Neural Correlates of Oral Stereognosis-An fMRI Study.

Oral stereognosis is the ability to recognize, discriminate and localize a bolus in the oral cavity. Clinical observation indicates deficits in oral stereognosis in patients with vascular or neurodegenerative diseases particularly affecting the parietal lobes. However, the precise neural representation of oral stereognosis remains unclear whereas the neural network of manual stereognosis has already been identified. We hypothesize that oral and manual stereognosis share common neuronal substrates whilst also showing somatotopic distribution. Functional magnetic resonance images (fMRI; Siemens Prisma 3 T) from 20 healthy right-handed participants (11 female; mean age 25.7 years) using a cross-modal task of oral and manual spatial object manipulation were acquired. Data were analyzed using FSL software using a block design and standard analytical and statistical procedures. A conjunction analysis targeted the common neuronal substrate for stereognosis. Activations associated with manual and oral stereognosis were found in partially overlapping fronto-parietal networks in a somatotopic fashion, where oral stereognosis is located caudally from manual stereognosis. A significant overlap was seen in the left anterior intraparietal sulcus. Additionally, cerebellar activations were shown particularly for the oral condition. Spatial arrangement of shaped boli in the oral cavity is associated with neuronal activity in fronto-parietal networks and the cerebellum. These findings have significant implications for clinical diagnostics and management of patients with lesions or atrophy in parietal lobule (e.g. Alzheimer's disease, stroke). More studies are required to investigate the clinical effect of damage to these areas, such as loss of oral stereognosis or an impaired oral phase.

The impact of movement sonification on haptic perception changes with aging.

Combining multisensory sources is crucial to interact with our environment, especially for older people who are facing sensory declines. Here, we examined the influence of textured sounds on haptic exploration of artificial textures in healthy younger and older adults by combining a tactile device (ultrasonic display) with synthetized textured sounds. Participants had to discriminate simulated textures with their right index while they were distracted by three disturbing, more or less textured sounds. These sounds were presented as a real-time auditory feedback based on finger movement sonification and thus gave the sensation that the sounds were produced by the haptic exploration. Finger movement velocity increased across both groups in presence of textured sounds (Rubbing or Squeaking) compared to a non-textured (Neutral) sound. While young adults had the same discrimination threshold, regardless of the sound added, the older adults were more disturbed by the presence of the textured sounds with respect to the Neutral sound. Overall, these findings suggest that irrelevant auditory information was taken into account by all participants, but was appropriately segregated from tactile information by young adults. Older adults failed to segregate auditory information, supporting the hypothesis of general facilitation of multisensory integration with aging.

Interference in geometry among people who are blind.

BACKGROUND: Geometry, a central branch of mathematics, is challenging for schoolchildren. Studies have shown that, when comparing perimeters of geometrical shapes, many sighted participants experience interference from the area variable, possibly stemming from the visual differences between the geometrical shapes. Accordingly, we hypothesized that such interference would not be observed in participants who are blind, who use the tactile modality to detect the properties of shapes. METHODS: Thirty participants, 15 who are blind and 15 with sight, explored pairs of geometrical shapes tactilely or visually, respectively, and compared areas and perimeters. RESULTS AND CONCLUSIONS: Surprisingly, accuracy and response time findings suggested that the two groups had a similar pattern of performance, and hence that area also interferes in comparison of perimeters among people who are blind.

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

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Relationship between oral stereognostic ability and dietary intake in older Japanese adults with complete dentures.

PURPOSE: Oral stereognostic ability (OSA) is a useful indicator of oral perception to recognize food characteristics during mastication. Previous studies have shown associations between dietary intake and oral health status, such as taste perception. However, the effect of oral sensory ability on dietary intake is unclear. The purpose of this study was to investigate the association between oral sensory ability and dietary intake in older Japanese complete denture wearers. METHODS: This cross-sectional study included 164 participants aged 69-71 or 79-81years old, wearing both maxillary and mandibular complete dentures. OSA test was used to evaluate oral tactile perception. Diet during the preceding month was assessed using a self-administered diet history questionnaire. Multivariable linear regression analysis was conducted to assess the association between OSA score and food and nutrient intake after adjusting for age, sex, socioeconomic factors, and occlusal force. RESULTS: The bivariate analysis showed that OSA score was significantly and positively correlated with intake of green and yellow vegetables and negatively correlated with intake of cereals among examined foods. OSA score was also positively correlated with intake of vitamins A, B2, and C and α-tocopherol (as a substitute for vitamin E) among examined nutrients. After adjusting for age, sex, socioeconomic factors, and occlusal force, OSA score remained significantly associated with intake of green and yellow vegetables and α-tocopherol. CONCLUSIONS: OSA was significantly associated with intake of green and yellow vegetables in older complete denture wearers.

Top-down modulation of shape and roughness discrimination in active touch by covert attention.

Due to limitations in perceptual processing, information relevant to momentary task goals is selected from the vast amount of available sensory information by top-down mechanisms (e.g. attention) that can increase perceptual performance. We investigated how covert attention affects perception of 3D objects in active touch. In our experiment, participants simultaneously explored the shape and roughness of two objects in sequence, and were told afterwards to compare the two objects with regard to one of the two features. To direct the focus of covert attention to the different features we manipulated the expectation of a shape or roughness judgment by varying the frequency of trials for each task (20%, 50%, 80%), then we measured discrimination thresholds. We found higher discrimination thresholds for both shape and roughness perception when the task was unexpected, compared to the conditions in which the task was expected (or both tasks were expected equally). Our results suggest that active touch perception is modulated by expectations about the task. This implies that despite fundamental differences, active and passive touch are affected by feature selective covert attention in a similar way.

Comparative tactile sensitivity of the fingertip and apical tongue using complex and pure tactile tasks.

Both the tongue and fingertip are highly tactile tissues relevant in texture perception, but work comparing relative sensitivity to elucidate potential differences in stimulus processing is limited. Presently, the acuity of the tongue and fingertip were compared using a series of tactile acuity tasks. We hypothesized the tongue would show superior acuity regardless of stimuli due to an absent epidermal barrier and its involvement in many high-sensitivity behaviors (e.g. eating, speaking). Acuity was determined using three different tests, two "purely-tactile" just noticeable difference (JND) tasks (punctate pressure and roughness sensitivity) and a more-complex, stereognostic letter-recognition task to evaluate point-and-edge sensitivity. JNDs were determined using the forced-choice staircase method for the punctate deformation force of a monofilament (F;0.0044-0.010 g) and the surface roughness of stainless steel coupons (Ra; 0.177-0.465 µm) in populations of 30 and 31 individuals, respectively. Point-and-edge sensitivity was assessed by determining the letter recognition threshold (RT) based on height (h;1.5-8.0 mm) in an additional 28 individuals using a modified staircase method. While subjects had significantly lower JNDs with their tongues for both "purely-tactile" tasks (punctate: 0.0017 ±â€¯0.0001 g vs. 0.0023 ±â€¯0.0002 g (fingertip), p = .018; roughness: 0.039 ±â€¯0.004 µm vs. 0.112 ±â€¯0.020 µm (fingertip), p < .001), subjects had significantly higher RTs with their tongues for the letter identification task (3.98 ±â€¯0.84 mm vs. 4.54 ±â€¯1.41 mm (fingertip), p = .0417). The latter difference is likely attributable to the more complex nature of the RT task and the finger's frequent involvement in object recognition. Binomial statistics (p = 1/2, α = 0.05) showed a significant number of subjects were better at the roughness task with their tongues (p = .021); however, a significant majority were better at the letter identification task with their fingers (p = .049); no significant difference was found for the punctate pressure task. While data appear to suggest the tongue is more sensitive to exclusively tactile stimuli, further study of other "pure-tactile" sensations should help clarify the contradictory results of the RT task.

Reduction of Pain Sensitivity after Somatosensory Therapy in Children with Autism Spectrum Disorders.

Children with autism spectrum disorders (ASD) often present with somatosensory dysfunction including an abnormal reactivity to tactile stimuli and altered pain perception. A therapy based on somatosensory stimuli has shown effectiveness in reducing pain sensitivity among adults with cerebral palsy. The present study aims at exploring the influence of somatosensory therapy on somatosensory parameters in children with ASD. Children with high-functioning ASD were randomly assigned to either the intervention (n = 29) or the control group (n = 30). The intervention group received a somatosensory therapy consisting of four types of exercises (touch, proprioception, vibration, stereognosis). Somatosensory function (pressure pain thresholds, tactile thresholds, stereognosis, proprioception) was assessed before and immediately after the therapy. Children in the intervention group showed a significant reduction of pain sensitivity and increase of tactile sensitivity after treatment, whereas children in the control group displayed increased pain sensitivity in the absence of changes of tactile sensitivity. No changes were observed for proprioception or stereognosis. The repetitive somatosensory stimulation therapy led to a decrease of pain sensitivity and an increase of tactile sensitivity. These findings may have important research and clinical implications, as promoting early tactile interventions in children with ASD may lead to a more adequate development of somatosensory processing and less somatosensory abnormalities upon adult life.

Hemispheric Dominance for Stereognosis in a Patient With an Infarct of the Left Postcentral Sensory Hand Area.

The concept of left hemispheric dominance for praxis, speech, and language has been one of the pillars of neurology since the mid-19th century. In 1906, Hermann Oppenheim reported a patient with bilateral stereoagnosia (astereognosis) caused by a left parietal lobe tumor and proposed that the left hemisphere was also dominant for stereognosis. Surprisingly, few cases of bilateral stereoagnosia caused by a unilateral cerebral lesion have been documented in the literature since then. Here we report a 75-year-old right-handed man who developed bilateral stereoagnosia after suffering a small infarct in the crown of the left postcentral gyrus. He could not recognize objects with either hand, but retained the ability to localize stimuli applied to the palm of his left (ipsilesional) hand. He was severely disabled in ordinary activities requiring the use of his hands. The lesion corresponded to Brodmann area 1, where probabilistic anatomic, functional, and electrophysiologic studies have located one of the multiple somatosensory representations of the hand. The lesion was in a strategic position to interrupt both the processing of afferent tactile information issuing from the primary somatosensory cortex (areas 3a and 3b) and the forward higher-order processing in area 2, the secondary sensory cortex, and the contralateral area 1. The lesion also deprived the motor hand area of its afferent regulation from the sensory hand area (grasping), while leaving intact the visuomotor projections from the occipital cortex (reaching). Our patient supports Oppenheim's proposal that the left postcentral gyrus of some individuals is dominant for stereognosis.

How does the interaction of presumed timing, location and extent of the underlying brain lesion relate to upper limb function in children with unilateral cerebral palsy?

BACKGROUND: Upper limb (UL) function in children with unilateral cerebral palsy (CP) vary largely depending on presumed timing, location and extent of brain lesions. These factors might exhibit a complex interaction and the combined prognostic value warrants further investigation. This study aimed to map lesion location and extent and assessed whether these differ according to presumed lesion timing and to determine the impact of structural brain damage on UL function within different lesion timing groups. MATERIALS AND METHODS: Seventy-three children with unilateral CP (mean age 10 years 2 months) were classified according to lesion timing: malformations (N = 2), periventricular white matter (PWM, N = 42) and cortical and deep grey matter (CDGM, N = 29) lesions. Neuroanatomical damage was scored using a semi-quantitative MRI scale. UL function was assessed at body function and activity level. RESULTS: CDGM lesions were more pronounced compared to PWM lesions (p = 0.0003). Neuroanatomical scores were correlated with a higher degree to UL function in the CDGM group (rs = -0.39 to rs = -0.84) compared to the PWM group (rrb = -0.42 to rs = -0.61). Regression analysis found lesion location and extent to explain 75% and 65% (p < 0.02) respectively, of the variance in AHA performance in the CDGM group, but only 24% and 12% (p < 0.03) in the PWM group. CONCLUSIONS: In the CDGM group, lesion location and extent seems to impact more on UL function compared to the PWM group. In children with PWM lesions, other factors like corticospinal tract (re)organization and structural connectivity may play an additional role.

A Protocol for Evaluation and Rehabilitation of Distal Radius Fractures Using Sensorimotor Input: A Case Series.

BACKGROUND: Proprioception and sensorimotor input are used to treat neurological and joint injuries. Following distal radius fractures (DRF) there is a temporary loss of proprioception that should be addressed. We created a protocol for evaluation, and a treatment plan following wrist surgery that is based on proprioceptive and sensorimotor input. We describe a series of patients undergoing surgery for DRF that were evaluated and treated with these protocols. METHODS: Both evaluation and treatment protocols included comprehensive sensorimotor procedures performed with eyes open and closed. These included Semmes- Weinstein, static and moving 2-point discrimination, vibration, temperature testing, Moberg pick-up- test, stereognosis and proprioception. RESULTS: A series of twelve patients was evaluated and treated with the protocol following surgical treatment for DRF. Patients demonstrated significant sensorimotor deficits, which improved utilizing the comprehensive sensorimotor treatment protocol. CONCLUSIONS: Further study is necessary to validate the results of this pilot series. Use of proprioception and sensorimotor input may improve outcomes of rehabilitation following DRF.

Stability of stereognosis after pediatric repetitive transcranial magnetic stimulation and constraint-induced movement therapy clinical trial.

OBJECTIVE: Poor sensibility affecting stereognosis, the ability to discriminate objects without visual input, can potentiate disuse of the paretic limb following stroke. The purpose of this study was to examine potential change in stereognosis after intervention. METHODS: Stereognosis testing in a secondary subgroup of 10 children with hemiparesis and baseline stereognosis deficits (ages 11-16) after a 13-day clinical trial of real or sham repetitive transcranial magnetic stimulation (rTMS) and constraint-induced movement therapy (CIMT) is reported. All children received 10 h of CIMT while wearing a cast full-time. RESULTS: Post-trial, 80% of participants from both intervention groups demonstrated improvement in stereognosis (95% CI: 44.4%-97.5%). Pre-trial to long-term follow-up (range: 21-57 months), 60% retained gains or improved (95% CI: 26.2%-87.8%). Between-group differences were not detected. DISCUSSION: Children demonstrated stereognosis change following intervention. Research on this change and potential minimal clinically important differences are indicated.

Reduced sensitivity for visual textures affects judgments of shape-from-shading and step-climbing behaviour in older adults.

Falls on stairs are a major hazard for older adults. Visual decline in normal ageing can affect step-climbing ability, altering gait and reducing toe clearance. Here we show that a loss of fine-grained visual information associated with age can affect the perception of surface undulations in patterned surfaces. We go on to show that such cues affect the limb trajectories of young adults, but due to their lack of sensitivity, not that of older adults. Interestingly neither the perceived height of a step nor conscious awareness is altered by our visual manipulation, but stepping behaviour is, suggesting that the influence of shape perception on stepping behaviour is via the unconscious, action-centred, dorsal visual pathway.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Manual Tactile Test Predicts Sensorimotor Control Capability of Hands for Patients With Peripheral Nerve Injury.

OBJECTIVES: To comprehend the merits of a Manual Tactile Test (MTT) in assessing hand sensorimotor functions by exploring the relations among 3 subtests along with the precision pinch performances for patients with peripheral nerve injuries (PNIs); and to understand the accuracy of the MTT by constructing the sensitivity and specificity of the test for patients with PNI. DESIGN: Case-control study. SETTING: Hospital and local community. PARTICIPANTS: Patients with PNI (n=28) were recruited along with age-, sex-, and handedness-matched healthy controls (n=28) (N=56). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Semmes-Weinstein monofilament, moving and static 2-point discrimination, roughness differentiation, stereognosis and barognosis subtests of the MTT, and precision pinch performance were used to examine the sensory and sensorimotor status of the hand. RESULTS: The worst results in all sensibility tests were found for the patients with PNI (P<.001) in comparison with the controls. Multiple linear regression analysis showed the MTT was a better indicator for predicting the sensorimotor capacity of hands in the patients with PNI (r(2)=.189, P=.003) than the traditional test (r(2)=.088, P=.051). The results of the receiver operating characteristic curve estimation show that the area under the curve was .968 and .959 for the roughness differentiation and stereognosis subtests, respectively, and .853 for the barognosis subtest, therefore revealing the accuracy of the MTT in assessing sensorimotor status for patients with PNI. CONCLUSIONS: This study indicates that the MTT is highly accurate and a significant predictor of sensorimotor performance in hands of patients with PNI. The MTT could therefore help clinicians obtain a better understanding of the sensorimotor and functional status of the hand with nerve injuries.

Development of a new haptic perception instrument: a pilot study / Desenvolvimento de um novo instrumento de avaliação da percepção háptica: um estudo piloto

ABSTRACT Objective Hand sensory tests do not consider distinct physiological receptors, nor detect normal range variations concerning developmental or pathological changes. We developed an instrument with a set of tests with timing and scoring for assessing haptic perception, which is the interaction between sensory and motor systems, in surfaces exploration, by moving hands. Method Firstly, group meetings were set for test/manual conception and materials testing. The test/manual were submitted to 30 reviewers in 3 stages (10 reviewers on each stage). Results The Hand Haptic Perception Instrument (HHPI) evaluates hand sensorimotor performance on six domains: depression, elevation, texture, compressibility, weight (barognosis) and form perception. Each domain requires specific materials. Score ranges from 0 to 57, being 0 the worst rating. Conclusion This methodological process allowed the development of six domains and instructions to assess haptic perception. This version of HHPI is a pilot model. Further studies will determine reliability and normality ranges.

RESUMO Objetivo Testes de sensibilidade manual não consideram receptores fisiológicos distintos, tampouco variações do desenvolvimento normal ou patológico. Desenvolvemos um instrumento, com pontuação e tempo de desempenho, para avaliar percepção háptica, que é a interação sensório-motora na exploração de superfícies, pelo movimento das mãos. Método Reuniões de grupo foram estabelecidas para desenvolver os testes/ manual e testar materiais. O instrumento e seu manual foram submetidos a 30 revisores, em 3 estágios (com 10 revisores em cada estágio). Resultados O instrumento de avaliação da percepção háptica manual (IAPHM) avalia o desempenho sensório-motor da mão em seis domínios: depressão, elevação, textura, compressibilidade, peso (barognosia) e percepção de forma. Cada domínio requer materiais específicos. A pontuação vai de 0 a 57, sendo 0 a pior pontuação. Conclusão Esse método permitiu o desenvolvimento do instrumento para avaliar percepção háptica. Essa versão do IAPHM é um modelo piloto. Estudos futuros determinarão confiabilidade e variações de normalidade.

Development of a new haptic perception instrument: a pilot study.

OBJECTIVE: Hand sensory tests do not consider distinct physiological receptors, nor detect normal range variations concerning developmental or pathological changes. We developed an instrument with a set of tests with timing and scoring for assessing haptic perception, which is the interaction between sensory and motor systems, in surfaces exploration, by moving hands. METHOD: Firstly, group meetings were set for test/manual conception and materials testing. The test/manual were submitted to 30 reviewers in 3 stages (10 reviewers on each stage). RESULTS: The Hand Haptic Perception Instrument (HHPI) evaluates hand sensorimotor performance on six domains: depression, elevation, texture, compressibility, weight (barognosis) and form perception. Each domain requires specific materials. Score ranges from 0 to 57, being 0 the worst rating. CONCLUSION: This methodological process allowed the development of six domains and instructions to assess haptic perception. This version of HHPI is a pilot model. Further studies will determine reliability and normality ranges.

The Effect of Treatment on Stereognosis in Children With Hemiplegic Cerebral Palsy.

PURPOSE: To determine if rehabilitation alone or combined with surgery or botulinum toxin injection improved stereognosis in children with hemiplegic cerebral palsy. METHODS: Inclusion criteria were children with spastic hemiplegic cerebral palsy who had stereognosis testing 2 separate times with documentation of intervening treatment. Sixty-three children were included, 30 girls and 33 boys at an average age of 9.1 years (range, 4.4-16.0 years). Twelve standardized objects were used for manual identification. Baseline and postintervention stereognosis results were recorded for the hemiplegic and the dominant limb of each patient. The patients were separated into 3 groups based on intervening treatment: surgery with rehabilitation (27 patients), botulinum toxin injection with rehabilitation (19 subjects), and rehabilitation alone (7 subjects). Results were also analyzed by patient age group. RESULTS: Baseline testing of the hemiplegic limb revealed that 27 patients (43%) exhibited severe stereognosis impairment (0-4 objects identified correctly), 18 (28%) were moderately impaired (5-8 objects), 13 (21%) were mildly impaired (9-11 objects), and 5 (8%) had intact stereognosis (12 objects). There was no statistically significant difference in change in stereognosis scores postintervention among the 3 different treatment groups or between patients who had surgery and those who did not have surgery. There was no statistically significant difference in stereognosis function or postintervention change based on patient age at time of testing. CONCLUSIONS: In this study, 92% of children with spastic hemiplegic cerebral palsy had stereognosis impairment with a wide spectrum of severity. After operative or nonoperative treatment interventions, stereognosis as a secondary outcome measure was not changed. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Impact of tactile function on upper limb motor function in children with Developmental Coordination Disorder.

This study investigated the presence of, and relationship between tactile dysfunction and upper limb motor function in children with Developmental Coordination Disorder (DCD) compared to typical developing (TD) children. Participants were 36 children aged 6-12 years. Presence of DCD (n=20) or TD (n=16) was confirmed using the Movement Assessment Battery for Children, second edition. All children participated in a comprehensive assessment of tactile registration (Semmes Weinstein Monofilaments); tactile spatial perception (Single Point Localisation (SPL) and two-point discrimination (2PD)); haptic perception (Stereognosis); speed of simple everyday manual tasks (Jebsen-Taylor Test of Hand Function (JTTHF)); and handwriting speed and accuracy (Evaluation Tool of Children's Handwriting (ETCH)). Compared to TD children, children with DCD demonstrated poorer localisation of touch in the non-dominant hand (p=0.04), slower speed of alphabet writing (p<0.05) and less legible handwriting (p<0.01), but no difference in speed of simple everyday manual tasks (JTTHF: p>0.05). Regression analysis showed that spatial tactile perception (SPL) predicted handwriting legibility (ETCH: r=0.11) and speed of functional tasks (JTTHF: r=0.33). These results suggest that tactile function, specifically single point localisation, should be a primary tactile assessment employed to determine reasons for upper limb motor difficulties experienced by children with DCD.

Useless hand syndrome with astereognosis in multiple sclerosis.

We report on a patient with multiple sclerosis (MS) who developed bilateral useless hand syndrome (UHS) and astereognosis. Clinical features of UHS in our patient are similar to limb-kinetic apraxia with astereognosis. Cervical T1-weighted magnetic resonance imaging revealed a gadolinium-enhanced lesion at the level of C3-C4, mainly involving the posterior cord. This patient suggests that posterior cord lesions at high cervical levels cause UHS and astereognosis in MS, involving the sensorimotor integration needed to execute complex finger movements.