Sensory Dysfunction Research Articles

Sensory Processing Measure Tools for Adolescents Aged 12 to 21 Years

Background and Objectives: Impairment in the way of sensory information by the central nervous system can cause functional problems in all areas of an adolescent’s activities, including education, self-care, social participation, and leisure. Therefore, in the presence of problems in such activities, it is necessary to evaluate and screen for sensory processing. In the present study, the sensory processing assessment tools that cover the adolescent age group were investigated. Methods: In this review, PubMed, Science Direct, Google, OTseeker, and Google Scholar databases were searched, and articles published between 2000 and 2022 on sensory processing assessment tools in adolescents and their psychometrics were selected. Keywords used included sensory integration dysfunction (SID), sensory processing disorder (SPD), adolescence, adolescent, assessment, measurement, reliability, validity, psychometry, environment, scale, and instrument. Results: The assessment tools identified to evaluate sensory processing in the adolescent age group include the “adolescent/adult sensory profile” (AASP), “Glasgow sensory questionnaire” (GSQ), “sensory processing measure (SPM)”, “sensory response in autism spectrum” (SR-AS) questionnaire, “sensory processing scale” (SPS), and “SPM-second edition” (SPM-2). Conclusion: The environment was considered as a factor that needs to be evaluated only in the second version of the SPM among the selected tools. The results of this review also showed that the only tool available in Persian in this field is the AASP, which does not seem to be a suitable tool for use in adolescence because the population studied in the psychometric evaluation of the Persian version was elderly people with dementia. Therefore, it seems necessary to prepare the Persian version and psychometric evaluation of an appropriate assessment tool for evaluating the sensory processing of Iranian adolescents.

Efficacy and safety of a third stereotactic radiosurgery for recurrent trigeminal neuralgia: an international, multicenter study.

Trigeminal Neuralgia (TN) is a debilitating facial pain disorder, often necessitating surgical interventions when medication proves insufficient. Stereotactic Radiosurgery (SRS) is an established therapeutic option. Limited studies explored the feasibility of a third SRS procedure. Our study investigates the safety and efficacy of a third SRS procedure for recurrent TN. We performed a retrospective analysis across multiple centers using databases collected prospectively. Pain status was evaluated utilizing the BNI Pain Intensity Scales. The Kaplan-Meier method was employed to estimate the time to recurrence, with group comparisons conducted using log-rank tests. Associations were explored using Chi-square and logistic regression models. Ten institutions contributed with a total of 35 patients. A third SRS revealed sustained effectiveness with a pain control rate of 82.7%. The median time to recurrence was 35.5months. New sensory dysfunction following the third procedure occurred in 22% of patients who had preserved sensory function after the second procedure. When considering those who developed sensory dysfunction after the second procedure, 40% of the entire cohort was affected. There were no significant differences in pain recurrence intervals among the three procedures. A meta-analysis, combining data from previous studies, showed that 89.6% of patients achieved some degree of pain control after a third SRS, with 27.4% experiencing new sensory dysfunction and a median time to recurrence of 31.6months. Our study, the largest on the topic, affirms the sustained effectiveness of a third SRS for TN, providing comparable pain relief to initial procedures. Notably, an extended pain-free interval after the third SRS session was observed. Facial sensory dysfunction emerged as the primary side effect. Larger studies are warranted to explore correlations with demographics and treatment parameters for a comprehensive understanding of repeat SRS in managing recurrent TN.

Sensory-Motor Neuropathy in Mfn2 T105M Knock-in Mice and Its Reversal by a Novel Piperine-Derived Mitofusin Activator.

Mitochondrial dysfunction is a hallmark of many genetic neurodegenerative diseases, but therapeutic options to reverse mitochondrial dysfunction are limited. While recent studies support the possibility of improving mitochondrial fusion/fission dynamics and motility to correct mitochondrial dysfunction and resulting neurodegeneration in Charcot-Marie-Tooth disease (CMT) and other neuropathies, the clinical utility of reported compounds and relevance of preclinical models are uncertain. Here, we describe motor and sensory neuron dysfunction characteristic of clinical CMT type 2 A in a CRISPR/Casp-engineered Mfn2 Thr105Met (T105M) mutant knock-in mouse. We further demonstrate that daily oral treatment with a novel mitofusin activator derived from the natural product piperine can reverse these neurologic phenotypes. Piperine derivative 8015 promoted mitochondrial fusion and motility in Mfn2-deficient cells in a mitofusin-dependent manner and reversed mitochondrial dysfunction in cultured fibroblasts and reprogrammed motor neurons from a human CMT2A patient carrying the MFN2 T105M mutation. Like previous mitofusin activators, 8015 exhibited stereospecific functionality, but the more active stereoisomer, 8015-P2, is unique in that it has subnanomolar potency and undergoes entero-hepatic recirculation which extends its in vivo half-life. Daily administration of 8015-P2 to Mfn2 T105M knock-in mice for 6 weeks normalized neuromuscular and sensory dysfunction and corrected histological/ultrastructural neurodegeneration and neurogenic myoatrophy. These studies describe a more clinically relevant mouse model of CMT2A and an improved mitofusin activator derived from piperine. We posit that 8015-P2 and other piperine derivatives may benefit CMT2A or other neurodegenerative conditions wherein mitochondrial dysdynamism plays a contributory role. SIGNIFICANCE STATEMENT: Mitochondrial dysfunction is widespread and broadly contributory in neurodegeneration, but difficult to target therapeutically. Here, we describe 8015-P2, a new small molecule mitofusin activator with ∼10-fold greater potency and improved in vivo pharmacokinetics versus comparators, and demonstrate its rapid reversal of sensory and motor neuron dysfunction in an Mfn2 T105M knock-in mouse model of Charcot-Marie-Tooth disease type 2 A. These findings further support the therapeutic approach of targeting mitochondrial dysdynamism in neurodegeneration.

Tractography analysis results of the trigeminus nerve, which contains fibers responsible for proprioception sensation and motor control in Adolescent Idiopathic Scoliosis.

Cross-sectional Study. It is not yet clear whether the loss of proprioceptive sensation and muscle weakness seen in adolescent idiopathic scoliosis (AIS) is the result of central nervous system dysfunction or secondary to spinal deformity. In our study, in order to find an answer to this question, we examined the microarchitecture of the nervus trigeminus, which is least affected by spinal deformity and contains both proprioceptive sensory and motor fibers. In this single-center, cross-sectional cohort study, 40 Lenke Type 3 (27 female, 13 male) AIS patients and 40 (25 female, 15 male) healthy individuals between the ages of 10-18 years. Tractography of the nervus trigenimus was performed using the "DSI Studio" program. The volumes of the targeted musculus pterygoideus lateralis and musculus pterygoideus medialis were measured using the Insight Segmentation and Registration Tool Kit (ITK -SNAP) program. The data were evaluated using the Statistical Package for the Social Sciences 22.0 program for Windows. There was no significant difference between the two groups in terms of baseline characteristics (p˃0.05). Left nervus trigeminus fiber number and fiber ratio were significantly higher in the control group compared to the scoliosis group p < 0.05. Right and left lateral pterygoid muscle showed lower volume and volume percentage in the scoliosis group compared to the control group (p < 0.05). According to the study data, proprioceptive sensory and motor control dysfunction in AIS is predicted to develop independently of spinal deformity.

Prenatal exposure to hypoxic risk conditions in autistic and neurotypical youth: Associated ventricular differences, sleep disturbance, and sensory processing.

There is a growing body of research that suggests conditions during the period of pregnancy and birth can affect how autism spectrum disorder (ASD) presents itself. This study aimed to investigate the incidence of oxygen deprivation during this period known as prenatal and perinatal hypoxic risk (HR) conditions in ASD compared with neurotypical control (NTC) youth. We also examined ventricular morphology variations associated with HR exposure, and to evaluate associations with clinical symptoms. Results from a cohort of 104 youth revealed a higher incidence of exposure to prenatal hypoxic conditions in the ASD group. Additionally, ASD individuals with prenatal hypoxic exposure (ASD + HR) demonstrated larger third ventricle volumes compared with both ASD and NTC individuals without such exposure (ASD-HR and NTC-HR, respectively). Furthermore, associations were identified between prenatal hypoxic exposure, third ventricle volume, sensory dysfunction, and severity of sleep disturbances. These findings suggest exposure to prenatal hypoxic risk conditions may exacerbate or modify the neurodevelopmental trajectory and symptom severity in ASD, emphasizing the need for better prenatal care and specific interventions to reduce these risks.

Developmental Syngap1 haploinsufficiency in medial ganglionic eminence-derived interneurons impairs auditory cortex activity, social behavior and extinction of fear memory.

Mutations in SYNGAP1, a protein enriched at glutamatergic synapses, cause intellectual disability associated with epilepsy, autism spectrum disorder and sensory dysfunctions. Several studies showed that Syngap1 regulates the time course of forebrain glutamatergic synapse maturation; however, the developmental role of Syngap1 in inhibitory GABAergic neurons is less clear. GABAergic neurons can be classified into different subtypes based on their morphology, connectivity and physiological properties. Whether Syngap1 expression specifically in Parvalbumin (PV) and Somatostatin (SST)-expressing interneurons, which are derived from the medial ganglionic eminence, plays a role in the emergence of distinct brain functions remains largely unknown. We used genetic strategies to generate Syngap1 haploinsufficiency in a) prenatal interneurons derived from the medial ganglionic eminence, b) in postnatal PV cells and c) in prenatal SST interneurons. We further performed in vivo recordings and behavioral assays to test whether and how these different genetic manipulations alter brain function and behavior in mice of either sex.Mice with prenatal-onset Syngap1 haploinsufficiency restricted to Nkx2.1-expressing neurons show abnormal cortical oscillations and increased entrainment induced by 40Hz auditory stimulation, but lack of stimulus-specific adaptation. This latter phenotype was reproduced in mice with Syngap1 haploinsufficiency restricted to PV, but not SST, interneurons. Prenatal-onset Syngap1 haploinsufficiency in Nkx2.1-expressing neurons led to impaired social behavior and inability to extinguish fear memories; however, neither postnatal PV- nor prenatal SST-specific mutant mice show these phenotypes. We speculate that Syngap1 haploinsufficiency in prenatal/perinatal PV interneurons may contribute to cortical activity and cognitive alterations associated with Syngap1 mutations.Significance statement Mutations in the human gene cause a form of developmental epileptic encephalopathy associated with intellectual disability, autism and sensory dysfunctions. Several studies have shown that in addition to playing a major role in the synaptic maturation and plasticity of forebrain excitatory neurons, Syngap1 affects GABAergic circuit function as well. Forebrain GABAergic neurons can be divided into different subtypes. Whether Syngap1 expression specifically in distinct interneuron populations and during specific developmental time windows plays a role in the emergence of distinct brain functions remains largely unknown. Here, we report that early, pre or perinatal Syngap1 expression in developing GABAergic neurons derived from the medial ganglionic eminence promotes the development of auditory cortex function, social behavior and ability to extinguish fear memories.

Electrophysiological Changes in Median Nerve among Young Male Cigarette Smokers

Background: Cigarette smoking has been associated with numerous cardiovascular and respiratory disorders. Chronic smoking may also disrupt neuronal function and damage neurons in the peripheral nervous system. Median nerve conduction study is an important electrodiagnostic test for the detection of peripheral nerve dysfunction. Objectives: To observe the impact of cigarette smoking on the electrophysiological status of median motor and sensory nerves in apparently healthy male cigarette smokers. Materials and Methods: This case-control study was carried out in the Department of Physiology, Sir Salimullah Medical College, Dhaka, from July 2017 to June 2018 on thirty male cigarette smokers aged 25 to 40 years. For comparison, thirty age and BMI matched non-smoker healthy male subjects were selected as controls. Motor and sensory nerve conduction parameters (latency, amplitude and nerve conduction velocity) of right median nerve were evaluated by standard methods, using standard nerve conduction study and electromyography machines in the Department of Neurology, Dhaka Medical College Hospital. For statistical analysis, unpaired t test was performed. Results: In this study, median sensory nerve latency was significantly prolonged (p ˂ 0.001) and sensory nerve conduction velocity was significantly slower (p ˂ 0.001) in cigarette smokers. The mean amplitude was also slightly reduced in smokers, but statistically, it was insignificant. However, the distal latency of median motor nerve was slightly prolonged whereas, the amplitude and motor nerve conduction velocity were slightly reduced in cigarette smokers in comparison to those of non-smokers. But the differences were not statistically significant. In addition, 10% of cigarette smokers had subclinical impairment in median sensory nerve function. Conclusion: Chronic cigarette smoking induces significant electrophysiological changes in median sensory nerve fibers and causes sensory nerve dysfunction, while it does not markedly affect median motor nerve fibers in young individuals. KYAMC Journal Volume: 15, No: 01, April 2024: 03-07.

Steroid response in a rare case of vertebrae butterfly with spinal cord compression caused by chronic subdural hematoma

IntroductionSpinal subdural hematoma (SSH) is a rare entity. Clinical symptoms include motor, sensory and/or autonomic dysfunction due to compression of the spinal cord. There is no standard consensus in the management of SSH. Here, we report a rare case of SSH of sudden onset following trauma, successfully treated with conservative therapy.AimThis case highlights butterfly vertebrae as an incidental imaging finding before SSH diagnosis.Case studyA 30-year-old female presented with weakness in the lower extremities after trauma, accompanied by paresthesia, urinary retention, and impaired defecating function. The thermoregulatory sweat exam revealed sudomotor dysfunction. Multiple slice computed tomography (MSCT) examination of the whole spine revealed wedge deformity of vertebral corpus (VC) L4 on the right lateral side, and VC L5 butterfly vertebrae. Spine magnetic resonance imaging (MRI) revealed an extramedullary intradural lesion at the T7 to T10 level suggestive of subdural hematoma.Results and discussionThe administration of methylprednisolone pulse therapy, combined with physical rehabilitation, led to a rapid and significant improvement in the patient's motor function. The absence of the spinal pain possibly indicated that there was no more extension of the hematoma; motor recovery, even if slight, should be a predictor of successful conservative therapy, and physical rehabilitation.ConclusionsSSH is an uncommon condition, with varying clinical presentation, and progression. This case report highlights significant improvement following conservative steroid treatment of a SSH. It also highlights a unique incidental finding of butterfly vertebra in a patient with paraparesis following trauma.

Using biothesiometer, Neuropathy Symptom Score, and Neuropathy Disability Score for the early detection of peripheral neuropathy: A cross-sectional study.

Patients with peripheral neuropathy could have damaged peripheral nerves, which leads to sensory and motor dysfunction. Diabetes, infections, and trauma are the major causes of peripheral neuropathy. Vibratory perception threshold (VPT) tools are commonly used to detect peripheral neuropathy. This study aims to determine the assessment of peripheral neuropathy through the different diagnostic tools in the community in Malaysia. A total number of 1283 participants were recruited from the seven retail pharmacies located in Selangor, Malaysia. The peripheral neuropathy test was conducted based on VPT tools on both feet using the digital biothesiometer. Following that, Neurological Symptom Score (NSS) and Neurological Disability Score (NDS) were taken from the participants to assess the neurological symptoms. Participants had an average age of 40.6 ± 12.9 years and were mostly of Chinese ethnicity (54.1%). The findings show that increasing age was associated with more severe peripheral neuropathy across the various assessment tools, but gender differences were found with the biothesiometer test and ethnicity has severity in the biothesiometer and disability scores. The sensitivity and specificity of the biothesiometer test were 0.63 and 0.84, respectively. The combined tool NSS and NDS had high specificity and a high positive predictive value, suggesting that it could be a reliable indicator of peripheral neuropathy when both scores are elevated. The findings show that the biothesiometer test, NSS, and NDS are considered screening VPT tools for diagnosing peripheral neuropathy. However, further evaluation and diagnostic testing are necessary in cases of a positive test result.

Recent onset mental illness severity: pilot study on the role of cognition, sensory modulation, and daily life participation.

Early detection of individuals at risk for onset of severe illness is crucial for prevention and early intervention, aiming to mitigate the long-term impact on both the individual and the community. While well-established models exist for predicting the onset and prolonged severity of illness, there is a gap in understanding illness-onset severity. This pilot study aimed to investigate premorbid objective and subjective dimensions of participation in daily life occupations, as well as sensory and cognitive functions as potential markers of the recent-onset mental illness severity. A total of 50 participants (men: N=26, 52%; women: N=24, 48%), aged 18-40 (M=26.2, SD=5.8) with recent-onset mental illness completed standard, well-established assessments of illness severity, cognitive biases and failures, neurocognitive status, participation in daily life, and sensory responsiveness thorough cross-sectional design. The differences between the groups of the illness severity were explored with descriptive statistics, followed by a Kruskal-Wallis test. Discriminant analysis was used suggesting a multi-varied model for the separation between the groups of illness severity. Three groups of illness severity exhibited differences in premorbid cognitive functions (F(2)=5.8, p<.01) and participation diversity (F(2)=3.8, p<.05). Combining these two indices explained 92% of the variance between the groups (Wilks' Λ = .68, χ2(4) = 17.7, p=.001), accurately classifying mild to marked illness severity (62.5-88.5%). The study contributes to revealing factors involved in the formation of more severe mental illness and suggesting possible avenues for early intervention and prevention. Cognitive biases and sensory modulation dysfunction may contribute to the illness formation. Still, the most effective markers of more severe mental illness onset are functional cognition and limited participation diversity. Since addressing these markers is a unique specialization within occupational therapy, the findings highlight the potential contribution theprofession can make to the early identification of the most vulnerable populations.

SENSE-Cog Lewy: Investigating the Impact of Sensory Loss on the Diagnosis, Clinical Features and Prognosis of Lewy Body Dementia

Abstract Background Lewy Body Dementia (LBD) accounts for 20% of the nearly 65,000 people with dementia in Ireland, but fewer than 5% of those affected receive a formal diagnosis. LBD includes both Parkinson’s disease dementia (PDD) and dementia with Lewy bodies (DLB) and can be characterised by fluctuating and progressive cognitive difficulties, vivid visual hallucinations and REM sleep behaviour disturbances. Sensory function such hearing, vision and olfactory function declines with age—but increasing evidence shows that abnormal patterns of sensory dysfunction can be one of the earliest clinical signs and predictors of progression of neurodegenerative diseases such as Lewy body dementia and Parkinson’s disease dementia. Methods A scoping review was undertaken using Embase, CINAHL, PsychINFO and PubMed. Only reports on people with LBD (DLB and PDD) from any stage, prodromal to late stage were considered. Papers primarily addressing other forms of neurocognitive disorders were excluded. Sensory loss was conceptualised as the loss of smell, vision and hearing. Two reviewers independently assessed each study for inclusion, and disagreements were resolved by a third reviewer. Results Reports on sensory loss in LBD were very few and most often were comparing sensory loss across different dementia types. Strong associations were observed between olfactory loss and particular visual impairment patterns and the severity of both cognitive and non-cognitive DLB symptoms. Olfactory impairment is a potential early biomarker of DLB and PDD and severity of olfactory dysfunction can predict cognitive decline. Visual hallucinations, for example, were found to be closely linked to visual impairment patterns such as pareidolia. Conclusion This study highlights a knowledge gap regarding the patterns of sensory loss in LBD and their relationship with cognitive and non-cognitive LBD symptoms. Sensory assessments represent potentially valuable diagnostic and prognosis tool in LBD, with further research required to understand the aetiological mechanisms underlying sensory impairment in LBD and other dementias.

Selective Vulnerability of GABAergic Inhibitory Interneurons to Bilirubin Neurotoxicity in the Neonatal Brain.

Hyperbilirubinemia (HB) is a key risk factor for hearing loss in neonates, particularly premature infants. Here we report that bilirubin (BIL)-dependent cell death in auditory brainstem of neonatal mice of both sexes is significantly attenuated by ZD7288, a blocker for hyperpolarization-activated cyclic nucleotide-gated (HCN) channel mediated current (Ih), or by genetic deletion of HCN1. GABAergic inhibitory interneurons predominantly express HCN1, on which BIL selectively acts to increase their intrinsic excitability and mortality by enhancing HCN1 activity and Ca2+-dependent membrane targeting. Chronic BIL elevation in neonatal mice in vivo increases the fraction of spontaneously active interneurons and their firing frequency, Ih and death, compromising audition at young adult stage in HCN1+/+, but not in HCN1-/- genotype. We conclude that HB preferentially targets HCN1 to injure inhibitory interneurons, fueling a feedforward loop in which lessening inhibition cascades hyperexcitability, Ca2+ overload, neuronal death and auditory impairments. These findings rationalize HCN1 as a potential target for managing HB encephalopathy.Significance Statement This study demonstrated that bilirubin preferentially targets GABAergic interneurons where it facilitates not only gating of HCN1 channels but also targeting of intracellular HCN1 to plasma membrane in calcium-dependent manner, resulting in neuronal hyperexcitability, injury and sensory dysfunction. These findings implicate HCN1 channel not only as a potential driver for auditory abnormalities in neonatal patients with bilirubin encephalopathy, but also potential intervention target for clinical management of neurological impairments associated with severe jaundice. Selective vulnerability of interneurons to neurotoxicity may be of general significance for understanding other forms of brain injury.

Temporal Pattern of Individual Neurological Function Recovery in Guillain-Barré Syndrome.

Background: There is paucity of studies on the temporal pattern of recovery of facial, bulbar, sensory, motor, and autonomic dysfunction in Guillain-Barré syndrome (GBS), although many studies have reported short- and long-term functional outcomes. We report the temporal pattern of recovery of various neurological functions in GBS, and compare the pattern of recovery between acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Methods: Forty-two patients with GBS were prospectively included, and their clinical details, including peak disability on a 0-6 scale, were noted. The day of complete recovery in motor, sensory, facial, bulbar, and autonomic functions during 3 months of follow-up was recorded. Results: Complete recovery of autonomic function occurred in all (median, 12 days), bulbar weakness in 91.3% (median, 15 days), facial weakness in 86.2% (median, 19 days), and sensory functions in 82.1% (median, 20 days). Only 9.5% of patients achieved normal motor function within 3 months. The days of complete recovery of bulbar, facial, autonomic, and motor deficits were comparable between AIDP and AMAN. Demyelinating GBS had an earlier recovery of bulbar and sensory functions. Conclusions: The neurological recovery in GBS occurs first in the autonomic, followed by the bulbar, facial, sensory, and motor functions. The demyelinating type had an earlier recovery of bulbar and sensory functions.

Modern Approaches to Diagnosing Cognitive Impairments in Patients with Multiple Sclerosis

Multiple sclerosis in patients can cause not only motor, sensory, cerebellar and autonomic dysfunctions, but also cognitive and psychoemotional disorders such as difficulty with learning and recalling information, problems focusing on tasks and maintaining attention, slowed ability to process information, depression, anxiety. Cognitive impairment can appear at any stage of the disease and can be observed in more than half of patients. &amp;nbsp;Patients with multiple sclerosis may not fully recognize or underestimate their complaints of psycho-emotional disturbances, fatigue or pain. &amp;nbsp;For this reason, doctors should rely on the results of neuropsychological tests. Like all symptoms of multiple sclerosis, cognitive impairment is highly variable and significantly affects patients' work habits, social interactions and quality of life. Therefore, the assessment of cognitive functions in patients with multiple sclerosis is of undoubted interest.

The reduction of imidazole propionate induced by intermittent fasting promotes recovery of peripheral nerve injury by enhancing migration of Schwann cells

Peripheral nerve injury (PNI) accompanied with sensory and motor dysfunction has serious effect on the quality of life of patients. Intermittent fasting (IF), as a dietary pattern, has rarely been reported to influence imidazole propionate (ImP), a microbial metabolite, in vivo. To date, the link between ImP and PNI is unknown. This study aimed to explore the impact of ImP on the recovery after PNI and determine whether IF could reduce the concentration of ImP in vivo. Sciatic nerve injury rat model and RSC96 cells were utilized with 16s RNA seq, HE staining, CCK-8 assay, Western blot (WB), Transmission electron microscopy (TEM), immunofluorescence, transwell and scratch wound healing assays as read outs. WB, TEM, transwell and wound healing assay showed an inhibitory effect of ImP on autophagy and migration of Schwann cells. This negative effect on migration was reversed by rapamycin. Detection of p-Erk and p-mTOR confirmed that the MAPK/Erk/mTOR pathway was involved in this process. In vivo, IF changed the composition of gut microbiome, including bacteria related to ImP production and reduced the concentration of ImP in serum. In sum, IF influenced the composition of gut microbiome and reduced the concentration of ImP in vivo. The reduction of ImP promoted migration of SCs through enhancing autophagy which involved MAPK/Erk/mTOR pathway.

CCL5 is essential for axonogenesis and neuronal restoration after brain injury

BackgroundTraumatic brain injury (TBI) causes axon tearing and synapse degradation, resulting in multiple neurological dysfunctions and exacerbation of early neurodegeneration; the repair of axonal and synaptic structures is critical for restoring neuronal function. C-C Motif Chemokine Ligand 5 (CCL5) shows many neuroprotective activities.MethodA close-head weight-drop system was used to induce mild brain trauma in C57BL/6 (wild-type, WT) and CCL5 knockout (CCL5-KO) mice. The mNSS score, rotarod, beam walking, and sticker removal tests were used to assay neurological function after mTBI in different groups of mice. The restoration of motor and sensory functions was impaired in CCL5-KO mice after one month of injury, with swelling of axons and synapses from Golgi staining and reduced synaptic proteins-synaptophysin and PSD95. Administration of recombinant CCL5 (Pre-treatment: 300 pg/g once before injury; or post-treatment: 30 pg/g every 2 days, since 3 days after injury for 1 month) through intranasal delivery into mouse brain improved the motor and sensory neurological dysfunctions in CCL5-KO TBI mice.ResultsProteomic analysis using LC-MS/MS identified that the “Nervous system development and function”-related proteins, including axonogenesis, synaptogenesis, and myelination signaling pathways, were reduced in injured cortex of CCL5-KO mice; both pre-treatment and post-treatment with CCL5 augmented those pathways. Immunostaining and western blot analysis confirmed axonogenesis and synaptogenesis related Semaphorin, Ephrin, p70S6/mTOR signaling, and myelination-related Neuregulin/ErbB and FGF/FAK signaling pathways were up-regulated in the cortical tissue by CCL5 after brain injury. We also noticed cortex redevelopment after long-term administration of CCL5 after brain injury with increased Reelin positive Cajal-Rerzius Cells and CXCR4 expression. CCL5 enhanced the growth of cone filopodia in a primary neuron culture system; blocking CCL5’s receptor CCR5 by Maraviroc reduced the intensity of filopodia in growth cone and also CCL5 mediated mTOR and Rho signalling activation. Inhibiting mTOR and Rho signaling abolished CCL5 induced growth cone formation.ConclusionsCCL5 plays a critical role in starting the intrinsic neuronal regeneration system following TBI, which includes growth cone formation, axonogenesis and synaptogensis, remyelination, and the subsequent proper wiring of cortical circuits. Our study underscores the potential of CCL5 as a robust therapeutic stratagem in treating axonal injury and degeneration during the chronic phase after mild brain injury.Graphical

Microenvironments‐Modulated Biomaterials Enhance Spinal Cord Injury Therapy

AbstractSpinal cord injury (SCI) results from various causes, including sports‐related incidents, degenerative cervical myelopathy, traffic accidents, and falls. SCI typically leads to sensory and motor dysfunction and even paralysis. Current treatments for SCI include systemic administration of high‐dose steroids and surgical decompression and stabilization. However, excessive use of glucocorticoids may increase susceptibility to infections and systemic bleeding. The long‐term effect of surgery intervention remains unclear, with ongoing debates regarding its timing, efficacy, and safety. Therefore, innovative approaches are urgently needed to alleviate secondary injuries and promote spinal recovery. One emerging therapeutic approach for SCI is modulating the microenvironments to achieve neuroprotection and neurogenesis during recovery. Several biomaterials with favorable physicochemical properties have been developed to enhance therapeutic effects by regulating microenvironments. This Review first discusses the pathology of SCI microenvironments and then introduces biomaterials‐based regulatory strategies targeting various microenvironmental components, including anti‐inflammation, anti‐oxidation, reduction of excitotoxicity, revascularization, neurogenesis, and scar density reduction. Additionally, the research and clinical application prospects for microenvironment regulation are presented.

Sensory Dysfunction, Microbial Infections, and Host Responses in Alzheimer's Disease.

Sensory functions of organs of the head and neck allow humans to interact with the environment and establish social bonds. With aging, smell, taste, vision, and hearing decline. Evidence suggests that accelerated impairment in sensory abilities can reflect a shift from healthy to pathological aging, including the development of Alzheimer's disease (AD) and other neurological disorders. While the drivers of early sensory alteration in AD are not elucidated, insults such as trauma and infections can affect sensory function. Herein, we review the involvement of the major head and neck sensory systems in AD, with emphasis on microbes exploiting sensory pathways to enter the brain (the "gateway" hypothesis) and the potential feedback loop by which sensory function may be impacted by central nervous system infection. We emphasize detection of sensory changes as first-line surveillance in senior adults to identify and remove potential insults, like microbial infections, that could precipitate brain pathology.

Time varying characteristic in somatosensory evoked potentials as a biomarker of spinal cord ischemic-reperfusion injury in rat.

Spinal cord ischemic-reperfusion injury (SCIRI) could occurs during surgical procedures without detection, presenting a complex course and an unfavorable prognosis. This may lead to postoperative sensory or motor dysfunction in areas innervated by the spinal cord, and in some cases, permanent paralysis. Timely detection of SCIRI and immediate waring can help surgeons implement remedial intervention to prevent irreversible spinal cord injury. Therefore, it is crucial to develop a precise and effective method for early detection of SCIRI. This study utilized rat models to simulate intraoperative SCIRI and employed somatosensory evoked potentials (SEP) for continuous monitoring during surgery. In this study, SEP signal changes were examined in six groups with varying severities of SCIRI and one normal control group. SEP signal changes were examined during operations in different groups and correlated with postoperative behavioral and histopathological data. The result demonstrated specific changes in SEP signals during SCIRI, termed as time-varying characteristics, which are associated with the duration of ischemia and subsequent reperfusion. Time-varying characteristics in SEP could potentially serve as a new biomarker for the intraoperative detection of SCIRI. This finding is significant for clinical surgeons to identify and guide early intervention of SCIRI timely. Additionally, this measurement is easily translatable to clinical application.

Sensory dysfunction in SMA type 2 and 3 - adaptive mechanism or concomitant target of damage?

BackgroundThe motor neuron survival protein performs numerous cellular functions; hence, spinal muscular atrophy (SMA) is considered to be a multi-organ disease with possible sensory system damage. The controversy surrounding the presence of sensory disturbances, prompted us to conduct standard electrophysiological studies and assess the sensory thresholds for different modalities in adults with SMA types 2 and 3. The study group consisted of 44 adult SMA patients (types 2 and 3). All patients underwent neurological examination using the Hammersmith Functional Motor Scale – Expanded (HFMSE). Standard sensory electrophysiological studies in the ulnar nerve and the estimation of vibratory, temperature, and warm- and cold-induced pain thresholds with temperature dispersion assessment were performed using quantitative sensory testing (QST).ResultsThe most repeatable result was the high amplitude of the sensory nerve action potentials (SNAP) in SMA patients compared to controls. This was higher in type 2 patients compared to type 3a and 3b patients and patients with low HFSME scores. Patients with SMA, especially type 3b presented a longer sensory latency and slower conduction velocity than did controls. Cold pain threshold was higher and warm dispersion larger in SMA. The vibratory limit was higher in patients with high HFSME scores.ConclusionsA high SNAP amplitude suggests sensory fibre hyperactivity, which may be based on overactivation of metabolic pathways as an adaptive mechanism in response to SMN protein deficiency with additionally coexisting small C- and A-delta fibre damage. SMA patients seem to have a concomitant, mild demyelinating process present at the early SMA stage.