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Needle examination in carpal tunnel syndrome
LETTERS
TO THE
Hendestiema G. New aspects on atelectasis formation and gas exchange impairment during anaesthesia. Clin Physiol 1989;9: 407-17. Thomas JA, McIntosh JM. Are incentive spirometry, intermittent positive pressure breathing, and deep breathing exercises effective in the prevention of postoperative pulmonary complications after upper abdominal surgery? A systematic overview and metaanalysis. Phys Ther 1994;74:3-16. Celli BR, Rodriguez KS, Snider GL. A controlled trial of intermittent positive pressure breathing, incentive spirometry, and deep breathing exercises in preventing pulmonary complications after abdominal surgery. Am Rev Respir Dis 1984;130:12-5.
Needle Examination in Carpal Tunnel Syndrome Balbierz and colleagues’ examined, through a retrospective review of EMGlnerve conduction studies, the utility of using the needle examination in the diagnosis of carpal tunnel syndrome (CTS). The data suggest the possibility of solely using motor nerve conduction studies in some subpopulations of patients. In their study, Balbierz and colleagues clearly demonstrated that if the motor nerve conduction study was normal, there was an 89.8% probability of having a normal EMG, thus posing several questions: “Is a needle examination always necessary?” “ Are we prepared to accept the responsibility of missing a diagnosis?” “ Are transpalmar sensory studies alone sufficient for diagnosing CTS in a subpopulation?” It has been my experience that if a patient has a negative Spurling’s sign, normal upper extremity reflexes, a positive Tinel’s, and no history of diabetes mellitus, thyroid disease, or pregnancy, then neither motor nerve conduction studies nor EMG examination offer significant additional information, if the transpalmar study was positive for suspected CTS. Langston B. Cleveland, MD Department of PM&R Divine Savior Hospital Portage, WI 53901 Reference 1. Balbierz JM, Cottrell AC, Come11 WD. Is needle examination always necessary in evaluation of carpal tunnel syndrome? Arch Phys Med Rehabil 1998;79-514-6.
An author replies Dr. Cleveland raises some interesting and important questions about how we diagnose carpal tunnel syndrome and what our responsibility is as electromyographers. First, to clarifyour subgroup of patients with a 90% chance of normal EMG had normal motor and sensory and midpalmar nerve conduction studies, not just normal motor studies. If the patients had slowing of the motor or sensory conduction across the carpal tunnel, the midpalmar studies were not done as the diagnosis was already established. Dr. Cleveland also asks, “Are we prepared to accept the responsibility of missing a diagnosis?” We were all trained that electrodiagnostic studies should be an extension of a good history and physical, not just a cookbook testing of a list of nerves and muscles. EMG should be thought of more as a consultation rather than a “test.” That is why we emphasized the importance of broad training in neuromuscular disorders and medicine in general. Without such training, the possibility of missing a diagnosis increases greatly. “Are transpalmar sensory studies alone sufficient for diagnosing carpal tunnel syndrome in a subpopulation?” If the transpalmar study is normal, I do not think you can rule out carpal tunnel
1141
EDITOR
syndrome necessarily, as a small percentage of patients present acutely with motor slowing only.’ If the transpalmar stimulation is prolonged, I would not be comfortable in calling it carpal tunnel syndrome without studying an ulnar or radial nerve (including at least one motor study) to rule out peripheral neuropathy. Peripheral neuropathy can be the first symptom of diabetes, and, once suspected, diabetes is relatively easy to diagnose and treat. Second, if the transpalmar stimulation is prolonged, studying the motor nerve and possibly doing needle examination can give additional information as to the severity of the carpal tunnel syndrome. Third, study of the median nerve distal to the lesion can help determine the degree of conduction block versus axonal injury, which can be helpful in prognosis and may change clinical management2z3 Janet M. Balbierz, MD University Medical Center The University of Utah Salt Lake City, UT 84132 References Gordon C, Bower BL, Johnson EW. Electrodiagnostic characteristics of acute carpal tunnel syndrome. Arch Phys Med Rehabil 1987;68:545-8. Pease WS, Cunningham ML, Walsh WE, Johnson EW. Determining neuropraxia in carpal tunnel syndrome. Am J Phys Med Rehabil 1988;67: 117-9. Lesser EA, Venkatesh S, Preston DC, Logigian EL. Stimulation distal to the lesion in patients with carpal tunnel syndrome. Muscle Nerve 1995;18:503-7.
Lumbar Spinal Stenosis The thoroughgoing review, “Lumbar Spinal Stenosis: A Review of Current Concepts in Evaluation, Management, and Outcome Measurements, “l is noted with interest. I write to point out the discovery of an effective and simple test which, in my own hands, usually excludes the presence of a clinically significant lumbar spinal stenosis (LSS) by the finding of myotomal weakness after a 5minute walk. This weakness is often accompanied by back, hip, or extremity pain.2 The test not only detects radicular problems and localizes the myotome, but also affords an excellent method for determining the adequacy of treatment on subsequent examinations. One must be wary, however, of not dealing with only reflex inhibition of a myotome as from a very painful lumbar facet joint, hip arthritis, or even gluteal myofascial trigger points. To rule out this phenomenon, careful examination and, possibly, use of lidocaine will indicate an immediate restoration of strength, proving thereby the presence of reflex inhibition. When used judiciously, the 5minute walk test2 adds a quick and valuable office test to our diagnostic repertoire and makes the observation that there is no clinical test for LSS no longer valid. Fred L. Snipes, MD Sherman, TX 75092 References 1. Fritz JM, Delitto A, Welch WC, Erhard RE. Lumbar spinal stenosis: a review of current concepts in evaluation, management, and outcome measurements. Arch Phys Med Rehabil 1998;79:700-8. 2. Snipes FL. The five minute walk test: a quick and simple office method for demonstrating lumbar radiculopathy [abstract]. Arch Phys Med Rehabil 1996;77:953. Arch
Phys
Med
Rehabil
Vol 79, September
1998
TO THE
Hendestiema G. New aspects on atelectasis formation and gas exchange impairment during anaesthesia. Clin Physiol 1989;9: 407-17. Thomas JA, McIntosh JM. Are incentive spirometry, intermittent positive pressure breathing, and deep breathing exercises effective in the prevention of postoperative pulmonary complications after upper abdominal surgery? A systematic overview and metaanalysis. Phys Ther 1994;74:3-16. Celli BR, Rodriguez KS, Snider GL. A controlled trial of intermittent positive pressure breathing, incentive spirometry, and deep breathing exercises in preventing pulmonary complications after abdominal surgery. Am Rev Respir Dis 1984;130:12-5.
Needle Examination in Carpal Tunnel Syndrome Balbierz and colleagues’ examined, through a retrospective review of EMGlnerve conduction studies, the utility of using the needle examination in the diagnosis of carpal tunnel syndrome (CTS). The data suggest the possibility of solely using motor nerve conduction studies in some subpopulations of patients. In their study, Balbierz and colleagues clearly demonstrated that if the motor nerve conduction study was normal, there was an 89.8% probability of having a normal EMG, thus posing several questions: “Is a needle examination always necessary?” “ Are we prepared to accept the responsibility of missing a diagnosis?” “ Are transpalmar sensory studies alone sufficient for diagnosing CTS in a subpopulation?” It has been my experience that if a patient has a negative Spurling’s sign, normal upper extremity reflexes, a positive Tinel’s, and no history of diabetes mellitus, thyroid disease, or pregnancy, then neither motor nerve conduction studies nor EMG examination offer significant additional information, if the transpalmar study was positive for suspected CTS. Langston B. Cleveland, MD Department of PM&R Divine Savior Hospital Portage, WI 53901 Reference 1. Balbierz JM, Cottrell AC, Come11 WD. Is needle examination always necessary in evaluation of carpal tunnel syndrome? Arch Phys Med Rehabil 1998;79-514-6.
An author replies Dr. Cleveland raises some interesting and important questions about how we diagnose carpal tunnel syndrome and what our responsibility is as electromyographers. First, to clarifyour subgroup of patients with a 90% chance of normal EMG had normal motor and sensory and midpalmar nerve conduction studies, not just normal motor studies. If the patients had slowing of the motor or sensory conduction across the carpal tunnel, the midpalmar studies were not done as the diagnosis was already established. Dr. Cleveland also asks, “Are we prepared to accept the responsibility of missing a diagnosis?” We were all trained that electrodiagnostic studies should be an extension of a good history and physical, not just a cookbook testing of a list of nerves and muscles. EMG should be thought of more as a consultation rather than a “test.” That is why we emphasized the importance of broad training in neuromuscular disorders and medicine in general. Without such training, the possibility of missing a diagnosis increases greatly. “Are transpalmar sensory studies alone sufficient for diagnosing carpal tunnel syndrome in a subpopulation?” If the transpalmar study is normal, I do not think you can rule out carpal tunnel
1141
EDITOR
syndrome necessarily, as a small percentage of patients present acutely with motor slowing only.’ If the transpalmar stimulation is prolonged, I would not be comfortable in calling it carpal tunnel syndrome without studying an ulnar or radial nerve (including at least one motor study) to rule out peripheral neuropathy. Peripheral neuropathy can be the first symptom of diabetes, and, once suspected, diabetes is relatively easy to diagnose and treat. Second, if the transpalmar stimulation is prolonged, studying the motor nerve and possibly doing needle examination can give additional information as to the severity of the carpal tunnel syndrome. Third, study of the median nerve distal to the lesion can help determine the degree of conduction block versus axonal injury, which can be helpful in prognosis and may change clinical management2z3 Janet M. Balbierz, MD University Medical Center The University of Utah Salt Lake City, UT 84132 References Gordon C, Bower BL, Johnson EW. Electrodiagnostic characteristics of acute carpal tunnel syndrome. Arch Phys Med Rehabil 1987;68:545-8. Pease WS, Cunningham ML, Walsh WE, Johnson EW. Determining neuropraxia in carpal tunnel syndrome. Am J Phys Med Rehabil 1988;67: 117-9. Lesser EA, Venkatesh S, Preston DC, Logigian EL. Stimulation distal to the lesion in patients with carpal tunnel syndrome. Muscle Nerve 1995;18:503-7.
Lumbar Spinal Stenosis The thoroughgoing review, “Lumbar Spinal Stenosis: A Review of Current Concepts in Evaluation, Management, and Outcome Measurements, “l is noted with interest. I write to point out the discovery of an effective and simple test which, in my own hands, usually excludes the presence of a clinically significant lumbar spinal stenosis (LSS) by the finding of myotomal weakness after a 5minute walk. This weakness is often accompanied by back, hip, or extremity pain.2 The test not only detects radicular problems and localizes the myotome, but also affords an excellent method for determining the adequacy of treatment on subsequent examinations. One must be wary, however, of not dealing with only reflex inhibition of a myotome as from a very painful lumbar facet joint, hip arthritis, or even gluteal myofascial trigger points. To rule out this phenomenon, careful examination and, possibly, use of lidocaine will indicate an immediate restoration of strength, proving thereby the presence of reflex inhibition. When used judiciously, the 5minute walk test2 adds a quick and valuable office test to our diagnostic repertoire and makes the observation that there is no clinical test for LSS no longer valid. Fred L. Snipes, MD Sherman, TX 75092 References 1. Fritz JM, Delitto A, Welch WC, Erhard RE. Lumbar spinal stenosis: a review of current concepts in evaluation, management, and outcome measurements. Arch Phys Med Rehabil 1998;79:700-8. 2. Snipes FL. The five minute walk test: a quick and simple office method for demonstrating lumbar radiculopathy [abstract]. Arch Phys Med Rehabil 1996;77:953. Arch
Phys
Med
Rehabil
Vol 79, September
1998