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2.
J Clin Neurophysiol ; 36(6): 415-421, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31688324

RESUMO

Blinking is one of the motor acts performed more frequently by healthy human subjects. It involves the reciprocal action of at least two muscles: the orbicularis oculi shows a brief phasic activation while the levator palpebrae shows transient inhibition. In clinical practice, noninvasive recording of the orbicularis oculi activity is sufficient to obtain useful information for electrodiagnostic testing. Blinking can be spontaneous, voluntary, or reflex. Although the analysis of spontaneous blinks can already furnish interesting data, most studies are based on reflex blinking. This article is a review of some of the alterations that can be observed in blinking, focusing in four patterns of abnormality that can be distinguished in the blink reflex: (1) afferent versus efferent, which allows characterization of trigeminal or facial lesions; (2) peripheral versus central, which distinguishes alterations in nerve conduction from those involving synaptic delay; (3) upper versus lower brainstem lesions, which indicates the lesions involving specific circuits for trigeminal and somatosensory blink reflexes; and (4) asymmetric abnormal excitability pattern, which shows a unilateral alteration in the descending control of excitability in brainstem circuits. The blink reflex excitability recovery curve to paired stimuli may provide information about other modulatory inputs to trigemino-facial circuits, such as those proposed for the connection between basal ganglia and trigeminal neurons. Finally, prepulse inhibition of blink reflex reflects the motor surrogate of subcortical gating on sensory volleys, which is still another window by which electrodiagnosis can document motor control mechanisms and their abnormalities in neurologic diseases.


Assuntos
Piscadela/fisiologia , Reflexo/fisiologia , Eletromiografia/métodos , Feminino , Humanos , Masculino , Doenças do Sistema Nervoso/diagnóstico
3.
Epileptic Disord ; 21(4): 353-357, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371276

RESUMO

Coughing is a reflex phenomenon that is protective for the upper airways, involving both a reflex arc in the brainstem and cortical control. Ictal coughing has been prominently reported in temporal lobe seizures, but precise anatomo-electrical correlations are lacking. We report a patient who presented with persistent coughing at seizure onset. We studied intracerebrally recorded seizures (using stereo-electroencephalography) in order to describe the anatomo-functional correlations associated with this sign. Coughing followed seizure onset in the medial temporal lobe. A functional connectivity study (h2 estimation of interdependencies) showed that during coughing, a network of cortical and subcortical regions was involved, particularly the perisylvian cortices and the caudate nucleus.


Assuntos
Encéfalo/fisiopatologia , Tosse/fisiopatologia , Eletroencefalografia , Epilepsia do Lobo Temporal/fisiopatologia , Eletroencefalografia/métodos , Humanos , Reflexo/fisiologia , Convulsões/fisiopatologia
4.
Exp Brain Res ; 237(10): 2595-2605, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31372688

RESUMO

The neural mechanisms of walking impairment after stroke are not well characterized. Specifically, there is a need for understanding the mechanisms of impaired plantarflexor power generation in late stance. Here, we investigated the association between two neurophysiologic markers, the long-latency reflex (LLR) response and dynamic facilitation of antagonist motor-evoked responses, and walking function. Fourteen individuals with chronic post-stroke hemiparesis and thirteen healthy controls performed both isometric and dynamic plantarflexion. Transcranial magnetic stimulation (TMS) assessed supraspinal drive to the tibialis anterior. LLR activity was assessed during dynamic voluntary plantarflexion and individuals post-stroke were classified as either LLR present (LLR+) or absent (LLR-). All healthy controls and nine individuals post-stroke exhibited LLRs, while five did not. LLR+ individuals revealed higher clinical scores, walking speeds, and greater ankle plantarflexor power during walking compared to LLR- individuals. LLR- individuals exhibited exaggerated responses to TMS during dynamic plantarflexion relative to healthy controls. The LLR- subset revealed dysfunctional modulation of stretch responses and antagonist supraspinal drive relative to healthy controls and the higher functioning LLR+ individuals post-stroke. These abnormal physiologic responses allow for characterization of individuals post-stroke along a dimension that is clinically relevant and provides additional information beyond standard behavioral assessments. These findings provide an opportunity to distinguish among the heterogeneity of lower extremity motor impairments present following stroke by associating them with responses at the nervous system level.


Assuntos
Extremidade Inferior/fisiopatologia , Reflexo/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Caminhada/fisiologia , Adulto , Idoso , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Tempo de Reação/fisiologia , Reflexo de Estiramento/fisiologia , Acidente Vascular Cerebral/complicações , Estimulação Magnética Transcraniana/métodos
5.
Med Hypotheses ; 131: 109286, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31443768

RESUMO

Traumatic retinal injuries are commonly encountered in most retinal subspecialty clinics. Retinal dialysis, detachment and other complications consequent to blunt trauma are often thought to be due to equatorial expansion of the globe following an antero-posterior compressive force. However, stretching of the globe along the primary anatomical equator may not hold true for the adjusted globe position as a consequence of the protective Bell's phenomenon which gets activated before impact. The upward and outward rolling of the globe likely creates a new equator, with the compressive forces acting along this new plane, thereby leading to stretching along the ocular coats closer to the retinal periphery. Additionally, the coup and countercoup mechanisms with increased vulnerability of temporal sclera predisposes to retinal complications more commonly along the temporal and the nasal retina. Further, retinal complications involving other quadrants can also be explained through understanding of the Bell's phenomenon.


Assuntos
Traumatismos Oculares/complicações , Movimentos Oculares/fisiologia , Modelos Biológicos , Reflexo/fisiologia , Retina/lesões , Perfurações Retinianas/etiologia , Ferimentos não Penetrantes/complicações , Animais , Traumatismos Oculares/fisiopatologia , Cabras , Humanos , Músculos Oculomotores/lesões , Pressão , Perfurações Retinianas/prevenção & controle , Ferimentos não Penetrantes/fisiopatologia
6.
Hypertension ; 74(4): 910-920, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31422690

RESUMO

Hypertension is associated with increased sympathetic activity. A component of this sympathoexcitation may be driven by increased signaling from sensory endings from the heart to the autonomic control areas in the brain. This pathway mediates the so-called cardiac sympathetic afferent reflex, which is also activated by coronary ischemia or other nociceptive stimuli in the heart. The cardiac sympathetic afferent reflex has been shown to be enhanced in the heart failure state and in renal hypertension. However, little is known about its role in the development or progression of hypertension or the phenotype of the sensory endings involved. To investigate this, we used the selective afferent neurotoxin, resiniferatoxin (RTX) to chronically abolish the cardiac sympathetic afferent reflex in 2 models of hypertension; the spontaneous hypertensive rats (SHRs) and AngII (angiotensin II) infusion (240 ng/kg per min). Blood pressure (BP) was measured in conscious animals for 2 to 8 weeks post-RTX. Epidural application of RTX to the T1-T4 spinal segments prevented the further BP increase in 8-week-old SHR and lowered BP in 16-week-old SHR. RTX did not affect BP in Wistar-Kyoto normotensive rats nor in AngII-infused rats. Epicardial application of RTX (50 µg/mL) in 4-week-old SHR prevented the BP increase whereas this treatment does not lower BP in 16-week-old SHR. When RTX was administered into the L2-L5 spinal segments of 16-week-old SHR, no change in BP was observed. These findings indicate that signaling via thoracic afferent nerve fibers may contribute to the hypertension phenotype in the SHR but not in the Ang II infusion model of hypertension.


Assuntos
Pressão Sanguínea/fisiologia , Gânglios Espinais/metabolismo , Coração/inervação , Hipertensão/metabolismo , Canais de Cátion TRPV/agonistas , Angiotensina II , Animais , Pressão Arterial/efeitos dos fármacos , Pressão Arterial/fisiologia , Pressão Sanguínea/efeitos dos fármacos , Diterpenos/farmacologia , Gânglios Espinais/efeitos dos fármacos , Coração/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Hipertensão/induzido quimicamente , Masculino , Neurotoxinas/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley , Reflexo/efeitos dos fármacos , Reflexo/fisiologia , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/metabolismo
7.
J Physiol Sci ; 69(5): 749-756, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31270742

RESUMO

The effects of the pharyngeal non-noxious mechanical stimulation on the secretion of immunoreactive thyroxin (iT4), immunoreactive calcitonin (iCT), and immunoreactive parathyroid hormone (iPTH) into thyroid venous blood were examined in anesthetized rats. Secretion rates of iT4, iCT, and iPTH were calculated from their concentration in thyroid venous plasma and the plasma flow rate. A mechanical stimulation was delivered to the pharynx by a rubber balloon placed on the tongue that was intermittently pushed into the pharyngeal cavity. Pharyngeal stimulation increased iT4 and iCT secretion, but iPTH secretion was unchanged. The secretion responses were abolished by transecting the superior laryngeal nerves (SLNs) bilaterally. The activities of the thyroid parasympathetic efferent nerves and the afferent nerves in the SLN increased significantly during pharyngeal stimulation. These results indicate that pharyngeal mechanical stimulation promotes thyroxin and calcitonin secretion from the thyroid gland by a reflex increase in SLN parasympathetic efferent activity, triggered by excitation of SLN mechanoreceptive afferents.


Assuntos
Calcitonina/metabolismo , Faringe/metabolismo , Glândula Tireoide/metabolismo , Tiroxina/metabolismo , Vias Aferentes/metabolismo , Animais , Estimulação Elétrica/métodos , Nervos Laríngeos/metabolismo , Masculino , Hormônio Paratireóideo/metabolismo , Ratos , Ratos Sprague-Dawley , Reflexo/fisiologia
8.
Handb Clin Neurol ; 160: 419-433, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31277866

RESUMO

The evaluation of autonomic function requires indirect assessment of neurophysiologic function using specialized equipment that is often available only at tertiary care centers, with few specialists available. However, the evaluation of autonomic function is rooted in basic physiology, and the results can be interpreted by careful consideration of the context of the problem. Many automated devices have become widely available to test autonomic function, but they tend to gather inadequate data leading to frequent misdiagnosis and clinical confusion. We review the details necessary for the neurophysiologist to properly perform, and interpret, autonomic function testing.


Assuntos
Doenças do Sistema Nervoso Autônomo/diagnóstico , Sistema Nervoso Autônomo/fisiologia , Reflexo/fisiologia , Sudorese/fisiologia , Manobra de Valsalva/fisiologia , Sistema Nervoso Autônomo/fisiopatologia , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Humanos , Teste da Mesa Inclinada/métodos
9.
Neurology ; 93(5): e518-e521, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31243069

RESUMO

OBJECTIVE: To determine whether high placebo effects observed in recently published clinical noninvasive vagal nerve stimulation (nVNS) trials can be attributed to an active modulation of the trigeminal-autonomic reflex by the sham device. METHODS: Twenty-eight healthy participants were investigated in a randomized, controlled, single-blind, within-participant design. The 4 different conditions of no stimulation, regular nVNS of the left cervical vagal nerve, stimulation of the posterior neck with the same device (sham I), and stimulation of the left cervical vagal nerve with a sham device (sham II) were applied in randomized order. Parasympathetic output (lacrimation) was provoked with kinetic oscillation stimulation (KOS) of the nasal mucosa. Lacrimation was quantified with the Schirmer II test, an objective measure of lacrimal secretion after local anesthesia, and the difference between baseline and KOS-induced lacrimation served as a measure of autonomic output. RESULTS: nVNS treatment resulted in a significant reduction of ipsilateral KOS-induced lacrimation compared to no stimulation (p = 0.003) and sham I (p = 0.02). A similar effect was observed for sham II (p = 0.003, p = 0.001). There was no significant difference between nVNS and sham II. CONCLUSION: These results suggest that both the regular nVNS and the sham device used in some of the clinical nVNS trials modulate the trigeminal-autonomic reflex. This could explain the high sham effect in these trials and suggests that stimulation of the posterior neck may be considered as a real sham condition.


Assuntos
Sistema Nervoso Parassimpático/fisiologia , Placebos , Reflexo/fisiologia , Lágrimas/fisiologia , Nervo Trigêmeo/fisiologia , Estimulação do Nervo Vago/métodos , Adulto , Sistema Nervoso Autônomo/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Método Simples-Cego , Adulto Jovem
10.
World J Gastroenterol ; 25(19): 2315-2326, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31148903

RESUMO

BACKGROUND: Electroacupuncture (EA) at ST36 can significantly improve gastrointestinal symptoms, especially in promoting gastrointestinal motility. The automatic nervous system plays a main role in EA, but few studies exist on how vagovagal and sympathetic reflexes affect EA to regulate gastrointestinal motility. AIM: To study the role of vagovagal and sympathetic reflexes in EA at ST36, as well as the associated receptor subtypes that are involved. METHODS: Gastric motility was measured with a manometric balloon placed in the gastric antrum area in anesthetized animals. The peripheral nervous discharge was measured using a platinum electrode hooking the vagus or greater splanchnic nerve, and the central nervous discharge was measured with a glass microelectrode in the dorsal motor nucleus of the vagus (DMV). The effects and mechanisms of EA at ST36 were explored in male Sprague-Dawley rats which were divided in to a control group, vagotomy group, sympathectomy group, and microinjection group [including an artificial cerebrospinal fluid group, glutamate (L-Glu) group, and γ-aminobutyric acid (GABA) group] and in genetically modified male mice [ß1ß2 receptor-knockout (ß1ß2-/-) mice, M2M3 receptor-knockout (M2M3-/-) mice, and wild-type control mice]. RESULTS: EA at ST36 promoted gastric motility during 30-120 s. During EA, both vagus and sympathetic nerve discharges increased, with a much higher frequency of vagus nerve discharge than sympathetic discharge. The gastric motility mediated by EA at ST36 was interdicted by vagotomy. However, gastric motility mediated by EA at ST36 was increased during 0-120 s by sympathectomy, which eliminated the delay effect of EA during 0-30 s, but it was lower than the control group during 30-120 s. Using gene knockout mice and their wild-type controls to explore the receptor mechanisms, we found that EA at ST36 decreased gastric motility in M2/3-/- mice, and promoted gastric motility in ß1/2-/- mice. Extracellular recordings showed that EA at ST36 increased spikes of the DMV. Microinjection of L-Glu into the DMV increased gastric motility, while EA at ST36 decreased gastric motility during 0-60 s, and promoted gastric motility during 60-120 s. Injection of GABA reduced or increased gastric motility, and reduced the promoting gastric motility effect of EA at ST36. CONCLUSION: These data suggest that EA at ST36 modulates gastric motility via vagovagal and sympathetic reflexes mediated through M2/3 and ß1/2 receptors, respectively. Sympathetic nerve activity mediated through ß1/2 receptors is associated with an early delay in modulation of gastric motility by EA at ST36.


Assuntos
Pontos de Acupuntura , Eletroacupuntura/métodos , Motilidade Gastrointestinal/fisiologia , Reflexo/fisiologia , Animais , Masculino , Camundongos , Modelos Animais , Ratos , Ratos Sprague-Dawley , Sistema Nervoso Simpático/fisiologia , Nervo Vago/fisiologia
11.
Physiology (Bethesda) ; 34(4): 264-282, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31165684

RESUMO

The carotid body has emerged as a therapeutic target for cardio-respiratory-metabolic diseases. With the expansive functions of the chemoreflex, we sought mechanisms to explain differential control of individual responses. We purport a remarkable correlation between phenotype of a chemosensory unit (glomus cell-sensory afferent) with a distinct component of the reflex response. This logic could permit differential modulation of distinct chemoreflex responses, a strategy ideal for therapeutic exploitation.


Assuntos
Encéfalo/fisiologia , Corpo Carotídeo/fisiologia , Animais , Células Quimiorreceptoras/fisiologia , Humanos , Lógica , Reflexo/fisiologia
12.
J Clin Neurosci ; 65: 17-22, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31080004

RESUMO

Pain sensitivity is a recognized feature of fibromyalgia syndrome (FMS) but the contribution of spinal nociceptive circuitry to this phenomenon is unknown. Therefore, the objectives were to study the changes in spinal nociception i.e. nociceptive flexion reflex (NFR) in patients with FMS and to investigate correlation if any, between NFR threshold, pain duration and tender points in FMS. One hundred and three patients with FMS and 74 healthy volunteers participated in the study. To record NFR, sural nerve was stimulated in the retro malleolar region and the reflex response was recorded from the short head of biceps femoris muscle. NFR was elicited at significantly lower [21.0(18.0-25.0)V] thresholds in FMS group when compared to healthy subjects [30.0(24.75-35.0)V; p = 0.001] indicating hyperalgesic response to electrocutaneous stimulation in FMS patients. The latency and other parameters of NFR were comparable in both the groups. No significant correlation was found among NFR threshold and pain duration or tender points. On the basis of results of present study, it may be concluded that the functional deficit of the spinal nociceptive system can contribute to hyperalgesia in FMS. This is first study that correlates a marker of central hyper-excitability (NFR threshold) with clinical symptoms (pain duration and tender points) of FMS.


Assuntos
Fibromialgia/fisiopatologia , Hiperalgesia/fisiopatologia , Nociceptividade/fisiologia , Limiar da Dor/fisiologia , Adulto , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/fisiopatologia , Reflexo/fisiologia
13.
Exp Brain Res ; 237(7): 1793-1803, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31053895

RESUMO

Transcutaneous spinal cord stimulation (tSCS) is a useful technique for the clinical assessment of neurological disorders. However, the characteristics of the spinal cord circuits activated by tSCS are not yet fully understood. In this study, we examined whether remote muscle contraction enhances the spinal reflexes evoked by tSCS in multiple lower-limb muscles. Eight healthy men participated in the current experiment, which required them to grip a dynamometer as fast as possible after the presentation of an auditory cue. Spinal reflexes were evoked in multiple lower-limb muscles with different time intervals (50-400 ms) after the auditory signals. The amplitudes of the spinal reflexes in all the recorded leg muscles significantly increased at 50-250 ms after remote muscle activation onset. This suggests that remote muscle contraction simultaneously facilitates the spinal reflexes in multiple lower-limb muscles. In addition, eight healthy men performed five different tasks (i.e., rest, hand grip, pinch grip, elbow flexion, and shoulder flexion). Compared to control values recorded just before each task, the spinal reflexes evoked at 250 ms after the auditory signals were significantly enhanced by the above tasks except for the rest task. This indicates that such facilitatory effects are also induced by remote muscle contractions in different upper-limb areas. The present results demonstrate the existence of a neural interaction between remote upper-limb muscles and spinal reflex circuits activated by tSCS in multiple lower-limb muscles. The combination of tSCS and remote muscle contraction may be useful for the neurological examination of spinal cord circuits.


Assuntos
Retroalimentação Sensorial/fisiologia , Extremidade Inferior/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Reflexo/fisiologia , Estimulação da Medula Espinal/métodos , Adulto , Humanos , Extremidade Inferior/inervação , Masculino , Adulto Jovem
14.
Exp Brain Res ; 237(8): 1959-1971, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31129695

RESUMO

Chronic ankle instability (CAI) is characterized by persistent giving way at the ankle following an acute lateral ankle sprain and is associated with an early onset of osteoarthritis. Researchers have reported that the cutaneous afferent pathway from certain leg muscles is modified in people with CAI while in a seated position. However, we do not know if these reflex modulations persist during functional activities. The purpose of this study was to further explore sensorimotor function in patients with CAI by analyzing cutaneous reflex modulation during gait. CAI (n = 11) and uninjured control (n = 11) subjects walked on a treadmill at 4 km/h and received non-noxious sural nerve stimulations at eight different time points during the gait cycle. Net electromyographic responses from four lower leg muscles were quantified 80-120 ms after stimulation for each phase of the gait cycle and compared between groups. We found that cutaneous reflex responses between groups were largely similar from the late stance to late swing phases, but uninjured control subjects, and not CAI subjects, experienced significant suppression in the medial gastrocnemius and lateral gastrocnemius muscles during the early stance phase of the gait cycle. Our results indicate that people with CAI lack a protective unloading response in the triceps surae following high-intensity sural nerve stimulation during the early stance phase of the gait cycle. Evaluating cutaneous reflex modulations may help to identify neural alterations in the reflex pathways that contribute to functional deficits in those with CAI.


Assuntos
Articulação do Tornozelo/fisiopatologia , Instabilidade Articular/fisiopatologia , Reflexo/fisiologia , Caminhada/fisiologia , Adolescente , Doença Crônica , Estimulação Elétrica/métodos , Eletromiografia/métodos , Teste de Esforço/métodos , Feminino , Humanos , Instabilidade Articular/diagnóstico , Masculino , Adulto Jovem
15.
eNeuro ; 6(2)2019.
Artigo em Inglês | MEDLINE | ID: mdl-31043462

RESUMO

There is evidence that a variety of central and afferent stimuli, including swallowing, can produce phase resetting in the respiratory rhythmicity. Also, there are reports about the intrinsic linkage between locomotion and respiration. However, little is known about the interaction between the central pattern generators (CPGs) for scratching and respiration. The present study aims to examine whether the activation of scratching CPG produces phase resetting of the respiratory rhythm. We employed decerebrate cats to apply brief tactile stimuli to the pinna during the inspiratory-expiratory transition. We observed that those stimuli to the pinna not eliciting fictive scratching did not reset the respiratory rhythm. However, when the pinna stimuli elicited fictive scratching, then the respiratory rhythm exhibited a significant phase resetting. We also found interneurons in the medulla oblongata exhibiting phase resetting related to scratching-CPG episodes. This second finding suggests that this type of resetting involves brainstem components of the respiratory CPG. These results shed new light on the resetting action from a spinal CPG on the respiratory rhythm.


Assuntos
Geradores de Padrão Central/fisiologia , Interneurônios/fisiologia , Bulbo/fisiologia , Periodicidade , Reflexo/fisiologia , Taxa Respiratória/fisiologia , Medula Espinal/fisiologia , Percepção do Tato/fisiologia , Animais , Gatos , Estado de Descerebração/fisiopatologia , Feminino , Masculino
16.
Eur Arch Otorhinolaryngol ; 276(6): 1737-1745, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31016388

RESUMO

PURPOSE: The aim of this study was to explore the diagnostic value of the combination of Acoustic Voice Quality Index (AVQI) and Glottal Function Index (GFI) as a screening tool for voice disorders, and to compare the AVQI measurements obtained using oral and smartphone (SP) microphones. METHODS: A study group consisted of 183 adult individuals including 86 subjects with normal voice and 97 patients with pathological voice. Voice recordings were performed simultaneously with an oral AKG Perception 220 and SP iPhone 6s microphones. To evaluate the diagnostic accuracy differentiating normal and pathological voice, the receiver-operating characteristic statistics [area under curve (AUC), positive and negative likelihood ratios (LR+ and LR-)], and correct classification rate (CCR) were used. RESULTS: The AVQI cut-off scores of 3.31 for oral and 3.32 for SP microphones were associated with very good test accuracy (AUC = 0.857 and AUC = 0.818), resulting in balance between sensitivity and specificity (70.0% vs 86.0% and 70% vs 87.0%). The CCR reached 78%. The combined AVQI and GFI cut-off scores of 6.65 for oral and 7.1 for SP microphones corresponded with excellent test accuracy (AUC = 0.976 and AUC = 0.965) and sensitivity and specificity (93.0% vs 93.0% and 91.0% vs 94%). Very respectable levels of LR+ and LR- both for oral microphone (13.3 and 0.08) and for SP microphone (15.6 and 0.10) voice recordings were achieved. CCRs of 93% and 92% confirmed the results of ROC statistics. CONCLUSIONS: Combination of AVQI and GFI measurements significantly improved diagnostic accuracy in differentiating normal vs pathological voice.


Assuntos
Glote/fisiopatologia , Smartphone , Acústica da Fala , Distúrbios da Voz/diagnóstico , Qualidade da Voz , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reflexo/fisiologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Adulto Jovem
17.
Neuroscience ; 408: 259-271, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30999033

RESUMO

Human studies have repeatedly shown that conditioning pain modulation (CPM) exerts an overall descending inhibitory effect over spinal nociceptive activity. Previous studies have reported a reduction of the nociceptive withdrawal reflex (NWR) under CPM. Still, how descending control influences the muscle activation patterns involved in this protective behavior remains unknown. This study aimed to characterize the effects of CPM on the withdrawal pattern assessed by a muscle synergy analysis of several muscles involved in the lower limb NWR. To trigger descending inhibition, CPM paradigm was applied using the cold-pressor test (CPT) as conditioning stimulus. Sixteen healthy volunteers participated. The NWR was evoked by electrical stimulation on the arch of the foot before, during and after the CPT. Electromyographic (EMG) activity of two proximal (rectus femoris and biceps femoris) and two distal (tibialis anterior and soleus) muscles was recorded. A muscle synergy analysis was performed on the decomposition of the EMG signals, based on a non-negative matrix factorization algorithm. Results showed that two synergies (Module I and II) were sufficient to describe the NWR pattern. Under CPM, Module I activation amplitude was significantly reduced in a narrow time-window interval (118-156 ms) mainly affecting distal muscles, whereas Module II activation amplitude was significantly reduced in a wider time-window interval (150-250 ms), predominantly affecting proximal muscles. These findings suggest that proximal muscles are largely under supraspinal control. The descending inhibitory drive exerted onto the spinal cord may adjust the withdrawal pattern by differential recruitment of the muscles involved in the protective behavior.


Assuntos
Músculo Esquelético/fisiopatologia , Nociceptividade/fisiologia , Limiar da Dor/fisiologia , Dor/fisiopatologia , Reflexo/fisiologia , Adulto , Estimulação Elétrica , Eletromiografia , Feminino , Humanos , Masculino , Medição da Dor , Adulto Jovem
18.
Am J Physiol Regul Integr Comp Physiol ; 316(6): R727-R734, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30943058

RESUMO

A reflex arising from contracting hindlimb muscle is responsible in part for the increases in arterial pressure and heart rate evoked by exercise. The afferent arm of this reflex comprises group III and IV afferents. δ-Opioid receptors are expressed predominately on the spinal endings of group III afferents, whereas µ-opioid receptors are expressed predominately on the spinal endings of group IV afferents. Using stimuli that activated group III afferents, namely static contraction, calcaneal tendon stretch, and lactic acid injection into the superficial epigastric artery, we tested the hypothesis that, in rats with either patent or ligated femoral arteries, activation of pre- and postsynaptic δ-opioid receptors in the dorsal horn attenuated pressor reflex responses to these stimuli. In rats with patent arteries or ligated femoral arteries, [d-Pen2,5]enkephalin (DPDPE), a δ-opioid agonist injected intrathecally (10 µg in 10 µl), significantly attenuated the pressor responses to contraction, stretch, and lactic acid (all P < 0.05). Naltrindole, a δ-opioid receptor antagonist, prevented the attenuation. In contrast, DPDPE did not attenuate the pressor response to capsaicin injection into the superficial epigastric artery in either group of rats (both P > 0.05). Intrathecal injection of saline (10 µl), the vehicle for DPDPE, had no effect on the pressor responses in either group of rats. We conclude that activation of spinal δ-opioid receptors attenuates reflexes evoked by group III afferents in both freely perfused and ligated rats.


Assuntos
D-Penicilina (2,5)-Encefalina/farmacologia , Condicionamento Físico Animal/fisiologia , Receptores Opioides delta/efeitos dos fármacos , Reflexo/fisiologia , Animais , Estado de Descerebração/fisiopatologia , Artéria Femoral/fisiopatologia , Frequência Cardíaca/fisiologia , Masculino , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Esforço Físico/fisiologia , Ratos Sprague-Dawley , Receptores Opioides mu/efeitos dos fármacos
19.
J Chin Med Assoc ; 82(1): 30-34, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30839400

RESUMO

BACKGROUNDS: Conditioned responses of paired nociceptive blink reflex (nBR) can reflect the excitability of trigeminofacial circuit. In the present study, we studied paired homotopic nBR with different inter-stimulus intervals (ISI). By monitoring different ISIs and consequential conditioned R2 of nBR, we aimed to investigate the impact of ISIs on the recovery cycle of nBR in normal individuals. METHODS: Twelve healthy volunteers (mean age: 29.9 ± 7.0 years; M/F: 7/5) were enrolled in this study. After individuals' reflex threshold was determined, triple pulses were given in pairs with ISIs 125 to 10000 milliseconds randomly. We calculated the ratio of conditioned and unconditioned nBR area-under-curve (AUC) (defined as recovery index), and amplitude of each ISI. RESULTS: The average latency of unconditioned nR2 is 42.6 ± 5.5 ms, with amplitude of 53.4 ± 43.9 µV and the AUC of 563.5 ± 480.6 ms·µV. The conditioned nBR/unconditioned nBR response ratio was less than 100% while the ISI is shorter than 1667 ms, suggesting an inhibited conditioned response. The recovery index and the amplitude of conditioned nBR gradually increased with increasing ISI. The recovery index was greater than 100% at ISI of 10 s (p = 0.005), implying full recovery and facilitation of conditioned nBR. CONCLUSION: Our study established the time-dependent dynamic recovery curve of paired nBR. The facilitated nBR at ISI longer than 10 s might be associated with temporal summation to the facial motor neurons after repeated stimuli. Our study results provided potential applications for patients with pain disorders involving trigeminofacial region.


Assuntos
Piscadela/fisiologia , Nervo Facial/fisiologia , Nociceptores/fisiologia , Reflexo/fisiologia , Nervo Trigêmeo/fisiologia , Adulto , Estimulação Elétrica , Feminino , Humanos , Masculino , Tempo de Reação
20.
Behav Neurosci ; 133(4): 398-413, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30869952

RESUMO

For almost 75 years, classical eyeblink conditioning has been an invaluable tool for assessing associative learning processes across many species, thanks to its high translatability and well-defined neural circuitry. Our laboratory has adapted the paradigm to extensively detail associative changes in the rabbit reflexive eyeblink response (unconditioned response, UR), characterized by postconditioning increases in the frequency, size, and latency of the UR when the periorbital shock unconditioned stimulus (US) is presented alone, termed conditioning-specific reflex modification (CRM). Because the shape and timing of CRM closely resembles the conditioned eyeblink response (CR) to the tone conditioned stimulus (CS), we previously tested whether CRs and CRM share a common neural substrate, the interpositus nucleus of the cerebellum (IP), and found that IP inactivation during conditioning blocked the development of both CRs and the timing aspect of CRM. The goal of the current study was to examine whether extinction of CRs and CRM timing, accomplished simultaneously with unpaired CS/US extinction, also involves the IP. Results showed that muscimol inactivation of the IP during extinction blocked CR expression but not extinction of CRs or CRM timing, contrasting with the literature showing IP inactivation prevents CR extinction during CS-alone presentations. The continued presence of the US throughout the unpaired extinction procedure may have been sufficient to overcome IP blockade, promoting plasticity in the cerebellar cortex and/or extracerebellar components of the eyeblink conditioning pathway that can modulate extinction of CRs and CRM timing. Results therefore add support to the distributed plasticity view of cerebellar learning. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Núcleos Cerebelares/fisiologia , Condicionamento Palpebral/fisiologia , Extinção Psicológica/fisiologia , Animais , Aprendizagem por Associação/fisiologia , Piscadela/fisiologia , Cerebelo , Condicionamento Clássico/fisiologia , Condicionamento Operante/fisiologia , Estimulação Elétrica , Masculino , Motivação , Muscimol/administração & dosagem , Coelhos , Reflexo/fisiologia , Incerteza
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