MEDLINE Abstracts: Diagnostic and Therapeutic Testing in Patients with Back Pain
MEDLINE Abstracts: Diagnostic and Therapeutic Testing in Patients with Back Pain
What's new concerning diagnostic and therapeutic testing in patients with low back pain? Find out in this easy-to-navigate collection of recent MEDLINE abstracts compiled by the editors at Medscape Orthopaedics and Sports Medicine.
Jarvik JG, Maravilla KR, Haynor DR, Levitz M, Deyo RA
Radiology 204(2):447-54, 1997 Aug
PURPOSE: To demonstrate the feasibility of a randomized trial to compare rapid magnetic resonance (MR) imaging with plain radiography as the initial imaging study in patients with low back pain, to test measures of the decision-making process and patient outcomes, and to offer a model for using randomized clinical trials to evaluate diagnostic tests. MATERIALS AND METHODS: The authors randomly selected 62 patients with low back pain to undergo either rapid MR imaging or plain radiography. The authors measured functional status, satisfaction, and general health status at baseline and at 3 months. The modified Roland scale was the primary outcome measure. In addition, the authors examined diagnostic and therapeutic decision making and resources used by each group. RESULTS: There were no statistically significant differences between the two patient groups with respect to outcome (Roland score: MR imaging = 12.5, radiography = 12.1). MR imaging provided more useful information to clinicians and resulted in greater patient reassurance. CONCLUSION: Randomly selecting patients to undergo imaging examinations and measuring outcomes is feasible; however, a larger, multicenter study is necessary to determine whether rapid MR imaging is a cost-effective replacement for plain radiography in patients with low back pain.
Wilkinson LS, Elson E, Saifuddin A, Ransford AO
Clinical Radiology 52(7):530-4, 1997 Jul
A retrospective study of case notes and magnetic resonance imaging (MRI) examinations was performed to assess the value of gadolinium enhanced MRI in the investigation of persistent back pain following lumbar spine surgery in patients who have not had a discectomy for disc herniation. Gadolinium enhancement is commonly used during MRI of patients with persistent back pain following surgery and epidural scar is frequently identified in patients who have had a previous discectomy. However the value of gadolinium enhancement in patients without previous discectomy had not been addressed. One hundred sets of case notes were examined and 24 patients with an accurate history of previous lumbar spine surgery without discectomy were identified. The nature of surgery and the MRI findings were correlated in these patients. Epidural enhancement was identified at seven sites in six patients (engorged epidural venous plexus, three; enhancement adjacent to degenerate discs, two; enhancement adjacent to facets, two). In no case was epidural scarring involving nerve roots identified. We conclude that routine gadolinium enhancement is unnecessary in patients without a history of discectomy for disc herniation.
Sorensen J, Bengtsson M
Acta Anaesthesiologica Scandinavica 41(5):581-5, 1997 May
BACKGROUND: Persistent pain following surgery in the treatment of chronic low-back pain patients is still relatively frequent. Most of these patients with persistent pain have clinical signs of neuropathic pain. The neuropathic pain might be sympathetically maintained pain (SMP) or sympathetically independent pain (SIP). Systemic administration of phentolamine, a competitive alpha-adrenergic antagonist, has been used as a diagnostic tool to identify patients with SMP. METHODS: Thirty-seven patients with persistent pain after low-back surgery (lumbar laminectomy, with or without discectomi, or a posterior fusion, with or without decompression) received intravenous phentolamine (0.5 mg/kg over 30 min) in a single-blind, placebo-controlled manner. Prior to this infusion the patients were classified clinically into different pain groups based on physical examination and imaging findings. An opioid epidural test blockade was used as a control. RESULTS: Clinical classification divided the patients into nociceptive pain (n = 7), neuropathic pain (n = 22) and mixed pain (n = 8). In the phentolamine test there were only one responder, 34 non-responders and 2 patients were placebo-responders. In the control epidural blockade there were 11 non-responders, 23 fentanyl/local anaesthetic-responders and 3 placebo-responders. CONCLUSIONS: SMP is either an uncommon cause of persistent pain in this type of failed back surgery patients or the phentolamine test, as we performed it, was unable to identify SMP.
Han TR, Kim JH, Paik NJ
Electromyography & Clinical Neurophysiology 37(4):241-50, 1997 Jun-Jul
H reflex is known as a useful electrodiagnostic test in the diagnosis of S1 radiculopathy. But, only the latency difference has been the useful parameter by previously published conventional method. Under the assumption that the constant appearance of initial negative biphasic H wave is critical to study H reflex using parameters such as amplitude, area and shape, we developed a new method using parameters such as amplitude, area and shape. To validate our assumption and to compare the diagnostic values between the conventional method and the new one, we studies H reflex in 330 subjects. One hundred sixty-two subjects were studied by conventional method and 168 subjects were studied by our new method. There was no definite difference in diagnostic values between two methods by latency criteria. However, new method was more specific for S1 radiculopathy than conventional method by amplitude and area criteria. Parameters such as amplitude, area and shape can be used significantly only in the new method. Therefore, we suggest new diagnostic criteria of abnormal response as follows: (1) H latency difference over 1.0 msec and H/H amplitude ratio less than 0.5 or (2) H latency over 30 msec or (3) unilateral absent evoked H response.
What's new concerning diagnostic and therapeutic testing in patients with low back pain? Find out in this easy-to-navigate collection of recent MEDLINE abstracts compiled by the editors at Medscape Orthopaedics and Sports Medicine.
Jarvik JG, Maravilla KR, Haynor DR, Levitz M, Deyo RA
Radiology 204(2):447-54, 1997 Aug
PURPOSE: To demonstrate the feasibility of a randomized trial to compare rapid magnetic resonance (MR) imaging with plain radiography as the initial imaging study in patients with low back pain, to test measures of the decision-making process and patient outcomes, and to offer a model for using randomized clinical trials to evaluate diagnostic tests. MATERIALS AND METHODS: The authors randomly selected 62 patients with low back pain to undergo either rapid MR imaging or plain radiography. The authors measured functional status, satisfaction, and general health status at baseline and at 3 months. The modified Roland scale was the primary outcome measure. In addition, the authors examined diagnostic and therapeutic decision making and resources used by each group. RESULTS: There were no statistically significant differences between the two patient groups with respect to outcome (Roland score: MR imaging = 12.5, radiography = 12.1). MR imaging provided more useful information to clinicians and resulted in greater patient reassurance. CONCLUSION: Randomly selecting patients to undergo imaging examinations and measuring outcomes is feasible; however, a larger, multicenter study is necessary to determine whether rapid MR imaging is a cost-effective replacement for plain radiography in patients with low back pain.
Wilkinson LS, Elson E, Saifuddin A, Ransford AO
Clinical Radiology 52(7):530-4, 1997 Jul
A retrospective study of case notes and magnetic resonance imaging (MRI) examinations was performed to assess the value of gadolinium enhanced MRI in the investigation of persistent back pain following lumbar spine surgery in patients who have not had a discectomy for disc herniation. Gadolinium enhancement is commonly used during MRI of patients with persistent back pain following surgery and epidural scar is frequently identified in patients who have had a previous discectomy. However the value of gadolinium enhancement in patients without previous discectomy had not been addressed. One hundred sets of case notes were examined and 24 patients with an accurate history of previous lumbar spine surgery without discectomy were identified. The nature of surgery and the MRI findings were correlated in these patients. Epidural enhancement was identified at seven sites in six patients (engorged epidural venous plexus, three; enhancement adjacent to degenerate discs, two; enhancement adjacent to facets, two). In no case was epidural scarring involving nerve roots identified. We conclude that routine gadolinium enhancement is unnecessary in patients without a history of discectomy for disc herniation.
Sorensen J, Bengtsson M
Acta Anaesthesiologica Scandinavica 41(5):581-5, 1997 May
BACKGROUND: Persistent pain following surgery in the treatment of chronic low-back pain patients is still relatively frequent. Most of these patients with persistent pain have clinical signs of neuropathic pain. The neuropathic pain might be sympathetically maintained pain (SMP) or sympathetically independent pain (SIP). Systemic administration of phentolamine, a competitive alpha-adrenergic antagonist, has been used as a diagnostic tool to identify patients with SMP. METHODS: Thirty-seven patients with persistent pain after low-back surgery (lumbar laminectomy, with or without discectomi, or a posterior fusion, with or without decompression) received intravenous phentolamine (0.5 mg/kg over 30 min) in a single-blind, placebo-controlled manner. Prior to this infusion the patients were classified clinically into different pain groups based on physical examination and imaging findings. An opioid epidural test blockade was used as a control. RESULTS: Clinical classification divided the patients into nociceptive pain (n = 7), neuropathic pain (n = 22) and mixed pain (n = 8). In the phentolamine test there were only one responder, 34 non-responders and 2 patients were placebo-responders. In the control epidural blockade there were 11 non-responders, 23 fentanyl/local anaesthetic-responders and 3 placebo-responders. CONCLUSIONS: SMP is either an uncommon cause of persistent pain in this type of failed back surgery patients or the phentolamine test, as we performed it, was unable to identify SMP.
Han TR, Kim JH, Paik NJ
Electromyography & Clinical Neurophysiology 37(4):241-50, 1997 Jun-Jul
H reflex is known as a useful electrodiagnostic test in the diagnosis of S1 radiculopathy. But, only the latency difference has been the useful parameter by previously published conventional method. Under the assumption that the constant appearance of initial negative biphasic H wave is critical to study H reflex using parameters such as amplitude, area and shape, we developed a new method using parameters such as amplitude, area and shape. To validate our assumption and to compare the diagnostic values between the conventional method and the new one, we studies H reflex in 330 subjects. One hundred sixty-two subjects were studied by conventional method and 168 subjects were studied by our new method. There was no definite difference in diagnostic values between two methods by latency criteria. However, new method was more specific for S1 radiculopathy than conventional method by amplitude and area criteria. Parameters such as amplitude, area and shape can be used significantly only in the new method. Therefore, we suggest new diagnostic criteria of abnormal response as follows: (1) H latency difference over 1.0 msec and H/H amplitude ratio less than 0.5 or (2) H latency over 30 msec or (3) unilateral absent evoked H response.
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