Myron M. LaBan

Practice parameter for electrodiagnostic studies in carpal tunnel syndrome: Summary statement

Orthodromic SNAPs were recorded over the median nerve using needle electrodes at the wrist and elbow after stimulation of the thumb and middle fingers. CMAPs were recorded with concentric needle electrodes placed in the endplate zone of the APB after stimulation at the wrist and elbow. NCVs were determined for 28 male and 20 female normal subjects aged 16 to 62 years. There was no significant difference in NCV between male and female subjects. There was a decrease in NCV with increasing age. No CTS patients were studied. 186. Occupational Disease Surveillance. Carpal tunnel syndrome. MMWR Morb Mortal Wkly Rep 1989;38:485-489. Background Reference Source: Baker, 1990. 187. *Osborn JB, Newell KJ, Rudney JD, Stoltenberg JL. Carpal tunnel syndrome among Minnesota dental hygienists. J Dent Hyg 1990;64(2):79-85. Criteria Met (2/6: 1,2) Source: Medline Search. 188. Padua L, Lo Monaco M, Valente EM, Tonali PA. A useful electrophysiologic parameter for diagnosis of carpal tunnel syndrome. Muscle Nerve 1996;19:48-53. Criteria Met (6/6: 1,2,3,4,5,6). Source: Medline Search. Abstract: In 43 patients (50 hands) with clinical manifestations of mild-moderate CTS and 36 healthy volunteers (40 hands), orthodromic sensory nerve conduction velocity (SNCV) was measured with surface electrodes in the median nerve between the third digit and palm and between the palm and wrist. These figures were used to calculate the ratio of distal to proximal conduction (distoproximal ratio). All 90 hands were also subjected to other nerve conduction studies used for diagnosis of CTS. All control hands presented distoproximal ratios less than 1.0 reflecting higher conduction rates in the proximal segment. In contrast, 49 of 50 CTS hands (98%) presented reversed ratios (>1.0) indicating compromised proximal conduction. The sensitivity of this test was significantly greater than that of other methods evaluated, including comparative studies and segmental study of the palm-wrist portion of the median nerve. Segmental study of median SNCV with calculation of the distoproximal ratio is a sensitive technique for diagnosis of CTS in patients with normal findings in standard nerve conduction studies. Note: The author indicated by correspondence that the mean ± SD for the Control DML in Table 1 should read 3.2 ± 0.4 and not 3.2 ± 0.8 as published. 189. Padua L, LoMonaco M, Gregori B, Valente EM, Padua R, Tonali P. Neurophysiological classification and sensitivity in 500 carpal tunnel syndrome hands. Acta Neurol Scand 1997;96:211-217. Criteria Med (6/6: 1,2,3,4,5,6) Source: Medline Search. Abstract: Prospective study of 500 hands (379 patients) with clinical diagnosis of CTS symptoms. Normal values from the same laboratory previously published (Padua, 1996). In the 500 CTS patients, DML was prolonged (55%), median orthodromic sensory latency was prolonged (D2, 74%; D3, 67%). Of the remaining 117 patients with normal DML and median orthodromic sensory studies over 14 cm, the median sensory palmwrist NCV over 8 cm was abnormal in 21% and the distoproximo ratio of the median palm and digit segments was abnormal in 87%. 190. Palliyath SK, Holden L. Refractory studies in early detection of carpal tunnel syndrome. Electromyogr Clin Neurophysiol 1990;30:307-309. Criteria Met (5/6: 1,3,4,5,6) Source: Medline Search. Abstract: Using paired stimuli and varying the inter-stimulus interval, the absolute refractory period (ARP) and relative refractory period (RRP), were determined in 10 patients with mild electrophysiologic changes suggestive of CTS. They found that the sensory RRP was sensitive in diagnosing early CTS. 191. *Pavesi G, Olivieri MF, Misk A, Mancia D. Clinicalelectrophysiological correlations in the carpal tunnel syndrome. Ital J Neurol Sci 1986;7:93-96. Criteria Met (3/6: 2,3,5) Source: Medline Search. 192. Pease WS, Cannell CD, Johnson EW. Median to radial latency difference test in mild carpal tunnel syndrome. Muscle Nerve 1989;12:905-909. Criteria Met (4/6: 1,3,5,6) Source: Medline Search. Abstract: The following techniques were studied: (a) antidromic DSL median radial differences to the thumb, (b) antidromic DSL after stimulation at the wrist and recording from the third digit, (c) median mid-palmar DSL compared as a ratio of the wrist to middle finger DSL, (d) median ulnar DSL latency difference between the ulnar Practice Parameter: Carpal Tunnel Syndrome Muscle & Nerve Supplement X 2002 S971 SNAP recorded from the little finger after stimulation at the wrist and the median DSL after stimulation at the wrist and recording from the middle finger, and (e) median motor DML after recording from the APB after stimulation at the wrist. Three hundred thirty-three symptomatic hands in 262 patients were initially evaluated with subgroups of patients with CTS evaluated with different tests. The median radial DSL difference and median ulnar DSL difference were most likely to be abnormal followed by median DSL then the palmto-wrist DSL latency ratio and lastly the DML. 193. Pease WS, Cunningham ML, Walsh WE, Johnson EW. Determining neurapraxia in carpal tunnel syndrome. Am J Phys Med Rehabil 1988;67:117-119. Criteria Met (5/6: 1,3,4,5,6) Source: Medline Search. Abstract: With needle stimulation at the wrist and midpalm, CMAPs were recorded over the APB in 25 CTS patients and 23 healthy asymptomatic persons. They found a significant difference in the amplitude of the CMAP in the CTS group when compared to the control group. They propose that this is evidence for conduction block (neurapraxia) in CTS. 194. Pease WS, Lee HH, Johnson EW. Forearm median nerve conduction velocity in carpal tunnel syndrome. Electromyogr Clin Neurophysiol 1990;30:299-302. Criteria Met (4/6: 1,3,4,5) Source: Medline Search. Abstract: The NCV of the median nerve in the forearm was determined by 2 methods: (a) stimulation in the forearm and recording the nerve action potential at the wrist, and (b) stimulation at the wrist and elbow with recording over the APB, in 21 CTS patients and 16 control subjects. They found that the forearm NCV was slowed in the CTS group using either technique. The authors have proposed that this suggest that there is proximal nerve dysfunction as a result of median nerve compression in the carpal tunnel. 195. *Peterson GW, Will AD. Newer electrodiagnostic techniques in peripheral nerve injuries. Orthop Clin North Am 1988;19:13-25. Criteria Met (0/6) Source: Narkis, 1990. 196. *Phalen GS. The carpal tunnel syndrome: clinical evaluation of 598 hands. Clin Orthop 1972;83:29-40. Background Reference. Source: Katz 1990 (J Rheumatology). 197. *Phalen GS. The carpal tunnel syndrome: seventeen years’ experience in diagnosis and treatment of 654 hands. J Bone Joint Surg 1966;48:211-228. Criteria Met (1/6: 2) Source: Meyers, 1989. 198. Phalen GS, Gardner WJ, LaLonde AA. Neuropathy of the median nerve due to compression beneath the transverse carpal ligament. J Bone Joint Surg 1950;32-A:109-112. Background Reference. Source: Braun, 1989. 199. Plaja J. Comparative value of different electrodiagnostic methods in carpal tunnel syndrome. Scan J Rehabil Med 1971;3:101-108. Criteria Met (4/6: 1,3,5,6) Source: Joynt, 1989. Abstract: The following techniques were studied: (a) CMAP potentials were recorded after stimulation at the wrist and recording with coaxial needle electrodes, (b) orthodromic SNAPs with stimulation over the index finger and recording with surface electrodes at the wrist, (c) needle EMG using a coaxial needle, (d) strength/duration curves and chronaxy. Fifty-six cases of CTS and 20 normal subjects were evaluated. Sensory latencies were more likely to be abnormal than the other techniques measured. 200. Preston DC, Logigian EL. Lumbrical and interossei recording in carpal tunnel syndrome [see comments]. Muscle Nerve 1992; 15: 1253-1257. Criteria Met (5/6: 1,3,4,5,6) Source: Medline Search. Abstract: Median motor studies are commonly “normal” in mild carpal tunnel syndrome (CTS). This reflects either the sparing of motor compared to sensory fibers, or the inability of conventional studies to detect an abnormality. A novel approach to demonstrate early motor fiber involvement in CTS is the placement of the same active electrode lateral to the third metacarpal, allowing recording from the second lumbrical or the deeper interossei, when stimulating the median or ulnar nerves at the wrist, respectively. We compared the difference between these latencies in 51 normal control hands to 107 consecutive patient hands referred with symptoms and signs suggestive of CTS, who were subsequently proven to have electrophysiologic CTS by standard nerve conduction criteria. A prolonged lumbrical-interossei latency difference (>0.4 ms) was found to be a sensitive indicator of CTS in all patient groups. It was also helpful in patients with coexistent polyneuropathy, where localization of median nerve pathology at the wrist was otherwise difficult. 201. *Preston DC, Ross MH, Kothari MJ, Plotkin GM, Venkatesh S, Logigian EL. The median-ulnar latency difference studies are comparable in mild carpal tunnel syndrome. Muscle Nerve 1994; 17: 1469-1471. Criteria Met (2/6: 1,3). Source: Medline Search. Abstract: Compares sensitivity 159 patients of orthodromic palm-wrist mixed palmar median-ulnar peak latency difference with normal <0.4 ms, antidromic wrist-D4 sensory median-ulnar onset latency difference with normal <0.5 ms, and the second lumbrical/interossei motor with normal <0.5 ms. See discussion of benefits of techniques and diagrams of electrode placements and line drawings of electrode and stimulator placement. 202. Preswick G. The effect of stimulus intensity in motor latency in carpal tunnel syndrome. J Neurol Neurosurg Psychiatry 1963;26:398-401. Criteria Met (4/6: 1,3,5,6) Source: Loong, 1971. Abstract: With stimulation at the wrist and coaxial needle electrode recording from the APB, DMLs were recorded at super-maximal stimulation and threshold stimulation in 29 CTS hands f

The Lumbar Herniated Disk of Pregnancy: A Report of Six Cases Identified by Magnetic Resonance Imaging

Although the mechanical and positional stresses of pregnancy are the primary inciting factors contributing to lumbosacral pain accompanying gestation, in approximately 1:10,000 cases a herniated disk (HNP) can be identified as the proximal cause of pain. Six patients are described, all of whom without antecedent history of pain presented with acute, disabling, gestational lumbosacral, and sciatic radiculopathy. Their ages ranged from 29 to 36, their parity from 0 to 1, and their gestational age at onset of symptoms from 6 weeks to 32 weeks. Each by magnetic resonance imaging (MRI) was identified as having an HNP, 2 at the L4-5 level and 4 at the L5-S1 level. During pregnancy, an MRI evaluation permits a detailed spinal examination without the ionizing effects of x-ray and its acknowledged biological risk to the developing fetus. This potential for an immediate and accurate diagnosis has significant implications for the management and subsequent planning of delivery.

Osteoporotic stress fractures in anorexia nervosa: Etiology, diagnosis, and review of four cases

Anorexia nervosa (AN) is a chronic eating disorder characterized by self-imposed semi-starvation that affects 1% of adolescent females. AN predisposes to osteoporosis through hypothalamic dysfunction, which may lead to elevated cortisol as well as diminished estrogen and progesterone. The osteoporosis associated with AN affects both trabecular and cortical bone and increases the risk of osseous fracture. Fractures in this population may go unrecognized, because planar X-rays may be nondiagnostic for 6 weeks or more. Four women with AN ranging in ages from 22 to 34 with skeletal pain and nondiagnostic roentgenographs are described. Stress fractures in these patients were subsequently identified by bone scan. Although moderate exercise in patients with AN-associated osteoporosis may be beneficial, strenuous exercise can be detrimental, with its potential risk of stress fractures and exacerbation of the underlying neurohormonal abnormalities. This risk for fracture may persist well after improvement in the patients AN.

Magnetic resonance imaging of the lumbar herniated disc in pregnancy.

Lumbosacral pain is a significant complaint in approximately one-half of all pregnancies. In 15%, the pain can be disabling. Although the mechanical and positional stresses of pregnancy have been cited as the primary source of this discomfort, in approximately 1:10,000 cases a herniated lumbar disc (HNP) can be identified as the proximal cause of pain. A 35-yr-old G4AB3PO patient presenting at 10 wk of pregnancy with severe incapacitating lumbar radiculopathy is described. Magnetic resonance imaging, selected by the patient as a diagnostic option, demonstrated a clinically suspected large midline HNP at the L5-S1 level. In the past, visualizing the presence of a HNP during pregnancy by either computerized axial tomography scan or myelography has exposed the fetus to ionizing radiation. However, magnetic resonance imaging now permits a more detailed evaluation without similar x-ray exposure. To date, no recognized biologic effect of MRI on the developing fetus has been reported. Although the long-term effects of an magnetic resonance imaging on the developing fetus have not been conclusively evaluated, its potential for accurate diagnosis and subsequent patient management, as well as planning the delivery, appears to outweigh any recognized hazard to the developing fetus.

Bilateral adrenal hemorrhage after anticoagulation prophylaxis for bilateral knee arthroplasty.

After joint arthroplasty, the risk of deep vein thrombosis and pulmonary embolism increases exponentially. Inadequate anticoagulation prophylaxis may not sufficiently reduce the risk of thrombosis, whereas excessive anticoagulation therapy may predispose the patient to a bleed. Bilateral adrenal hemorrhage is a relatively rare but potentially catastrophic life-threatening event. An 82-yr-old woman is described who was rehospitalized from a subacute rehabilitation facility complaining of epigastric pain radiating into her flank. Eight days previously, she had undergone an uncomplicated bilateral total knee arthroplasty and was subsequently administered subcutaneous heparin and warfarin. An abdominal computed tomographic scan subsequently demonstrated bilateral small adrenal hemorrhages. Acute adrenal insufficiency (Addisons disease) caused by hemorrhage within the adrenal cortices, although still uncommon, can be expected to increase as anticoagulation prophylaxis after joint arthroplasty becomes routine.

Physical medicine and rehabilitation workforce study: The supply of and demand for physiatrists☆☆☆

OBJECTIVE Analysis, results, and implications of a supply and demand workforce model for physical medicine and rehabilitation. Explicit issues addressed include: (1) the supply implications of maintaining current (1994-1995) output of physiatrists from residency programs; (2) the implications of continued growth in managed care on the demand for the services of physiatrists; (3) likely future supply and demand conditions; and (4) strategies to adapt to future conditions. DESIGN A workforce model of the supply and demand for physiatrists was developed. Parameters of the model are estimated using econometric models and by applying the judgments of a consensus panel. The model evaluated several different scenarios regarding managed care growth, competition from other providers and other factors. RESULTS Based on the analysis, physiatrists will continue to be in excess demand through the year 2000. More aggressive growth in managed care can affect this result. CONCLUSIONS Based on an overall assessment of supply and demand conditions, and under the assumption that the supply of new entrants each year remains in the range of 1994-1995 levels, demand for physiatrists will continue to exceed supply, on average, through the year 2000. Excess supply has, and will, emerge in selected geographic areas. If the profession is successful in informing the market regarding the advantages of physiatry, the profession can continue to grow without experiencing excess supply, in the aggregate, for the foreseeable future.

Varicosities of the paravertebral plexus of veins associated with nocturnal spinal pain as imaged by magnetic resonance venography : A brief report

LaBan MM, Wang A-M, Shetty A, Sessa GR, Taylor RS: Varicosities of the paravertebral plexus of veins associated with nocturnal spinal pain as imaged by magnetic resonance venography.

Young lumbar spinal stenotic: review of 268 patients younger than 51 years.

LaBan MM, Imas A: “Young” lumbar spinal stenotic: Review of 268 patients younger than 51 years. Am J Phys Med Rehabil 2003;82:69–71. Historically, most patients with the lumbar spinal stenosis have been older than 66 yr when initially diagnosed; however, with a growing awareness of this entity, it is increasingly being identified at an earlier age. A 5-yr retrospective review of hospital records was initiated to determine the frequency of lumbar spinal stenosis in a population of patients of <51 yr of age. Of 2751 patients admitted with this diagnosis, 268 (9.8%) were <51 yr of age.

Electromyographic detection of paraspinal muscle metastasis. Correlation with magnetic resonance imaging.

Electromyographic (EMG) examination demonstrating marked segmental compromise of the posterior primary ramus distal to the spinal root with relative sparing of the anterior ramus may be the earliest objective evidence of paraspinal muscle metastasis. Antecedent studies are often initially normal, failing to disclose the underlying cause of back pain. Although paraspinal muscle metastasis has been histopathologically demonstrated at postmortem, attempts to image the suspected malignancy with computed tomography have been unsuccessful because the tumor in muscle remains isodense. This study reports the use of magnetic resonance imaging (MRI) to substantiate the existence of EMG-suspected paraspinal muscle metastasis. An EMG pattern of segmental posterior primary ramus denervation is not pathognomonic of metastasis. A confirmatory MRI, however, does permit earlier treatment with palliative radiation therapy.

Paravertebral venous plexus distention (Batson's): an inciting etiologic agent in lumbar radiculopathy as observed by venous angiography.

LaBan MM, Wilkins JC, Wesolowski DP, Bergeon B, Szappanyos BJ: Paravertebral venous plexus distention (Batson’s): an inciting etiologic agent in lumbar radiculopathy as observed by venous angiography. Am J Phys Med Rehabil 2001; 80:129–133.Can the paravertebral plexus of veins adjacent to the spinal nerve root within the narrow confines of the lateral neural canal be a collateral generator of radicular pain when no other evidence of spinal pathology is evident? A patient with complaints of intractable lumbar radiculopathy and an otherwise unremarkable clinical neuromusculoskeletal examination, as well as normal imaging and electrodiagnostic studies, is reviewed with special reference to symptomatic and paravertebral venous responses to both a Valsalva maneuver and dipyridamole infusion as imaged by magnetic venous angiography.