RESUMO
OBJECTIVES: Status epilepticus (SE) is a serious event associated with high mortality. This study aims to validate the recently developed ADAN (Abnormal speech, ocular Deviation, Automatisms, and Number of motor epileptic seizures) scale for detecting high risk for SE. MATERIAL AND METHODS: Prospective, multicenter, observational study in adults with suspected epileptic seizures. Consecutive recruitment took place over a 27-month period in 4 hospital emergency departments (EDs). The main endpoint was the proportion of patients with criteria for SE based on the collection and analysis of clinical characteristics and the ADAN scale criteria on arrival at the ED. RESULTS: Of the 527 patients recruited, 203 (38.5%) fulfilled the criteria that predicted SE. Multiple regression analysis demonstrated that the 4 ADAN criteria were the only variables independently associated with a final diagnosis of SE (P .001). The predictive power of the scale was 90.9% (95% CI, 88.4%-93.4%) for a final SE diagnosis. We established 3 risk groups based on ADAN scores: low (score, 0-1: 8.7%), moderate (2, 46.6%), and high (> 2, 92.6%). A cut point of more than 1 had a sensitivity of 88.2% for predicting SE, specificity of 77.8%, positive predictive value of 71.3%, and negative predictive value of 91.3%. CONCLUSION: The ADAN scale is a prospectively validated, simple clinical tool for identifying patients in the ED who are at high risk for SE.
OBJETIVO: El estado epiléptico (EE) es una enfermedad grave con elevada mortalidad. Este estudio tiene como objetivo validar la escala ADAN, propuesta recientemente para identificar pacientes con alto riesgo de desarrollar un EE. METODO: Se realizó un estudio prospectivo, multicéntrico y observacional que incluyó a pacientes adultos con sospecha de crisis epilépticas. Se llevó a cabo un reclutamiento consecutivo durante 27 meses en los servicios de urgencias (SU) de cuatro hospitales. La variable principal fue la proporción de pacientes que cumplían criterios para EE. Se han recopilado y analizado las características clínicas y la puntuación en la escala ADAN a su llegada al SU. RESULTADOS: Se reclutaron 527 pacientes, de los cuales 203 (38,5%) cumplieron criterios de EE. En el análisis de regresión múltiple, se demostró que el habla anormal, la desviación ocular, los automatismos y el número de crisis epilépticas motoras fueron las únicas variables independientemente asociadas con un diagnóstico final de EE (p 0,001). La capacidad predictiva de la escala fue del 90,9% (intervalo de confianza del 95%, 88,4-93,4) para identificar el EE como diagnóstico final. Se establecieron tres grupos de riesgo: bajo (0 1 puntos: 8,7%), moderado (2: 46,6%) y alto (> 2: 92,6%). Una puntuación de corte > 1 punto proporcionó una sensibilidad del 88,2%, especificidad del 77,8%, valor predictivo positivo del 71,3% y valor predictivo negativo del 91,3% para predecir el EE. CONCLUSIONES: La escala ADAN es una herramienta clínica simple y validada de manera prospectiva para identificar, en los SU, a los pacientes con elevado riesgo de EE.
Assuntos
Serviço Hospitalar de Emergência , Estado Epiléptico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco/métodos , Estado Epiléptico/diagnósticoRESUMO
PURPOSE: Transcranial direct current stimulation (tDCS) can change the excitability of the central nervous system and contribute to motor recovery of stroke patients. The aim of our study was to examine the short- and long-term effects of real versus sham bihemispheric tDCS combined with repetitive peripheral nerve stimulation in patients with acute stroke and a severe motor impairment. METHODS: The study was prospective, randomized, double blind, and placebo controlled. Nineteen acute stroke patients (ischemic and hemorrhagic) with upper limb Fugl-Meyer mean score of <19 were randomized in two groups: one group received five consecutive daily sessions of anodal tDCS over the affected hemisphere and cathodal over unaffected hemisphere combined with repetitive peripheral nerve stimulation and the other received sham tDCS associated to repetitive peripheral nerve stimulation. Clinical and neurophysiological assessment was applied before tDCS, 5 days after tDCS, and 3, 6, and 12 months after tDCS. RESULTS: There were significant time-related changes in both groups of patients in motor evoked potentials, somatosensory evoked potentials, Hmax:Mmax ratio, upper limb Fugl-Meyer scores, and Modified Ashworth scales scores ( P < 0.05). However, no significant differences between groups were present at any time ( P > 0.05). CONCLUSIONS: Bihemispheric tDCS and repetitive peripheral nerve stimulation with the parameters of our study did not add significant short- or long-term clinical improvement or change in neurophysiological data in severe acute stroke patients in comparison to sham stimulation. The severity of motor impairment in stroke patients may influence a possible response to an interventional tDCS treatment.
Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Estimulação Transcraniana por Corrente Contínua , Humanos , Nervos Periféricos , Estudos Prospectivos , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/terapia , Resultado do Tratamento , Extremidade SuperiorRESUMO
OBJECTIVES: De novo aphasic status epilepticus (ASE) in patients without a previous history of epilepsy and without cerebral lesions (aphasic NOSE) is rare. The aim of the study is to describe its clinical characteristics, etiologies, and outcome. MATERIALS & METHODS: Single-center study including consecutive patients presenting to the emergency department between 2011 and 2019 with acute aphasia, which was finally diagnosed as aphasic NOSE. Subsequent episodes of aphasia (>5 min) were recorded and divided into confirmed ASE and postictal aphasic episodes (non-ASE). Clinical characteristics of the two types of episodes were compared. RESULTS: Nineteen patients were included, suffering fifty episodes of epileptic aphasia, episodes per patient 2.6 (range 1-7). Fifteen patients (71.4%) were women, mean age at ASE onset was 66.05 years old (SD 6.3). Nine (47%) patients died, 6 of them (66.7%) during the aphasic episode. Ictal EEG was available in 37 episodes, confirming the diagnosis of ASE in 12 episodes; in 8 episodes, the EEG fulfilled the criteria of possible ASE. The most frequent etiologies were inflammatory and vascular. Comparing ASE with non-ASE episodes, ASE was longer than non-ASE (225 vs 65 h, p .024) and was treated more frequently with BZD (76 vs 24%, p .001) but with a longer delay (22.2 vs 1.5 h, p .06). CONCLUSIONS: ASE is a treatable, highly relapsing emergency, with the subsequent relapses ASE or postictal aphasia. EEG is diagnostic in half of the patients, while in others imaging techniques are also useful. Benzodiazepines should be administered. Persistent aphasia, of more than 65 hours' duration, is highly suggestive of ASE.
Assuntos
Afasia , Epilepsia , Estado Epiléptico , Idoso , Algoritmos , Afasia/diagnóstico , Afasia/tratamento farmacológico , Afasia/etiologia , Eletroencefalografia/métodos , Epilepsia/complicações , Feminino , Humanos , Estado Epiléptico/diagnóstico , Estado Epiléptico/tratamento farmacológico , Estado Epiléptico/etiologiaRESUMO
BACKGROUND: Acute symptomatic seizures (ASS) are a common manifestation of autoimmune encephalitis (AE), but the risk of developing epilepsy as a sequela of AE remains unknown, and factors predisposing the development of epilepsy have not been fully identified. OBJECTIVE: To assess the risk of developing epilepsy in AE and study related risk factors. MATERIALS AND METHODS: This was a retrospective single centre study including patients diagnosed with AE according to criteria described by Graus et al., with a minimum follow-up of 12 months after AE resolution. The sample was divided according to whether patients developed epilepsy or not. RESULTS: A total of 19 patients were included; 3 (15.8%) had AE with intracellular antibodies, 9 (47.4%) with extracellular antibodies, and 7 (36.8%) were seronegative. During follow-up, 3 patients (15.8%) died, 4 (21.1%) presented relapses of AE, and 11 (57.89%) developed epilepsy. There was a significant association between the development of epilepsy and the presence of hippocampal atrophy in control brain magnetic resonance imaging (MRI) (p = 0.037), interictal epileptiform discharges (IED) on control electroencephalogram (EEG) (p = 0.045), and immunotherapy delay (p = 0.016). CONCLUSIONS: Hippocampal atrophy in neuroimaging, IED on EEG during follow-up, and immunotherapy delay could be predictors of the development of epilepsy in patients with AE.
RESUMO
BACKGROUND: The diagnosis of nonconvulsive status epilepticus (NCSE) in patients with nonepileptiform EEG patterns remains a challenge. OBJECTIVE: To evaluate the usefulness of single photon emission computerized tomography (SPECT) and its quantification (QtSPECT) in the diagnosis of NCSE. METHODS: We retrospectively reviewed patients admitted with clinical suspicion of NCSE who underwent an HMPAO-SPECT simultaneously with scalp EEG showing nonepileptiform patterns, in a 5-year period. After a complete diagnostic workup, treatment, and clinical evolution, disregarding the SPECT results, patients were classified into confirmed NCSE (n = 11) and non-NCSE (n = 8). Then, we compared the EEG and SPECT results in both groups. RESULTS: Lateralized rhythmic delta activity (LRDA) was predominant in the NCSE group (45.4%, p = .045), while lateralized irregular slowing was observed equally in both groups. Patients with NCSE showed significant hyperperfusion compared with non-NCSE patients (p = .026). QtSPECT correctly classified 91% of patients in NCSE and 75% patients with non-NCSE (p = .006). CONCLUSIONS: Regional cerebral blood flow measured with SPECT could be useful in the diagnosis of NCSE in cases of an EEG pattern with lateralized slow activity and high clinical suspicion.
Assuntos
Estado Epiléptico , Eletroencefalografia , Neuroimagem Funcional , Humanos , Estudos Retrospectivos , Estado Epiléptico/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
OBJECTIVE: To follow prospectively a group of patients with seizures or epilepsy and suggestive clinical features of autoimmune aetiology and find out how many are finally diagnosed with acute symptomatic seizures (ASS) secondary to autoimmune encephalitis or autoimmune-related epilepsy, and how many develop epilepsy. METHODS: Consecutive patients meeting the inclusion criteria from 2010 to 2018 were identified. Patients were classified as confirmed, probable autoimmune, non-autoimmune, or unknown. RESULTS: One-hundred and nine patients were included, 64 (48.7 %) women, mean age 55.2 years (SD 17.9). ASS were reported by 61 patients (56 %), while 48 presented epilepsy (44 %). During follow-up 18 patients died (16.5 %). Final diagnosis was autoimmune-relatedepilepsy (confirmed + probable) in 22 cases and ASS secondary to autoimmune encephalitis (confirmed or probable) in 27, non-autoimmune aetiologies or other diagnosis in 49 (44 %), and unknown aetiology in 11 (10.2 %). Neuronal antibodies (ab) were found in 27 patients (24.7 %). T-lymphocyte infiltration in temporal lobes was observed in 2/8 patients (20 %). Neuronal ab were more frequent in the autoimmune groups: 17 patients (29.8 %) vs 1(2.3 %), p:0.001, and they suffered more autoimmune diseases: 37 (75.5 %) vs 12 (24.48 %), p:0.0001, and 34 (69 %) vs 22 (44.9 %) p:0.027, respectively. All patients with GAD ab 17/17 (100 %) evolved to chronic disease. Four patients (29 %) with ASS secondary to autoimmune encephalitis developed epilepsy. SIGNIFICANCE: ASS secondary to autoimmune encephalitis or autoimmune-related epilepsy will be diagnosed in nearly half of patients who have been suspected of it. The only diagnostic clue is neuronal ab. Patients who have suffered ASS secondary to autoimmune encephalitis may develop epilepsy over time.
Assuntos
Encefalite , Epilepsia , Doença de Hashimoto , Encefalite/complicações , Encefalite/epidemiologia , Epilepsia/complicações , Epilepsia/epidemiologia , Feminino , Doença de Hashimoto/complicações , Doença de Hashimoto/epidemiologia , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Convulsões/complicações , Convulsões/epidemiologiaRESUMO
BACKGROUND: The diagnosis of nonconvulsive status epilepticus (NCSE) can pose a challenge. Electroencephalogram (EEG) patterns can be difficult to interpret, and the absence of an EEG correlate does not rule out the diagnosis of NCSE. In this setting, neuroimaging tools to help in the diagnosis are crucial. Our aim was to evaluate the role of 99mTc-hexamethyl propyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) and quantitative HMPAO-SPECT (QtSPECT) in patients with clinical suspicion of NCSE, and to evaluate their value in the final diagnosis of NCSE. METHODS: We recruited consecutive patients admitted in our center with suspicion of NCSE, and selected those who underwent an HMPAO-SPECT. All patients were admitted to the neurology ward and underwent an EEG. We divided the patients into those who were finally with diagnosed NCSE (NCSE-p) and those who were not (non-NCSE) according to the Salzburg Diagnostic EEG criteria. Sensitivity and specificity of the diagnostic tools were calculated. The SPECTs were acquired in a Skylight SPECT (Philips Healthcare, Amsterdam). The injections were done during the clinical episode suspected of being an NCSE. The HMPAO-SPECT was analyzed by two experts and was also quantified. All data were normalized to the SPM SPECT template. We used an external healthy normal database to obtain a Z-score map for each individual versus the normal database. The Z-score maximum (Zmax) was extracted from each region of the AAL atlas as was the percentage of voxels with a Z-score higher than 2.5 (N(%)). A logistic regression combining the Zmax, N(%), and the effect of patient age was fitted to predict the final NCSE diagnosis. A receiver operator characteristic (ROC) curve and the area under the curve (AUC) were obtained to evaluate the classification performance. RESULTS: We included 55 patients, 21 of them women (38.9%), with a median age of 62.1â¯years old (range 25-84). Thirty-six patients were with diagnosed NCSE (62.9%). Initial EEG had a sensitivity of 61.1% and a specificity of 89%. Most of the patients were critically ill with diagnostic difficulties, and it could be one of the main reasons to find low sensitivity of the Salzburg diagnostic EEG criteria. The Zmax and N(%) were significantly higher in NCSE-p than in non-NCSE (pâ¯=â¯0.005 and pâ¯<â¯0.001, respectively). The HMPAO-SPECT qualitative analysis had a sensitivity of 80.5% and specificity of 89.5% while QtSPECT had a sensitivity of 82% and specificity of 81%. CONCLUSION: Both 99mTc-HMPAO-SPECT and QtSPECT can be useful in the diagnosis of NCSE. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".
Assuntos
Oximas , Compostos Radiofarmacêuticos , Estado Epiléptico/diagnóstico por imagem , Estado Epiléptico/diagnóstico , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletroencefalografia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Neuroimagem , Curva ROC , Estudos Retrospectivos , Convulsões , Sensibilidade e EspecificidadeRESUMO
X-Adrenoleukodystrophy (X-ALD) and its adult-onset, most prevalent variant adrenomyeloneuropathy (AMN) are caused by mutations in the peroxisomal transporter of the very long-chain fatty acid ABCD1. AMN patients classically present spastic paraparesis that can progress over decades, and a satisfactory treatment is currently lacking. Oxidative stress is an early culprit in X-ALD pathogenesis. A combination of antioxidants halts the clinical progression and axonal damage in a murine model of AMN, providing a strong rationale for clinical translation. In this phase II pilot, open-label study, 13 subjects with AMN were administered a high dose of α-tocopherol, N-acetylcysteine, and α-lipoic acid in combination. The primary outcome was the validation of a set of biomarkers for monitoring the biological effects of this and future treatments. Functional clinical scales, the 6-minute walk test (6MWT), electrophysiological studies, and cerebral MRI served as secondary outcomes. Most biomarkers of oxidative damage and inflammation were normalized upon treatment, indicating an interlinked redox and inflammatory homeostasis. Two of the inflammatory markers, MCP1 and 15-HETE, were predictive of the response to treatment. We also observed a significant decrease in central motor conduction time, together with an improvement or stabilization of the 6MWT in 8/10 subjects. This study provides a series of biomarkers that are useful to monitor redox and pro-inflammatory target engagement in future trials, together with candidate biomarkers that may serve for patient stratification and disease progression, which merit replication in future clinical trials. Moreover, the clinical results suggest a positive signal for extending these studies to phase III randomized, placebo-controlled, longer-term trials with the actual identified dose. ClinicalTrials.gov Identifier: NCT01495260.
Assuntos
Adrenoleucodistrofia/sangue , Adrenoleucodistrofia/tratamento farmacológico , Antioxidantes/administração & dosagem , Quimiocina CCL2/sangue , Ácidos Hidroxieicosatetraenoicos/sangue , Adrenoleucodistrofia/diagnóstico por imagem , Adulto , Biomarcadores/sangue , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/sangue , Masculino , Pessoa de Meia-Idade , Condução Nervosa/efeitos dos fármacos , Condução Nervosa/fisiologia , Projetos Piloto , Estudos Prospectivos , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVE: Patients with adrenomyeloneuropathy may have dysfunctions of visual, auditory, motor and somatosensory pathways. We thought on examining the nociceptive pathways by means of laser evoked potentials (LEPs), to obtain additional information on the pathophysiology of this condition. METHODS: In 13 adrenomyeloneuropathic patients we examined LEPs to leg, arm and face stimulation. Normative data were obtained from 10 healthy subjects examined in the same experimental conditions. We also examined brainstem auditory evoked potentials (BAEPs), pattern reversal full-field visual evoked potentials (VEPs), motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs). RESULTS: Upper and lower limb MEPs and SEPs, as well as BAEPs, were abnormal in all patients, while VEPs were abnormal in 3 of them (23.1%). LEPs revealed abnormalities to stimulation of the face in 4 patients (30.7%), the forearm in 4 patients (30.7%) and the leg in 10 patients (76.9%). CONCLUSIONS: The pathologic process of adrenomyeloneuropathy is characterized by a preferential involvement of auditory, motor and somatosensory tracts and less severely of the visual and nociceptive pathways. This non-inflammatory distal axonopathy preferably damages large myelinated spinal tracts but there is also partial involvement of small myelinated fibres. SIGNIFICANCE: LEPs studies can provide relevant information about afferent pain pathways involvement in adrenomyeloneuropathic patients.
Assuntos
Adrenoleucodistrofia/fisiopatologia , Vias Aferentes/fisiopatologia , Encéfalo/fisiopatologia , Potenciais Evocados por Laser/fisiologia , Nociceptividade/fisiologia , Dor/fisiopatologia , Adulto , Eletroencefalografia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Medição da Dor , Adulto JovemRESUMO
INTRODUCTION: Stroke-like migraine attacks after radiation therapy (SMART) is a late-onset complication of brain irradiation of unknown physiopathology. Our aim was to present three patients with SMART syndrome who had clinical and neuroimage studies suggestive of status epilepticus. PATIENTS: Patient 1. A 69-year-old woman, who was treated with radiation therapy 14 years before her first admission to the Neurology Department, presented with several episodes of headache, speech disturbances, and weakness of left limbs with altered awareness. Patient 2. A 49-year-old man, who was treated with whole brain radiation 20 years before the onset of symptoms, developed some episodes consisting of headache and numbness of the right side of face and right arm; the latest episodes were accompanied by visual disturbances followed by generalized tonic-clonic seizures. Patient 3. A 40-year-old man, who received cranial irradiation 20 years before, suffered three episodes of behavioral disturbance, aphasia, headache, and visual aura followed by left homonymous hemianopia. RESULTS: All three patients suffered seizures mostly with visual aura. Electroencephalography showed interictal epileptiform discharges or focal slowing. Brain magnetic resonance image (MRI), positron emission tomography (PET), or ictal-single-photon emission computed tomography (SPECT) showed focal cortical hyperperfusion. Focal diffusion restriction and focal gadolinium-enhancement were observed on MRI. All patients were treated with antiepileptic drugs, being effective in one of them. One patient needed anesthesic coma, and the other patient responded to therapy with corticosteroids. CONCLUSIONS: Taking into account clinical evolution and ictal neuroimaging studies, status epilepticus could explain the origin of these episodes in SMART syndrome. Although most patients have reversible symptoms, in some cases, aggressive treatment to avoid sequelae is needed. This article is part of a Special Issue entitled "Status Epilepticus".
Assuntos
Neoplasias Encefálicas/radioterapia , Irradiação Craniana/efeitos adversos , Transtornos de Enxaqueca/etiologia , Estado Epiléptico/etiologia , Adulto , Idoso , Anticonvulsivantes/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/diagnóstico , Transtornos de Enxaqueca/tratamento farmacológico , Neuroimagem , Estado Epiléptico/diagnóstico , Estado Epiléptico/tratamento farmacológico , SíndromeRESUMO
PRIMARY OBJECTIVE: Music-Supported Therapy (MST) has been developed recently in order to improve the use of the affected upper extremity after stroke. This study investigated the neuroplastic mechanisms underlying effectiveness in a patient with chronic stroke. METHODS: MST uses musical instruments, a midi piano and an electronic drum set emitting piano sounds, to retrain fine and gross movements of the paretic upper extremity. Data are presented from a patient with a chronic stroke (20 months post-stroke) with residual right-sided hemiparesis who took part in 20 MST sessions over the course of 4 weeks. RESULTS: Post-therapy, a marked improvement of movement quality, assessed by 3D movement analysis, was observed. Moreover, functional magnetic resonance imaging (fMRI) of a sequential hand movement revealed distinct therapy-related changes in the form of a reduction of excess contralateral and ipsilateral activations. This was accompanied by changes in cortical excitability evidenced by transcranial magnetic stimulation (TMS). Functional MRI in a music listening task suggests that one of the effects of MST is the task-dependent coupling of auditory and motor cortical areas. CONCLUSIONS: The MST appears to be a useful neurorehabilitation tool in patients with chronic stroke and leads to neural reorganization in the sensorimotor cortex.
Assuntos
Musicoterapia/métodos , Plasticidade Neuronal/fisiologia , Paresia/reabilitação , Recuperação de Função Fisiológica/fisiologia , Reabilitação do Acidente Vascular Cerebral , Estimulação Magnética Transcraniana/métodos , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Atividade Motora/fisiologia , Paresia/fisiopatologia , Acidente Vascular Cerebral/fisiopatologiaRESUMO
Creutzfeldt-Jakob disease (CJD) is a rare human transmissible spongiform subacute encephalopathy. The most common clinical manifestations of CJD include rapidly progressive dementia, behavioural changes, cerebellar dysfunction and myoclonus. Other seizure types are rare and nonconvulsive status epilepticus (SE) is exceptional. We report a case of a 44-year-old man who presented a psychotic episode followed by akinetic mutism and refractory nonconvulsive SE. The final diagnosis was CJD. Continuous video-EEG monitoring revealed the ictal pattern of nonconvulsive SE to be periodic sharp wave complexes characteristic of CJD. [Published with video sequences].
Assuntos
Síndrome de Creutzfeldt-Jakob/fisiopatologia , Estado Epiléptico/etiologia , Adulto , Núcleo Caudado/patologia , Córtex Cerebral/patologia , Corpo Estriado/patologia , Síndrome de Creutzfeldt-Jakob/patologia , Eletroencefalografia , Humanos , Imageamento por Ressonância Magnética , Masculino , Estado Epiléptico/patologiaRESUMO
OBJECTIVE: Quantitative sensory testing (QST) is a subjective method of assessing thermal sensation, but it does not provide an objective measure of physiological changes. Our aim was to establish whether fluctuations in sudomotor autonomic activity correlate with warmth and heat pain (thermoalgesic) perception. METHODS: We conducted various thermal stimuli protocols in 22 healthy volunteers and recorded the visual analog scale (VAS) and sudomotor activity using surface electrodes attached to the hand. Sympathetic skin responses (SSR) and the mean level of electrodermal activity (EDA) were measured. EDA was analyzed by looking at the four VAS-based phases, which were divided into segments defined by the relevant psychophysical markers. RESULTS: In all stimuli paradigms, the mean delay time of the SSR was 1.6 s after the warmth or pain sensation. There was an association between the low amplitude (predominantly negative) SSR and warm stimuli, and the large amplitude (predominantly positive) SSR and heat pain stimuli (chi-square; P < 0.05). Mean EDA was significantly higher during the pain phase in comparison with pre-perception, warmth and post-perception phases. INTEPRETATION: Thermoalgesic stimuli induce reflex changes in sudomotor activity that correlate with subjective perception of warmth and heat pain sensations. This association may be useful in clinical practice.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Dor , Limiar Sensorial , Pele/inervação , Sensação Térmica/fisiologia , Adulto , Feminino , Temperatura Alta , Humanos , Masculino , Medição da Dor , Percepção/fisiologiaRESUMO
Spinothalamic tract lesions in patients with Wallenberg's syndrome can be demonstrated by abnormalities in the laser evoked potentials (LEPs) to stimulation of the affected side. However, before reaching the structures generating LEPs, laser stimuli can induce effects at a subcortical level. We examined LEPs and laser-induced prepulse inhibition of the blink reflex in seven patients with Wallenberg's syndrome within a month after the infarct. All patients had abnormally elevated thresholds for temperature and pain sensation, and for pinprick pain induced by laser stimuli, in the affected vs the non-affected side. LEPs to stimulation of the affected side were abnormal because of absent, reduced or delayed responses. However, the same laser stimuli that were unable to induce LEPs generated normal inhibition of the blink reflex response when applied 250ms before a trigeminal nerve electrical stimulus. The percentage inhibition induced in the R2 response of the blink reflex by laser stimulation of the affected side was not different from that induced by stimulation of the non-affected side, or in control subjects. These results are compatible with either a different pathway for prepulse inhibition and evoked potentials or a reduced energy requirement of the sensory input generating prepulse inhibition in comparison to that generating evoked potentials.
Assuntos
Piscadela/fisiologia , Potenciais Evocados/fisiologia , Síndrome Medular Lateral/fisiopatologia , Inibição Neural/fisiologia , Adulto , Idoso , Análise de Variância , Piscadela/efeitos da radiação , Potenciais Evocados/efeitos da radiação , Feminino , Lateralidade Funcional , Humanos , Lasers , Síndrome Medular Lateral/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Bulbo/patologia , Pessoa de Meia-Idade , Inibição Neural/efeitos da radiação , Limiar da Dor/fisiologia , Tempo de Reação/fisiologiaRESUMO
Laser stimuli (LS) were used to induce sudomotor skin responses (SSRs) in ten healthy human subjects. LS were applied to the dorsum of the hand by means of a CO(2) laser stimulator at an intensity of 120% pain perception threshold. SSRs induced by LS were of longer latency than those induced by electrical stimuli. However, response amplitude and duration were similar with either stimuli. The possibility to activate the sudomotor system by means of stimulation of pain afferents might be of clinical applicability for the functional assessment of pain pathways.
Assuntos
Potenciais de Ação/fisiologia , Lasers , Sistema Nervoso Simpático/fisiologia , Adulto , Estimulação Elétrica , Feminino , Mãos/inervação , Humanos , Masculino , Pessoa de Meia-Idade , Dor/fisiopatologia , Tempo de Reação/fisiologia , Pele/inervaçãoRESUMO
The patient cooperation usually required for neurophysiological assessment of autonomic cardioregulatory function is difficult to obtain from patients with bradykinesia. A particularly interesting condition occurs in multiple system atrophy (MSA), which features both bradykinesia and autonomic dysfunction. Another characteristic of patients with MSA is their normal motor reaction to a startling stimulus. We used startle as a stimulus for testing autonomic cardioregulatory function in patients with MSA, thus avoiding the need for patient cooperation. In 10 healthy volunteers and 8 MSA patients, we recorded the electrocardiographic QRS complex with surface electrodes attached over the chest and delivered an acoustic startle stimulus after 8 seconds of baseline recording. We calculated the ratio between the pre-stimulus and the post-stimulus heart beat intervals (R-R ratio) by dividing the mean prestimulus R-R interval by the shortest R-R interval obtained within 10 seconds poststimulus. Healthy volunteers had a significant shortening of the R-R interval. The peak of the effect occurred after 2 to 5 seconds, with a mean R-R ratio of 1.14 (S.D. = 0.09). In contrast, R-R shortening was markedly reduced in patients, even though they had a normal motor response. The mean R-R ratio in patients was 1.03 (S.D. = 0.03), significantly lower than in healthy volunteers (P < 0.01). Our results demonstrate an abnormally reduced modulation of the heart beat frequency in patients with MSA, compatible with a dysfunction on pathways responsible for autonomic regulation. The method described here may be useful in the assessment of cardioregulatory function in poorly cooperative patients with normal startle responses.