Somatosensory Impairment Research Articles

F75. Hybrid-Assistive-Neuromuscular-Dynamic-Stimulation (HANDS) therapy induces cortical sensory plasticity in patients with chronic stroke

Introduction The hybrid assistive neuromuscular dynamic-stimulation (HANDS) therapy is closed-loop electromyography-controlled neuromuscular electrical stimulation (NMES) with a wrist-hand splint for patients with moderate to severe hemiparesis even including chronic stroke. It is repeatedly reported HANDS therapy induce significant recovery in upper extremity motor function for relatively severe paresis with a minimal ability for volitional muscle activation, who do not meet the criteria for other intensive therapies such as constrained-induced movement therapy. Although almost the half of stroke survivors are suffering from somatosensory impairment, and it is indicated that the sensory recovery would have a certain beneficial impact on motor functional recovery, neither the detailed mechanisms of somatosensory recovery nor the interaction with motor recovery are not determined enough especially for chronic stroke. On these ground, we have investigated the effect of HANDS therapy on the feature of sensory recovery. Methods For 23 chronic stroke patients with hemiplegia, 3 weeks inpatient HANDS therapy intervention was taken place. Median and Tibial nerve Sensory Evoked Potential (SEP) and behavioral sensory assessments including Semmes-Weinstein monofilament test and thumb-localizing test were performed at pre and posttreatment, as well as the motor functional assessments. Results A significant increase in the number of SEP peaks in the Median nerve and a significant reduction in the latency gap between N20 and P45 were observed in the paretic side after the intervention, whereas no significant difference was observed in any of these behavioral assessments. Although motor functional recovery was observed as in the previous studies, there was no significant correlation detected between motor function and each sensory related indices including SEP peak number and behavioral assessments. Conclusion Our result firstly suggests that closed-loop electromyography-controlled NMES training induce a sort of plastic changes especially in the level of cortex even in the chronic stroke patients. SEP would be a good evaluation modality which has higher sensitivity to detect a smaller plastic change induced by rehabilitative intervention.

Does sensorimotor upper limb therapy post stroke alter behavior and brain connectivity differently compared to motor therapy? Protocol of a phase II randomized controlled trial

BackgroundThe role of somatosensory feedback in motor performance has been warranted in the literature. Although sensorimotor deficits are common after stroke, current rehabilitation approaches primarily focus on restoring upper limb motor ability. Evidence for integrative sensorimotor rehabilitation approaches is scarce, as is knowledge about neural correlates of somatosensory impairments after stroke and the effect of rehabilitation on brain connectivity level. Therefore, we aim to investigate changes in sensorimotor function and brain connectivity following a sensorimotor therapy program compared to an attention-matched motor therapy program for the upper limb after stroke.MethodsAn assessor-blinded randomized controlled trial will be conducted. Sixty inpatient rehabilitation patients up to eight weeks after stroke will be included. Patients will be randomized to either an experimental group receiving sensorimotor therapy or a control group receiving attention-matched motor therapy for the upper limb, with both groups receiving conventional therapy. Thus, all patients will receive extra therapy, a total of 16 1-h sessions over four weeks. Patients will be assessed at baseline, after four weeks of training, and after four weeks of follow-up. Primary outcome measure is the Action Research Arm Test. Secondary outcome measures will consist of somatosensory, motor and cognitive assessments, and a standardized resting-state functional magnetic resonance imaging protocol.DiscussionThe integration of sensory and motor rehabilitation into one therapy model might provide the added value of this therapy to improve sensorimotor performance post stroke. Insight in the behavioral and brain connectivity changes post therapy will lead to a better understanding of working mechanisms of therapy and will provide new knowledge for patient-tailored therapy approaches.Trial registrationClinicalTrials.gov, NCT03236376. Registered on 8 August 2017.

Validation of French upper limb Erasmus modified Nottingham Sensory Assessment in stroke.

Somatosensory impairment of the upper limb (UL) occurs in approximately 50% of adults post-stroke, associated with loss of hand motor function, activity and participation. Measurement of UL sensory impairment is a component of rehabilitation contributing to the selection of sensorimotor techniques optimizing recovery and providing a prognostic estimate of UL function. To date, no standardized official French version of a measure of somatosensory impairment has been established. To develop and validate a French version of the Erasmus modified Nottingham Sensory Assessment somatosensory (EmNSA-SS) and stereognosis (EmNSA-ST) component for evaluating the UL among adults with stroke. This study is a single-center observational cross-sectional study. A French version of the EmNSA for UL was developed by forward-backward translation and cross-cultural adaptation. Fifty stroke patients were recruited to establish concurrent-criterion-related validity, internal consistency, intra- and inter-rater reproducibility with intracorrelation coefficients (ICCs) for reliability and the minimal detectable change with 95% confidence interval (MDC95) for agreement, as well as ceiling and floor effects. Criterion validity was assessed against the Fugl-Meyer Assessment-Sensory (FMA-S) for the UL. The median (range) EmNSA-SS score was 41.5 (1-44). The Spearman rank correlation coefficient between EmNSA-SS and FMA-S total scores was moderate (rho=0.74, P<0.001). The EmNSA-SS/ST internal consistency was adequate across subscales; with Cronbach α ranging from 0.82-0.96. For the EmNSA-SS total score, intra- and inter-rater reliability was excellent (ICC=0.92 in both cases), with MDC95 of 12.3 and 14.6, respectively. EmNSA-SS/ST total scores demonstrated no ceiling or floor effects. The French EmNSA is a valid and reproducible scale that can be used for comprehensive and accurate assessment of somatosensory modalities in adults post-stroke. Taking less than 30min to administer, the instrument has clinical utility for use in patients with cognitive comorbidities and at various stages of recovery in multidisciplinary clinical practice and research settings.

Effects of Somatosensory Impairment on Participation After Stroke.

Our objective was to determine the effect of loss of body sensation on activity participation in stroke survivors. Participants (N = 268) were assessed at hospital admission for somatosensory and motor impairment using the National Institutes of Health Stroke Scale. Participation was assessed using the Activity Card Sort (ACS) in the postacute phase. Between-group differences in activity participation were analyzed for participants with and without somatosensory impairment and with or without paresis. Somatosensory impairment was experienced in 33.6% of the sample and paresis in 42.9%. ACS profiles were obtained at a median of 222 days poststroke. Somatosensory loss alone (z = 1.96, p = .048) and paresis in upper and lower limbs without sensory loss (z = 4.62, p < .001) influenced activity participation. Somatosensory impairment is associated with reduced activity participation; however, paresis of upper and lower limbs can mask the contribution of sensory loss.

Relationship Between Motor Paralysis and Impairments in Tactile Sensitivity in Elderly Stroke Patients

Summary Background Human hand functions are affected by neurological disturbances. We hypothesized that the degree of somatosensory impairments after stroke may be related to the severity of motor paralysis. In order to examine this hypothesis, we investigated the relationship between the classification of the Brunnstrom stage and tactile sensation impairments in elderly stroke patients. Methods Participants were 61 elderly inpatients with hemiparesis after stroke. We measured the tactile-pressure threshold and handgrip strength in both hands and assessed motor impairments of the hand using the six Brunnstrom stages. Differences due to hemiparesis after stroke were examined using paired t-tests. Spearman's rank correlation was performed to elucidate the relationship between Brunnstrom stage scores and the tactile-pressure threshold or handgrip strength. Results Significant differences were observed in the tactile-pressure threshold and handgrip strength between the impaired and unimpaired sides (p Conclusion These results suggest that the degree of sensory impairments after stroke is related to the severity of motor paralysis classified by the Brunnstrom stage.

Perceived and Functional Balance Control Is Negatively Affected by Diminished Touch and Vibration Sensitivity in Relatively Healthy Older Adults and Elderly.

Background: Severe diminished foot somatosensation, for example, caused by neuropathies and advanced aging, contributes to balance deficits and increased fall risk. However, little is known about somatosensory impairment and functional and subjective balance problems in relatively healthy elderly. Method: Vibration perception thresholds (VPTs) were assessed with a biothesiometer and tactile pressure sensation thresholds (TPSTs) with 20 monofilaments in 34 relatively healthy community-dwelling older adults (M = 69.4 years). Balance was evaluated with functional balance tests and questionnaires. A stepwise regression analysis was performed to determine the extent to which VPTs, TPSTs, and age could explain balance impairments. Results: High VPTs had negative effects on Berg Balance Scale and Dizziness Handicap Inventory scores (p ≤ .011), as did high TPSTs on walking speed and Figure-8 test (p ≤ .001). With visual information available, one-leg standing time (OLST) was significantly affected by ipsilateral VPTs on solid and TPSTs on compliant surface (p ≤ .002). Without visual information, age was the only factor with a main effect on OLST (p < .001). Age had no significant correlations with TPSTs or VPTs. Discussion: Somatosensation appears to be very important for perceived as well as functional balance control in older adults. Our findings have important clinical implications when assessing balance impairment and impending fall risk.

What is the current practice of therapists in the measurement of somatosensation in children with cerebral palsy and other neurological disorders?

Somatosensation is the ability to detect and recognise body sensations such as touch, vibration, pressure, pain, temperature and proprioception. Cerebral palsy is a neurological disorder that is often accompanied by impairments in somatosensation. Current somatosensory assessments have limited psychometrics established for use with these children. The aim of this study was to identify therapists' current practice and perspectives related to the assessment of somatosensation in children with neurological disorders. A cross-sectional questionnaire was used to identify the somatosensory assessments currently used in clinical practice, time allocated to assessment, and therapists' satisfaction and confidence using the available assessments of somatosensation. The questionnaire was adapted from a previously utilised questionnaire that identified therapists' use of somatosensory assessments with adults post-stroke. A total of 135 therapists responded to the questionnaire. Seventy-nine (92%) occupational therapists and 44 (89.7%) physiotherapists indicated that they currently assessed or treated children with somatosensory deficits. Sixty-four (82.1%) occupational therapists and 38 (86.3%) physiotherapists regarded assessment of somatosensation in children with neurological disorders as important to very important. However, only seven (8.8%) occupational therapists and seven (15.9%) physiotherapists reported confidence in their ability to do so. The methods with which therapists detect and measure somatosensory impairment in children with neurological disorders are variable, with non-standardised and/or informal assessments most frequently used. Despite there being recommendations of best practice for the assessment of specific domains of somatosensation in children with cerebral palsy, current practice does not yet mirror these recommendations. Additionally, therapists have low satisfaction and confidence with what they are currently using, highlighting the need for a comprehensive and standardised assessment of somatosensation for use in children with neurological disorders.

Brain Hypometabolism in Cerebellar Ataxia, Neuropathy, Vestibular Areflexia Syndrome

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a slowing progressive ataxic disorder characterized by bilateral vestibulopathy, cerebellar ataxia and somatosensory impairment. Autonomic dysfunction is recently considered as a core feature in CANVAS in addition to these symptoms. In most cases, patients with CANVAS show cerebellar atrophy in brain imaging, but some cases show minimal or no atrophy of cerebellum. Brain (18F)-fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) study can be a complimentary tool to diagnosis CANVAS in cases of no structural abnormality such as cerebellar atrophy. Hereby, we present a case of CANVAS with minimal atrophy of cerebellum but showing a prominent hypometabolism in cerebellum, thalamus and posterior cingulate cortex in 18F-FDG PET. Keywords: Bilateral vestibulopathy; Cerebellar ataxia; Primary dysautonomias; Positron-emission tomography 중심 단어: CANVAS, ìžìœ¨ì‹ ê²½ë¶€ì „, FDG-PET

Somatosensory function is impaired in patients with idiopathic REM sleep behaviour disorder

BackgroundIdiopathic REM sleep behaviour disorder (iRBD) has been recognised as a significant biomarker for developing a neurodegenerative alpha-synucleinopathy, which is why iRBD is considered to be a prodromal state for alpha-synucleinopathies including Parkinson's disease (PD). Many patients with PD suffer from complaints of pain and present impaired somatosensory function. We hypothesized that pain perception and somatosensory function could be altered already in a preclinical stage of PD including iRBD. Hence, the objective of this study was to investigate pain perception and somatosensory function in patients with iRBD. MethodsQuantitative sensory testing (QST), laser evoked potentials (LEPs), and conditioned pain modulation (CPM) testing were performed in 13 iRBD patients without any clinical signs of PD or narcolepsy (11 males, 2 females, mean age 65.2 years) and 15 gender- and age-matched healthy control subjects (12 males, 3 females, mean age 65.8 years). ResultsThermal detection thresholds were higher in the iRBD group compared with the control group (cold detection threshold (CDT) p = 0.020, thermal sensory limen (TSL) p = 0.001), indicating an impaired temperature sensation in iRBD patients. The N2/P2 LEPs amplitude was smaller in iRBD patients than controls, but not statistically significant (p = 0.053). ConclusionsThis study found an impaired somatosensory function in iRBD patients, suggesting that somatosensory impairment might be an early feature in the neurodegenerative process of PD.

Human neurophysiology to diagnose, prevent and treat pain

Neurophysiological techniques are useful to diagnose, predict and treat chronic pain, in particular of neuropathic origin. In this talk we shall succinctly review these different approaches, as well as the possibility they open to «back translation» of results gathered in humans to animal models. Definite diagnosis of neuropathic pain (NP) needs confirmation of a lesion or a disease of somatosensory systems, and neurophysiology is crucial to obtain such information. Lesions responsible for NP relate essentially to small fibres A-delta and C in the periphery, and the spino-thalamo-cortical system of pain/temperature at central levels. Among the methods to record responses in pain/temperature pathways, evoked potentials to laser (LEPs) or contact thermodes (CHEPs) are simple and reliable. Their diagnostic efficacy increases when they are coupled to vegetative reactions (SSR), psychophysical measures (reaction times, quantitative sensory tests), and concomitant exploration of non-nociceptive systems (large fibres, dorsal columns). The diagnostic workout should ideally respond to: (a) is there objective somatosensory impairment in painful regions? (b) which is the respective alteration of different sub-systems? (c) are the results concordant with imaging? and (d) how do results aid to patient management? Identification/prevention of neural lesions during surgery can minimise the development of postoperative pain. Joint analysis of nociceptive cortical responses and MRI allowed to classify ∼90% of patients with central pain post-thalamic stroke, and time-frequency LEP analysis may distinguish patients with and without pain following brainstem lesions. All these elements suggest that early neurophysiological studies of patients at risk may help to detect those with highest probability of developing NP, and hence open the way to anticipatory therapy. Recording of sympathetic skin or pupillary responses allows assessing the vegetative arousal provoked by a painful stimulus, indicating that the stimulus was actually perceived. Association and dissociation between vegetative and cortical responses are especially useful in the objective evaluation of allodynic phenomena and clinically dubious perception anomalies. Current trends aim at developing neurophysiological indexes of nociception in non-communicating patients (coma, general anaesthesia). Non-invasive cortical stimulation using magnetic repetitive impulses (rTMS) or scalp-applied currents (tDCS, tACS) are used not only to predict efficacy of subsequent neurosurgical stimulation, but also, increasingly, as stand-alone methods of pain relief. Recent developments allow certain of these techniques to be applied by the patients themselves at home, via internet-based interfacing and control from the hospital.

Somatosensory impairment and its association with balance limitation in people with multiple sclerosis

BackgroundSomatosensory impairments are common in multiple sclerosis. However, little data are available to characterize the nature and frequency of these problems in people with multiple sclerosis. ObjectiveTo investigate the frequency of somatosensory impairments and identify any association with balance limitations in people with multiple sclerosis. MethodsThe design was a prospective cross-sectional study, involving 82 people with multiple sclerosis and 30 healthy controls. Tactile and proprioceptive sensory acuity were measured using the Rivermead Assessment of Somatosensory Performance. Vibration duration was assessed using a tuning fork. Duration for the Timed Up and Go Test and reaching distance of the Functional Reach Test were measured to assess balance limitations. The normative range of sensory modalities was defined using cut-off points in the healthy participants. The multivariate linear regression was used to identify the significant predictors of balance in people with multiple sclerosis. ResultsProprioceptive impairments (66.7%) were more common than tactile (60.8%) and vibration impairments (44.9%). Somatosensory impairments were more frequent in the lower limb (78.2%) than the upper limb (64.1%). All sensory modalities were significantly associated with the Timed Up and Go and Functional Reach tests (p<0.05). The Timed Up and Go test was independently predicted by the severity of the neurological lesion, Body Mass Index, ataxia, and tactile sensation (R2=0.58), whereas the Functional Reach test was predicted by the severity of the neurological lesion, lower limb strength, and vibration sense (R2=0.49). ConclusionsSomatosensory impairments are very common in people with multiple sclerosis. These impairments are independent predictors of balance limitation.

Body representation disorders predict left right orientation impairments after stroke: A voxel-based lesion symptom mapping study

IntroductionDeficits in the ability to distinguish between the left and right side of the body can severely impair daily life functioning. The current study examined the relation between left right orientation (LRO) impairments and somatosensory related deficits, ranging from primary somatosensory impairments to body representation impairments, in patients who suffered a recent stroke. We also examined which areas in the brain are associated with LRO impairments using a Voxel-based Lesion Symptom Mapping (VLSM) analysis. MethodWe tested 47 first-ever stroke patients and 48 age-matched healthy controls. LRO was assessed with the Bergen Right Left Discrimination Test (BRLD). Impairments on primary somatosensory function (touch perception, proprioception), higher order somatosensory function (finger gnosis, subjective sense of body ownership) and other cognitive functions (language, attention & working memory, visuospatial neglect) were entered as predictors in a logistic regression analyses. Outcome measures consisted of the BRLD-total performance which was further subdivided in performance for 1) first person perspective stimuli, 2) third person perspective stimuli, 3) alternating between first- and third person perspective. ResultsImpairments on BRLD-total performance was predicted by impairments in finger gnosis and visuospatial neglect. For items placed in third person perspective, performance was predicted by body representation impairments; finger agnosia and the subjective sense of body ownership. VLSM analysis showed a significant association between LRO impairments and damage to the right insula. DiscussionThe current study suggests that the somatosensory system is important for LRO. Furthermore, the results indicate that an affected body representation may hinder adopting a third person perspective that may subsequently also lead to LRO impairments. The right insular cortex appeared crucially involved in these processes.

Co-occurrence of Pain Symptoms and Somatosensory Sensitivity in Burning Mouth Syndrome: A Systematic Review.

BackgroundBurning mouth syndrome (BMS) is a chronic and spontaneous oral pain with burning quality in the tongue or other oral mucosa without any identifiable oral lesion or laboratory finding. Pathogenesis and etiology of BMS are still unknown. However, BMS has been associated with other chronic pain syndromes including other idiopathic orofacial pain, the dynias group and the family of central sensitivity syndromes. This would imply that BMS shares common mechanisms with other cephalic and/or extracephalic chronic pains. The primary aim of this systematic review was to determine whether BMS is actually associated with other pain syndromes, and to analyze cephalic and extracephalic somatosensory sensitivity in these patients.MethodsThis report followed the PRISMA Statement. An electronic search was performed until January 2015 in PubMed, Cochrane library, Wiley and ScienceDirect. Searched terms included “burning mouth syndrome OR stomatodynia OR glossodynia OR burning tongue OR oral burning”. Studies were selected according to predefined inclusion criteria (report of an association between BMS and other pain(s) symptoms or of cutaneous cephalic and/or extracephalic quantitative sensory testing in BMS patients), and a descriptive analysis conducted.ResultsThe search retrieved 1512 reports. Out of these, twelve articles met criteria for co-occurring pain symptoms and nine studies for quantitative sensory testing (QST) in BMS patients. The analysis reveals that in BMS patients co-occurring pain symptoms are rare, assessed by only 0.8% (12 of 1512) of the retrieved studies. BMS was associated with headaches, TMD, atypical facial pain, trigeminal neuralgia, post-herpetic facial pain, back pain, fibromyalgia, joint pain, abdominal pain, rectal pain or vulvodynia. However, the prevalence of pain symptoms in BMS patients is not different from that in the age-matched general population. QST studies reveal no or inconsistent evidence of abnormal cutaneous cephalic and extracephalic somatosensory sensitivity.ConclusionsThere is no evidence for a high rate of other pain symptoms or somatosensory impairments co-occurring with BMS. These results thus suggest that BMS rather depends on specific mechanisms, likely at the trigeminal level. Nevertheless, more thoroughly conducted research is required to draw definitive conclusion.

Accurate muscle morphological measurement using diffusion tensor magnetic resonance (DT-MR) images in the subject-specific muscle modelling (S2MM)

The aim of this study was to evaluate the influence of somatosensory impairment, distal muscle weakness and foot deformities on the balance in 21 CMT1A patients using a baropodometric platform.Stabilometric analysis by measuring sway area and velocity of a centre of pressure (CoP) both at open and closed eyes were used to assess postural imbalance. Static analysis, by measuring the load and the plantar surface of forefoot, midfoot and hindfoot was used to define the footprint shape and to assess as a whole foot deformities. Stabilometric and static results were compared with those of a control group. In CMT1A patients, stabilometric findings were correlated with static parameters, Achilles’ tendon retraction, distal muscle strength and CMT examination score (CMTES). CMT1A patients compared to controls had lower plantar surface and load on midfoot, and higher load on a forefoot. CMT1A patients had a greater postural instability, since they had a higher CoP velocity, both at open and closed eyes. Moreover, the CoP velocity correlated inversely with the strength of ankle dorsi-flexion muscles and directly with CMTES as whole and with the item “motor symptoms legs”. Postural imbalance was not correlated with sensory impairment and foot deformities as expressed by static analysis and Achilles’ tendon retraction.In this study we demonstrated an altered balance in CMT1A patients during upright standing. The imbalance in our CMT patients seems to be related to the weakness of ankle dorsi-flexor muscles rather than sensory impairment or foot deformities. These results could be due to a mildly affected CMT1A population, evaluated in an early stage of the disease.

The effect of ankle foot orthosis stiffness on trunk movement and walking energy cost in cerebral palsy

The aim of this study was to evaluate the influence of somatosensory impairment, distal muscle weakness and foot deformities on the balance in 21 CMT1A patients using a baropodometric platform.Stabilometric analysis by measuring sway area and velocity of a centre of pressure (CoP) both at open and closed eyes were used to assess postural imbalance. Static analysis, by measuring the load and the plantar surface of forefoot, midfoot and hindfoot was used to define the footprint shape and to assess as a whole foot deformities. Stabilometric and static results were compared with those of a control group. In CMT1A patients, stabilometric findings were correlated with static parameters, Achilles’ tendon retraction, distal muscle strength and CMT examination score (CMTES). CMT1A patients compared to controls had lower plantar surface and load on midfoot, and higher load on a forefoot. CMT1A patients had a greater postural instability, since they had a higher CoP velocity, both at open and closed eyes. Moreover, the CoP velocity correlated inversely with the strength of ankle dorsi-flexion muscles and directly with CMTES as whole and with the item “motor symptoms legs”. Postural imbalance was not correlated with sensory impairment and foot deformities as expressed by static analysis and Achilles’ tendon retraction.In this study we demonstrated an altered balance in CMT1A patients during upright standing. The imbalance in our CMT patients seems to be related to the weakness of ankle dorsi-flexor muscles rather than sensory impairment or foot deformities. These results could be due to a mildly affected CMT1A population, evaluated in an early stage of the disease.

Does somatosensation change with age in children and adolescents? A systematic review

Somatosensory modalities, such as touch, proprioception and haptic ability, greatly influence the achievement of developmental milestones for children. Describing somatosensory impairment, natural variability and typical or expected developmental changes across age groups will help establish frameworks for intervention in clinical populations. This systematic review aimed to determine how different somatosensory modalities develop across childhood into adolescence to use as a point of reference for children at risk of somatosensory impairment. Searches of five electronic databases were undertaken through EBSCO-host (MEDLINE, CINAHL, PsycINFO, SPORTDiscus and ERIC) for studies measuring at least one somatosensory modality in typically developing individuals between birth and 18 years and analysed by age. Characteristics of studies were collected including country of origin, sample size, demographics and outcome measure used. Quality assessment and data extraction were performed by two independent reviewers. Twenty three cross-sectional studies were included from a total of 188 articles retrieved: 8 examined aspects of touch, 5 proprioception and 10 haptic ability. Variability of study designs and variation in assessment tools precluded any formal meta-analysis. Somatosensation matures through childhood into adolescence; however, the present review found the pattern of somatosensory development varied depending on the assessment tool used and the aspect of somatosensation being measured, making it difficult to describe typical performance. There is a need for comprehensive assessment batteries to measure the somatosensation, including touch, proprioception and haptic ability, of children at risk of somatosensory impairment to aid in the development of effective interventions.

Postural instability in Charcot-Marie-Tooth 1A disease

The aim of this study was to evaluate the influence of somatosensory impairment, distal muscle weakness and foot deformities on the balance in 21 CMT1A patients using a baropodometric platform.Stabilometric analysis by measuring sway area and velocity of a centre of pressure (CoP) both at open and closed eyes were used to assess postural imbalance. Static analysis, by measuring the load and the plantar surface of forefoot, midfoot and hindfoot was used to define the footprint shape and to assess as a whole foot deformities. Stabilometric and static results were compared with those of a control group. In CMT1A patients, stabilometric findings were correlated with static parameters, Achilles’ tendon retraction, distal muscle strength and CMT examination score (CMTES). CMT1A patients compared to controls had lower plantar surface and load on midfoot, and higher load on a forefoot. CMT1A patients had a greater postural instability, since they had a higher CoP velocity, both at open and closed eyes. Moreover, the CoP velocity correlated inversely with the strength of ankle dorsi-flexion muscles and directly with CMTES as whole and with the item “motor symptoms legs”. Postural imbalance was not correlated with sensory impairment and foot deformities as expressed by static analysis and Achilles’ tendon retraction.In this study we demonstrated an altered balance in CMT1A patients during upright standing. The imbalance in our CMT patients seems to be related to the weakness of ankle dorsi-flexor muscles rather than sensory impairment or foot deformities. These results could be due to a mildly affected CMT1A population, evaluated in an early stage of the disease.

Somatosensory Impairments in the Upper Limb Poststroke

Background. A thorough understanding of the presence of different upper-limb somatosensory deficits poststroke and the relation with motor performance remains unclear. Additionally, knowledge about the relation between somatosensory deficits and visuospatial neglect is limited. Objective. To investigate the distribution of upper-limb somatosensory impairments and the association with unimanual and bimanual motor outcomes and visuospatial neglect. Methods. A cross-sectional observational study was conducted, including 122 patients within 6 months after stroke (median = 82 days; interquartile range = 57-133 days). Somatosensory measurement included the Erasmus MC modification of the (revised) Nottingham Sensory Assessment (Em-NSA), Perceptual Threshold of Touch (PTT), thumb finding test, 2-point discrimination, and stereognosis subscale of the NSA. Upper-limb motor assessment comprised the Fugl-Meyer assessment, motricity index, Action Research Arm Test, and Adult-Assisting Hand Assessment Stroke. Screening for visuospatial neglect was performed using the Star Cancellation Test. Results. Upper-limb somatosensory impairments were common, with prevalence rates ranging from 21% to 54%. Low to moderate Spearman ρ correlations were found between somatosensory and motor deficits (r = 0.22-0.61), with the strongest associations for PTT (r = 0.56-0.61) and stereognosis (r = 0.51-0.60). Visuospatial neglect was present in 27 patients (22%). Between-group analysis revealed somatosensory deficits that occurred significantly more often and more severely in patients with visuospatial neglect (P < .05). Results showed consistently stronger correlations between motor and somatosensory deficits in patients with visuospatial neglect (r = 0.44-0.78) compared with patients without neglect (r = 0.08-0.59). Conclusions. Somatosensory impairments are common in subacute patients poststroke and are related to motor outcome. Visuospatial neglect was associated with more severe upper-limb somatosensory impairments.

Associations Between Sensorimotor Impairments in the Upper Limb at 1 Week and 6 Months After Stroke.

Longitudinal information regarding the prevalence of upper limb somatosensory deficits and the association with motor impairment and activity limitations is scarce. The aim of this prospective cohort study was to map the extent and distribution of somatosensory deficits, and to determine associations over time between somatosensory deficits and motor impairment and activity limitations. We recruited 32 participants who were assessed 4 to 7 days after stroke, and reassessed at 6 months. Somatosensory measurements included the Erasmus-modified Nottingham sensory assessment (Em-NSA), perceptual threshold of touch, thumb finding test, 2-point discrimination, and stereognosis subscale of the NSA. Evaluation of motor impairment comprised the Fugl-Meyer assessment, Motricity Index, and Action Research Arm Test. In addition, at 6 months, activity limitation was determined using the adult assisting hand assessment stroke, the ABILHAND, and hand subscale of the Stroke Impact Scale. Somatosensory impairments were common, with 41% to 63% experiencing a deficit in one of the modalities within the first week and 3% to 50% at 6 months. In the acute phase, there were only very low associations between somatosensory and motor impairments (r = 0.03-0.20), whereas at 6 months, low to moderate associations (r = 0.32-0.69) were found for perceptual threshold of touch, thumb finding test, and stereognosis with motor impairment and activity limitations. Low associations (r = 0.01-0.29) were found between somatosensory impairments in the acute phase and motor impairments and activity limitations at 6 months. This study showed that somatosensory impairments are common and suggests that the association with upper limb motor and functional performance increases with time after stroke.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A138).

Altered Spontaneous Activity in Patients with Persistent Somatoform Pain Disorder Revealed by Regional Homogeneity.

Persistent somatoform pain disorder (PSPD) is a mental disorder un-associated with any somatic injury and can cause severe somatosensory and emotional impairments in patients. However, so far, the neuro-pathophysiological mechanism of the functional impairments in PSPD is still unclear. The present study assesses the difference in regional spontaneous activity between PSPD and healthy controls (HC) during a resting state, in order to elucidate the neural mechanisms underlying PSPD. Resting-state functional Magnetic Resonance Imaging data were obtained from 13 PSPD patients and 23 age- and gender-matched HC subjects in this study. Kendall’s coefficient of concordance was used to measure regional homogeneity (ReHo), and a two-sample t-test was subsequently performed to investigate the ReHo difference between PSPD and HC. Additionally, the correlations between the mean ReHo of each survived area and the clinical assessments were further analyzed. Compared with the HC group, patients with PSPD exhibited decreased ReHo in the bilateral primary somatosensory cortex, posterior cerebellum, and occipital lobe, while increased ReHo in the prefrontal cortex (PFC) and default mode network (including the medial PFC, right inferior parietal lobe (IPL), and left supramarginal gyrus). In addition, significant positive correlations were found between the mean ReHo of both right IPL and left supramarginal gyrus and participants’ Self-Rating Anxiety Scale (SAS) scores, and between the mean ReHo of the left middle frontal gyrus and Visual Analogue Scale (VAS) scores. Our results suggest that abnormal spontaneous brain activity in specific brain regions during a resting state may be associated with the dysfunctions in pain, memory and emotional processing commonly observed in patients with PSPD. These findings help us to understand the neural mechanisms underlying PSPD and suggest that the ReHo metric could be used as a clinical marker for PSPD.