Nerve Conduction Studies In Children Research Articles

Normal Values of Nerve Conduction Studies in Children Aged 7 Days to 14 Years Referred to Electrodiagnosis Clinic of Iranian Children's Medical Center

Background: The normal values of nerve conduction studies (NCS) are different in children compared to adults. Moreover, racial and geographical factors can affect these values. Objectives: The present study aimed to investigate the normal NCS values in children of different ages. Methods: The present cross-sectional study included children referred to the Electrodiagnosis Clinic of the Children's Medical Center in Iran, who had normal NCS results based on the references and had no exclusion criteria. The patients were divided into 8 age groups (7 days to one month, 1 - 3 months, 3 - 6 months, 6 - 12 months, 1 - 2 years, 2 - 4 years, 4 - 6 years, and 6 - 14 years), and the NCS was performed using a Nihon Kohden electromyogram. The NCS values in the normal range were included in the analysis. Results: The normal ranges of amplitude and conduction velocity of 4 motor nerves (median, ulnar, deep peroneal, and tibial) and 2 sensory nerves (median and medial plantar), as well as the F-wave latency values of 2 nerves (ulnar and tibial), were established as the reference values for the pediatric patients. Conclusions: The NCS parameters of Iranian children were slightly different from the normal references reported by studies in other countries. Moreover, the SNAP and CMAP amplitudes and motor conduction velocity of these children usually reached the normal values of the adult population earlier.

Electromyogram (EMG) and Nerve Conduction Study (NCS) Findings in Children with Neuromuscular Disorders

Background: An electromyogram (EMG) measures the electrical activity of muscles when they're at rest and when they're being used. On the other hand, nerve conduction study (NCS) is a medical diagnostic test used to evaluate the function, especially the ability of electrical conduction, of the motor and sensory nerves of the human body. Both are used to diagnose the status of neuromuscular disorders even in children. Aim of the study: The aim of this study was to assess the findings of electromyogram and nerve conduction study in children with neuromuscular disorders. Methods: This retrospective, observational study was conducted in the department of Paediatric Neuroscience, Dhaka Shishu Hospital & BICH, Dhaka, Bangladesh during the period from January 2010 to December 2016. In total 65 suspected children with neuromuscular disorders were selected as the study subjects. After elaborating the history taking and physical examination a provisional diagnosis was made and sent for NCS and EMG to trained personnel at Bangladesh Protibondhi Foundation along with other necessary investigations. All data were recorded and the “clinical and etiological” profile was correlated with the neurophysiologic findings retrospectively. Results: As investigation reports of EMG, among all participants, we found normal findings in 21 participants. Besides these, a variety of SMA and/or late-onset SMA were found in 16 participants. Moreover, diffuse fibrillation, biphasic complex, repetitive spontaneous discharge was found among 6 participants. On the other hand, as per the investigation reports of NCS among all the participants, the normal finding was in 34 participants. Besides this low amplitude CMAP and SNAP, low amplitude CMAP, variable sensory conduction velocity, and slow conduction velocity with temporal dispersion were found in 3, 6, another 3, and 4 participants respectively. The compatibilities of electrophysiological diagnosis were found at 68% for detecting neurogenic disease and 71% for detecting myogenic disease. On the other hand, the compatibilities of the Nerve Conduction Study were found 46% for detecting neurogenic disease and 50% for detecting myogenic disease. Conclusion: NCS and EMG are crucial investigations to reach confirmation as well as the exclusion of the diagnosis of neuromuscular disorder in children.

Clinical and neurophysiological spectrum of polyneuropathies in children

Peripheral neuropathy is a disorder of the peripheral nerves and results from a disturbance of structure and/or function of the peripheral sensory, motor and/or autonomic neurons. The possible aetiology of peripheral neuropathies is diverse, but inflammatory and hereditary diseases of the peripheral nerves predominate in childhood. The aim of this study was to determine the clinical and electrophysiological profile of large nerve fibre neuropathy detected by nerve conduction studies (NCS) in children over a 10-year period at the Children's Clinical University Hospital in Latvia. Based on NCS findings, 165 children between 2008 and 2018 were diagnosed with polyneuropathy. In our study, the majority of children had peripheral neuropathy due to acquired causes, mostly due to diabetes mellitus; roughly one in five of the patients had hereditary neuropathy. Almost half of the patients had motor deficits, which were more prevalent in toxic and inflammatory neuropathies. A little less than a third of patients complained of pain as well as presenting with autonomic dysfunction symptoms. The NCS demonstrated a demyelinating neuropathy in 52 cases (31%), an axonal neuropathy in 34 cases (21%), and mixed polyneuropathy in 79 cases (48%). Our study investigated the clinical and electrophysiological characteristics of polyneuropathies diagnosed with NCS in children. Most of the polyneuropathies in our study were hereditary and diabetic neuropathies with combined (myelin and axon) damage to nerve fibres. Almost all clinical symptoms of polyneuropathy were present in all aetiological groups.

NMP06 Some peculiarities of nerve conduction study in children with spinal muscular atrophy

NMP06 Some peculiarities of nerve conduction study in children with spinal muscular atrophy

IAP039 Some abnormalities of nerve conduction study in children with Bell's palsy

IAP039 Some abnormalities of nerve conduction study in children with Bell's palsy

EMG and nerve conduction studies in children with congenital muscular dystrophy

Motor and sensory nerve conduction velocities (NCVs) and needle electromyography (EMG) results were reviewed in 26 children with different types of congenital muscular dystrophy (CMD), including patients with mutations in the genes LAMA2, FKRP, and COL6A2. In every patient, at least one EMG examination detected myopathic changes that were predominant in proximal muscles, although EMG performed at birth was normal in two patients. Brief bursts of high-frequency repetitive discharges were electrically elicited in four patients. Uniformly slowed motor NCVs without signs of denervation were observed in seven patients: five merosin-deficient, one merosin-positive, and one with unavailable merosin status. The merosin-deficient neuropathy also involved sensory nerves in three patients and worsened with age in two. In conclusion, myopathic EMG changes were typical and early findings in all types of CMD. An associated neuropathy was detected in most patients with merosin-deficient CMD, and also in a child with normal merosin expression.

Pediatric Electrodiagnosis

Electromyography (EMG) and nerve conduction studies (NCS) are of proven value in the diagnosis of acute and chronic neuromuscular diseases in children. With the use of electrodiagnostic studies, it is often possible to identify the disorder as one of nerve, neuromuscular junction, or muscle. The purpose of this article is to review the techniques of EMG and NCS in children and to describe an approach to the evaluation of focal and generalized neuromuscular disorders.

Penetrance of the hereditary motor and sensory neuropathy la mutation

The clinical expression of hereditary motor and sensory neuropathy type I (HMSN I) is age-dependent. Autosomal dominant HMSN I is heterogeneous at a molecular level with genes localized on chromosomes 1, 17, and possibly other chromosomes. In order to define accurately the penetrance of a single HMSN I gene mutation, we performed nerve conduction studies in HMSN I families whose genetic defect was linked to chromosome 17 (HMSN Ia). All HMSN Ia subjects tested had slow nerve conduction velocities with a mean median velocity 20 +/- 6 m/sec, which did not change with age. The range of conduction velocities from affected individuals did not overlap those from their clinically normal relatives, indicating complete penetrance of the gene from early childhood. The results indicate that motor nerve conduction studies in children can add additional information for linkage studies and genetic counseling.

Nerve conduction studies in children with Friedreich's ataxia and ataxia-telangiectasia.

SUMMARYNerve conduction was studied in nine patients with Friedreich's ataxia aged between 2 1/2 and 21 1/2 years. The younger children exhibited only progressive ataxia, depressed tendon reflexes and minimal peripheral sensory loss, whereas the older patients exhibited the more complete clinical picture with skeletal deformities, cardiomyopathy and extensor plantar responses. In all cases, electrodiagnostic studies showed normal or slightly low conduction velocity in the motor fibres of the median and lateral popliteal nerves, contrasting with marked reduction or absence of sensory action potentials in median nerves. Sensory action potentials in ulnar nerves and ascending nerve action potentials in lateral popliteal nerves were found to be similarly depressed when tested.This characteristic pattern of findings in motor and sensory nerves proved helpful in the early diagnosis of Friedreich's ataxia. It was not encountered in Charcot‐Marie‐Tooth disease or in the Roussy‐Levy syndrome, in which conduction in motor fibres is usually more markedly impaired. It also assisted in the differentiation from other conditions in which cerebellar ataxia and polyneuropathy may be combined. Other predominantly sensory neuropathies may yield similar results on nerve conduction studies, but can generally be distinguished by their different clinical presentation.Two girls of 17 and 13 years with ataxia‐telangiectasia had similar findings on conduction studies as patients with Friedreich's ataxia. However, sensory neuropathy in ataxia‐telangiectasia appears to develop later or more slowly. Its possible pathological basis is discussed.RÉSUMÉConduction nerveuse chez des enfants atteints de l'ataxie de Friedreich et d'ataxie‐telangiectasieLa conduction nerveuse a étéétudiée chez 9 malades atteints de l'ataxie de Friedreich, âgés de 2 1/2 à 21 1/2 ans. Les enfants les plus jeunes montraient seulement une ataxie progressive, des réflexes tendineux diminuàs et une perte de la sensibilité périphérique minime tandis que chez les malades plus âgés, on observait un tableau clinique plus complet avec déformations osseuses, cardiomyopathie et signes de Babinski. Dans tous les cas, les études électrodiagnostiques ont montré une vitesse de conduction normale ou légèrement abaissée dans les fibres motrices du nerf médian et poplité latéral, contrastant avec une réduction marquée ou une absence de potentiel d'action sensorielle dans les nerfs médians. Les potentiels d'action sensorielle dans les nerfs cubitaux et potentiel d'action ascendant dans les nerfs poplités latéraux ont été de la même façon trouvés diminués au cours des tests.Cet ensemble caractéristique de données dans les nerfs sensoriels et moteurs se montre utile dans le diagnostic de l'ataxie de Friedreich; il n'a pas été rencontré dans l'atrophie de Charcot‐Marie ni dans le syndrome de Roussy‐Levy où, dans les deux cas, la conduction dans les nerfs moteurs est plus gravement altérée. Cet ensemble aide également à différentier l'ataxie de Friedreich des autres maladies dans lesquelles l'ataxie cérébelleuse et une polyneuropathie peuvent être combinées. D'autres neuropathies à prédominance sensorielle peuvent donner des résultats semblables dans l'étude des conductions nerveuses, mais généralement elles peuvent être distinguées à partir d'éléments cliniques différents.Deux jeunes filles de 17 et 13 ans, avec ataxie‐telangiectasie ont présenté des études de conduction semblables à celles de l'ataxie de Friedreich. Cependant, la neuropathie sensorielle dans l'ataxie‐telangiectasie semble se développer plus tard ou plus lentement. Ses bases pathologiques possibles sont discutées.ZUSAMMENFASSUNGUntersuchung der Nervenleitgeschwindigkeit bei Patienten mit Friedreich'scher Ataxie und Ataxia teleangiectaticaBei 9 Patienten mit Friedreich'scher Ataxie im Alter von 2 1/2 bis 21 1/2 Jahren wurde die Nervenleitgeschwindigkeit untersucht. Die jüngeren Kinder zeigten nur eine progressive Ataxie, abgeschwächte Sehnenreflexe und einen leichten peripheren Sensibilitätsausfall, während die älteren Patienten das vollständige klinische Bild mit Skelettdeformierungen, Kardiomyopathie und positivem Babinski boten. Bei allen Fällen zeigten die elektrodiagnostischen Untersuchungen normale oder nur leicht herabgesetzte Nervenleitgeschwindigkeiten der motorischen Fasern des N. medianus und des N. popliteus lateralis im Gegensatz zur deutlichen Verminderung oder zum Ausfall sensorischer Aktionspotentiale des N. medianus. Die sensorischen Aktionspotentiale des N. ulnaris und die afferenten Aktionspotentiale im N. popliteus lateralis waren bei der Untersuchung in ähnlicher Weise herabgesetzt.Dieses charakteristische Befundmuster an den motorischen und sensorischen Nervenfasern erwies sich als hilfreich bei der Frühdiagnose der Friedreich'schen Ataxie; es wurde nicht bei der Charcot‐Marie‐Tooth'schen Erkrankung oder beim Roussy‐Levy Syndrom festgestellt; bei diesen beiden ist die Leitgeschwindigkeit der motorischen Fasern in der Regel sehr viel stärker herabgesetzt. Es war außerdem von Nutzen bei der Differential‐diagnose zwischen Friedreich'scher Ataxie und anderen Erkrankungen, bei denen cerebelläre Ataxie und Polyneuropathie kombiniert sein können. Andere vorwiegend sensible Polyneuropathien lassen möglicherweise ähnliche Resultate bei der Nervenleitgeschwindigkeitsmessung erkennen, können aber im allgemeinen durch ihr unterschiedliches klinisches Bild differenziert werden.Zwei Mädchen im Alter von 17 und 13 Jahren mit einer Ataxia teleangiectatica zeigten ähnliche Befunde bei Nervenleitgeschwindigkeitsuntersuchungen wie Patienten mit Friedreich'scher Ataxie. Die sensorische Neuropathie der Ataxia teleangiectatica scheint sich jedoch später oder langsamer zu entwickeln. Die mögliche pathologische Ursache wird diskutiert.