Absence of H-Reflex as an Additional Neurophysiological Sign of the Development of Acute Inflammatory Demyelinating Polyneuropathy in Children

Войтенков, В. Б.; Klimkin, A. V.; Скрипченко, Н В; Grigoryev, Sergey; Aksenova, A. I.

doi:10.1134/s0362119718080157

Cited by 2 publications

(8 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…- Simon et al (2015) 11.3 ± 0.7 --Estímulo no tornozelo e registro no AH Amplitude (mV) Latência distal (ms) Duração (ms) Kerasnoudis et al (2015) 19,1 ± 7,4 3,9 ± 0,6 - Kohara et al (2000) 11,8 (6 -21,3) 4,3 (3,3 -6,0) -Isose et al ( 2009) -4,2 ± 0,06 5,2 ± 0,09 Fonte: A autora Os sinais de reflexo-H obtidos com o novo método de atribuição de velocidades de condução e a nova parametrização dos MUAPs aproximaram-se de sinais obtidos experimentalmente em sujeitos saudáveis, como pode ser visto na Figura 17. Os valores de latência distal e amplitude dos sinais de reflexo-H simulados estão de acordo com dados encontrados na literatura (FISHER, 2002;FRIGON et al, 2007; LACHMAN, T.; SHAHANI, B. T.; YOUNG, 1980;VOITENKOV et al, 2018). A quantidade de MUs que são afetadas pelo bloqueio de condução é baseada em dados da literatura de estudos realizados em sujeitos acometidos com a AIDP.…”

Section: Objetivosunclassified

“…Apesar de a maior parte dos exames eletrofisiológicos de condução sensorial não apresentar anormalidades, reflexos H são ausentes em aproximadamente 90% dos casos de AIDP (VOITENKOV et al, 2018;VUCIC et al, 2004) O momento de inércia do pé é dado pela Equação 5:…”

Section: Objetivosunclassified

“…Os valores de latência obtidos nas simulações dos CMAPs foram um pouco abaixo dos valores médios encontrados emCleland et al (2006) eGupta et al (2008), porém foram mais próximos ao valor médio de latência reportado em Alam, Chaudhry e Cornblath (1998) eVoitenkov et al (2018). Assim como para os resultados de amplitude, ao levar em consideração o valor médio e o desvio padrão, todos os valores de latência obtidos nas simulações podem ser considerados como compatíveis com dados potencialmente obtidos de sujeitos com AIDP As durações dos CMAPs foram um pouco menores que os valores médios obtidos na literatura, sendo próximos ao "valor de corte" considerado emIsose et al (2009).…”

unclassified

“…fibras Ia na AIDP,Voitenkov et al (2018), por outro lado, sugerem que as alterações no reflexo H podem refletir uma lesão desmielinizante com redução e dispersão da condução ao longo das fibras motoras, enquanto emSumner (1981), o autor relata que a perda prematura dos reflexos tendinosos profundos pode ser decorrente do bloqueio do fluxo fusimotor em vez do bloqueio ou dispersão temporal nas fibras Ia de maior diâmetro.Como não foi encontrada na literatura uma explicação clara e consistente sobre como as aferentes Ia são afetadas na AIDP, decidiu-se explorar dois cenários de simulação: o primeiro em que as aferentes Ia não sofrem alterações, e o segundo em que a velocidade de condução das aferentes Ia é reduzida. Para o segundo caso, os limites inferior e superior da distribuição de velocidade de condução das aferentes Ia foram alterados com base em dados de potenciais evocados somato-sensitivos (PES) obtidos em Gilmore e Nelson (1989) e em dados de condução sensorial obtidos no nervo sural em estudos de.…”

unclassified

“…. Quando presentes, os reflexos H apresentam maior latência ou menor amplitude (GORDON;WILBOURN, 2001;VOITENKOV et al, 2018) Dachy et al (2010). eSheikh (2020) sugerem que há um envolvimento das Tanto os dados de PES quanto os dados de condução do nervo sural são referentes a aferentes cutâneas.…”

unclassified

See 4 more Smart Citations

Efeitos de neuropatias periféricas desmielinizantes em tarefas de controle motor estudados por meio de um modelo neuromuscular multiescala.

Oliveira¹

View full text Add to dashboard Cite

Multiscale computational models of the neuromuscular system provide a better understanding of the phenomena involved in motor control, as they are based on well-known biophysical, neurophysiological, and biomechanical mechanisms, whose quantifiers are available for analysis. The use of these models for the study of peripheral neuropathies can be useful to obtain a better understanding of the impacts of these neuropathies, as well as serving as a basis for suggesting new proposals for early diagnosis and follow-up. Despite that, multiscale models of the neuromuscular system have not been widely used to study these types of diseases. In the present work, a phenomenological model of motor and sensory axons is proposed, capable of representing axons of subjects with peripheral neuropathies. These axonal representations were inserted into an existing multiscale model of the neuromuscular system, which was elaborated and validated for healthy subjects by previous researchers. As the starting model represents leg muscles, the initial focus was on neuropathies that mainly affect the lower limbs, especially acute inflammatory demyelinating polyneuropathy, a variant of Guillain-Barré syndrome. The existing axon delay model was modified so that it would be possible to represent the axonal conduction velocity of motor and sensory axons, as well as the number of functional motor units. To obtain a representative model of subjects affected by the neuropathy, the model parameters were strongly based on electrophysiological findings of patients available in the literature. Different neuropathy scenarios were simulated in two motor control tasks (force task and position task). The results suggested that it is possible to detect changes in quantitative features of both torque and surface electromyography signals, in force and position tasks, in patients with the studied polyneuropathy. These findings can complement qualitative and quantitative assessments classically used in clinical neurology, aiding early diagnosis and follow-up of the disease. In addition, the developed model allows straightforward adaptation for other conditions not covered in the present research, being only necessary to make the appropriate changes in the model parameters.

show abstract

Section: Objetivosunclassified

unclassified

See 3 more Smart Citations

Efeitos de neuropatias periféricas desmielinizantes em tarefas de controle motor estudados por meio de um modelo neuromuscular multiescala.

Oliveira¹

View full text Add to dashboard Cite

show abstract

Electrophysiological and functional signs of Guillain–Barré syndrome predicted by a multiscale neuromuscular computational model

Oliveira¹,

Watanabe²,

Kohn³

2022

J. Neural Eng.

View full text Add to dashboard Cite

Objective. The diagnosis of nerve disorders in humans has relied heavily on the measurement of electrical signals from nerves or muscles in response to electrical stimuli applied at appropriate locations on the body surface. The present study investigated the demyelinating subtype of Guillain-Barré syndrome using multiscale computational model simulations to verify how demyelination of peripheral axons may affect plantar flexion torque as well as the ongoing electromyogram (EMG) during voluntary isometric or isotonic contractions. Approach. Changes in axonal conduction velocities, mimicking those found in patients with the disease at different stages, were imposed on a multiscale computational neuromusculoskeletal model to simulate subjects performing unipodal plantar flexion force and position tasks. Main results. The simulated results indicated changes in the torque signal during the early phase of the disease while performing isotonic tasks, as well as in torque variability after partial conduction block while performing both isometric and isotonic tasks. Our results also indicated changes in the root mean square values and in the power spectrum of the soleus EMG signal as well as changes in the synchronisation index computed from the firing times of the active motor units. All these quantitative changes in functional indicators suggest that the adoption of such additional measurements, such as torques and ongoing EMG, could be used with advantage in the diagnosis and be relevant in providing extra information for the neurologist about the level of the disease. Significance. Our findings enrich the knowledge of the possible ways demyelination affects force generation and position control during plantarflexion. Moreover, this work extends computational neuroscience to computational neurology and shows the potential of biologically compatible neuromuscular computational models in providing relevant quantitative signs that may be useful for diagnosis in the clinic, complementing the tools traditionally used in neurological electrodiagnosis.

show abstract

Absence of H-Reflex as an Additional Neurophysiological Sign of the Development of Acute Inflammatory Demyelinating Polyneuropathy in Children

Cited by 2 publications

References 6 publications

Efeitos de neuropatias periféricas desmielinizantes em tarefas de controle motor estudados por meio de um modelo neuromuscular multiescala.

Efeitos de neuropatias periféricas desmielinizantes em tarefas de controle motor estudados por meio de um modelo neuromuscular multiescala.

Electrophysiological and functional signs of Guillain–Barré syndrome predicted by a multiscale neuromuscular computational model

Contact Info

Product

Resources

About