Matches with leg muscles affected
Nerve degeneration with HSP begins in the tip of the spine (sacral area) and moves upwards into the lower back (lumbar) area over time as the condition progresses. Distinct muscles and muscle groups are supplied by the nerves in the different parts of the spine. Impaired function of these muscles matches with the degenerating nerves in the different spinal locations. As more nerves degenerate, more muscles and muscle groups show impaired function.
A comprehensive treatment of Hereditary Spastic Paraplegia (HSP) should consider the specific pathophysiological changes in the spinal cord. Here we reported a detailed characterization of the spinal motoneuronal output in HSP during locomotion.
We recorded kinematics and electromyographic (EMG) activity of 12 leg muscles in 29 patients with pure forms of HSP and compared them with 30 controls while walking at matched speeds. We assessed the spinal locomotor output by evaluating EMG patterns and by mapping them onto the rostrocaudal location of the spinal motoneuron pools.
The activity profiles of muscles innervated from the sacral segments were significantly wider in patients. Similarly, spinal maps revealed a tendency for spreading the main loci of activation, involving initially the sacral segments and, at more severe stages, the lumbar segments.
The degeneration of the corticospinal tract in HSP is associated with a widening of spinal locomotor output spreading from caudal to rostral segments.
The findings highlight pathophysiologically relevant differential changes in the spinal locomotor output in HSP related to the specific innervation of muscles in the spinal cord, and might be helpful for developing future therapeutic strategies and identifying physiological markers of the disease.
SOURCE: Clin Neurophysiol. 2018 Mar;129(3):516-525. doi: 10.1016/j.clinph.2017.11.028. Epub 2017 Dec 23. PMID: 29353180 Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.
Differential changes in the spinal segmental locomotor output in Hereditary Spastic Paraplegia.
1 Centre of Space Bio-medicine, University of Rome Tor Vergata, 00133 Rome, Italy; Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179 Rome, Italy. Electronic address: [email protected]
2 Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179 Rome, Italy.
3 Rehabilitation Centre Policlinico Italia, 00162 Rome, Italy; Department of Medical and Surgical Sciences and Biotechnologies, 04100 Sapienza University of Rome, Latina, Italy.
4 INAIL, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Monte Porzio Catone, 00040 Rome, Italy.
5 Department of Engineering, Roma TRE University, 00145 Rome, Italy.
6 Department of Medical and Surgical Sciences and Biotechnologies, 04100 Sapienza University of Rome, Latina, Italy.
7 Centre of Space Bio-medicine, University of Rome Tor Vergata, 00133 Rome, Italy; Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, 00179 Rome, Italy; Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy.