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1.
Clin Oral Investig ; 28(10): 555, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39327312

RESUMO

OBJECTIVES: The subepithelial connective tissue graft (SCTG) plus coronal advanced flap is commonly evaluated by clinical parameters, but potential sensory changes (patients' perception of painful or painless sensations) need to be further explored. This preliminary study aimed to qualitatively evaluate the somatosensory profile of recipient and palatal donor sites of SCTG. MATERIALS AND METHODS: Sensory tests were applied at SCTG recipient and donor sites at baseline, after 3 and 6 months. A single calibrated examiner applied Douleur Neuropathique 4 questionnaire (DN4), qualitative sensory test (QualST), discriminating the areas as hypersensitive, hyposensitive or normosensitive, and two-point acuity test. Descriptive statistics, non-parametric Kruskal Wallis test for QualST evaluation and ANOVA for Two-point test (p < 0.05) were used. RESULTS: QualST revealed that recipient areas presented no significant differences in tactile, pressure and thermal tests. Brush test revealed hyposensitivity after 3 months (p = 0.03). In donor areas, only thermal evaluation showed a significant difference (p = 0.01), being hypersensitive after 3 months and hyposensitive after 6 months. At baseline, all evaluations in recipient and donor areas were normosensitive. According to DN4, no patient reported pain in recipient and donor sites. Non-painful sensory perception was reported as numbness in recipient (3.14% of patients) and donor (18.4%) areas. No significant differences were found for two-point acuity test values. CONCLUSIONS: Somatosensory variations were observed in donor and recipient areas using qualitative tests, with no detection of painful sensations, only non-painful sensations of numbness and electric shock. CLINICAL RELEVANCE: This preliminary study demonstrated that alterations of hypo- and hypersensitivity may occur in donor and recipient areas of gingival grafts. However, when present, these alterations were non-painful and did not impact oral functions. CLINICAL REGISTRATION: ReBEC #RBR-7zz3b6p.


Assuntos
Tecido Conjuntivo , Humanos , Masculino , Feminino , Tecido Conjuntivo/transplante , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto , Retalhos Cirúrgicos , Sítio Doador de Transplante , Idoso
2.
Proc Natl Acad Sci U S A ; 121(29): e2316765121, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38990946

RESUMO

How does the brain simultaneously process signals that bring complementary information, like raw sensory signals and their transformed counterparts, without any disruptive interference? Contemporary research underscores the brain's adeptness in using decorrelated responses to reduce such interference. Both neurophysiological findings and artificial neural networks support the notion of orthogonal representation for signal differentiation and parallel processing. Yet, where, and how raw sensory signals are transformed into more abstract representations remains unclear. Using a temporal pattern discrimination task in trained monkeys, we revealed that the second somatosensory cortex (S2) efficiently segregates faithful and transformed neural responses into orthogonal subspaces. Importantly, S2 population encoding for transformed signals, but not for faithful ones, disappeared during a nondemanding version of this task, which suggests that signal transformation and their decoding from downstream areas are only active on-demand. A mechanistic computation model points to gain modulation as a possible biological mechanism for the observed context-dependent computation. Furthermore, individual neural activities that underlie the orthogonal population representations exhibited a continuum of responses, with no well-determined clusters. These findings advocate that the brain, while employing a continuum of heterogeneous neural responses, splits population signals into orthogonal subspaces in a context-dependent fashion to enhance robustness, performance, and improve coding efficiency.


Assuntos
Macaca mulatta , Córtex Somatossensorial , Animais , Córtex Somatossensorial/fisiologia , Modelos Neurológicos , Masculino
3.
J Dent ; 147: 105148, 2024 08.
Artigo em Inglês | MEDLINE | ID: mdl-38909648

RESUMO

OBJECTIVE: This cohort study aimed to assess the incidence of somatosensory alterations after implant surgery using standardized quantitative and qualitative sensory testing. METHODS: 33 participants with single-tooth loss, undergoing immediate implant loading were included. Quantitative Sensory Testing (QST) and Qualitative Sensory Testing (QualST) were conducted at eight time points over a year (baseline to 1 year). Two-Way Repeated Measures ANOVA and post hoc Tukey test were used on QST values and Cochran Q test on QualST. RESULTS: The study revealed significant increase in thermal thresholds overtime. At the operated side, overall Cold Pain Threshold (extraoral: p = 0.030; intraoral: p < 0.001), and Cold Detection Threshold (intraoral: p < 0.001) increased overtime. In contralateral region, maxilla Cold Detection Threshold (extraoral: p = 0.024; intraoral: p = 0.031), Warm Detection Threshold (extraoral: p = 0.026; intraoral: p = 0.047) and overall Cold Pain Threshold (extraoral and intraoral: p < 0.001) also increased. QualST showed extraoral pinprick (p = 0.032) and intraoral pinprick (p = 0.000), cold (p = 0.000) and touch (p = 0.002) stimuli abnormalities overtime. CONCLUSIONS: Somatosensory alterations after implant surgery were detected in both quantitative and qualitative sensory assessments, but rapidly decreased during the first follow-ups, and then continuously until 1-year. CLINICAL SIGNIFICANCE: This study provides clinical and controlled evidence on the real effect of the somatosensory alterations overtime, leading to a better understanding of neurosensory behaviour after single-tooth dental implant rehabilitation.


Assuntos
Implantes Dentários para Um Único Dente , Carga Imediata em Implante Dentário , Limiar da Dor , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Seguimentos , Adulto , Limiar da Dor/fisiologia , Idoso , Limiar Sensorial/fisiologia , Temperatura Baixa , Estudos de Coortes , Maxila/cirurgia , Distúrbios Somatossensoriais/etiologia
4.
HardwareX ; 18: e00529, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38690151

RESUMO

Understanding the somatosensory system and its abnormalities requires the development of devices that can accurately stimulate the human skin. New methods for assessing the somatosensory system can enhance the diagnosis, treatments, and prognosis for individuals with somatosensory impairments. Therefore, the design of NeuroSense, a tactile stimulator that evokes three types of daily life sensations (touch, air and vibration) is described in this work. The prototype aims to evoke quantitative assessments to evaluate the functionality of the somatosensory system and its abnormal conditions that affect the quality of life. In addition, the device has proven to have varying intensities and onset latencies that produces somatosensory evoked potentials and energy desynchronization on somatosensory cortex.

5.
Medicines (Basel) ; 10(8)2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37623813

RESUMO

An aura is a subjective experience felt in the initial phase of a seizure. Studying auras is relevant as they can be warning signs for people with epilepsy. The incidence of aura tends to be underestimated due to misdiagnosis or underrecognition by patients unless it progresses to motor features. Also, auras are associated with seizure remission after epilepsy surgery and are an important prognostic factor, guiding the resection site and improving surgical outcomes. Somatosensory auras (SSAs) are characterized by abnormal sensations on one or more body parts that may spread to other parts following a somatotopic pattern. The occurrence of SSAs among individuals with epilepsy can range from 1.42% to 80%. The upper extremities are more commonly affected in SSAs, followed by the lower extremities and the face. The most common type of somatosensory aura is paresthetic, followed by painful and thermal auras. In the primary somatosensory auras, sensations occur more commonly contralaterally, while the secondary somatosensory auras can be ipsilateral or bilateral. Despite the high localizing features of somatosensory areas, cortical stimulation studies have shown overlapping sensations originating in the insula and the supplementary sensorimotor area.

6.
BrJP ; 6(3): 237-243, July-sept. 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1520292

RESUMO

ABSTRACT BACKGROUND AND OBJECTIVES: Conventional electrodiagnostic studies (EDX) are frequently used to support the diagnosis of peripheral neuropathic pain. However, routine EDX has poor diagnostic yield for identifying small fiber neuropathy, which may be cause of neuropathic pain in some patients. This study aimed to assess the gain in diagnostic yield brought by adding pain-related evoked potentials with concentric electrode (CN-PREP) and nociceptive withdrawal reflex (NWR) assessments to EDX. METHODS: Transversal observational accuracy study which included patients referred to routine EDX in a tertiary-care hospital who reported chronic neuropathic pain in their lower limbs. Besides routine EDX, subjects underwent CN-PREP and NWR assessments. Diagnostic yield and tolerability were examined and compared between test studies. RESULTS: The study enrolled 100 patients (54% female), with 57 ± 12 years. EDX was altered in 47% of all patients. The addition of CN-PREP alone, and NWR combined with CN-PREP increased diagnostic yield to 69% and 72%, respectively. CN-PREP proved to be well tolerable, while NWR was associated with higher test-related pain intensity and discontinuation rate (9% vs. 0%). Considering EDX as the reference test, CN-PREP sensitivity was 85.1% and specificity 58.5%. CONCLUSION: Combining CN-PREP with the routine EDX for patients with neuropathic pain is feasible and results in increased diagnostic yield. Conversely, the addition of NWR to the aforementioned tests provides little improvement to this yield and is less tolerable to the patient. Further studies are needed to determine the actual sensitivity and specificity of CN-PREP when compared to the gold-standard for small fiber neuropathy diagnosis, i.e. intraepidermal nerve fiber density assessment.


RESUMO JUSTIFICATIVA E OBJETIVOS: Estudos convencionais de eletrodiagnóstico (EDX) são frequentemente usados para apoiar o diagnóstico de dor neuropática periférica. No entanto, o EDX de rotina tem baixo rendimento diagnóstico para identificar neuropatia de pequenas fibras. O objetivo deste estudo foi avaliar o ganho no rendimento diagnóstico pela adição de avaliações de potenciais evocados relacionados à dor com eletrodo concêntrico (CN-PREP) e reflexo de retirada nociceptiva (NWR) ao EDX. MÉTODOS: Estudo de precisão observacional transversal que incluiu pacientes encaminhados para EDX de rotina com dor neuropática crônica em membros inferiores. Além do EDX de rotina, os indivíduos foram submetidos às avaliações CN-PREP e NWR. O rendimento diagnóstico e a tolerabilidade foram examinados e comparados entre os estudos de teste. RESULTADOS: O estudo envolveu 100 pacientes (54% mulheres), com 57 ± 12 anos. O EDX estava alterado em 47%. A adição de CN-PREP sozinho e NWR combinado com CN-PREP aumentou o rendimento diagnóstico para 69% e 72%, respectivamente. O CN-PREP provou ser bem tolerável, enquanto o NWR foi associado a maior intensidade de dor relacionada ao teste e taxa de descontinuação (9% vs. 0%). Considerando o EDX como teste de referência, a sensibilidade do CN-PREP foi de 85,1% e a especificidade de 58,5%. CONCLUSÃO: A combinação do CN-PREP com o EDX de rotina para pacientes com dor neuropática é viável e resulta em maior rendimento diagnóstico. Já a adição de NWR aos testes mencionados fornece pouca melhora nesse rendimento e é menos tolerável para o paciente. Mais estudos são necessários para determinar a real sensibilidade e especificidade do CN-PREP quando comparado ao padrão-ouro para diagnóstico de neuropatia de pequenas fibras, ou seja, a avaliação da densidade de fibras nervosas intraepidérmicas.

7.
J Comp Neurol ; 531(18): 1909-1925, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36592397

RESUMO

We studied the organization of the inferior parietal cortex (IPC) in five capuchin monkey (6 hemispheres) using cytoarchitectonic (Nissl), myeloarchitectonic (Gallyas), and immune-architectonic (SMI-32 monoclonal antibody) techniques. We partitioned the IPC into five distinct areas: PFG, PG, Opt, PFop, and PGop. Since we used parasagittal sections, we were not able to study area PF due to its far lateral position, which yielded slices that were tangential to the pial surface. Areas PFG, PG, and Opt were in the convexity close to the lateral sulcus, while PFop and PGop were positioned more posteriorly, in the opercular region of IPC. Of all the five regions, area Opt was the one most similar to its analogue in the macaque, especially as revealed with SMI-32 staining. Namely, in both primate species area Opt showed a low density of large pyramidal neurons. Additionally, the apical dendrites of these neurons were sparse and vertically orientated, resembling columns. We also found area PG to be similar: both species exhibited cell body layers with a radial arrangement. On the other hand, Nissl staining revealed area PFG to be architectonically different between New and Old-World monkeys: PFG in the capuchin showed a comparatively higher cell density than in macaques, especially in layers II and IV. These results suggest that evolution may have enabled the functional specialization of these brain regions based on behavioral demands of upper limb use. The small differences in the IPC of the two primates may be linked to interspecies variability.


Assuntos
Cebus , Lobo Parietal , Animais , Macaca , Neurônios/fisiologia , Mapeamento Encefálico
8.
Korean J Pain ; 36(1): 113-127, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36581601

RESUMO

Background: Resting-state functional connectivity (rs-FC) may aid in understanding the link between pain-modulating brain regions and the descending pain modulatory system (DPMS) in fibromyalgia (FM). This study investigated whether the differences in rs-FC of the primary somatosensory cortex in responders and non-responders to the conditioned pain modulation test (CPM-test) are related to pain, sleep quality, central sensitization, and the impact of FM on quality of life. Methods: This cross-sectional study included 33 females with FM. rs-FC was assessed by functional magnetic resonance imaging. Change in the numerical pain scale during the CPM-test assessed the DPMS function. Subjects were classified either as non-responders (i.e., DPMS dysfunction, n = 13) or responders (n = 20) to CPM-test. A generalized linear model (GLM) and a receiver operating characteristic (ROC) curve analysis were performed to check the accuracy of the rs-FC to differentiate each group. Results: Non-responders showed a decreased rs-FC between the left somatosensory cortex (S1) and the periaqueductal gray (PAG) (P < 0.001). The GLM analysis revealed that the S1-PAG rs-FC in the left-brain hemisphere was positively correlated with a central sensitization symptom and negatively correlated with sleep quality and pain scores. ROC curve analysis showed that left S1-PAG rs-FC offers a sensitivity and specificity of 85% or higher (area under the curve, 0.78, 95% confidence interval, 0.63-0.94) to discriminate who does/does not respond to the CPM-test. Conclusions: These results support using the rs-FC patterns in the left S1-PAG as a marker for predicting CPM-test response, which may aid in treatment individualization in FM patients.

9.
Brain Behav Evol ; 98(6): 275-289, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38198769

RESUMO

INTRODUCTION: The study of non-laboratory species has been part of a broader effort to establish the basic organization of the mammalian neocortex, as these species may provide unique insights relevant to cortical organization, function, and evolution. METHODS: In the present study, the organization of three somatosensory cortical areas of the medium-sized (5-11 kg body mass) Amazonian rodent, the paca (Cuniculus paca), was determined using a combination of electrophysiological microelectrode mapping and histochemical techniques (cytochrome oxidase and NADPH diaphorase) in tangential sections. RESULTS: Electrophysiological mapping revealed a somatotopically organized primary somatosensory cortical area (S1) located in the rostral parietal cortex with a characteristic foot-medial/head-lateral contralateral body surface representation similar to that found in other species. S1 was bordered laterally by two regions housing neurons responsive to tactile stimuli, presumably the secondary somatosensory (S2) and parietal ventral (PV) cortical areas that evinced a mirror-reversal representation (relative to S1) of the contralateral body surface. The limits of the putative primary visual (V1) and primary auditory (A1) cortical areas, as well as the complete representation of the contralateral body surface in S1, were determined indirectly by the histochemical stains. Like the barrel field described in small rodents, we identified a modular arrangement located in the face representation of S1. CONCLUSIONS: The relative location, somatotopic organization, and pattern of neuropil histochemical reactivity in the three paca somatosensory cortical areas investigated are similar to those described in other mammalian species, providing additional evidence of a common plan of organization for the somatosensory cortex in the rostral parietal cortex of mammals.


Assuntos
Cuniculidae , Córtex Somatossensorial , Animais , Córtex Somatossensorial/fisiologia , Roedores , Lobo Parietal/fisiologia , Mapeamento Encefálico , América do Sul
10.
Proc Natl Acad Sci U S A ; 119(52): e2213847119, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36534792

RESUMO

Do sensory cortices process more than one sensory modality? To answer these questions, scientists have generated a wide variety of studies at distinct space-time scales in different animal models, and often shown contradictory conclusions. Some conclude that this process occurs in early sensory cortices, but others that this occurs in areas central to sensory cortices. Here, we sought to determine whether sensory neurons process and encode physical stimulus properties of different modalities (tactile and acoustic). For this, we designed a bimodal detection task where the senses of touch and hearing compete from trial to trial. Two Rhesus monkeys performed this novel task, while neural activity was recorded in areas 3b and 1 of the primary somatosensory cortex (S1). We analyzed neurons' coding properties and variability, organizing them by their receptive field's position relative to the stimulation zone. Our results indicate that neurons of areas 3b and 1 are unimodal, encoding only the tactile modality in both the firing rate and variability. Moreover, we found that neurons in area 3b carried more information about the periodic stimulus structure than those in area 1, possessed lower response and coding latencies, and had a lower intrinsic time scale. In sum, these differences reveal a hidden processing-based hierarchy. Finally, using a powerful nonlinear dimensionality reduction algorithm, we show that the activity from areas 3b and 1 can be separated, establishing a clear division in the functionality of these two subareas of S1.


Assuntos
Córtex Somatossensorial , Percepção do Tato , Animais , Córtex Somatossensorial/fisiologia , Percepção do Tato/fisiologia , Tato , Lobo Parietal , Células Receptoras Sensoriais
11.
Front Hum Neurosci ; 16: 1043501, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36504625

RESUMO

The ability to learn motor skills implicates an improvement in accuracy, speed and consistency of movements. Motor control is related to movement execution and involves corticospinal neurons (CSp), which are broadly distributed in layer 5B of the motor and somatosensory cortices. CSp neurons innervate the spinal cord and are functionally diverse. However, whether CSp activity differs between different cortical areas throughout motor learning has been poorly explored. Given the importance and interaction between primary motor (M1) and somatosensory (S1) cortices related to movement, we examined the functional roles of CSp neurons in both areas. We induced the expression of GCaMP7s calcium indicator to perform photometric calcium recordings from layer 5B CSp neurons simultaneously in M1 and S1 cortices and track their activity while adult mice learned and performed a cued lever-press task. We found that during early learning sessions, the population calcium activity of CSp neurons in both cortices during movement did not change significantly. In late learning sessions the peak amplitude and duration of calcium activity CSp neurons increased in both, M1 and S1 cortices. However, S1 and M1 CSp neurons display a different temporal dynamic during movements that occurred when animals learned the task; both M1 and S1 CSp neurons activate before movement initiation, however, M1 CSp neurons continue active during movement performance, reinforcing the idea of the diversity of the CSp system and suggesting that CSp neuron activity in M1 and S1 cortices throughout motor learning have different functional roles for sensorimotor integration.

13.
Parasit Vectors ; 15(1): 487, 2022 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-36566237

RESUMO

Toxoplasma gondii is able to manipulate the host immune system to establish a persistent and efficient infection, contributing to the development of brain abnormalities with behavioral repercussions. In this context, this work aimed to evaluate the effects of T. gondii infection on the systemic inflammatory response and structure of the primary somatosensory cortex (PSC). C57BL/6 and BALB/c mice were infected with T. gondii ME49 strain tissue cysts and accompanied for 30 days. After this period, levels of cytokines IFN-γ, IL-12, TNF-α and TGF-ß were measured. After blood collection, mice were perfused and the brains were submitted to immunohistochemistry for perineuronal net (PNN) evaluation and cyst quantification. The results showed that C57BL/6 mice presented higher levels of TNF-α and IL-12, while the levels of TGF-ß were similar between the two mouse lineages, associated with the elevated number of tissue cysts, with a higher occurrence of cysts in the posterior area of the PSC when compared to BALB/c mice, which presented a more homogeneous cyst distribution. Immunohistochemistry analysis revealed a greater loss of PNN labeling in C57BL/6 animals compared to BALB/c. These data raised a discussion about the ability of T. gondii to stimulate a systemic inflammatory response capable of indirectly interfering in the brain structure and function.


Assuntos
Córtex Somatossensorial , Síndrome de Resposta Inflamatória Sistêmica , Toxoplasma , Toxoplasmose , Animais , Camundongos , Interleucina-12/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Córtex Somatossensorial/imunologia , Córtex Somatossensorial/parasitologia , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Síndrome de Resposta Inflamatória Sistêmica/parasitologia , Toxoplasma/patogenicidade , Toxoplasmose/imunologia , Toxoplasmose/parasitologia , Fator de Crescimento Transformador beta/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
14.
J. health med. sci. (Print) ; 8(4): 259-265, oct.2022. tab, ilus
Artigo em Espanhol | LILACS | ID: biblio-1443243

RESUMO

La siringomielia supone un desafío diagnóstico, ya que es una entidad poco reconocida si no se tiene conciencia de su existencia. Al ser un cuadro progresivo, cuya clínica puede presentarse de forma larvada y ser coincidente con otras patologías neurológicas tales como la esclerosis múltiple, su detección suele realizarse en etapas tardías sobre todo en población adulta y más aún cuando se presenta de forma adquirida. Por lo que el estudio imagenológico con Resonancia Magnética adquiere especial relevancia, permitiendo identificar y clasificar la enfermedad, lo que brindará la base para decidir terapía.


Syringomyelia is a diagnostic challenge, since it is a poorly recognized disease, especially if its existence remains unknown. Being a progressive disease, whose clinic can present in a latent way and be coincident with other neurological pathologies such as multiple sclerosis, its detection is usually conducted in late stages, especially in the adult population and even more when it presents in an acquired way. Therefore, the imaging study with Magnetic Resonance acquires special relevance, allowing to be identified and classified, which will provide the basis for deciding on therapy


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Siringomielia/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Siringomielia/terapia
15.
Odovtos (En línea) ; 24(2)ago. 2022.
Artigo em Inglês | LILACS, SaludCR | ID: biblio-1386589

RESUMO

Abstract Evidence has been reported that shows that somatosensory perception can be altered by a trigeminal injury resulting from maxillofacial surgical procedures. However, the surgical procedures that most frequently cause trigeminal lesions and the risk factors are unknown. In the same way, there is little information on what has been determined in preclinical models of trigeminal injury. This article integrates relevant information on trigeminal injury from both clinical findings and primary basic science studies. This review shows that the age and complexity of surgical procedures are essential to induce orofacial sensory alterations.


Resumen Se han reportado evidencias que demuestran que la percepción somatosensorial puede ser alterada por la lesión trigeminal producto de procedimientos quirúrgicos maxilofaciales. Sin embargo, se desconoce cuáles son los procedimientos quirúrgicos que más frecuentemente producen lesiones trigeminales, y los factores de riesgo. De la misma forma hay poca información sobre lo que se ha determinado en modelos preclínicos de lesión trigeminal. El objetivo de este artículo es integrar información relevante sobre la lesión trigeminal desde los hallazgos clínicos como los principales estudios de ciencia básica. Esta revisión demuestra que la edad y el tipo de procedimiento son fundamentales para inducir alteraciones sensoriales orofaciales, así como los procesos neurobiológicos que subyacen a estos padecimientos.


Assuntos
Humanos , Cirurgia Bucal , Distúrbios Somatossensoriais , Dor Facial , Traumatismos do Nervo Trigêmeo
16.
J Neurosurg Case Lessons ; 3(23): CASE21315, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35733824

RESUMO

BACKGROUND: Primary central nervous system germinomas of the medulla oblongata are extremely rare and usually have been found in young female Asian patients. The authors present an illustrative case of a patient who presented with severe medullary and posterior cord syndrome, the first South American case published to date, to the authors' knowledge. OBSERVATIONS: Initially, the radiological differential diagnosis did not include this entity. The lesion was located at the obex and exhibited a well-delineated contrast enhancement without hydrocephalus. An emergency decompressive partial resection following functional limits was performed. After histological confirmation, radiotherapy was indicated, with complete remission achieved at a 6-month follow-up. The patient, however, continued to have a severe proprioceptive disorder. The literature review identified 21 other such patients. The mean age for this location was 23 years, with a strong female and Asian origin predilection. All tumors exhibited contrast enhancement, and only one presented with hydrocephalus. LESSONS: In the absence of elevated tumor markers, radiological clues such as a well-delineated, contrast-enhanced lesion arising from the obex, without hydrocephalus, associated with demographic features such as young age, female sex, and Asian heritage, should evoke a high level of suspicion for this diagnosis. Gross total resection must not be attempted, because this tumor is potentially curable with high-dose radiotherapy.

17.
Front Neuroanat ; 16: 763245, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35370567

RESUMO

The plasticity of the central nervous system (CNS) allows the change of neuronal organization and function after environmental stimuli or adaptation after sensory deprivation. The so-called critical period (CP) for neuroplasticity is the time window when each sensory brain region is more sensitive to changes and adaptations. This time window is usually different for each primary sensory area: somatosensory (S1), visual (V1), and auditory (A1). Several intrinsic mechanisms are also involved in the start and end of the CP for neuroplasticity; however, which is its duration in S1, VI, and A1? This systematic review evaluated studies on the determination of these time windows in small rodents. The careful study selection and methodological quality assessment indicated that the CP for neuroplasticity is different among the sensory areas, and the brain maps are influenced by environmental stimuli. Moreover, there is an overlap between the time windows of some sensory areas. Finally, the time window duration of the CP for neuroplasticity is predominant in S1.

18.
Percept Mot Skills ; 129(3): 570-590, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35452588

RESUMO

Considering that somatosensory impairments may impact motor performance in individuals with cerebral palsy (CP), a better understanding of these relations is relevant to planning interventions. To synthesize research evidence to date on the interrelationships between the somatosensory functions of touch and proprioception with motor functions in persons with CP, we systematically searched Embase, CINAHL, PsycINFO, and Medline databases for studies relating these variables that were published in English from the inception of these databases to November 2020. We targeted the following content categories in our literature search: (a) cerebral palsy; (b) sensory functions; (c) tactile functions; (d) proprioception functions; and (e) motor functions. The selection, data extraction, and methodological quality assessment of these studies were performed in duplicate. We retrieved and analyzed information regarding the studies' methodological approaches and synthesized results. The 11 studies that met our inclusion criteria showed that, in individuals with CP, impairments in tactile discrimination, proprioception, and stereognosis are related to motor functions in terms of overall manual ability, grip strength, postural control and locomotion. Thus, clinical practitioners should attend to somatosensory aspects of motor impairment in individuals with CP. More research is needed to clarify the direction of these associations.


Assuntos
Paralisia Cerebral , Transtornos Motores , Percepção do Tato , Humanos , Propriocepção , Tato
19.
Front Hum Neurosci ; 16: 860965, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35479184

RESUMO

Background: We investigated whether transcranial magnetic stimulation (rTMS) over the primary somatosensory cortex (S1) and sensory stimulation (SS) could promote upper limb recovery in participants with subacute stroke. Methods: Participants were randomized into four groups: rTMS/Sham SS, Sham rTMS/SS, rTMS/SS, and control group (Sham rTMS/Sham SS). Participants underwent ten sessions of sham or active rTMS over S1 (10 Hz, 1,500 pulses, 120% of resting motor threshold, 20 min), followed by sham or active SS. The SS involved active sensory training (exploring features of objects and graphesthesia, proprioception exercises), mirror therapy, and Transcutaneous electrical nerve stimulation (TENS) in the region of the median nerve in the wrist (stimulation intensity as the minimum intensity at which the participants reported paresthesia; five electrical pulses of 1 ms duration each at 10 Hz were delivered every second over 45 min). Sham stimulations occurred as follows: Sham rTMS, coil was held while disconnected from the stimulator, and rTMS noise was presented with computer loudspeakers with recorded sound from a real stimulation. The Sham SS received therapy in the unaffected upper limb, did not use the mirror and received TENS stimulation for only 60 seconds. The primary outcome was the Body Structure/Function: Fugl-Meyer Assessment (FMA) and Nottingham Sensory Assessment (NSA); the secondary outcome was the Activity/Participation domains, assessed with Box and Block Test, Motor Activity Log scale, Jebsen-Taylor Test, and Functional Independence Measure. Results: Forty participants with stroke ischemic (n = 38) and hemorrhagic (n = 2), men (n = 19) and women (n = 21), in the subacute stage (10.6 ± 6 weeks) had a mean age of 62.2 ± 9.6 years, were equally divided into four groups (10 participants in each group). Significant somatosensory improvements were found in participants receiving active rTMS and active SS, compared with those in the control group (sham rTMS with sham SS). Motor function improved only in participants who received active rTMS, with greater effects when active rTMS was combined with active SS. Conclusion: The combined use of SS with rTMS over S1 represents a more effective therapy for increasing sensory and motor recovery, as well as functional independence, in participants with subacute stroke. Clinical Trial Registration: [clinicaltrials.gov], identifier [NCT03329807].

20.
Arq. neuropsiquiatr ; Arq. neuropsiquiatr;80(2): 208-210, Feb. 2022. graf
Artigo em Inglês | LILACS | ID: biblio-1364371

RESUMO

ABSTRACT In 1951, the physiologist George Duncan Dawson presented his work with the averaging of the signal in the evoked potentials (EPs), opening a new stage in the development of clinical neurophysiology. The authors present aspects of Professor Dawson's biography and a review of his work on the EPs and, mainly, the article reveals the new technique in detail that would allow the growth of the clinical application of the visual, auditory, and somatosensory EPs.


RESUMO Em 1951 o fisiologista George Duncan Dawson apresentou seu trabalho com a promediação de sinal nos potenciais evocados, abrindo uma nova etapa no desenvolvimento da neurofisiologia clínica. Os autores apresentam aspectos da biografia do professor Dawson e uma revisão de seus trabalhos sobre os potenciais evocados, principalmente do artigo que mostrava a nova técnica, que viria a permitir o crescimento da aplicação clínica dos potenciais evocados visual, auditivo e somatossensitivo.


Assuntos
Humanos , História do Século XX , Invenções , Neurofisiologia/métodos , Potenciais Evocados , Potenciais Somatossensoriais Evocados , Potenciais Evocados Visuais
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