Back to Search
Start Over
Segmental motor neuron dysfunction in amyotrophic lateral sclerosis: Insights from H reflex paradigms.
- Source :
-
Muscle & nerve [Muscle Nerve] 2024 Mar; Vol. 69 (3), pp. 303-312. Date of Electronic Publication: 2024 Jan 14. - Publication Year :
- 2024
-
Abstract
- Introduction/aims: In amyotrophic lateral sclerosis (ALS), the role of spinal interneurons in ALS is underrecognized. We aimed to investigate pre- and post-synaptic modulation of spinal motor neuron excitability by studying the H reflex, to understand spinal interneuron function in ALS.<br />Methods: We evaluated the soleus H reflex, and three different modulation paradigms, to study segmental spinal inhibitory mechanisms. Homonymous recurrent inhibition (H' <subscript>RI</subscript> ) was assessed using the paired H reflex technique. Presynaptic inhibition of Ia afferents (H' <subscript>Pre</subscript> ) was evaluated using D1 inhibition after stimulation of the common peroneal nerve. We also studied inhibition of the H reflex after cutaneous stimulation of the sural nerve (H' <subscript>Pos</subscript> ).<br />Results: Fifteen ALS patients (median age 57.0 years), with minimal signs of lower motor neuron involvement and good functional status, and a control group of 10 healthy people (median age 57.0 years) were studied. ALS patients showed reduced inhibition, compared to controls, in all paradigms (H' <subscript>RI</subscript> 0.35 vs. 0.11, p = .036; H' <subscript>Pre</subscript> 1.0 vs. 5.0, p = .001; H' <subscript>Pos</subscript> 0.0 vs. 2.5, p = .031). The clinical UMN score was a significant predictor of the amount of recurrent and presynaptic inhibition.<br />Discussion: Spinal inhibitory mechanisms are impaired in ALS. We argue that hyperreflexia could be associated with dysfunction of spinal inhibitory interneurons. In this case, an interneuronopathy could be deemed a major feature of ALS.<br /> (© 2024 Wiley Periodicals LLC.)
Details
- Language :
- English
- ISSN :
- 1097-4598
- Volume :
- 69
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Muscle & nerve
- Publication Type :
- Academic Journal
- Accession number :
- 38220221
- Full Text :
- https://doi.org/10.1002/mus.28035