Peripheral Nervous System Function Research Articles

Effects of menstrual cycle on divided attention in dual-task performance

Purpose Monthly hormonal fluctuation in women causes changes in peripheral systems and central nervous system structure and functions. In this study, we investigated the effects of menstrual cycle periods in women on attention during multitasking. Single and dual task conditions were tested in different menstrual cycle periods. Materials and methods A total of forty women with regular menstrual cycles participated in this study. They were not any type of medication or hormonal treatment. Fine motor skills and Go/No-go tasks were performed on the 10th day of the late follicular phase, and then the tests were repeated on the 20th day of the late luteal phase. Fine motor tasks were performed by Annett's peg-moving test. Auditory stimuli were used in Go/No-go task. In dual tasks, both tasks were performed simultaneously. Results There was no difference between follicular and luteal phases in single fine motor and Go/No-go task. In dual task condition Go/No-go task % error rate decreased in the luteal phase. Similarly, Go/No-go task reaction time decreased in the luteal phase. Non-dominant hand performance was increased in the luteal phase during the dual-task condition compared to the follicular phase. Conclusions When these results are evaluated together, declining error rates and reaction times indicates women successfully multitask in the luteal phase in dual tasks condition. This suggests that divided attention in women leads to better performance in the luteal phase than in the follicular phase.

Update on PET Tracer Development for Muscarinic Acetylcholine Receptors.

The muscarinic cholinergic system regulates peripheral and central nervous system functions, and, thus, their potential as a therapeutic target for several neurodegenerative diseases is undoubted. A clinically applicable positron emission tomography (PET) tracer would facilitate the monitoring of disease progression, elucidate the role of muscarinic acetylcholine receptors (mAChR) in disease development and would aid to clarify the diverse natural functions of mAChR regulation throughout the nervous system, which still are largely unresolved. Still, no mAChR PET tracer has yet found broad clinical application, which demands mAChR tracers with improved imaging properties. This paper reviews strategies of mAChR PET tracer design and summarizes the binding properties and preclinical evaluation of recent mAChR tracer candidates. Furthermore, this work identifies the current major challenges in mAChR PET tracer development and provides a perspective on future developments in this area of research.

Metal–organic frameworks for electrochemical sensors of neurotransmitters

• Development of MOF-derived electrodes for electrochemical sensors of neurotransmitters is reviewed. • MOFs act complementarily or synergistically with various materials. • Particular attention is paid to the structure-performance relationship. • The current challenges and perspectives in this area are discussed. Neurotransmitters (NTs) control many behavioral and physiological functions in central and peripheral nervous system, and their detection is of great importance to disease diagnosis and environmental monitoring. Electrochemical sensors have been popular and convenient methods for detection of NTs that are electroactive or can be coupled with electroactive reactions. Metal–organic frameworks (MOFs), constructed by organic ligands connecting metal-based nodes, are promising candidates for electrochemical sensors due to their large surface areas, hybrid structures, tailorable functional sites, and variable catalytic activity. This article gives an overview of the general aspects of MOFs for electrochemical assays of NTs and focused on the state-of-art of the sensors based on MOFs and the composites of MOFs with various materials (mainly carbon-based materials, organic polymers and metal or metal oxide nanoparticle). The use of MOF-derived materials as electrode modifiers is also included.

Clinical and neuroendocrinological characteristics of delayed orthostatic hypotension in Parkinson's disease.

Delayed orthostatic hypotension (DOH), a fall in blood pressure after a 3-min cutoff, is clinically meaningful. The aim of this study was to elucidate the clinical and neuroendocrinological characteristics of DOH in patients with Parkinson's disease (PD). A total of 132 patients with newly diagnosed PD were enrolled. Baseline clinical characteristics, including olfactory function, and changes in norepinephrine (NE) and vasopressin (ADH) concentrations during the head-up tilt test (HUT), were examined. Fifty-five patients (42%) had classical orthostatic hypotension (COH), and 19 patients (14%) had DOH. Patients with COH and DOH tended to have more severe hyposmia than patients without OH. A multivariate linear regression model showed that hyposmia was associated with DOH and COH. The increase of heart rate against the fall in blood pressure was significantly lower in patients with COH and DOH than those without OH. The NE levels at supine rest and after upright tilting were lower in the COH group than in the PD without OH and DOH groups. The levels of ADH were higher in the DOH group than in the COH group at supine rest and higher than in the PD without OH group after upright tilting. There was no significant difference in the cardiac 123I-MIBG scintigraphy between the COH and DOH groups. Compared with patients without OH, patients with DOH had severe hyposmia. Relatively preserved peripheral sympathetic nervous system function in patients with DOH suggests that DOH might be an early and milder form of OH in PD.

Peripheral Nervous System Involvement in Late-Onset Cobalamin C Disease?

Background: Cobalamin C (cblC) has a fundamental role in both central and peripheral nervous system function at any age. Neurologic manifestations may be the earliest and often the only manifestation of hereditary or acquired cblC defect. Peripheral neuropathy remains a classical but underdiagnosed complication of cblC defect, especially in late-onset cblC disease caused by mutations in the methylmalonic aciduria type C and homocysteinemia (MMACHC) gene. So the clinical, electrophysiological, and pathological characteristics of late-onset cblC disease are not well-known.Methods: A retrospective study of patients with late-onset cblC disease was conducted at our hospital on a 3-year period. The neuropathy was confirmed by the nerve conduction study. Sural biopsies were performed in 2 patients.Results: Eight patients were identified, with a mean onset age of 16.25 ± 6.07 years. All patients had methylmalonic aciduria, homocysteinemia, compound heterozygous MMACHC gene mutations were detected in all patients, and 7/8 patients with c.482G>A mutation. One patient concomitant with homozygote c.665C>T mutation in 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. All patients showed limb weakness and cognitive impairment. Five patients had possible sensorimotor axonal polyneuropathy predominantly in the distal lower limbs. Sural biopsies showed loss of myelinated and unmyelinated fibers. Electro microscopy revealed crystalline-like inclusions bodies in Schwann cells and axonal degeneration.Conclusion: Late-onset cblC disease had possible heterogeneous group of distal axonal neuropathy. c.482G>A mutation is a hot spot mutation in late-onset cblC disease.

Intracellular Alpha-Synuclein and Immune Cell Function.

Intracellular alpha-synuclein has numerous effects on different functions of the cell. Although it is expressed in a wide spectrum of cell types from different lineages, most of our knowledge about it was generated by studying neuronal or glial cells. However, the role of immune cells in Parkinson’s disease and related synucleinopathies has recently emerged. Altered immune cell phenotypes and functions have been reported not only in animal models, but also in human disease. While the response of immune cells to extracellular alpha-synuclein has been thoroughly studied, insights into the effects of endogenously expressed or taken-up alpha-synuclein on the function of immune cells remain scarce. Such insights may prove to be important for understanding the complex cellular and molecular events resulting in neurodegeneration and aid the development of novel therapies. We review the current state of knowledge about how alpha-synuclein and its pathologic manifestations affect the phenotype and function of peripheral and central nervous system (CNS) immune cells, and discuss the potential of this topic for advancing our understanding of synucleinopathies.

Pattern of postruminal administration of l-tryptophan affects blood serotonin in cattle

Serotonin (5-HT) has many important functions in both central and peripheral nervous systems. Although it has been demonstrated that manipulation of serotonin metabolism is possible in many species, there is limited information about l-tryptophan (TRP), a serotonin precursor, in cattle, and these provide conflicting results. Furthermore, there is no study evaluating how different patterns of intra-abomasal infusion of TRP impact circulating 5-HT. The objective of this study was to evaluate if intra-abomasal infusion patterns of TRP can affect circulating 5-HT and other metabolites from TRP metabolism in the plasma and serum and circulating glucose and insulin in cattle. Eight ruminally cannulated Holstein steers were used in a replicated 4 × 4 Latin square design. Each received intra-abomasal water infusion (control) or intra-abomasal TRP infusion (50 mg/kg BW) in 3 different patterns: a pulse infusion once a day (pulse once), pulse infusion twice a day (pulse twice), or continuous infusion (continuous). For continuous treatment, the TRP dose was diluted in tap water and infused by a peristaltic pump (300 mL/h). To equalize conditions, the other treatments had a water infusion (300 mL/h). The steers were fed every 2 h, and blood was collected from a jugular vein catheter every 4 h for 24 h after the initial infusion. Urine produced during the 24 h period was collected. Serum and plasma TRP, 5-HT and kynurenine, plasma glucose, and serum insulin concentrations were analyzed. Urine was analyzed for concentrations of 5-hydroxyindoleacetic acid. Both serum TRP and kynurenine were increased (P < 0.05) by all TRP infusion treatments, but concentrations in pulse dose treatments were greater than those in continuous infusion. Serum 5-HT increased (P < 0.05) with both pulse TRP infusion treatments; however, the continuous TRP infusion did not increase the serum 5-HT. Plasma 5-HT, glucose, and insulin had a tendency to increase with TRP pulse infusions. The urinary 5-hydroxyindoleacetic acid excretion was highest for pulse dose treatments. An acute supply of TRP in 1 or 2 daily doses increases serum 5-HT and increases circulating glucose and insulin in cattle. The TRP and kynurenine concentrations are similar in plasma and serum. However, the serum 5-HT concentration is more responsive to TRP administration than plasma.

Physiological Responses of Fish to Oil Spills.

Millions of tons of oil are spilled in aquatic environments every decade, and this oil has the potential to greatly impact fish populations. Here, we review available information on the physiological effects of oil and polycyclic aromatic hydrocarbons on fish. Oil toxicity affects multiple biological systems, including cardiac function, cholesterol biosynthesis, peripheral and central nervous system function, the stress response, and osmoregulatory and acid-base balance processes. We propose that cholesterol depletion may be a significant contributor to impacts on cardiac, neuronal, and synaptic function as well as reduced cortisol production and release. Furthermore, it is possible that intracellular calcium homeostasis-a part of cardiotoxic and neuronal function that is affected by oil exposure-may be related to cholesterol depletion. A detailed understanding of oil impacts and affected physiological processes is emerging, but knowledge of their combined effects on fish in natural habitats is largely lacking. We identify key areas deserving attention in future research.

A Contemporary Review of Neurological Sequelae of COVID-19

Coronavirus 2019 (COVID-19) is currently the center of what has become a public health crisis. While the virus is well-known for its trademark effects on respiratory function, neurological damage has been reported to affect a considerable proportion of severe cases. To characterize the neuro-invasive potential of this disease, a contemporary review of COVID-19 and its neurological sequelae was conducted using the limited, but growing, literature that is available. These neurological squeal are based on the manifestations that the virus has on normal central and peripheral nervous system function. The authors present the virology of the SARS-CoV-2 agent by analyzing its classification as an enveloped, positive-stranded RNA virus. A comprehensive timeline is then presented, indicating the progression of the disease as a public health threat. Furthermore, underlying chronic neurological conditions potentially lead to more adverse cases of COVID-19. SARS-CoV-2 may reach ACE2 receptors on neuronal tissue through mode of the general circulation. The CNS may also be susceptible to an immune response where a “cytokine storm” can manifest into neural injury. Histological evidence is provided, while symptoms such as headache and vertigo are highlighted as CNS manifestations of COVID-19. Treatment of these symptoms is addressed with paracetamol being recommended as a possible, but not conclusive, treatment to some CNS symptoms. The authors then discuss the peripheral nervous system sequelae and COVID's impact on causing chemosensory dysfunction starting with viral attack on olfactory sensory neurons and cells types within the lining of the nose. Histological evidence is also provided while symptoms such as anosmia and ageusia are characterized as PNS manifestations. Possible treatment options for these symptoms are then addressed as a major limitation, as anecdotal, and not conclusive evidence can be made. Finally, preventive measures of the neurological sequelae are addressed using a multidirectional approach. Postmortem examinations of the brains of COVID-19 patients are suggested as being a possible key to formulating new understandings of its neuropathology. Lastly, the authors suggest a more comprehensive neurological follow-up of recovered patients, in order to better characterize the neurological sequelae of this illness.

Neurophysiological impairments in multiple sclerosis-Central and peripheral motor pathways.

A systematic review of the literature was conducted comparing neurophysiological outcomes in persons with multiple sclerosis (PwMS) to healthy controls (HC), in studies of the central nervous system (CNS) function comprising motor evoked potentials (MEP) elicited by transcranial magnetic stimulation (TMS) and in studies of the peripheral nervous system (PNS) function comprising electroneuronography (ENG) outcomes elicited by peripheral nerve stimulation. Studies comparing neuromuscular function, assessed during maximal voluntary contraction (MVC) of muscle, were included if they reported muscle strength along with muscle activation by use of electromyography (EMG) and/or interpolated twitch technique (ITT). Studies investigating CNS function showed prolonged central motor conduction times, asymmetry of nerve conduction motor pathways, and prolonged latencies in PwMS when compared to HC. Resting motor threshold, amplitude, and cortical silent periods showed conflicting results. CNS findings generally correlated with disabilities. Studies of PNS function showed near significant prolongation in motor latency of the median nerve, reduced nerve conduction velocities in the tibial and peroneal nerves, and decreased compound muscle action potential amplitudes of the tibial nerve in PwMS. ENG findings did not correlate with clinical severity of disabilities. Studies of neuromuscular function showed lower voluntary muscle activation and increased central fatigue in PwMS, whereas EMG showed divergent muscle activation (ie, EMG amplitude) during MVC. When comparing the existing literature on neurophysiological motor examinations in PwMS and HC, consistent and substantial impairments of CNS function were seen in PwMS, whereas impairments of the PNS were less pronounced and inconsistent. In addition, impairments in muscle activation were observed in PwMS.

Wpływ kwasu α-liponowego, monofosforanu urydyny i witamin z grupy B na funkcję ośrodkowego i obwodowego układu nerwowego

Wpływ kwasu α-liponowego, monofosforanu urydyny i witamin z grupy B na funkcję ośrodkowego i obwodowego układu nerwowego

Exploring the Roles of Central and Peripheral Nervous System Function in Gait Stability: Preliminary Insights from Cancer Survivors

BackgroundImpairments in central and/or peripheral nervous systems are known to be associated with altered gait; however, the interplay between cognitive function, peripheral sensation, and orbital gait stability remains largely unclear. Elucidating these relationships is expected to provide a clearer understanding of potential fall risk factors across various populations and targets for novel interventions. Many patients diagnosed with cancer are treated with chemotherapy agents known to be neurotoxic to the central and/or peripheral nervous systems that can contribute to movement deficiencies, making this population a novel model to investigate these relationships. Research QuestionThe purpose of this exploratory study was to investigate how central and peripheral nervous system impairments associate with orbital stability during single- and dual-task gait. MethodsTwenty cancer survivors were enrolled and separated into three groups: no prior chemotherapy exposure (CON, n = 6), and prior treatment with chemotherapy and having no/mild chemotherapy-induced peripheral neuropathy (CIPN) symptoms (-CIPN, n = 8) or moderate/severe CIPN symptoms (+CIPN, n = 6). Testing included single- and dual-task (i.e., serial sevens) treadmill walking as well as a computerized test of executive function. Maximum Floquet multipliers were calculated to assess orbital stability during gait. ResultsWorse executive function was associated with decreased orbital stability during the dual-task condition in the +CIPN group (Spearman’s ρ = 0.94, P = 0.017). Additionally, decreased orbital stability during dual-task gait was observed for the -CIPN group compared to the CON group (ES = 1.96, P = 0.019). SignificanceExecutive dysfunction was associated with decreased gait stability during challenging dual-task gait in survivors with sensory symptoms of CIPN. The association between combined central and peripheral nervous system impairments and decreased gait stability in cancer survivors provides a novel demonstration of potential compensatory strategies that accompany deficiencies in these functions. Future work is needed to confirm these relationships and whether they hold in other populations.

Characteristics of patients with vitamin B12-responsive neuropathy: a case series with systematic repeated electrophysiological assessment

ABSTRACTBackground: Vitamin B12 (B12) has a fundamental role in both central and peripheral nervous system function at all ages. Neurologic manifestations may be the earliest and often the only manifestation of B12 deficiency. Mostly because of the poor sensitivity of methods of determination for B12 levels, peripheral neuropathy remains a classical but underdiagnosed complication of B12 deficiency. So the clinical and electrophysiological characteristics of B12-responsive neuropathy are not well known.Methods: A retrospective study of patients with B12-responsive neuropathy was conducted at our hospital on a 3-year period. The criteria for inclusion were: (a) neuropathy confirmed by the electrophysiological study (nerve conduction study); and (b) improvement of at least 1 point of the total Overall Neuropathy Limitations Scale score after vitamin B12 treatment.Results: Nine patients were identified. Serum B12 level was low in only four. Four patients had sensorimotor (predominantly sensory) axonal polyneuropathy while five had only sensory neuronopathy. Six improved in less than 1 month after B12 supplementation.Conclusion: B12-responsive neuropathy is a more heterogeneous group of neuropathy than previously described. B12 deficiency is a cause of peripheral neuropathy and should systematically be ruled out in the clinical setting of idiopathic neuropathy or sensory neuronopathy because of potential reversibility.Abbreviations: B12: vitamin B12; CMAP: compound muscle action potentials; DRG: dorsal root ganglia; ENMG: electroneuromyography; MCCT: motor central conduction time; MEP: motor evoked potentials; MMA: methylmalonic acid; MMCoAM: L-methylmalonyl–CoenzymeA mutase; ONLS: overall neuropathy limitations scale; SCV: sensory conduction velocities; SNAP: sensory nerve action potentials; SNN: sensory neuronopathy; SSS: SNAP sum score

Emerging Targeted Therapy for Tumors with NTRK Fusion Proteins.

The oncogenesis-promoting role of chromosomal rearrangements for several hematologic and solid malignancies is well recognized. However, identifying targetable, actionable, and druggable chromosomal rearrangements remains a challenge. Targeting gene fusions and chromosomal rearrangements is an effective strategy in treating gene rearrangement-driven tumors. The NTRK (Neurotrophic Tyrosine Receptor Kinase) gene family encodes three tropomyosin-related kinase (TRK) receptors that preserve central and peripheral nervous system development and function. NTRK genes, similar to other genes, are subject to alterations, including fusions. Preclinical studies have demonstrated that TRK fusion proteins promote oncogenesis by mediating constitutive cell proliferation and survival. Several clinical trials have estimated the safety and efficacy of TRK fusion kinase receptor inhibitors and have demonstrated encouraging antitumor activity in patients with NTRK-rearranged malignancies. Specifically, larotrectinib and entrectinib have emerged as potent, safe, and promising TRK inhibitors. Herein, we discuss the potential oncogenic characteristics of TRK fusion proteins in various malignancies and highlight ongoing clinical trials of kinase inhibitors targeting them.

The role of nervous system in adaptive response of bone to mechanical loading.

Bone tissue is remodeled through the catabolic function of the osteoclasts and the anabolic function of the osteoblasts. The process of bone homeostasis and metabolism has been identified to be co-ordinated with several local and systemic factors, of which mechanical stimulation acts as an important regulator. Very recent studies have shown a mutual effect between bone and other organs, which means bone influences the activity of other organs and is also influenced by other organs and systems of the body, especially the nervous system. With the discovery of neuropeptide (calcitonin gene-related peptide, vasoactive intestinal peptide, substance P, and neuropeptide Y) and neurotransmitter in bone and the adrenergic receptor observed in osteoclasts and osteoblasts, the function of peripheral nervous system including sympathetic and sensor nerves in bone resorption and its reaction to on osteoclasts and osteoblasts under mechanical stimulus cannot be ignored. Taken together, bone tissue is not only the mechanical transmitter, but as well the receptor of neural system under mechanical loading. This review aims to summarize the relationship among bone, nervous system, and mechanotransduction.

The Post-finasteride Syndrome: Clinical Manifestation of Drug-Induced Epigenetics Due to Endocrine Disruption

Post-finasteride syndrome (PFS) is a disorder characterized by a set of clinical symptoms experienced during use or after drug discontinuation. This cluster of symptoms encompasses overall sexual dysfunction (SD), erectile dysfunction (ED), loss of libido, depression, suicidal ideation, anxiety, panic attacks, insomnia, and cognitive dysfunction. To date, there is lack of comprehensive understanding of the biochemical and pathophysiological mechanisms responsible for the adverse effects of finasteride. More importantly, there is lack of knowledge and effective clinical tools for treatments of this condition, resulting in outright dismissal of complaints by individuals afflicted with this syndrome. Psychological symptoms and cognitive dysfunction of PFS are far more serious and difficult to treat than sexual dysfunction symptoms and may lead young men to contemplate, attempt, or even commit suicide. Therefore, an urgent need exists to fill the knowledge gap in physiology, pathophysiology, and clinical management of patients with PFS. Finasteride treatment impairs biosynthesis and function of neurosteroids, which are critical regulators of central (CNS) as well as peripheral nervous system functions and modulate a host of neurotransmitter receptors, such as gamma amino butyric acid receptors. Thus, finasteride-induced neuroendocrine disruption of biosynthesis of critical signaling molecules results in pathophysiological states, which contribute to inhibition of biochemical pathways responsible for a host of physiological functions, ranging from sexual activity, mood, and cognition. In addition, finasteride-induced epigenetic changes in gene expression, including upregulation of androgen receptors (AR), increased histone acetylation, and methylation results in undesirable biological outcomes such as impairment of dopaminergic signaling and modulation of other neurotransmitter receptors, may be the underlying mechanism causing persistent or permanent adverse effects, manifested in anxiety, depression, and suicidal ideation. The medical community has an obligation not to turn a blind eye on this rare yet debilitating condition in young men. Patients with this condition should not be stereotyped or stigmatized by untrained and unprepared clinicians, due to lack of awareness and knowledge pertaining to this new and rare syndrome. Greater awareness and education is needed among the medical and scientific communities in order to develop better approaches for managing men with PFS. It is paramount that steps are taken to develop better understanding of the underlying mechanisms contributing to the onset and progression of PFS and to promote educational and training programs to increase awareness and improve management of this condition.

Peripheral Neuropathy, Sensory Processing, and Balance in Survivors of Acute Lymphoblastic Leukemia.

Purpose To compare peripheral nervous system function and balance between adult survivors of childhood acute lymphoblastic leukemia (ALL) and matched controls and to determine associations between peripheral neuropathy (PN) and limitations in static balance, mobility, walking endurance, and quality of life (QoL) among survivors. Patients and Methods Three hundred sixty-five adult survivors of childhood ALL and 365 controls with no cancer history completed assessments of PN (modified Total Neuropathy Score [mTNS]), static balance (Sensory Organization Test [SOT]), mobility (Timed Up and Go), walking endurance (6-minute walk test), QoL (Medical Outcomes Study 36-Item Short Form Survey), and visual-motor processing speed (Wechsler Adult Intelligence Scale). Results PN, but not impairments, in performance on SOT was more common in survivors than controls (41.4% v 9.5%, respectively; P < .001). In multivariable models, higher mTNS scores were associated with longer time to complete the Timed Up and Go (β = 0.15; 95% CI, 0.06 to 0.23; P < .001), shorter distance walked in 6 minutes (β = -4.39; 95% CI, -8.63 to -0.14; P = .04), and reduced QoL (β = -1.33; 95% CI, -1.79 to -0.87; P < .001 for physical functioning; β = -1.16; 95% CI, -1.64 to -0.67; P < .001 for role physical; and β = -0.88; 95% CI, -1.34 to -0.42; P < .001 for general health). Processing speed (β = 1.69; 95% CI, 0.98 to 2.40; P < .001), but not mTNS score, was associated with anterior-posterior sway on the SOT. Conclusion PN in long-term ALL survivors is associated with movement, including mobility and walking endurance, but not with static standing balance. The association between processing speed and sway suggests that static balance impairment in ALL survivors may be influenced by problems with CNS function, including the processing of sensory information.

Analysis of peripheral nerve and autonomic nervous system function and the stage of microangiopathy in patients with secondary Raynaud's phenomenon in the course of connective tissue diseases.

The pathogenesis of secondary Raynaud's phenomenon (SRP) associated with connective tissue diseases (CTD) is not entirely understood. Nervous system dysfunction and microangiopathy are considered to be causes of this pathology. Peripheral and autonomic nervous system function, the stage of microangiopathy, and the relationships between these in patients with SRP were analyzed. In the study, 20 patients with CTD-related SRP and 30 healthy controls were subject to capillaroscopy, standard conduction velocity tests and conduction velocity distribution (CVD) tests in ulnar and peroneal nerves, heart rate variability (HRV), and sympathetic skin response (SSR) tests. There were no significant differences in the standard motor and sensory conduction velocity tests, or in CVD tests in the ulnar and peroneal nerves in SRP patients compared with the controls. The patients with SRP had a significantly lower SSR amplitude and longer latency in hands and feet. The patients with CTD-related SRP had a significantly lower mean HRV with higher low frequency (LF) values in the spectral analysis and expiration/inspiration ratio (E/I) during deep breathing. There was no correlation between the stage of microangiopathy and neurophysiological test results. Correct standard conduction velocity and CVD testing in patients with SPR suggest that vasomotor disturbances may occur in CTD regardless of peripheral neuropathy. The lack of relationship between SSR and microangiopathy could confirm that these 2 processes occur independently in patients with CTD-related SRP. Autonomic nervous system impairment together with normal peripheral nerve function suggest the central origin of CTD-related SRP.

Association of Insulin and Cholesterol Levels With Peripheral Nervous System Function in Overweight Adults: A 3-Year Follow-up.

The purpose of this prospective 3-year follow-up was to investigate the association of glucose, insulin, and cholesterol levels with peripheral nervous system function in overweight and obese subjects. Forty nondiabetic overweight and obese adults were enrolled, of whom 29 completed the follow-up. Peripheral nervous system function was measured and defined by conduction studies of the peroneal motor nerve and the radial, sural, and medial plantar sensory nerves. Serum insulin and glucose levels were determined with an oral glucose tolerance test, and cholesterol levels were measured. The measurements were performed at baseline and after 3 years. The change in serum insulin level at 120 minutes after an oral glucose tolerance test was positively associated with changes in peroneal nerve conduction velocities and F-wave mean, sural nerve conduction and medial plantar nerve conduction velocities. Action potential amplitudes decreased consistently and significantly in all sensory nerves. The change in serum insulin level at 120 minutes appears to be positively associated with changes in nerve conduction velocities more than 3 years but not with nerve action potential amplitudes. Significant decreases in the action potential amplitudes of all sensory nerves suggest that such changes might be the earliest detectable sign of damage to the peripheral nervous system in overweight and obese people without type 2 diabetes.

Diabetic and sympathetic influences on the water permeability barrier function of human skin as measured using transepidermal water loss: A case-control study.

The presence of long-standing hyperglycemic conditions has been suggested to lead to many skin problems associated with an impaired skin barrier function. However, the relationship between impaired skin barrier status and altered peripheral nervous system function has not yet been determined. The purpose of this study was to investigate the water evaporation rate as a measure of the permeability barrier function of diabetic skin and its relationship to diabetic sensorimotor polyneuropathy (DSPN) and peripheral autonomic neuropathy (PAN) using well-controlled confounding variables.This case-control study included 42 participants with chronic diabetes and 43 matched healthy controls. The diabetic group underwent a nerve conduction study and sympathetic skin response (SSR) test to confirm the presence of DSPN and PAN, respectively. Different skin regions were analyzed using the noninvasive Tewameter instrument (Courage + Khazaka Electronic GmbH, Cologne, Germany). The impacts of PAN, DSPN, age, and diabetes duration on the values of transepidermal water loss (TEWL) were each analyzed and compared between the groups.Regardless of the presence of DSPN or PAN, the TEWL values as measured on the distal extremities were significantly lower in the diabetic group than in the control group. In the diabetic group, participants with abnormal SSR test results showed decreased TEWL values in the finger, sole, and first toe, as compared with participants with normal SSR test results. In the control group, age showed a negative correlation with the TEWL values with respect to some measured regions. However, in the diabetic group, there was no significant correlation between either patient age or diabetes duration and TEWL values.The presence of a long-term hyperglycemic state can reduce the permeability barrier function of the skin, a phenomenon that might be related to the presence of an impaired peripheral sympathetic nervous system, rather than peripheral sensorimotor denervation.