Spinal Cord Lesion: Effects of and Perspectives for Treatment

Following central motor lesions, two forms of adaptation can be observed which lead to improved mobility: (1) the development of spastic muscle tone, and (2) the activation of spinal locomotor centers induced by specific treadmill training. Tension development during spastic gait is different from that during normal gait and appears to be independent of exaggerated monosynaptic stretch reflexes. Exaggerated stretch reflexes are associated with an absence or reduction of functionally essential polysynaptic reflexes. When supraspinal control of spinal reflexes is impaired, the inhibition of monosynaptic reflexes is missing in addition to a reduced facilitation of polysynaptic reflexes. Therefore, overall leg muscle activity becomes reduced and less well modulated in patients with spasticity. Electrophysiologicai and histological studies have shown that a transformation of motor units takes place following central motor lesions with the consequence that regulation of muscle tone is achieved at a lower level of neuronal organization which in turn enables the patient to walk. Based on observations of the locomotor capacity of the spinal cat, recent studies have indicated that spinal locomotor centers can be activated and trained in patients with complete or incomplete paraplegia when the body is partially unloaded. However, the level of electromyographic activity in the gastrocnemius (the main antigravity muscle during gait) is considerably lower in the patients compared to healthy subjects. During the course of a daily locomotor training program, the amplitude of gastrocnemius, electromyographic activity increases significantly during the stance phase, while inappropriate tibialis anterior activation decreases. Patients with incomplete paraplegia benefit from such training programs such that their walking ability on a stationary surface improves. The pathophysiology and functional significance of spastic muscle tone and the effects of treadmill training on the locomotor pattern underlying new attempts to improve the mobility of patients with paraplegia are reviewed.

[1]  Volker Dietz,et al.  The Syndrome of Spastic Paresis , 2003 .

[2]  L. Edström Selective changes in the sizes of red and white muscle fibres in upper motor lesions and Parkinsonism. , 1970, Journal of the neurological sciences.

[3]  P. J. Delwaide,et al.  Human Monosynaptic Reflexes and Presynaptic Inhibition , 1973 .

[4]  J. Noth,et al.  B‐50 (GAP‐43) in the spinal cord caudal to hemisection: Indication for lack of intraspinal sprouting in dorsal root axons , 1993, Journal of neuroscience research.

[5]  B. Dobkin,et al.  Human lumbosacral spinal cord interprets loading during stepping. , 1997, Journal of neurophysiology.

[6]  H. Barbeau,et al.  New Experimental Approaches in the Treatment of Spastic Gait Disorders , 1992 .

[7]  K H Mauritz,et al.  Chronic transformation of muscle in spasticity: a peripheral contribution to increased tone. , 1985, Journal of neurology, neurosurgery, and psychiatry.

[8]  L. Illis Is there a central pattern generator in man? , 1995, Paraplegia.

[9]  V. Dietz,et al.  Motor unit involvement in spastic paresis: Relationship between leg muscle activation and histochemistry , 1986, Journal of the Neurological Sciences.

[10]  V. Dietz,et al.  Human postural reflexes and gravity — An under water simulation , 1989, Neuroscience Letters.

[11]  S. Rossignol,et al.  Recovery of locomotion after chronic spinalization in the adult cat , 1987, Brain Research.

[12]  V. Dietz,et al.  Ambulatory capacity in spinal cord injury: significance of somatosensory evoked potentials and ASIA protocol in predicting outcome. , 1997, Archives of physical medicine and rehabilitation.

[13]  K. Pearson,et al.  Reversal of the influence of group Ib afferents from plantaris on activity in medial gastrocnemius muscle during locomotor activity. , 1993, Journal of neurophysiology.

[14]  S. Katoh,et al.  Neurological recovery after conservative treatment of cervical cord injuries. , 1994, The Journal of bone and joint surgery. British volume.

[15]  B. Dobkin,et al.  Modulation of locomotor-like EMG activity in subjects with complete and incomplete spinal cord injury. , 1995, Journal of neurologic rehabilitation.

[16]  J Quintern,et al.  Electrophysiological studies of gait in spasticity and rigidity. Evidence that altered mechanical properties of muscle contribute to hypertonia. , 1981, Brain : a journal of neurology.

[17]  B. Bussel,et al.  Myoclonus in a patient with spinal cord transection. Possible involvement of the spinal stepping generator. , 1988, Brain : a journal of neurology.

[18]  W. Rymer,et al.  Stretch reflex dynamics in spastic elbow flexor muscles , 1989, Annals of neurology.

[19]  R. Benecke The Role of the Corticospinal Tract in Spasticity Studied by Magnetic Brain Stimulation , 1993 .

[20]  P. Jacobs,et al.  Involuntary stepping after chronic spinal cord injury. Evidence for a central rhythm generator for locomotion in man. , 1994, Brain : a journal of neurology.

[21]  A. Wernig,et al.  Laufband Therapy Based on‘Rules of Spinal Locomotion’is Effective in Spinal Cord Injured Persons , 1995, The European journal of neuroscience.

[22]  A. Thilmann,et al.  Pathological stretch reflexes on the "good" side of hemiparetic patients. , 1990, Journal of neurology, neurosurgery, and psychiatry.

[23]  V. Dietz,et al.  Locomotor activity in spinal man , 1994, The Lancet.

[24]  V. Dietz,et al.  Reflex activity and muscle tone during elbow movements in patients with spastic paresis , 1991, Annals of neurology.

[25]  Heffner Rs,et al.  The Role of the Corticospinal Tract in the Evolution of Human Digital Dexterity , 1983 .

[26]  V. Dietz,et al.  Locomotor capacity of spinal cord in paraplegic patients , 1995, Annals of neurology.

[27]  V. Dietz,et al.  Normal and impaired regulation of muscle stiffness in gait: A new hypothesis about muscle hypertonia , 1983, Experimental Neurology.

[28]  Arthur Brown,et al.  Discussion on , 1908 .

[29]  D. Burke,et al.  Are spinal "presynaptic" inhibitory mechanisms suppressed in spasticity? , 1972, Journal of the neurological sciences.

[30]  S. Rossignol,et al.  Enhancement of locomotor recovery following spinal cord injury. , 1994, Current opinion in neurology.

[31]  S. Andreassen,et al.  Non–reflex and reflex mediated ankle joint stiffness in multiple sclerosis patients with spasticity , 1993, Muscle & nerve.

[32]  G Colombo,et al.  Locomotor capacity and recovery of spinal cord function in paraplegic patients: a clinical and electrophysiological evaluation. , 1998, Electroencephalography and clinical neurophysiology.

[33]  J. Fung,et al.  The combined effects of clonidine and cyproheptadine with interactive training on the modulation of locomotion in spinal cord injured subjects , 1990, Journal of the Neurological Sciences.

[34]  A. Thilmann,et al.  The mechanism of spastic muscle hypertonus. Variation in reflex gain over the time course of spasticity. , 1991, Brain : a journal of neurology.

[35]  M. Schwab,et al.  Recovery from spinal cord injury mediated by antibodies to neurite growth inhibitors , 1995, Nature.

[36]  A. Wernig,et al.  Laufband locomotion with body weight support improved walking in persons with severe spinal cord injuries , 1992, Paraplegia.

[37]  L M Harrison,et al.  Patterns of central motor reorganization in hemiplegic cerebral palsy. , 1993, Brain : a journal of neurology.

[38]  S. Grillner Control of Locomotion in Bipeds, Tetrapods, and Fish , 1981 .

[39]  Symposium synopsis , 1986 .

[40]  R. Kuhn,et al.  FUNCTITONAL CAPACITY OF THE ISOLATED HUMAN SPINAL CORD , 1950 .

[41]  V. Dietz Human neuronal control of automatic functional movements: interaction between central programs and afferent input. , 1992, Physiological reviews.

[42]  A Curt,et al.  From spinal shock to spasticity , 2000, Neurology.

[43]  V. Dietz,et al.  Stretch-induced electromyographic activity and torque in spastic elbow muscles. Differential modulation of reflex activity in passive and active motor tasks. , 1993, Brain : a journal of neurology.

[44]  R. Kuhn,et al.  Functional capacity of the isolated human spinal cord. , 1950, Brain : a journal of neurology.

[45]  M. Faist,et al.  A quantitative assessment of presynaptic inhibition of Ia afferents in spastics. Differences in hemiplegics and paraplegics. , 1994, Brain : a journal of neurology.

[46]  K H Mauritz,et al.  Control mechanisms for restoring posture and movements in paraplegics. , 1989, Progress in brain research.

[47]  J. Taylor REFLEX ACTIVITY , 1960 .

[48]  J. Minderhoud,et al.  Tizanidine versus baclofen in the treatment of spasticity in multiple sclerosis patients , 1988, Acta neurologica Scandinavica.

[49]  V. Dietz,et al.  Regulation of Muscle Stiffness in Human Locomotion , 1984, International journal of sports medicine.

[50]  V. Dietz,et al.  Tension development and muscle activation in the leg during gait in spastic hemiparesis: independence of muscle hypertonia and exaggerated stretch reflexes. , 1984, Journal of neurology, neurosurgery, and psychiatry.

[51]  V. Dietz,et al.  Functional outcome following spinal cord injury: significance of motor-evoked potentials and ASIA scores. , 1998, Archives of physical medicine and rehabilitation.

[52]  B. Bussel,et al.  Late flexion reflex in paraplegic patients. Evidence for a spinal stepping generator , 1989, Brain Research Bulletin.

[53]  P. Nathan,et al.  Effects on movement of surgical incisions into the human spinal cord. , 1994, Brain : a journal of neurology.

[54]  V. Dietz,et al.  Traumatic cervical spinal cord injury: relation between somatosensory evoked potentials, neurological deficit, and hand function. , 1996, Archives of physical medicine and rehabilitation.

[55]  G Colombo,et al.  Locomotor pattern in paraplegic patients: training effects and recovery of spinal cord function , 1998, Spinal Cord.

[56]  E. Roth,et al.  Neuromuscular stimulation in spinal cord injury. II: Prevention of secondary complications. , 1992, Archives of physical medicine and rehabilitation.

[57]  R. Young,et al.  Spasticity, disordered motor control , 1980 .