Details

Autor(en) / Beteiligte

• Shin-Yi Lin, Cindy
• Howells, James
• Rutkove, Seward
• Nandedkar, Sanjeev
• Neuwirth, Christoph
• Noto, Yu-ichi
• Shahrizaila, Nortina
• Whittaker, Roger G.
• Bostock, Hugh
• Burke, David
• Tankisi, Hatice

Titel

Neurophysiological and imaging biomarkers of lower motor neuron dysfunction in motor neuron diseases/amyotrophic lateral sclerosis: IFCN handbook chapter

Ist Teil von

• Clinical neurophysiology, 2024-06, Vol.162, p.91-120

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2024

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• •Conventional nerve conduction studies, H-reflex studies, and needle electromyography are important tools for the diagnosis of Motor Neuron Disease (MND)•High-density surface EMG, nerve excitability testing, electrical impedance myography, MUNIX, and MScanFit are potential biomarkers for MND.•Neuromuscular ultrasonography can detect changes in nerve and muscle architecture including dynamic changes such as fasciculations. This chapter discusses comprehensive neurophysiological biomarkers utilised in motor neuron disease (MND) and, in particular, its commonest form, amyotrophic lateral sclerosis (ALS). These encompass the conventional techniques including nerve conduction studies (NCS), needle and high-density surface electromyography (EMG) and H-reflex studies as well as novel techniques. In the last two decades, new methods of assessing the loss of motor units in a muscle have been developed, that are more convenient than earlier methods of motor unit number estimation (MUNE),and may use either electrical stimulation (e.g. MScanFit MUNE) or voluntary activation (MUNIX). Electrical impedance myography (EIM) is another novel approach for the evaluation that relies upon the application and measurement of high-frequency, low-intensity electrical current. Nerve excitability techniques (NET) also provide insights into the function of an axon and reflect the changes in resting membrane potential, ion channel dysfunction and the structural integrity of the axon and myelin sheath. Furthermore, imaging ultrasound techniques as well as magnetic resonance imaging are capable of detecting the constituents of morphological changes in the nerve and muscle. The chapter provides a critical description of the ability of each technique to provide neurophysiological insight into the complex pathophysiology of MND/ALS. However, it is important to recognise the strengths and limitations of each approach in order to clarify utility. These neurophysiological biomarkers have demonstrated reliability, specificity and provide additional information to validate and assess lower motor neuron dysfunction. Their use has expanded the knowledge about MND/ALS and enhanced our understanding of the relationship between motor units, axons, reflexes and other neural circuits in relation to clinical features of patients with MND/ALS at different stages of the disease. Taken together, the ultimate goal is to aid early diagnosis, distinguish potential disease mimics, monitor and stage disease progression, quantify response to treatment and develop potential therapeutic interventions.