Bildgebende Verfahren zur Darstellung des Muskelparenchyms und -mesenchyms sind ein wesentlicher Baustein der Diagnostik von neuromuskulären Erkrankungen. Dabei ermöglicht die Muskelsonografie eine hochauflösende Darstellung des Muskelgewebes und dadurch eine zuverlässige Differenzierung zwischen fibrolipomatös veränderten und nicht betroffenen Muskelgruppen.
Klinisch-neurophysiologische Untersuchungen ermöglichen auch im Kindesalter eine frühzeitige, funktionelle Lokalisation neuromuskulärer Störungen und ergänzen genetische und bildgebende Diagnostik entscheidend. Ziel dieses CME-Artikels ist es, die grundlegenden Methoden der pädiatrischen klinischen Neurophysiologie praxisnah darzustellen und ihre Bedeutung im diagnostischen Entscheidungsprozess zu vermitteln.
Small fiber neuropathies (SFN) are an etiologically heterogeneous group of diseases of the peripheral nervous system caused by isolated or predominant damage to thinly myelinated A delta fibers and/or unmyelinated C fibers. Clinically, the main symptom is chronic neuropathic pain, as well as sensory and autonomic symptoms. In 1944, Joseph Erlanger and Herbert Gasser won the Nobel Prize for their discovery of highly differentiated functions of single nerve fibers, which is still fundamental for our current understanding of SFN. Small fiber neuropathies were first defined by John et al. in 1992 as small fiber dysfunction in neurological examination and the presence of paresthesia. Symptoms often manifest in a length-dependent distribution pattern, but can also occur in a patchy and non-length-dependent distribution. Clinically, variable deficits in temperature and pinprick perception as well as tactile sensation may be present. Nerve conduction studies are normal by definition. Diagnosis is made by clinical examination and skin biopsy with reduced intraepidermal nerve fiber density (IENFD) and/or abnormal quantitative sensory testing. Despite new developments and improved tools, all tests have relevant limitations to date so that there is still no established gold standard for SFN diagnosis. Treatment focuses primarily on symptomatic pain relief using analgesics, antidepressants, and anti-seizure drugs. For the treatment of SFN, evidence-based recommendations are limited. In this article, we present a current overview of SFN with a special focus on diagnosis and treatment, highlighting the challenges arising in clinical practice without a gold standard.
Clinical neurophysiology is a cornerstone in the diagnostic work-up of neuromuscular disorders in children. Although molecular genetic testing has advanced rapidly, neurophysiological methods are experiencing renewed relevance due to technical improvements that facilitate their application and reduce patient burden. When combined with high-resolution nerve and muscle ultrasound, these techniques allow bedside assessment of structure and function of the peripheral nervous system.This CME article aims to provide a practical overview of the core methods of pediatric clinical neurophysiology and to emphasize their role in clinical decision-making.The article systematically reviews motor and sensory nerve conduction studies, F-waves and H-reflexes, repetitive nerve stimulation, needle and single-fiber electromyography, and pediatric nerve ultrasound. Special attention is given to age-dependent normative values, developmental aspects such as myelination and growth, and methodological challenges specific to infants and young children. Clinical case examples illustrate the diagnostic value of these techniques in hereditary, inflammatory, traumatic, and neuromuscular disorders.Clinical neurophysiology enables precise functional localization along the motor system and provides early insights into axonal, demyelinating, and neuromuscular junction disorders. It complements genetic and imaging diagnostics and remains an essential component of pediatric neurological care.
The application of surface electromyography provides a broad spectrum of information for assessing muscle function. One parameter that is relevant both clinically and in performance-related aspects is muscle fiber conduction velocity (MFCV). MFCV is an indicator of muscle fiber cross-sectional area, the recruitment order of motor units, and changes in peripheral properties of the neuromuscular system. Due to the more complex signal acquisition, this parameter has so far been limited in its widespread practical application.
Surface electromyography (sEMG) is a non-invasive technique that provides valuable insights into neuromuscular activation and movement coordination, offering a unique perspective on neuromechanical control in both health and disease. This article highlights the clinical potential of sEMG in the diagnostic workup of movement disorders such as cerebral palsy, brachial plexus injuries, and spasticity. By quantifying muscle coordination, detecting pathological coactivation, and assessing motor unit activity, sEMG enables a comprehensive understanding of impaired movement patterns. Despite its usefulness, barriers such as a lack of training, standardization, and clinical integration remain. International initiatives like SENIAM and CEDE aim to address these challenges by establishing guidelines for signal acquisition and interpretation. With continued interdisciplinary collaboration, sEMG holds significant potential to enhance clinical decision-making in neurorehabilitation and personalized medicine.
High-density surface electromyography (HDsEMG) enables non-invasive assessment of entire motor unit populations with high spatial and temporal resolution. It complements classical needle EMG, which excels in the precise analysis of single motor unit potentials. In conditions with population-level alterations, such as amyotrophic lateral sclerosis, hereditary neuropathies, diabetic polyneuropathy, or spasticity, HDsEMG provides novel insights into the organisation and dynamics of motor control. Advances in motor unit decomposition further enable the reliable separation of superimposed signals and the detailed analysis of firing rates and recruitment patterns. Thus, HDsEMG offers clinically relevant opportunities for sensitive monitoring of disease progression and therapy effects. However, standardised workflows, validated metrics, and trained personnel are required before routine clinical implementation can be achieved.
Bei der Sicherung der Verdachtsdiagnose einer Endplattenstörung ist die Elektrophysiologie schneller als der Antikörpernachweis verfügbar. Zur Verfügung stehen verbreitet die repetitive Nervenstimulation (RNS) und wenig verbreitet die Einzelfasermyographie (sfEMG). Die RNS ist zwar einfach durchführbar aber nicht sehr sensitiv. Die Verbreitung der sfEMG als zuverlässigere Methode hat nach der Abwendung von wiederverwendbaren spezialisierten Nadeln sehr abgenommen, und die Abwandlung der Technik mit Routineausrüstung und der normalen konzentrischen Nadel hat diesen Trend nicht umgekehrt. Wir wollen die technischen und physiologischen Grundlagen der Technik, ihre praktische Durchführung, typische zuverlässige und möglicherweise qualitativ eingeschränkte Signalformen und die Wertigkeit der sfEMG im klinischen Kontext erklären.
Die Methoden des intraoperativen Neuromonitorings (IONM) haben sich bei komplexen intraduralen Wirbelsäuleneingriffen etabliert. Aufgrund der personal- und kostenintensiven Anwendung sowie der Schwierigkeit, intraoperative Signalveränderungen in den Kontext von operativem Ablauf und konkretem neurologischem Outcome zu setzen, wird der Einsatz bei anderen, weniger komplexen Wirbelsäuleneingriffen kontrovers diskutiert. Der Artikel stellt die Wertigkeit und den Nutzen des IONM in der Wirbelsäulenchirurgie dar.
