a-standardized-protocol-for-functional-motor-mapping-using-navigated

A Standardized Protocol for Functional Motor Mapping Using Navigated Transcranial Magnetic Stimulation

Navigated transcranial magnetic stimulation (nTMS) is based on the integration of individual brain imaging data to determine the precise positioning of ...

Aarhus University Hospital

Aarhus University

There is a need for a consensus on a clinical scale for evaluating upper motor neuron (UMN) burden in amyotrophic lateral sclerosis (ALS) to improve consistency in clinical diagnosis, research and monitoring of disease progression. The Penn upper motor neuron score (PUMNS) is the most commonly published scale, however, the reliability of the scale has only been evaluated in a single study involving two raters. The objective of this study was to evaluate the inter-rater reliability of the PUMNS in ALS patients among multiple raters, and to discuss an updated UMN score including the signs with the highest inter-rater reliability. This study included seven ALS patients (mean age: 71 ± 11.5, six males, one female). Each patient was evaluated with the PUMNS by eight raters from different centers blinded to previous observations. The intra-class correlation coefficient (ICC) was calculated to assess the inter-rater reliability of the total PUMNS. The inter-rater reliability of the binary subscores was assessed with Gwet's AC1 coefficient. The inter-rater agreement for the total PUMNS yielded an ICC of 0.81 (95% CI 0.56;0.96). Items with the highest inter-rater reliability included Hoffman's sign, Babinski's sign, clonus and deep tendon reflexes, while the facial reflex (Gwet's AC1 -0.038 (95% CI -0.25,0.18)) and crossed adduction (0.18 (95% CI (-0.32,0.67)) had the lowest inter-rater reliability. In conclusion, PUMNS demonstrated good inter-rater reliability overall, while some of the subscores had poor inter-rater reliability. Based on this, we call for an updated UMN score to enhance diagnostic accuracy and research consistency in ALS.

Variability of the Penn upper motor neuron score in amyotrophic lateral sclerosis: need for a revised score.

To investigate the relationship between short-interval intracortical inhibition (SICI), short-interval intracortical facilitation (SICF) and amyotrophic lateral sclerosis (ALS) phenotype, using threshold-tracking transcranial magnetic stimulation (TMS).

Short-interval intracortical inhibition and facilitation in amyotrophic lateral sclerosis related to disease phenotype.

To evaluate whether continuously tracking unconditioned thresholds for maintaining constant motor-evoked potential (MEP) amplitudes improves the variability of amplitude-based short-interval intracortical inhibition (SICI) measurements.

Short-interval intracortical inhibition (SICI): effect of target tracking on variability of responses for 1 mV and 200µV test-alone targets.

Restless limbs syndrome (RLS) is a neurological disorder characterized by an uncontrollable urge to move the limbs. Although it affects up to 10% of the general population, its underlying mechanisms remain poorly understood. Neurophysiological excitability testing may help elucidate mechanisms related to sensorimotor integration, axonal ion channel dysfunction and impaired neural inhibition. This study aimed to assess both CNS and PNS function by examining cortical, spinal and peripheral nerve excitability within the same individuals for the first time. To investigate potential widespread excitability changes in RLS, we specifically analysed hand muscles, offering new insights into the extent of neural involvement beyond the lower limbs. The study included 56 RLS patients, divided into treated and untreated groups, along with 32 healthy controls. Notably, none of the patients experienced symptoms in their hands. Cortical excitability was assessed via threshold-tracking transcranial magnetic stimulation (TMS) to evaluate intracortical inhibition and facilitation. Sensory-motor integration was measured via long-latency reflexes (LLRs), while spinal cord excitability was assessed using F-waves, H-reflexes and RIII-reflexes. Axonal excitability was examined using the extended TRONDNF protocol. TMS revealed a significant reduction in short-interval intracortical inhibition (SICI) in patients, particularly at inter-stimulus intervals (ISIs) of 2.5 and 3 ms. When averaging across ISIs from 1 to 7 ms, patients on medication exhibited significantly less inhibition compared to healthy controls. Long-interval intracortical inhibition (LICI) was also reduced at ISIs of 150 and 200 ms, while facilitation parameters remained within normal ranges. Patients exhibited increased amplitude of the second component of the LLR recorded from the abductor pollicis brevis, whereas RIII reflex measurements showed no significant differences. Axonal excitability testing revealed a graded increase in hyperpolarization-activated currents in patients with more severe symptoms. The observed reductions in SICI and LICI suggest impaired intracortical inhibition in the M1 hand area, offering indirect evidence of cortical dysfunction in regions clinically unaffected by the disease. The increased LLR amplitudes further indicate altered sensorimotor integration at the cortical level, whereas the absence of significant changes in RIII reflexes suggests that segmental spinal dysfunction within the pain pathway of the upper limbs is unlikely. Finally, axonal excitability findings point to a potential role of hyperpolarization-activated currents in either contributing to or predisposing individuals to RLS symptoms.

Article	Year
Variability of the Penn upper motor neuron score in amyotrophic lateral sclerosis: need for a revised score. Journal of neurology\| PubMed ID: 39954119	2025
Short-interval intracortical inhibition and facilitation in amyotrophic lateral sclerosis related to disease phenotype. Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology\| PubMed ID: 40482593	2025
Short-interval intracortical inhibition (SICI): effect of target tracking on variability of responses for 1 mV and 200µV test-alone targets. Neurophysiologie clinique = Clinical neurophysiology\| PubMed ID: 40639034	2025
Central and peripheral excitability in restless limbs syndrome. Brain communications\| PubMed ID: 41523188	2026

Gaia Fanella

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