Standardization of the face-hand test in a Brazilian multicultural population: prevalence of sensory extinction and implications for neurological diagnosis

OBJECTIVE: The face-hand test is a simple, practical, and rapid test to detect neurological syndromes. However, it has not previously been assessed in a Brazilian sample; therefore, the objective of the present study was to standardize the face-hand test for use in the multi-cultural population of Brazil and identify the sociodemographic factors affecting the results. METHODS: This was a cross sectional study of 150 individuals. The sociodemographic variables that were collected included age, gender, race, body mass index and years of education. Standardization of the face-hand test occurred in 2 rounds of 10 sensory stimuli, with the participant seated to support the trunk and their vision obstructed in a sound-controlled environment. The face-hand test was conducted by applying 2 rounds of 10 sensory stimuli that were applied to the face and hand simultaneously. The associations between the face-hand test and sociodemographic variables were analyzed using Mann-Whitney tests and Spearman correlations. Binomial models were adjusted for the number of face-hand test variations, and ROC curves evaluated sensitivity and specificity of sensory extinction. RESULTS: There was no significant relationship between the sociodemographic variables and the number of stimuli perceived for the face-hand test. There was a high relative frequency of detection, 8 out of 10 stimuli, in this population. Sensory extinction was 25.3%, which increased with increasing age (OR=1.4[1:01–1:07]; p=0.006) and decreased significantly with increasing education (OR=0.82[0.71-0.94]; p=0.005). CONCLUSION: In the Brazilian population, a normal face-hand test score ranges between 8–10 stimuli, and the results indicate that sensory extinction is associated with increased age and lower levels of education.

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.

La ilusión de la mano de goma: factores implicados, bases neurales y aplicaciones clínicas / The rubber hand illusion: involved factors, neural basis and clinical applications

The "Rubber Hand Illusion" is a procedure aimed to induce the sensation of an own hand through the efficient utilization of a false one in healthy people. Some modifications in original methods could weaken or even abolish the illusion. In addition, several personality traits could be involved in the intensity of subjective perception of the illusion, and some psychopathological traits could facilitate it. The neural substrate underlying to this cognitive phenomenon is very uncertain, even the current research have found several correlations between activity of some cerebral areas and the performance of illusion. The body awareness is an essential factor to a suitable interaction with the environment, and the disturbance of this process may cause serious mental diseases. The progress made at the Rubber Hand Illusion has helped to explore several fields where this procedure might be a good tool to detect some pathologies and their treatment.

La "Ilusión de la Mano de Goma" es un procedimiento que permite inducir a un sujeto sano la sensación de que una mano falsa es su propia mano. Pequeñas modificaciones en el método original puede alterar o incluso abolir la ilusión. Asimismo se han detectado varios factores individuales que influyen en la intensidad de la vivencia subjetiva de la ilusión, además de ciertos rasgos psicopatológicos sensibles a la aparición de la misma. Como cualquier fenómeno cognitivo, la ilusión de la mano de goma tiene un sustrato neural, y aunque sigue siendo incierto, las recientes investigaciones han detectado ciertas correlaciones entre distintas áreas cerebrales y la aparición de la ilusión. La conciencia corporal es fundamental para una correcta interacción con el entorno circundante, por lo que su perturbación puede causar una auténtica psicopatología. Los avances en el paradigma de la ilusión de la mano de goma están permitiendo conocer los distintos ámbitos donde este procedimiento puede resultar un buen instrumento para la detección y el tratamiento de distintas patologías.

Assessment of light touch sensation in the hands of systemic sclerosis patients

INTRODUCTION: Systemic sclerosis is a relatively rare connective tissue disorder characterized by severe and progressive fibrosis of the skin. Due to the current lack of available information on this subject, the aim of the present study was to assess light touch sensations in the hands of patients with systemic sclerosis. METHODS: We completed a cross-sectional comparative study. Light touch sensations were evaluated in 30 individuals, including 15 patients with systemic sclerosis who exhibited changes in the dermis of their hands without loss of the distal phalanx and 15 subjects who did not exhibit changes in the upper limbs (control group). The groups were age- and sex-matched. Tactile sensory evaluations were performed using the Semmes-Weinstein monofilament test and the two-point discrimination test. RESULTS: Statistically significant differences were found between groups in the monofilament test. The study group had lower scores across all points of the hand when compared with the control group. Differences were also found when dominant and non-dominant hands were compared (p<0.05). Statistically significant differences were found between groups for a subset of the assessed points in the two-point discrimination test. CONCLUSIONS: The results of a monofilament test showed that tactile sensation, specifically light touch and deep pressure sensations, is altered in the hands of systemic sclerosis patients. .

La parádola de los seis ciegos y el elefante indostano o comprendiendo la esencia de la medicina interna / The fable of the six blind men and the elephant from indostan or understanding the internal medicine essence

Existe una antigua fábula popularizada en un poema escrito por el poema norteamericano John G Saxe en 1860. En él se demuestra como podemos estar equivocados si sustentamos nuestras opiniones con base a una insuficiente evidencia obtenida a través de un inadecuado estudio. Cada uno de los seis ciegos del poema se acercó al elefante para investigar cómo era pero tomando solo una parte aislada del animal. Cada uno se hizo de una solida pero errónea opinión de lo que realmente era un elefante. Discutieron entre sí defendiendo sus impresiones y como Saxe escribiera, "Los ciegos disputan y se querellan: cada uno está seguro de haber hecho bien su prueba...¡Cada uno tiene un poco de razón...y todos están equivocados!". El autor asimila al elefante a un paciente cuya queja es interpretada de manera diferente al ser analizada a través del juicio prejuiciado de diversos especialistas al interpretar fragmentos inconexos del todo indivisible que es el ser humano

There is old Indian fable made popular in a poem written by John G. Saxe in 1860. It demonstrates how we can be so very wrong by basing our opinions on insufficient evidence gained through inadequate studies. Each of the six blind men in the poem walked up to an imposing elephant to investigate what it investigate what it was-but each touched only one part of the animal. Each man had a faulty yet strong opinion of what an elephant was really like and disputed the others with great vigor. As Saxe wrote, "through each was partly in the right, and all were in the wrong! "The author compares the elephant to a patient whose complaint is interpreted differently when analyzed through the prejudiced judgment of various specialist who interpret unconnected fragments of the fully indivisible human being

Avaliação funcional do equilíbrio e da sensibilidade cutânea plantar de idosos moradores na comunidade / Balance and plantar cutaneous sensitivity functional assessment in community-dwelling elderly

Desequilíbrio é um dos muitos fatores de risco que aumenta a susceptibilidade de um idoso a quedas. O equilíbrio pode ser avaliado mediante testes posturais e de sensibilidade plantar. OBJETIVO: Avaliar a ocorrência de desequilíbrio e perda de sensibilidade cutânea plantar em idosos da comunidade e verificar a existência de associação entre ambas as alterações. CASUÍSTICA E MÉTODOS: Estudo transversal descritivo envolvendo 45 idosos submetidos à escala de equilíbrio de Berg (EEB) e ao teste de sensibilidade plantar com monofilamento de nylon. Foram utilizados os testes qui-quadrado e exato de Fisher e elaboradas curvas ROC para estudo da sensibilidade e especificidade da EEB. RESULTADOS: Idosos com alteração do equilíbrio e da sensibilidade cutânea foram em número de 2 e 4, respectivamente. Houve associação significativa entre queixa de desequilíbrio e perda da sensibilidade (p = 0,047) e ocorreu concordância razoável (Kappa: 0,6457) entre a EEB e o teste da sensibilidade. Verificou-se também associação significativa entre 6 dos 14 tarefas da EEB e o teste sensorial. CONCLUSÃO: Idosos vivendo com independência na comunidade, em sua maioria, apresentam equilíbrio e sensibilidade cutânea plantar normais. Quando alteradas estas funções mostram-se associadas de forma que, se os testes forem realizados conjuntamente, a precisão da avaliação do equilíbrio idoso aumenta.

Impaired balance is one of several factors that increase an elderly's susceptibility to falls. Balance assessment can be performed using postural tests and plantar cutaneous sensitivity tests. AIM: To assess balance disorders and loss of plantar cutaneous sensitivity in the elderly and look for association between these alterations. MATERIALS AND METHODS: A descriptive cross-sectional study involving 45 elderly submitted to the Berg Balance Scale (BBS) and the plantar sensitivity test with nylon monofilament. We used chi-square and Fisher's exact tests, and ROC curves were created in order to study the sensitivity and specificity of BBS. RESULTS: Two and 4 individuals showed balance and cutaneous sensation disorders, respectively. There was a significant association between the complaint of impaired balance and loss of skin sensitivity (p = 0.047), and there was a reasonable agreement (Kappa: 0.6457) between the BBS and the sensorial test. A significant association was also found among 6 of the 14 BBS tasks and the sensitivity test. CONCLUSION: Most of the elderly living independently in the community showed normal balance and plantar cutaneous sensation. When impaired, these functions appeared associated in a way that if the tests are performed together, the accuracy of the evaluation of the balance increases.

Neuroplasticidad y dolor / Neuroplasticity and pain

Todas las formas de dolor incluyen el desarrollo de un estado de hiperalgesia que ilustra la naturaleza dinámica y plástica de la sensación de dolor. La hiperalgesia es la característica más importante del proceso doloroso y es la expresión de la hipersensibilidad de las vías del dolor inducida por la sensibilización de los receptores periféricos que registran eventos dolorosos y de las neuronas que transmiten y procesan esta información sensorial al SNC. Los nociceptores periféricos se sensibilizan adquiriendo una mayor y a veces nueva capacidad de respuesta a los estímulos periféricos. Por otra parte, un proceso de plasticidad sináptica, del cual se ha identificado una variedad de componentes moleculares, interviene en la amplificación central de las señales de las aferencias nociceptivas, lo cual evoca la hipersensibilidad de las neuronas centrales. El resultado final es un proceso sensorial que, a pesar de haber sido puesto en marcha inicialmente por una lesión, puede no mantener una relación estrecha con la lesión original y convertirse en un estado de dolor crónico sin tener una causa definida.

All froms of pain include the development of a hyperalgesic state that illustrates the dynamic and plastic nature of pain sesation. Hyperalgesia is the most prominent feature of the pain process and is the expression of hypersensitivity of the pain pathway induced by the sensitization of the peripheral receptors that signal painful events and of the neurons that transmit and process this sensory information to the CNS. Peripheral nociceptors can be sensitized, acquiring enhanced, and sometimes novel, responsiveness to peripheral stimuli. On the other hand a process of synaptic plasticity, of which several molecular components have already been identified, mediates the central amplification of the afferent signals that leads to the hypersensitivity of central neurons. The final result is a sensory process that, although initially triggered by injury, may not keep a close relationship with the originating injury and develop into a chronic pain state in the absence of a defined cause.