% CI: 0.28-0.608). Our findings contribute to informing medical guidelines.

A 6-Month Follow-up Study on Adherence and Satisfaction with Lower Limb Prostheses and Orthoses Delivered to Community-Dwelling People in Japan.

Introduction: We aimed to evaluate adherence and satisfaction with prostheses and orthoses (POs) of the lower extremities delivered to community-dwelling patients and to assess the relationship of adherence and satisfaction with patient background factors, including medical status, physical findings, and level of participation. Methods: : We conducted a descriptive cohort study. Consecutive patients with disability who applied for lower extremity POs were invited to enroll. The patients' background information was collected at enrolment, and they were asked at 6 months after PO delivery whether they were using their PO as expected prior to its delivery, and, on a numerical rating scale (NRS, 0 - 10), if they were satisfied with their POs. Furthermore, the relationship between usage/satisfaction and the participants' backgrounds was evaluated and the participants' comments regarding their POs were summarized. Results: : This study analyzed the data of 51 participants (mean age, 56.5 ± 19 years). At the 6-month follow-up, 45 participants used POs as much as they had expected before delivery; this group was younger than their counterparts (52.7 versus 69.2 years). The median satisfaction score using the NRS was 8.5. Older participants (r = - 0.33), participants who were able to attach and remove their POs, and those who were independent in locomotion scored lower on satisfaction. Other background factors were not different regarding adherence or satisfaction. Conclusions: : This study demonstrated the difficulty in predicting the usage and satisfaction with lower limb POs from users' backgrounds. Producer-user communication, particularly with patients of older age and/or a higher level of participation, may improve adherence and satisfaction.

Validating scapular motion measurements using an optical motion analyzer and gravity magnetic resonance imaging.

[Purpose] This study aimed to validate whether scapular motion measured using a pad with retroreflective markers and optical motion analyzer (VICON MX) can reflect the motion calculated by images using multi-posture (gravity) magnetic resonance imaging. [Participants and Methods] The participants were 12 healthy males (12 dominant-side shoulders). The measurement items were the scapular angle at shoulder flexion 140° and 160° and abduction 100°, 120°, 140°, and 160°. The scapular angle changes were extracted from the upward/downward and internal/external rotations. Angular changes were calculated by subtracting the scapular angle in static position (drooped upper limb and external shoulder rotation) during resting chair sitting from the scapular angle in each of the six limb positions and subtracting it at shoulder abduction 100° from the scapular angle at shoulder abduction 120°, 140°, and 160°. [Results] The results showed no agreement in most cases and no consistent bias. [Conclusion] The result questions the validity of scapular motion analysis using pads with optical markers. However, the facility environment imposes many study limitations, and this method requires further validation eventually.

Neuromuscular electrical stimulation in the intensive care unit prevents muscle atrophy in critically ill older patients: A retrospective cohort study.

Critically ill patients in the intensive care unit (ICU) develop muscle atrophy and decreased physical function. Though neuromuscular electrical stimulation (NMES) therapy has been shown to be effective in preventing this, but its effect on older patients is unknown. To examine the course of critically ill older patients treated with NMES in the ICU and to define the impact of its use. A retrospective cohort study was conducted using older ICU patients (≥65 years) categorized into a control group (n = 20) and an NMES group (n = 22). For subgroup analysis, each group was further classified into pre-old age (65-74 years) and old age (≥75 years). The control group showed significant decrease in muscle thickness during ICU and hospital stay. The NMES group showed lower reduction in muscle thickness and showed decrease in muscle echo intensity during hospital stay, compared to the control group. NMES inhibited decrease in muscle thickness in the pre-old age group versus the old age group. The decreasing effect of NMES on echo intensity during hospital stay manifested only in the pre-old age group. We did not find much difference in physical functioning between the NMES and control groups. Lower limb muscle atrophy reduces in critically ill older patients (≥65 years) with NMES and is pronounced in patients aged < 75 years. The impact of NMES on the physical functioning of older patients in ICU needs to be further investigated.

Combining transcranial direct current stimulation and peripheral electrical stimulation to improve upper limb function in a patient with acute central cord syndrome: a case report.

We report the immediate improvement of weakened muscles after combined treatment with transcranial direct current stimulation (tDCS) and peripheral electrical stimulation (PES) in a patient with acute central cord syndrome (CCS) who presented with severe upper limb motor dysfunction. A 70-year-old man sustained CCS with severe motor deficits in the left upper limb, which did not improve with conventional training until 6 days after injury. On the seventh day after the injury, the left upper limb was targeted with combined tDCS (1 mA for 20 minutes/day, anode on the right, cathode on the left) and PES (deltoid and wrist extensors, 20 minutes/day at the motor threshold), and his performance score immediately improved from 0 to 6 on the Box and Block test. After four sessions, the left upper limb function improved to 32 on the Box and Block test, and manual muscle test scores of the stimulated deltoid and wrist extensors improved from 1 to 2. This improvement of the left upper limb led to improved self-care activities such as eating and changing clothes. Exercise combined with tDCS and PES may be a novel treatment for upper limb movement deficits after acute CCS.

The Effect of Static Stretching Duration on Muscle Blood Volume and Oxygenation.

ABSTRACT: Matsuo, H, Kubota, M, Shimada, S, Kitade, I, Matsumura, M, Nonoyama, T, Koie, Y, Naruse, H, Takahashi, A, Oki, H, Kokubo, Y, and Matsumine, A. The effect of static stretching duration on muscle blood volume and oxygenation. J Strength Cond Res 36(2): 379-385, 2022-Muscle blood volume increases due to stretching; however, the minimum duration of stretching to sustainably increase the muscle blood volume after stretching has not yet been elucidated. This study examined whether the duration of static stretching influenced the muscle blood volume and oxygenation. Ten healthy male subjects participated in this controlled laboratory study. Static stretching of the gastrocnemius muscle was performed for 5 durations (20 seconds, and 1, 2, 5, and 10 minutes). Changes in both the total-Hb (ΔtHb), as an index of blood volume, and tissue oxygenation index (ΔTOI) from baseline were determined using near-infrared spectroscopy. Both the ΔtHb and ΔTOI decreased during stretching and increased after stretching. The minimum value of ΔtHb during stretching did not differ in each of the 5 durations, but minimum ΔTOI progressively decreased with longer durations of stretching. The peak value of ΔtHb after stretching increased with longer durations of stretching. The value of ΔtHb at 5 minutes after the end of stretching increased with more than 2 minutes of stretching compared with 20 seconds of stretching, although the value of ΔtHb did not significantly differ between the 2, 5, and 10 minutes' durations. These findings suggest that a longer duration of stretching elicits a decrease in muscle oxygenation during stretching, and an increase in both the muscle blood volume and oxygenation after stretching. The results indicated that the minimum duration of stretching to sustain an increase in the muscle blood volume after stretching is 2 minutes.

Center of pressure velocities in patients with body lateropulsion: three case report series of Wallenberg's syndrome.

PURPOSE: In patients with Wallenberg's syndrome who present with body lateropulsion (BL), whether the center of pressure (COP) position and velocity characterize postural dysregulation is unknown. We measured time-course changes in COP parameters in three BL patients. METHODS: Three patients with acute Wallenberg's syndrome presented with BL. COP was measured for time-course changes during first standing and every week thereafter. COP positions, which indicate the deviation in the center of gravity, were calculated. COP velocities associated with dynamic movements of the center of gravity were analyzed separately for the BL and non-BL sides. RESULTS: All patients showed that COP position shifted to the BL side in first standing and changed to the center over time. COP velocities to the BL side were fast in first standing. Two of the three patients had significantly faster COP velocities to the BL side than to the non-BL side (p < .05), and one did not. In all three cases, the faster COP velocities to the BL side decreased significantly after 2 weeks compared to the initial standing position (p < .001). The change seemed to be related to the time when independent walking became possible. CONCLUSIONS: Fast COP velocity to the BL side might reflect postural dysregulation in patients with BL. These findings might be useful information for devising effective rehabilitation in patients with BL.

Effects of knee extension exercise starting within 4 h after total knee arthroplasty.

PURPOSE: To determine the beneficial effects of knee extension exercise applied from 4 h after TKA. METHODS: Patients undergoing TKA for osteoarthritis were assigned to early rehabilitation (n = 41) and control rehabilitation (n = 39) groups. Rehabilitation of knee extension exercise was started within 4 h postoperative in the early group and 2 days after surgery in the control group. Joint range of motion and pain were assessed before surgery and at 3 days to 12 months after surgery. Muscle strength and gait parameters were assessed before and 3 weeks after surgery. RESULTS: Extension range of motion was significantly increased in the early group than the control at 3 days, 3 weeks and 6 months after surgery. In gait parameters, peak knee flexion and extension angles during stance phase were significantly improved in the early group than the control group at 3 weeks after surgery. Flexion range of motion was increased in the early group than the control at 12 months after surgery. CONCLUSION: Starting knee extension exercise within 4 h after TKA reduced the early loss of extension range of motion and improved gait pattern and seemed to contribute to be better functional outcome one year after surgery.

Injuries and Illnesses Observed in Athletes from Beginner to Elite Levels at the 18th National Sports Festival for Persons with Disabilities in Japan.

OBJECTIVES: : This study aimed to describe the injuries and illnesses that occurred at the 18th National Sports Festival for Persons with Disabilities in Japan, which was attended by more than 3000 athletes from beginner to elite levels. METHODS: : Records from medical stations set up at the venues for each sport were reviewed. The incidence rates (IRs) were calculated as the number of medical station visits per 1000 athlete-days. The backgrounds of injuries and illnesses were investigated. RESULTS: : In total, 3277 athletes attended the festival, and 134 eligible medical station visits were analyzed. Overall, 102 athletes complained of injuries. For the whole schedule of the festival, IRs were 15.5 for injuries and illnesses and 11.8 for injuries alone. For injuries and illnesses, high IRs were seen in soccer (39.8), basketball (25.6), and foot baseball (22.4); for injuries alone, high IRs were also seen in soccer (33.6), basketball (25.6), and foot baseball (16.8). The most frequent symptoms were internal symptoms (n=32), contusions (n=30), and wounds (n=24). Joint sprains occurred in various sports, whereas muscle strains happened mainly in disciplines demanding sprinting or high agility. Of the 55 cases that occurred during events or public rehearsals, 45 were traumatic, whereas the relation to sports activities was not described in 51 cases. Of participants with internal symptoms, 11 were suggested to have viral infections. We identified 21 injuries caused by falls. CONCLUSIONS: : Minor trauma and viral infection were the most frequently observed symptoms among injuries and illnesses, respectively. Structured medical records and organized surveillance systems should be utilized to improve data collection and understand the onset of injury and illness.

Increase in masseter muscle activity by newly fabricated complete dentures improved brain function.

Purpose To reveal effects of improvement of masseter muscle activity on brain function in elderly people wearing complete dentures.Methods Subjects were 14 edentulous patients with a chief complaint of the inconvenience of their complete dentures. The surface electromyographic (EMG) activity of the masseter muscles was measured. Brain activities were analyzed with functional magnetic resonance imaging (fMRI), employing chewing gum as the task program. Cognitive functions were evaluated with Trail Making Test Part A (TMT-A), Rey Auditory Verbal Learning Test (RAVLT) and Rey-Osterrieth Complex Figure Test (R-OCFT). Those evaluations were performed in which subjects wore their old dentures (OD) or newly fabricated dentures (ND).Results We compared ND condition with OD condition. The masseter muscle activity significantly increased in ND condition (p < 0.05, Wilcoxon signed rank test). The brain activity increased significantly in the superior frontal gyrus, precentral gyrus, putamen, inferior parietal lobule, cerebellum, inferior frontal lobe, and middle frontal gyrus under the ND condition than under the OD condition (p < 0.01, uncorrected, cluster size > 10 voxels). Results of TMT-A, RAVLT, and R-OCFT were also significantly improved (p < 0.05, Wilcoxon signed rank test).Conclusions In the edentulous elderly, the brain activity was increased following the improvement of the masseter muscle activity. Consequently, it is possible that the improvement of the masseter muscle activity might influence on the attention, verbal skills, and visual memory.

Effects of tooth loss on brain structure: a voxel-based morphometry study.

PURPOSE: One of the most prominent issues in a super-aging society is the rapid increase in dementia patients. Cross-sectional studies in dentistry have indicated that patients with dementia have worse oral health compared to healthy people. The purpose of this study was to clarify the influence of tooth loss on brain structure by comparing the volumes of gray matter (GM) and white matter (WM) between edentulous and dentulous subjects. METHODS: Subjects were recruited from the Denture Clinic at Iwate Medical University Hospital Dental Center. Experiments were performed on edentulous (5 males, 8 females, 81.8±1.24years) and dentulous subjects (4 males, 7 females, 77.1±4.25years). Patients with dementia were excluded from this study. Brain volumes of GM and WM in edentulous and dentulous subjects were compared using intracranial volume, age, gender and history of hypertension as covariates. Analyzed brain areas were identified by transforming the Montreal Neurological Institute coordinate into the anatomical coordinate in edentulous subjects. RESULTS: The analysis of WM structural images found no morphological differences between dentulous and edentulous subjects. However, significant atrophy of GM was observed in the hippocampus, caudate nucleus and temporal pole of the right hemisphere in edentulous subjects. CONCLUSIONS: The results of this study suggest that tooth loss was a causal factor for volume reduction in brain areas related to memory, learning and cognition.

Increased Anterior Pelvic Angle Characterizes the Gait of Children with Attention Deficit/Hyperactivity Disorder (ADHD).

BACKGROUND: Children with attention deficit/hyperactivity disorder (ADHD) frequently have motor problems. Previous studies have reported that the characteristic gait in children with ADHD is immature and that subjects demonstrate higher levels of variability in gait characteristics for the lower extremities than healthy controls. However, little is known about body movement during gait in children with ADHD. The purpose of this study was to identify the characteristic body movements associated with ADHD symptoms in children with ADHD. METHODS: Using a three-dimensional motion analysis system, we compared gait variables in boys with ADHD (n = 19; mean age, 9.58 years) and boys with typical development (TD) (n = 21; mean age, 10.71 years) to determine the specific gait characteristics related to ADHD symptoms. We assessed spatiotemporal gait variables (i.e. speed, stride length, and cadence), and kinematic gait variables (i.e. angle of pelvis, hip, knee, and ankle) to measure body movement when walking at a self-selected pace. RESULTS: In comparison with the TD group, the ADHD group demonstrated significantly higher values in cadence (t = 3.33, p = 0.002) and anterior pelvic angle (t = 3.08, p = 0.004). In multiple regression analysis, anterior pelvic angle was associated with the ADHD rating scale hyperactive/impulsive scores (ß = 0.62, t = 2.58, p = 0.025), but not other psychiatric symptoms in the ADHD group. CONCLUSIONS: Our results suggest that anterior pelvic angle represents a specific gait variable related to ADHD symptoms. Our kinematic findings could have potential implications for evaluating the body movement in boys with ADHD.

Effects of 14 frequently used drugs on prostate-specific antigen expression in prostate cancer LNCaP cells.

Prostate cancer occurs more frequently among older males and such elderly individuals often have chronic underlying disorders for which various drugs are administered for treatment. The levels of prostate-specific antigen (PSA), a widely used prostate cancer marker, are influenced by a number of drugs, such as non-steroidal anti-inflammatory drugs and statins. In the present study, the drugs prescribed to patients on a repeat prescription collected at the pharmacy of the Gifu Pharmaceutical University (Gifu, Japan) were examined for their effects on the levels of PSA expression in prostate cancer LNCaP cells. Among the 14 drugs investigated, betamethasone, an agonist of the glucocorticoid receptor, was found to increase the levels of PSA mRNA expression in the LNCaP cells. This betamethasone-induced expression was mediated, at least in part, through androgen receptor (AR) transcriptional activation. Dexamethasone, a typical agonist of the glucocorticoid receptor, was also found to stimulate the AR transcriptional activity, however, to a lesser extent than betamethasone. Therefore, it would be interesting to examine in future studies whether the serum PSA levels in prostate cancer patients are influenced by betamethasone.

Postoperative gait analysis and hip muscle strength in patients with pelvic ring fracture.

The aims of present study were (1) to determine changes in kinematic and kinetic variables at 3 and 12 months after open reduction and internal fixation (ORIF) of pelvic ring fracture and (2) to determine the factor(s) associated with gait disorders that correlate with gait parameters measured at 12 months after surgery. Nineteen patients with pelvic ring fractures underwent ORIF and examined at 3 and 12 months postoperatively. The study also included a similar number of age-matched control subjects. Peak hip abduction angle, peak hip extension moment in the stance, peak hip abduction moment, and peak ankle plantarflexion moment at 3 months after ORIF were significantly lower than the respective control values. At 12 months, complete recovery was noted in peak hip abduction moment and peak ankle plantarflexion moment, whereas the recovery in peak hip abduction angle and peak hip extension moment in the stance was partial. The existence of neurological lesions and strength asymmetry of hip abductor and adductor at 3 months post-ORIF correlated with decreased peak hip abduction moment after ORIF. Our results highlighted characteristic gait patterns up to 12 months after ORIF for pelvic fracture, and these patterns correlated with neurological lesion and weakness of hip abductor and adductor muscles.

Changes in gait pattern and hip muscle strength after open reduction and internal fixation of acetabular fracture.

OBJECTIVES: To characterize changes in the gait pattern at 3 and 12 months after surgery for acetabular fracture, to assess the relationship between various gait parameters and hip muscle strength, and to determine the factors associated with gait disorders that correlate with gait parameters measured at 12 months after surgery. DESIGN: Prospective cohort study. SETTING: University hospital. PARTICIPANTS: Patients (N=19) with acetabular fractures were treated by open reduction and internal fixation (ORIF) and examined at 3 and 12 months postoperatively. The study also included a similar number of sex- and age-matched control subjects. INTERVENTIONS: Postoperative rehabilitation program. MAIN OUTCOME MEASURES: Spatiotemporal, kinematic, and kinetic variables of gait and strength of hip flexor, adductor, and abductor muscles at 3 and 12 months after ORIF. RESULTS: Walking velocity at 3 months after ORIF was slower in the patients than in the control subjects; however, walking velocity at 12 months was similar in the 2 groups. Although most of the kinematic and kinetic variables showed recovery to control levels at 3 and 12 months after ORIF, recovery was incomplete for pelvic forward tilt and hip abduction moment even at 12 months after ORIF. The greatest loss of muscle strength was noted in the hip abductors, where the average deficit was 35.4% at 3 months and 24.6% at 12 months. There was a significant relationship between hip abductor muscle strength and hip abduction moment at 3 months (R(2)=.63); however, this relationship diminished at 12 months (R(2)=.14). The presence of associated injuries correlated with lack of recovery of the peak hip abduction moment. CONCLUSIONS: Pelvic forward tilt and peak hip abduction moment showed incomplete recovery at 12 months after ORIF with subsequent conventional and home exercise rehabilitation programs. Our results suggest that improvement of hip abductor muscle strength in the early postoperative period could improve the peak hip abduction moment.

Development of a chronic cervical cord compression model in rat: changes in the neurological behaviors and radiological and pathological findings.

Cervical myelopathy is caused by chronic segmental compression of the spinal cord because of degenerative changes of the spine. However, the exact mechanisms of chronic cervical cord compression are not fully understood. The purpose of this study was to validate a new animal model of chronic cervical cord compression capable of reproducing the clinical course without laminectomy in rats. A polyethylene line attached to a plastic plate was fastened with three turns around the vertebral body of C4 in 1-month-old rats. After surgery, the polyethylene line grows deeper into the dorsal wall of the spinal canal along with the growth of the spinal canal and vertebral body, producing a gradual compression of the spinal cord. The results show that this cervical canal stenosis (CCS) model in rats caused motor deficits and sensory disturbances 9 months after initiating CCS; however, no clinical manifestations took place until 6 months. The intramedullary high-intensity area on T2-weighted images was observed in 70% of the CCS model rats at 12 months after initiating CCS. In histological sections, the spinal cord was compressed along the entire circumference at 12 months after initiating CCS. The number of ventral neurons was decreased, and the white matter showed wallerian degeneration. This model might reproduce characteristic features of clinical chronic cervical cord compression, including progressive motor and sensory disturbances after a latency period and insidious neuronal loss, and represents chronic compression of the cervical spinal cord in humans.

Up-regulation of the lysyl hydroxylase 2 gene by acetaminophen and isoniazid is modulated by transcription factor c-Myb.

OBJECTIVES: Lysyl hydroxylase 2 (LH2), an isoform of hydroxylase, catalyses the hydroxylation of lysine residues in the telopeptide of collagen to form stable and irreversible cross-linkages in collagen. Increased activity of this enzyme in activated stellate cells in human liver has been proposed to relate to the promotion of hepatic fibrosis. In the present study, we examined the regulation of LH2 expression in drug-induced liver injury in order to clarify the mechanisms behind the hepatic fibrosis caused by certain drugs. METHODS: The mRNA and protein expression of the target gene were detected by real-time reverse transcription-polymerase chain reaction (RT-PCR) with specific primers and Western blotting with a specific antibody, respectively. KEY FINDINGS: The expression of LH2 was increased in HepG2 cells incubated with acetaminophen and isoniazid. This increase was accompanied by an increase in the expression of c-myeloblastosis viral oncogene homolog (Myb) mRNA. Over-expression of c-Myb in cells transfected with a c-Myb expression plasmid, pMbm I, caused an increase in the expression of LH2 mRNA. Mutation of the Myb-binding site in the promoter region of the LH2 gene resulted in a loss of transcriptional activation in the reporter gene assay. CONCLUSIONS: These results suggest that c-Myb modulates the expression of the LH2 gene in HepG2 cells incubated with drugs causing hepatic fibrosis.

Microvascular system of the lumbar dorsal root ganglia in rats. Part II: neurogenic control of intraganglionic blood flow.

OBJECT: The dorsal root ganglion (DRG) should not be overlooked when considering the mechanism of low-back pain and sciatica, so it is important to understand the morphological features of the vascular system supplying the DRG. However, the neurogenic control of intraganglionic blood flow has received little attention in the past. The authors used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerves in blood vessels of the DRG. METHODS: Ten Wistar rats were used. To investigate the mechanism of vasomotion on the lumbar DRG, the authors used immunohistochemical methods. Sections were incubated overnight with antisera to tyrosine hydroxylase (TH), aromatic L-amino-acid decarboxylase (AADC), 5-hydroxytryptamine, substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP), somatostatin (SOM), neuropeptide Y (NPY), leucine-enkephalin, and cholineacetyl transferase (Ch-E). The avidin-biotin complex method was used as the immunohistochemical procedure, and the sections were observed under a light microscope. RESULTS: In the immunohistochemical study, TH-, AADC-, SP-, CGRP-, VIP-, SOM-, NPY-, and Ch-E-positive fibers were seen within the walls of blood vessels in the DRG. This study revealed the existence of a comprehensive perivascular adrenergic, cholinergic, and peptidergic innervation of intraganglionic blood vessels, with a possible role in neurogenic regulation (autoregulation) of intraganglionic circulation. CONCLUSIONS: The presence of perivascular nerve plexuses around intraganglionic microvessels suggests that autonomic nerves play an important role in intraganglionic circulation.

Intraneural blood flow analysis during an intraoperative Phalen's test in carpal tunnel syndrome.

Phalen's test has been one of the most significant of clinical signs when making a clinical diagnosis of idiopathic carpal tunnel syndrome (CTS). However, it is unknown whether intraneural blood flow changes during Phalen's test in patients with CTS. In this study, an intraoperative Phalen's test was conducted in patients with CTS to observe the changes in intraneural blood flow using a laser Doppler flow meter. During Phalen's test, intraneural blood flow showed a sharp decrease, which lasted for 1 min. Intraneural blood flow decreased by 56.7%-100% (average, 78.0%) in the median nerve relative to the blood flow before the test. At 1 min after completing the test, intraneural blood flow returned to the baseline value. After carpal tunnel release, there was no marked decrease in intraneural blood flow. This study demonstrated that the blood flow in the median nerve is reduced when Phalen's test is performed in vivo.

Lidocaine cytotoxicity to the zygapophysial joints in rabbits: changes in cell viability and proteoglycan metabolism in vitro.

STUDY DESIGN.: To examine whether lidocaine cytotoxicity to chondrocytes has been implicated in the development of osteoarthritis of the zygapophysial joints. OBJECTIVE.: This study was performed to determine the effects of varying concentrations and exposure times of lidocaine on the viability and proteoglycan metabolism of rabbit zygapophysial chondrocytes in vitro. SUMMARY OF BACKGROUND DATA.: Zygapophysial joint injections are commonly administered with lidocaine for chronic spinal pain in orthopedic treatment. A lot of studies on the effect of zygapophysial joint injections are clinical, but many questions on the effect of lidocaine to zygapophysial chondrocytes remain unanswered. METHODS.: Cartilage was obtained from zygapophysial joints of adult rabbits. Chondrocytes in alginate beads were cultured in medium containing 6% fetal calf serum at 370 mOsmol at cell densities of 4 million cells/mL. They were then cultured for 24 hours under 21% oxygen with 0.125%, 0.25%, 0.5%, and 1% lidocaine, and without lidocaine as control. The cell viability profile across intact beads was determined by manual counting using fluorescent probes (LIVE/DEAD assay) and transmission electron microscopy. Lactate production was measured enzymatically as a marker of energy metabolism. Glycosaminoglycan (GAG) accumulation was measured using a modified dimethylmethylene blue assay. RESULTS.: Cell viability decreased in a time- and dose-dependent manner in the concentration range of 0.125% to 1.0% lidocaine under the confocal microscope. Under the electron microscope, apoptosis increased as the concentration of lidocaine increased. GAG accumulation/tissue volume decreases as the concentration of lidocaine increased. However, GAG produced per million cells and the rate of lactate production per live cell was significantly higher for cells cultured at 0.5% and 1% lidocaine than the control group. CONCLUSION.: While these in vitro results cannot be directly extrapolated to the clinical setting, this data suggestcaution in prolonged exposure of zygapophysial cartilage to high concentration lidocaine.