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Brain Research Bulletin Oct 2019Spinal dorsal roots can be affected by a wide range of lesions, leading to a significant loss of proprioceptive information transmission and greatly affecting motor...
Spinal dorsal roots can be affected by a wide range of lesions, leading to a significant loss of proprioceptive information transmission and greatly affecting motor behavior. In this context, the reimplantation of lesioned roots with platelet-rich plasma (PRP) may allow nerve regeneration. Therefore, the present study evaluated sensorimotor improvement following dorsal root rhizotomy and repair with PRP. For this purpose, female Lewis rats were subjected to unilateral rhizotomy (RZ) of the L4-L6 dorsal roots and divided into the following groups: (1) the unlesioned control group; (2) the group that underwent rhizotomy (RZ) without repair; and (3) the group that underwent RZ followed by root repair with PRP. PRP was obtained from human blood and characterized regarding platelet concentration, integrity, and viability. Reflex arc recovery was evaluated weekly for eight weeks by the electronic von Frey method. The spinal cords were processed 1 week postlesion to evaluate the in vivo gene expression of TNFα, TGF-β, BDNF, GDNF, VEGF, NGF, IL-4, IL-6, IL-13 by qRT-PCR and eight weeks postlesion to evaluate changes in the glial response (GFAP and Iba-1) and excitatory synaptic circuits (VGLUT1) by immunofluorescence. The results indicated that PRP therapy partially restores the paw withdrawal reflex over time, indicating the reentry of primary afferents from the dorsal root ganglia into the spinal cord without exacerbating glial reactivity. Additionally, the analysis of mRNA levels showed that PRP therapy has immunomodulatory properties. Overall, the present data suggest that the repair of dorsal roots with PRP may be considered a promising approach to improve sensorimotor recovery following dorsal rhizotomy.
Topics: Animals; Axons; Female; Ganglia, Spinal; Nerve Growth Factors; Neuroglia; Platelet-Rich Plasma; Rats; Rats, Inbred Lew; Recovery of Function; Reflex; Rhizotomy; Spinal Cord; Spinal Cord Injuries; Spinal Cord Regeneration; Spinal Nerve Roots
PubMed: 31351157
DOI: 10.1016/j.brainresbull.2019.07.024 -
Modern Trends in Neurology 1967
Review
Topics: Animals; Cats; Denervation; Electrophysiology; Humans; Mitochondria; Motor Neurons; Reflex; Reflex, Abnormal; Spinal Cord; Spinal Cord Injuries; Spinal Nerve Roots; Surface Properties; Synapses; Synaptic Transmission; Synaptic Vesicles; Time Factors
PubMed: 4369327
DOI: No ID Found -
American Journal of Physical Medicine &... 1994The pronator reflex has been used in evaluating the 6th and 7th cervical roots. It has been described as a muscle stretch reflex of the pronator muscles; however, a...
The pronator reflex has been used in evaluating the 6th and 7th cervical roots. It has been described as a muscle stretch reflex of the pronator muscles; however, a review of the literature did not elucidate which muscles are active in this reflex. We examined 10 healthy subjects with surface electromyograms recorded over the pronator quadratus and pronator teres and used a Teca reflex hammer to produce a muscle stretch and trigger the electromyogram sweep. A reproducible response was found in all patients when recordings were made over the pronator teres (mean latency, 9.7 +/- 1.8 ms). No response was found in any of the subjects when recordings were made over the pronator quadratus. We conclude that the pronator reflex represents a muscle stretch reflex of the pronator teres (and not the pronator quadratus), which would make it helpful in evaluating C6 and C7 root lesions.
Topics: Electromyography; Forearm; Humans; Muscles; Pronation; Reaction Time; Reflex; Spinal Nerve Roots
PubMed: 7917163
DOI: 10.1097/00002060-199409000-00006 -
Journal of Hypertension. Supplement :... Dec 1992To evaluate the effects of afferent renal nerve activity on reflex control of the cardiovascular system and volume balance. (Review)
Review
PURPOSE
To evaluate the effects of afferent renal nerve activity on reflex control of the cardiovascular system and volume balance.
ANATOMICAL AND ELECTROPHYSIOLOGICAL EVIDENCE
In the kidney, receptors sensitive to mechanical and chemical stimuli have been identified. Afferent fibres from the kidney have been shown to travel along renal nerves and dorsal roots, mainly from T9 to L4, and to project to the central nervous system at spinal and supraspinal levels. Most of the brainstem regions involved in cardiovascular control and several regions of the anterior hypothalamus (including vasopressin-secreting neurons) receive inputs from renal afferents.
REFLEX EFFECTS ON THE CARDIOVASCULAR SYSTEM
The electrical stimulation of afferent renal nerve fibres can either increase or decrease systemic arterial pressure. The hypertensive response to electrical stimulation of renal afferents is the result of widespread activation of the sympathetic nervous system, leading to an increase in peripheral vascular resistance. Activation of afferent renal nerve fibres by an intrarenal artery infusion of adenosine elicits sustained increases in arterial pressure, heart rate and cardiac output without changing total peripheral resistance, indicating reflex activation of the sympathetic nervous system, predominantly restricted to the heart. An increase in the plasma vasopressin concentration, observed during the electrical stimulation of renal afferents, might help to mediate the hypertensive response to afferent renal nerve stimulation.
RENORENAL REFLEXES
The existence of neural renorenal reflexes, by which one kidney can influence the functioning of the opposite kidney, is well established. Contralateral renorenal reflexes, which are inhibitory in nature, are tonically active and mainly control the secretion of renin from juxtaglomerular cells and the tubular reabsorption of sodium and water.
CONCLUSIONS
The evidence suggests that sensory information from the kidney contributes to the overall regulation of cardiovascular homeostasis and volume balance.
Topics: Afferent Pathways; Animals; Cardiovascular Physiological Phenomena; Hypertension, Renovascular; Kidney; Neurons, Afferent; Reflex; Sensory Receptor Cells; Sympathetic Nervous System; Water-Electrolyte Balance
PubMed: 1291646
DOI: No ID Found -
Journal of Clinical Neurophysiology :... Dec 2014The H-reflex of the flexor carpi radialis (FCR H-reflex) has not been commonly used for the diagnosis of cervical radiculopathy when compared with the routinely tested... (Comparative Study)
Comparative Study
OBJECTIVE
The H-reflex of the flexor carpi radialis (FCR H-reflex) has not been commonly used for the diagnosis of cervical radiculopathy when compared with the routinely tested soleus H-reflex. Although both S1 and S2 roots innervate the soleus, the H-reflex is selectively related to S1 nerve root function clinically. Flexor carpi radialis is also innervated by two nerve roots which are C6 and C7. Although they are among the most common roots involved in cervical radiculopathy, few studies reported if the attenuation of the FCR H-reflex is caused by lesions affecting C7 or C6 nerve roots, or both. We aimed to identify whether an abnormal FCR H-reflex was attributed to the C7 or C6 nerve root lesion, or both. The sensitivities of needle electromyography, FCR H-reflex, and provocative tests in unilateral C7 or C6 radiculopathy were also compared in this study.
METHODS
A concentric needle electrode recorded bilateral FCR H-reflexes in 41 normal subjects (control group), 51 patients with C7 radiculopathy, and 54 patients with C6 radiculopathy. Clinical, radiological, and surgical approaches identified the precise single cervical nerve root involved in all patient groups. The H-reflex and M-wave latencies were measured and compared bilaterally. Abnormal FCR H-reflex was defined as the absence of the H-reflex or a side-to-side difference over 1.5 milliseconds which was based on the normal side-to-side difference of the H-reflex latency of 16.9 milliseconds (SD = 1.7 milliseconds) from the control group. We also determined standard median and ulnar conduction and needle electromyography. The provocative tests included bilateral determination of the Shoulder Abduction and Spurling's tests in all radiculopathy group patients.
RESULTS
Abnormal FCR H-reflexes were recorded in 45 (88.2%) of C7 radiculopathy group patients, and 2 (3.7%) of C6 radiculopathy group patients (P < 0.05). Needle electromyography was abnormal in 41 (80.4%) of C7 radiculopathy patients and 43 (79.6%) of C6 radiculopathy patients. Provocative tests were positive in 15 (29.4%) of C7 radiculopathy patients and 25 (46.3%) of C6 radiculopathy patients.
CONCLUSIONS
Flexor carpi radialis H-Reflex provides a sensitive assessment of evaluating the C7 spinal reflex pathway. Clinically, a combination of the FCR H-reflex with needle electromyography may yield the highest level of diagnostic information for evaluating clinical cases of C7 radiculopathy.
Topics: Adult; Case-Control Studies; Cervical Vertebrae; Electric Stimulation; Electromyography; H-Reflex; Humans; Middle Aged; Muscle, Skeletal; Neurologic Examination; Predictive Value of Tests; Radiculopathy; Reaction Time; Reflex, Abnormal; Time Factors
PubMed: 25462138
DOI: 10.1097/WNP.0000000000000104 -
Archives of Physical Medicine and... Mar 1990The H-reflex was recorded from the flexor carpi radialis, vastus medialis, and soleus muscles in patients with radiculopathy at C7, L4, and S1 roots. Reflex parameters...
The H-reflex was recorded from the flexor carpi radialis, vastus medialis, and soleus muscles in patients with radiculopathy at C7, L4, and S1 roots. Reflex parameters were compared to normal standards and correlated with other electrophysiologic (eg, electromyography) and clinical evaluations, as well as magnetic resonance imaging scan reports. The H-reflex had significantly smaller peak-to-peak amplitude and longer latency. The stimulus threshold for eliciting the reflexes was substantially higher than normal standards, and the reflex was polyphasic in most patients. A strong correlation was recorded between the pathologic changes in reflex parameters and electrophysiologic and clinical findings of different segmental lesions. Magnetic resonance imaging reports showed moderate correlation with the H-reflex changes. A test of specificity showed that soleus and vastus medialis H-reflexes were 100% specific for lumbosacral segments; flexor carpi radialis was 90% specific for cervical spinal segments. These results indicate that flexor carpi radialis, vastus medialis, and soleus H-reflexes are useful and valid methods for testing C7, L4, and S1 radiculopathy.
Topics: Action Potentials; Adult; Arm; Electromyography; Female; H-Reflex; Humans; Leg; Male; Middle Aged; Muscles; Peripheral Nervous System Diseases; Reaction Time; Reflex, Monosynaptic; Sensitivity and Specificity; Spinal Nerve Roots
PubMed: 2156485
DOI: No ID Found -
Journal of Neurosurgery Sep 1993The variability of reflex responses during selective dorsal rhizotomy was studied in eight children between the ages of 3 and 7 years. For a given dorsal root or...
The variability of reflex responses during selective dorsal rhizotomy was studied in eight children between the ages of 3 and 7 years. For a given dorsal root or rootlet, the electrical reflex threshold and response varied considerably when observed over several minutes. Changes in electrode pressure, mechanical dissection of the root, and reflex spatial facilitation were all found to contribute to the variability. Even when electrode pressure was held constant, intrinsic spinal cord reflex variability substantially weakened the predictability of the intraoperative selection method used during this surgery.
Topics: Child; Child, Preschool; Differential Threshold; Dissection; Electric Stimulation; Electrophysiology; Humans; Intraoperative Period; Neural Inhibition; Pressure; Reflex; Spinal Cord; Spinal Nerve Roots; Time Factors
PubMed: 8360730
DOI: 10.3171/jns.1993.79.3.0346 -
Electroencephalography and Clinical... Feb 1998H-reflexes in normals were elicited by percutaneous electrical and magnetic stimulation of proximal nerve roots at the cauda equina. H-M interval to S1 nerve root...
H-reflexes in normals were elicited by percutaneous electrical and magnetic stimulation of proximal nerve roots at the cauda equina. H-M interval to S1 nerve root stimulation at the level of the S1 foramen was 6.8 +/- 0.33 ms, with side to side difference of 0.16 +/- 0.13 ms. Compression/ischemia of the sciatic nerve in the mid-thigh abolished the H-reflex to stimulation of the tibial nerve at the popliteal fossa when the H-reflex to S1 nerve root stimulation was preserved. The length of the S1 nerve root in human cadavers was measured to be 17.5 +/- 03 cm, providing an estimated dorsal root conduction velocity of 67.3 m/s and a ventral root conduction velocity of 54 m/s. We conclude that the H-M interval to S1 root stimulation can provide reliable measures of conduction within the spinal canal including proximal afferents, anterior horn cells and ventral roots.
Topics: Adult; Cauda Equina; Electric Stimulation; H-Reflex; Humans; Ischemia; Magnetics; Middle Aged; Reaction Time; Sciatic Nerve; Spinal Nerve Roots
PubMed: 11003059
DOI: 10.1016/s0924-980x(97)00058-1 -
Archives of Physical Medicine and... Apr 1978This study was designed to evaluate whether the H reflex latency obtained from the triceps surae following tibial-nerve stimulation was of value in detecting and...
This study was designed to evaluate whether the H reflex latency obtained from the triceps surae following tibial-nerve stimulation was of value in detecting and differentiating S1 from L5 radiculopathy. Thirty-two patients were studied, 15 with a definite unilateral L5 radiculopathy and 17 with a definite unilateral S1 radiculopathy. Data revealed a mean H reflex latency difference of 0.03 msec (range--0.1 to 0.2 msec) between the affected and unaffected extremities for the 15 patients with L5 radiculopathy and of 2.9 msec (range 1.3 to 4.1 msec) for the 13 patients with S1 radiculopathy where an H reflex could be recorded. The H reflex was unobtainable in the affected extremity in four of the patients with S1 radiculopathy. It is concluded that H reflex latency testing is a valuable tool in helping to differentiate S1 from L5 radiculopathy.
Topics: Adult; Diagnosis, Differential; Electrodiagnosis; Female; H-Reflex; Humans; Male; Nervous System Diseases; Neural Conduction; Reflex, Monosynaptic; Spinal Nerve Roots
PubMed: 646608
DOI: No ID Found -
The Orthopedic Clinics of North America Jul 1992A wide-based spastic gait is the classical presentation of the patient with cervical spondylotic myelopathy. A complete neurologic evaluation is needed to determine the... (Review)
Review
A wide-based spastic gait is the classical presentation of the patient with cervical spondylotic myelopathy. A complete neurologic evaluation is needed to determine the degree of involvement and to classify the clinical syndrome. The natural history seems to be one of static neurologic deficit or episodic progression.
Topics: Cervical Vertebrae; Diagnosis, Differential; Humans; Intervertebral Disc; Nerve Compression Syndromes; Reflex; Spinal Cord Compression; Spinal Nerve Roots; Spinal Osteophytosis
PubMed: 1620540
DOI: No ID Found