Proprioceptive Function Research Articles

Proprioceptive function of the cruciate complex of the knee joint (literature review)

The question of the role of proprioceptive sensitivity in ensuring the normal kinematics of the joints, including the knee, has increasingly attracted the attention of researchers in recent decades. The position on the significance of intra-articular receptors and the concept of proprioception are not new [2, 3]. At the end of the 19th century, Duchenne was one of the first to point out the clinical significance of articular sensitivity. The term "proprioception" was introduced by Sherrington in 1906 [57]. Abbott et al. [4] and Gardner [27] found that the ligaments of the knee joint have a rich sensory innervation that acts as the first link in the kinematic chain. Abbott noted that the impulses that arise in the ligaments are transmitted through the central nervous system to the muscles and this allows you to establish normal, uniform, coordinated movements. Pathologically strong impulses arising from excessive stretching of the ligaments cause contraction of the conjugate muscle group, thereby preventing damage to the soft tissue component of the knee joint.

Amyotrophic lateral sclerosis and delayed onset muscle soreness in light of the impaired blink and stretch reflexes - watch out for Piezo2.

Amyotrophic lateral sclerosis (ALS) is a fatal, multisystem neurodegenerative disease that causes the death of motoneurons (MNs) progressively and eventually leads to paralysis. In contrast, delayed onset muscle soreness (DOMS) is defined as delayed onset soreness, muscle stiffness, loss of force-generating capacity, reduced joint range of motion, and decreased proprioceptive function. Sensory deficits and impaired proprioception are common symptoms of both ALS and DOMS, as impairment at the proprioceptive sensory terminals in the muscle spindle is theorized to occur in both. The important clinical distinction is that extraocular muscles (EOM) are relatively spared in ALS, in contrast to limb skeletal muscles; however, the blink reflex goes through a gradual impairment in a later stage of disease progression. Noteworthy is, that, the stretch of EOM induces the blink reflex. The current authors suggest that the impairment of proprioceptive sensory nerve terminals in the EOM muscle spindles are partially responsible for lower blink reflex, beyond central origin, and implies the critical role of Piezo2 ion channels and Wnt-PIP2 signaling in this pathomechanism. The proposed microinjury of Piezo2 on muscle spindle proprioceptive terminals could provide an explanation for the painless dying-back noncontact injury mechanism theory of ALS.

Treatment with platelet-rich plasma attenuates proprioceptor abnormalities in a rat model of postpartum stress urinary incontinence.

Stress urinary incontinence (SUI) is the most prevalent form of urinary incontinence, and vaginal delivery is a major risk factor for developing SUI. We evaluated the hypothesis that applying the autologous platelet rich plasma (PRP) to the pelvic floor muscles via injection affects expression of proprioceptors and improves postpartum stress urinary incontinence (PSUI) in rats. Virgin female Sprague-Dawley rats were divided into control (n = 10) and experimental group(n = 20). Vaginal dilation was used to establish PSUI, and the rats in the experimental group were further divided into the PSUI group (n = 10) and PSUI+PRP group (n = 10). Pelvic floor muscles from rats in the PSUI+PRP group were positioned under ultrasound guidance for PRP injection. The morphology and number of pelvic floor muscle spindles were assessed using H&E staining, proprioceptors evaluated by gold chloride staining, and changes in the expression of neurotrophin-3 (NT-3) and skeletal myosin MY-32 determined by immunohistochemistry. After 28days,bladder leak point pressure (BLPP) and abdominal leaking-urine point pressure (ALPP) in rats with PSUI were significantly lower than in control animals (P<0.01). Both BLPP and ALPP increased significantly in the PSUI+PRP group (P<0.01). Compared with the control group, muscle spindle morphology and structure in the PSUI and PSUI+PRP groups had different pathological changes,with higher variations in the PSUI group. The positive signals for NT-3/MY-32 expression in control rats were higher than those from PSUI or PSUI+PRP groups, however, the expression for NT-3/MY-32 in PSUI+PRP animals was higher than that seen in the PSUI group (P < 0.01). PSUI rats have an abnormal expression of pelvic proprioceptors, which affect proprioceptive function, and further the contractibility of pelvic floor muscles. A PRP injection may restore the sensory function of pelvic proprioceptors, thus improving urine leakage in PSUI rats.

A Meta-Analysis of Systemic Evaluation of Knee Ligament Injury or Intervention of Knee Proprioceptive Function Recovery.

Objective The knee ligaments, as a passive knee joint stability device, provide protection for the knee joint and ensure its functional integrity. This role has long been known and recognized by people. The original purpose of knee ligament reconstruction after knee ligament injury is to restore its anatomical structure and mechanical stability mechanism. Methods Taking athletes as the research object, randomized controlled trials (RCTs) on improving ankle joint function of athletes related to proprioception training at home and abroad were included. The search time was from the establishment of the database to December 31, 2019, and the references of related documents were traced. Two researchers independently screened the literature, extracted data, and evaluated the quality of the literature. RevMan 5.3 software was used for data analysis. Results The extensor strength, flexor strength, and flexor strength/extensor strength of the affected limb were higher than before the operation one year after surgery (P < 0.01). The Lysholm score, Lysholm instability score, and one-foot jump distance were all higher than those before surgery (P < 0.05); the difference of KT-2000 for both knees was smaller than that before surgery (P < 0.05). Conclusion In maintaining the anterior stability of the knee joint, the knee ligament provides 85% static resistance to prevent the tibia from moving forward, so knee ligament injury will cause knee instability. The proprioceptive feedback mechanism plays an important role in maintaining the functional stability of joints.

The time from injury to surgery is an important factor affecting the mechanoreceptors at stump of torn anterior cruciate ligament.

Restoration of proprioceptive function after anterior cruciate ligament (ACL) reconstruction is as important as mechanical stability. For this purpose, remnant of the torn ACL is the only source of nerve endings. Our aim in this study is to investigate the quantity of mechanoreceptors in the remnants ACL stumps in injured knees and to correlate that with the quantity in intact ACL in control cases. 48 patients that underwent ACL reconstruction between January 2016 and December 2018 as study group and 20 knees of 10 fresh frozen cadavers that as control group included in the study. Remaining stumps from study group and native ACL from control group were collected and investigated with S100 immunostaining. The type and number of mechanoreceptors in standardized areas was determined. The correlation of number of mechanoreceptors and time to surgery after ACL rupture were evaluated. The free nerve endings (FNE) and total number of mechanoreceptors were significantly lower in the study group as compared to the control group (p < 0.001 and p = 0.004, respectively). The number of Golgi-Mazzoni corpuscle decreased significantly with time (p = 0.041 CC: -0.438). The time from injury to surgery is an important factor affecting the mechanoreceptors at stump of torn ACL. The surgeon and patient should be aware of the fact that delay in surgery could lead to the loss of mechanoreceptors.

Proprioceptive Training with Visual Feedback Improves Upper Limb Function in Stroke Patients: A Pilot Study.

Proprioceptive deficit is one of the common sensory impairments following stroke and has a negative impact on motor performance. However, evidence-based training procedures and cost-efficient training setups for patients with poststroke are still limited. We compared the effects of proprioceptive training versus nonspecific sensory stimulation on upper limb proprioception and motor function rehabilitation. In this multicenter, single-blind, randomized controlled trial, 40 participants with poststroke hemiparesis were enrolled from 3 hospitals in China. Participants were assigned randomly to receive proprioceptive training involving passive and active movements with visual feedback (proprioceptive training group [PG]; n = 20) or nonspecific sensory stimulation (control group [CG]; n = 20) 20 times in four weeks. Each session lasted 30 minutes. A clinical assessor blinded to group assignment evaluated patients before and after the intervention. The primary outcome was the change in the motor subscale of the Fugl-Meyer assessment for upper extremity (FMA-UE-M). Secondary outcomes were changes in box and block test (BBT), thumb localization test (TLT), the sensory subscale of the Fugl-Meyer assessment for upper extremity (FMA-UE-S), and Barthel Index (BI). The results showed that the mean change scores of FMA-UE were significantly greater in the PG than in the CG (p = 0.010 for FMA-UE-M, p = 0.033 for FMA-UE-S). The PG group was improved significantly in TLT (p = 0.010) and BBT (p = 0.027), while there was no significant improvement in TLT (p = 0.083) and BBT (p = 0.107) for the CG group. The results showed that proprioceptive training was effective in improving proprioception and motor function of the upper extremity in patients with poststroke. This trial is registered in the Chinese Clinical Trial Registry (ChiCTR2000037808).

Impaired wrist position sense is linked to motor abnormalities in young adults with a probable developmental coordination disorder

Proprioceptive deficits have been found to underlie motor abnormalities in individuals with movement disorders. This study investigated wrist proprioceptive acuity in young adults with and without probable developmental coordination disorder (DCD) and examined how proprioceptive acuity is linked to different domains of motor function. Thirty participants were included in this study (age, 19–22 years), ten with probable DCD and 20 controls. Wrist proprioceptive acuity was assessed using a joint position sense paradigm under contralateral and ipsilateral conditions. The Bruininks − Oseretsky Test of Motor Proficiency 2nd Edition (BOT-2) was used to measure different domains of motor ability. Compared to the control group, young adults with probable DCD exhibited significantly increased proprioceptive error variability in contralateral (p < 0.0001) and ipsilateral conditions (p < 0.05). Furthermore, wrist proprioceptive error variability was significantly associated with the levels of body coordination measured by BOT-2 (r = − 0.55). This study verified impaired wrist proprioceptive function in young adults with probable DCD, which is likely to contribute to motor impairment in adults with DCD.

Research on the relevant effects of Taijiquan exercise on the changes of lower limb muscle strength in the elderly based on nano biometric IC technology

With the improvement of people's living standards and medical standards, the ageing of population structure has become a global social problem. The authors studied the influence of Taijiquan exercise on lower limb function of the elderly, and this paper provides a theoretical basis for preventing or delaying the decline of lower limb function of the elderly. The research method of sports biomechanics is used to analyse the gait data before and after Taijiquan practice in the elderly, and to explore the changes of the influence of Taijiquan on the kinematic parameters and kinetic parameters of the lower extremities, and reveal the physical fitness of Taijiquan for the elderly. Improve the role. Studies have shown that Tai Chi practice can significantly improve the lower limb muscle strength and proprioceptive function of the elderly.

The Effect of Whole-Body Vibration on Proprioception and Motor Function for Individuals with Moderate Parkinson Disease: A Single-Blind Randomized Controlled Trial.

Introduction Previous studies have shown that whole-body vibration (WBV) may have a potential impact on gait and balance in individuals with Parkinson's disease (PD). However, this body of work has proven inconclusive due to the diverse disease progression and broad age range associated with PD. The effects of WBV on proprioception, a sense frequently affected by PD, has rarely been studied. Objective To investigate the short-term effect of WBV on proprioception and motor function for individual with moderate PD. Design A single-blind randomized controlled trial. Setting. A hospital and a laboratory. Participants. 32 participants with moderate PD were recruited and randomly assigned into either the WBV or conventional therapy groups. Interventions. For the WBV group, each treatment session included five, one-minute bouts of whole-body vibration paired with one-minute rest (frequency: 6 Hz; amplitude: 3 mm). Each conventional therapy participant received balance and mobility training for 10 minutes. Main Outcome Measures. Outcome measures included proprioceptive sensitivity of the upper limb, position sense of the knee joint, Unified Parkinson's disease rating scale : motor section (UPDRS-motor), functional reach test (FRT), and the timed up and go test (TUG). Results No statistically significant difference was found between groups. However, both groups showed a significant improvement in motor function after treatment, including UPDRS-motor (P = 0.04), less affected side of FRT (P = 0.019), and TUG (P = 0.006). Conclusions Although the effect of WBV was not superior to the conventional therapy, it provided a passive and safe clinical intervention as an alternative treatment, especially for individuals with motor impairment or poor balance function.

Contribution of Sensory Function to Preclinical Indicators of Physical and Cognitive Functioning With Aging

There are well established associations between sensory loss and physical and cognitive deficits with aging, but gaps remain in our understanding of the associations between sensory function and early preclinical indicators of physical and cognitive decline. This symposium will present data from the Baltimore Longitudinal Study of Aging (BLSA) on a series of studies investigating the links among sensory function, motor function, and physical and cognitive outcomes in older adults. In the first study, Dr. Gross will present an operational definition of early cognitive impairment (ECI) based on a combination of two cognitive measures – the Card Rotations test and the California Verbal Learning Test Immediate Recall – to predict progression to MCI/AD. In the second study, Dr. Cai will evaluate the relationship between multisensory impairment (in vision, hearing, olfaction, proprioception and vestibular function) and the algorithmic definition of ECI. In the third study, Dr. Armstrong will evaluate the association between multisensory impairment and another biomarker of ECI or preclinical AD, specifically PET-PiB deposition. In the fourth study, Dr. Schrack, will present the joint contribution of multisensory (hearing and vision) impairment and motor function (gait speed) on risk of incident MCI/AD in longitudinal analyses. Finally, Dr. Martinez Amezcua will present the longitudinal association between hearing and vestibular function and decline in higher level physical function and endurance performance. Taken together, these studies present compelling data about the contribution of sensory function to preclinical indicators of physical and cognitive functioning with aging.

Twelve Weeks of a Staged Balance and Strength Training Program Improves Muscle Strength, Proprioception, and Clinical Function in Patients with Isolated Posterior Cruciate Ligament Injuries.

Ligament reconstruction is indicated in patients with an isolated posterior cruciate ligament (PCL) injury who fail conservative treatment. To eliminate the need for PCL reconstruction, an ideal rehabilitation program is important for patients with an isolated PCL injury. The purpose of this study was to investigate the improvement in functional outcome, proprioception, and muscle strength after a Both Sides Up (BOSU) ball was used in a balance combined with strength training program in patients with an isolated PCL injury. Ten patients with isolated PCL injuries were recruited to receive a 12 week training program as a study group. In the control group (post-PCL reconstruction group), ten subjects who had undergone isolated PCL reconstruction for more than 2 years were enrolled without current rehabilitation. The Lysholm score, IKDC score, proprioception (active and passive), and isokinetic muscle strength tests at 60°/s, 120°/s, and 240°/s, were used before and after training on the injured and normal knees in the study group, and in the post-PCL reconstruction group. The results were analyzed with a paired t-test to compare the change between pre-training, post-training, and the normal leg in the study group, and with an independent t-test for comparisons between the study and post-PCL reconstruction groups. Both the Lysholm and IKDC scores were significantly improved (p < 0.01) after training, and no difference was observed compared to the post-PCL reconstruction group. The active and passive proprioception was improved post-training compared to pre-training, with no difference to that in the post-PCL reconstruction group. Isokinetic knee quadriceps muscle strength was significantly greater post-training than pre-training in PCL injured knees at 60°/s, 120°/s, and 240°/s, and in hamstring muscle strength at 60°/s and 120°/s. Muscle strength in the post-training injured knee group showed no significant difference compared to that in the post-training normal leg and the post-PCL reconstruction group. The post-training improvement of muscle strength was higher in the PCL injured leg compared to the normal leg and there was no difference between the dominant and non-dominant injured leg in the study group. After 12 weeks of BOSU balance with strength training in patients with an isolated PCL injury, the functional outcome, proprioception, and isokinetic muscle strength were significantly improved, and comparable to the contralateral normal leg and the post-PCL reconstruction group. We suggest that programs combining BOSU balance and strength training should be introduced in patients with a PCL injury to promote positive clinical results.

Proprioceptive and Clinical Outcomes after Remnant Preserved Anterior Cruciate Ligament Reconstruction: Assessment with Minimal Confounding Factors.

ObjectiveTo evaluate the proprioceptive and clinical function of the knee joint after anterior cruciate ligament reconstruction (ACLR) with various amounts of remnant preserved with as few confounding factors as possible.MethodsThis retrospective study included 46 patients who underwent ACLR with remnant preservation between March 2013 and February 2019. These patients had less than 6 months injury‐to‐surgery interval and no concomitant injuries. The researchers divided these subjects into two groups based on the length of the remnant preserved after ACLR, with group A defined as having more than 1/3 of the original length preserved and group B defined as less than 1/3 of the original length preserved. Clinical scores were obtained using the Lysholm knee scoring scale and the Tegner activity scale. The Lysholm score was calculated preoperatively, at 3, 6, and 12 months postoperatively, and at the last follow up. The Tegner score was calculated preoperatively, at 12 months postoperatively and at the last follow up. Anterior laxity was measured using the KT2000 arthrometer preoperatively and at 12 months postoperatively. Proprioceptive function was evaluated through reproduction of passive positioning (RPP) and threshold to detection of passive motion (TDPM). Both RPP and TDPM were measured at the angle of 15° at 3, 6, and 12 months postoperatively. Unpaired t‐tests were performed to investigate the difference in each parameters between the two groups.ResultsIn the present study, 20 patients were classified into group A and 26 into group B. All patients were followed up for an average of 34.70 ± 12.79 months. All 46 patients were satisfied with the outcome of the surgery and no complications were reported at the end of the study. No significant differences were found between the two groups in terms of the Lysholm score and anterior laxity by KT2000 at all time points. The Tegner score was significantly higher in group A at 12 months postoperatively and at the final follow‐up. In addition, group A's RPP was significantly better than that of group B's when tested at the angles of 15° and 30° at 3 months postoperatively, and at the angle of 15° at 6 months postoperatively. Group A's TDPM was also significantly better than that of group B's at all three tested angles at 3 months postoperatively, and at the angle of 15° at 6 months postoperatively.ConclusionPatients with ACLR with more than 1/3 of the original length preserved demonstrated a higher activity level 12 months postoperatively and better proprioceptive function at 15° of extension at 3 and 6 months postoperatively.

Structure of Long-Range Direct and Indirect Spinocerebellar Pathways as Well as Local Spinal Circuits Mediating Proprioception.

Proprioception, the sense of limb and body position, generates a map of the body that is essential for proper motor control, yet we know little about precisely how neurons in proprioceptive pathways are wired. Defining the anatomy of secondary neurons in the spinal cord that integrate and relay proprioceptive and potentially cutaneous information from the periphery to the cerebellum is fundamental to understanding how proprioceptive circuits function. Here, we define the unique anatomic trajectories of long-range direct and indirect spinocerebellar pathways as well as local intersegmental spinal circuits using genetic tools in both male and female mice. We find that Clarke's column neurons, a major contributor to the direct spinocerebellar pathway, has mossy fiber terminals that diversify extensively in the cerebellar cortex with axons terminating bilaterally, but with no significant axon collaterals within the spinal cord, medulla, or cerebellar nuclei. By contrast, we find that two of the indirect pathways, the spino-lateral reticular nucleus and spino-olivary pathways, are in part, derived from cervical Atoh1-lineage neurons, whereas thoracolumbar Atoh1-lineage neurons project mostly locally within the spinal cord. Notably, while cervical and thoracolumbar Atoh1-lineage neurons connect locally with motor neurons, no Clarke's column to motor neuron connections were detected. Together, we define anatomic differences between long-range direct, indirect, and local proprioceptive subcircuits that likely mediate different components of proprioceptive-motor behaviors.SIGNIFICANCE STATEMENT We define the anatomy of long-range direct and indirect spinocerebellar pathways as well as local spinal proprioceptive circuits. We observe that mossy fiber axon terminals of Clarke's column neurons diversify proprioceptive information across granule cells in multiple lobules on both ipsilateral and contralateral sides, sending no significant collaterals within the spinal cord, medulla, or cerebellar nuclei. Strikingly, we find that cervical spinal cord Atoh1-lineage neurons form mainly the indirect spino-lateral reticular nucleus and spino-olivary tracts and thoracolumbar Atoh1-lineage neurons project locally within the spinal cord, whereas only a few Atoh1-lineage neurons form a direct spinocerebellar tract.

Criteria Identification For Returning To Sport After Achilles Tendon Injury

Background: The Achilles tendon rupture is a pathology of growing incidence due to the increase in the intensity of amateur sports practices and the continuation of this practice with the rise in age. The rupture follows a degradation of the tendon’s structure, known as degenerative tendinopathy, which is symptomatic only in rare cases. In the absence of prior pain, iterative rupture is the complication to be feared and prevented. Unfortunately, after orthopedic or surgical treatment, there is no consensus concerning criteria for returning to sports. Such criteria would aim to prevent the risk of recurrence and the appearance of other sports injuries.Methods: A current literature review using the PubMed database in June 2021.Results: The literature doesn’t show any validated criteria for returning to sport.Conclusion: Consequently, this work seeks to propose objective criteria for validating the return to sport in connection with the physical and psychological qualities of the subject, abrogating temporal criteria, too formal and remote from the clinical view. Thus, the physiotherapist is advised to take an interest in the ankle's range of motion and the stiffness of the tendon, strength and endurance of the calf muscle, the quality of the proprioceptive and postural functions on a more functional plan, based on the quality of the jumps and then on the subject's running pattern. Finally, a psychological assessment completes the battery of tests that will validate the return to sport.

Assessment of Dysfunctional Movements and Asymmetries in Children and Adolescents Using the Functional Movement Screen-A Narrative Review.

The Functional Movement Screen (FMS) is a screening tool that identifies dysfunctional movements in seven test items requiring an interplay of cognitive, perceptual, proprioceptive, and motor functions that involve muscular strength/endurance, flexibility, mobility, coordination, and balance. The results of the FMS include an overall composite score, scores on the individual test items, and identification of compensatory movement patterns and left-right asymmetries on 5 bilateral test items. Although there is a plethora of literature on the use of the FMS in adults, there is a growing body of evidence indicating its use in children. The available research in children involves school children and young athletes in at least 20 different sports in over 20 countries and comparisons between pre- and post-pubescent children, and normal weight, overweight, and obese children. Studies that include measures of adiposity and physical activity levels, or report prevalence of asymmetries and dysfunctional movement patterns are not well represented in the children’s literature. The purpose of this paper is to synthesize the currently available literature in children and suggest potential uses of the FMS by coaches, physical educators, and other health/fitness professionals, appropriate interpretation of results, and future research in children.

Effects of balance training with stroboscopic glasses on postural control in chronic ankle instability patients.

To compare (1) the effects of balance training with and without stroboscopic glasses on postural control and (2) the effects of the training on visual reliance in patients with CAI. A randomized controlled clinical trial. Twenty-eight CAI patients were equally assigned to one of 2groups: strobe or control group. The strobe group wore stroboscopic glasses during a 4-week balance training. Static postural control, a single-leg hop balance test calculated by Dynamic Postural Stability Index (DPSI), and the Y-Balance test (YBT) were measured. During the tests, there were different visual conditions: eyes-open (EO), eyes-closed (EC), and strobe vision (SV). Romberg ratios were then calculated as SV/EO, and EC/EO and used for statistical analysis. The strobe group showed a higher pretest-posttest difference in velocity in the medial-lateral direction and vertical stability index under SV compared with the control group (p<.05). The strobe group showed higher differences in EC/EO for velocity in the medial-lateral and anterior-posterior directions, and 95% confidence ellipse area (p<.05), and in SV/EO for velocity in the medial-lateral, 95% confidence ellipse area, and YBT-anterior direction (p<.05). The 4-week balance training with stroboscopic glasses appeared to be effective in improving postural control and altering visual reliance in patients with CAI.

Evaluation in Ayres Sensory Integration® (EASI) Vestibular and Proprioceptive Tests: Construct Validity and Internal Reliability.

Vestibular and proprioceptive functions play a critical role in occupational performance and participation. Assessment of these functions in a reliable and valid manner is part of a comprehensive assessment in the Ayres Sensory Integration® frame of reference, commonly applied in pediatric occupational therapy. To report on reliability and validity of six tests of vestibular and proprioceptive functions of the Evaluation in Ayres Sensory Integration (EASI). We used Rasch analyses to examine and modify the number of items and scoring categories on the six tests and known-groups analysis to examine group differences. We evaluated internal consistency using Cronbach's α and Rasch person reliability. The sample contained typically developing children (n = 150) and children with sensory integration concerns (n = 84); all participated voluntarily. Outcomes and Measures: The EASI is used to measure sensory and motor functions in children ages 3 to 12 yr. The six tests of vestibular and proprioceptive functions were analyzed in this study. Data from >96% of items conformed to the expectations of the model. We found statistically significant group differences (ps < .001-.128; ds = 0.20-1.31), with the typically developing children group scoring significantly higher on all but one test, and moderate to strong evidence of internal consistency (Rasch person-reliability indices ≥ 0.80; strata > 3) for five of six tests. The EASI vestibular and proprioceptive tests have strong construct validity and internal reliability, indicating that they are psychometrically sound clinical measures. What This Article Adds: The development of occupational therapy assessments with strong psychometric properties, such as the EASI tests of vestibular and proprioceptive functions, enhances clinical practice and research by elucidating the factors affecting participation in accurate and dependable ways so that occupational therapy interventions can be focused and effective.

Antimalarial primaquine for spinal sensory and motor blockade in rats.

The purpose of the experiment was to estimate whether intrathecal antimalarial drugs could provoke spinal block, and their comparison with lidocaine. Rats were intrathecally administrated with antimalarial agents (primaquine, chloroquine, hydroxychloroquine and amodiaquine) and lidocaine, and neurobehavioural examinations (nociception, proprioception and motor function) were assessed; n = 8 per group. One-way and two-way analysis of variance were designed to analyse data. At a concentration of 20 mM, primaquine (0.46 mg/rat) exhibited the longest duration and the most potent effect of nociceptive, proprioceptive and motor blockade (P < 0.01) among five drugs, whereas the other antimalarial drugs displayed a lesser or similar potency of spinal blockade compared with lidocaine (0.29 mg/rat). In dose-dependent studies, primaquine was more potent (P < 0.01) than lidocaine for spinal block. At ED25, ED50 and ED75 equipotent doses, primaquine produced a greater duration of spinal motor, proprioceptive and nociceptive blockade when compared with lidocaine (P < 0.01). Primaquine, chloroquine, hydroxychloroquine and amodiaquine produced spinal blockade. Primaquine was more potent and displayed a prolonged life of local anaesthetic effect compared with lidocaine, whereas the other antimalarial drugs displayed a lesser or similar potency compared with lidocaine.

The Effect of Calcium Ions on Mechanosensation and Neuronal Activity in Proprioceptive Neurons

Proprioception of all animals is important in being able to have coordinated locomotion. Stretch activated ion channels (SACs) transduce the mechanical force into electrical signals in the proprioceptive sensory endings. The types of SACs vary among sensory neurons in animals as defined by pharmacological, physiological and molecular identification. The chordotonal organs within insects and crustaceans offer a unique ability to investigate proprioceptive function. The effects of the extracellular environment on neuronal activity, as well as the function of associated SACs are easily accessible and viable in minimal saline for ease in experimentation. The effect of extracellular [Ca2+] on membrane properties which affect voltage-sensitivity of ion channels, threshold of action potentials and SACs can be readily addressed in the chordotonal organ in crab limbs. It is of interest to understand how low extracellular [Ca2+] enhances neural activity considering the SACs in the sensory endings could possibly be Ca2+ channels and that all neural activity is blocked with Mn2+. It is suggested that axonal excitability might be affected independent from the SAC activity due to potential presence of calcium activated potassium channels (K(Ca)) and the ability of Ca2+ to block voltage gated Na+ channels in the axons. Separating the role of Ca2+ on the function of the SACs and the excitability of the axons in the nerves associated with chordotonal organs is addressed. These experiments may aid in understanding the mechanisms of neuronal hyperexcitability during hypocalcemia within mammals.

Using Smartphones for Clinical Assessment in Cervical Spondylotic Myelopathy a Feasibility Study.

Degenerative cervical myelopathy (DCM) is characterized by a progressive deterioration in spinal cord function. Its evaluation requires subjective clinical examination with wide interobserver variability. Objective quantification of spinal cord function remains imprecise, even though validated myelopathy-grading scales have emerged and are now widely used. We created a Smartphone Application, the N-Outcome App, with the aim of quantifying accurately and reliably spinal cord dysfunction using a 5-minute Test. A patient suffering from DCM was clinically evaluated before surgery, at 3 and 6 months follow-up after surgical decompression of the cervical spinal cord. Standard scores (Nurick grade, modified Japanese Orthopedic Association (mJOA) score) were documented at these time points. A 5-minute motor and proprioceptive performance test aided by a smartphone with the N-outcome App was also performed. Motor performance in rapid alternating movements and finger tapping improved in correlation with improvements in standard grading scale scores. Clinical improvements were seen in maximum reflex acceleration and in Romberg testing which showed less closed/open eyes variation, suggesting pyramidal and proprioceptive function recovery. We demonstrate that using the N-Outcome App as an adjunct to clinical evaluation of compressive myelopathy is feasible and potentially useful. The results correlate with the results of clinical assessment obtained by standard validated myelopathy scores.