Stable muscle atrophy in long-term paraplegics with complete upper motor neuron lesion from 3- to 20-year SCI.
METHODS
Unrandomized trial.


OBJECTIVE
To investigate the structural and functional relationships and the progression of muscle atrophy up to 20 years of spastic paraplegia.


METHODS
Clinical follow-up in Vienna, Austria; muscle biopsies analyzed by light microscopy in Padova and by electron microscopy (EM) in Chieti, Italy.


METHODS
Force was measured as knee extension torque; trophism by computer tomography scan; tissue composition and fiber morphology by histopathology and EM.


RESULTS
In the long-term group of patients (17.0+/-2.6 years), force and size of thigh muscles were only slightly different from those of mid-term subjects (2.2+/-0.5 years). Histology and ultrastructure confirm that the difference in average size of muscle fibers between long-term and mid-term paralyzed leg muscles is actually very small. In addition, muscle fibers maintain the striated appearance characteristic of normal skeletal fibers even after 14-20 years of paralysis. Ultrastructural alterations of the activating and metabolic machineries, and the presence of fibers with lower motor neuron denervation features, may explain the low-force output and the reduced endurance of paretic muscles.


CONCLUSIONS
The stable muscle atrophy that characterizes long-lasting spastic paraplegia suggests that there are no upper-time limits to begin a training program based on functional electrical stimulation.
Kern
H
H
Department of Physical Medicine, Ludwig Boltzmann Institute of Electrostimulation and Physical Rehabilitation, Wilhelminenspital, Vienna, Austria.
Hofer
C
C
Mödlin
M
M
Mayr
W
W
Vindigni
V
V
Zampieri
S
S
Boncompagni
S
S
Protasi
F
F
Carraro
U
U
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D009133:Muscular Atrophy / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D010264:Paraplegia / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D011859:Radiography; D013119:Spinal Cord Injuries / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology; D013904:Thoracic Vertebrae; D013997:Time Factors