Jasper R. Daube

Plasma Exchange in Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Plasma exchange has been reported to be efficacious in chronic inflammatory demyelinating polyradiculoneuropathy. We performed a prospective double-blind trial in which patients with static or worsening disease were randomly assigned to plasma exchange (n = 15) or to sham exchange (n = 14) for three weeks. After three weeks, we observed statistically significant differences in combined measurements of nerve conduction (total, motor, proximal, velocity, and amplitude) favoring patients who had received plasma exchange. Improvement to a greater degree than for any patient receiving sham exchange was detected in the neurologic-disability score in five patients (P = 0.025) and in subset scores for weakness and reflex in four patients (P less than 0.057). We conclude that for some patients with chronic inflammatory demyelinating polyradiculoneuropathy, plasma exchange has an ameliorating effect on neurologic dysfunction and nerve conduction, but in others no improvement is observed. Because plasma was replaced with normal serum albumin, a humoral factor or factors may have a role in the neurologic deficit of this disorder.

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

3,4-Diaminopyridine in the Treatment of Lambert–Eaton Myasthenic Syndrome

Lambert-Eaton myasthenic syndrome is characterized by muscle weakness, hyporeflexia, and autonomic dysfunction, which result from impaired release of acetylcholine from cholinergic nerve terminals. It is frequently associated with cancer, it is autoimmune-mediated, and treatment has been unsatisfactory. 3,4-Diaminopyridine enhances the release of acetylcholine. In this prospective, double-blind, placebo-controlled crossover study of 12 patients with Lambert-Eaton myasthenic syndrome (7 of whom had cancer), 3,4-diaminopyridine in doses up to 100 mg per day was effective in treating both the motor and the autonomic deficits of the syndrome. Muscle strength increased from an average of 70 percent of normal to 81 percent of normal in the upper extremities, and from 45 to 65 percent of normal in the lower extremities. The amplitudes of compound-muscle-action potentials nearly doubled, increasing from an average of 2.9 mV to 5.0 mV in the arm and from 1.6 mV to 3.1 mV in the leg. Autonomic symptoms were relieved. One patient had a seizure after 10 months of treatment, but other side effects from the drug were minimal and dose-related. We conclude that 3,4-diaminopyridine, either alone or in conjunction with other therapies, may be useful in the treatment of Lambert-Eaton myasthenic syndrome.

Combined azathioprine and prednisone in chronic inflammatory‐demyelinating polyneuropathy

Twenty-seven patients with static or worsening chronic inflammatory-demyelinating polyradiculoneuropathy were randomly assigned to alternate day decremental prednisone therapy alone or with azathioprine (2 mg/kg) for 9 months. No statistically significant alterations were demonstrated between these treatment schedules.

Relationship between symptoms and disordered continence mechanisms in women with idiopathic faecal incontinence

Background and aims: Anal sphincter weakness and rectal sensory disturbances contribute to faecal incontinence (FI). Our aims were to investigate the relationship between symptoms, risk factors, and disordered anorectal and pelvic floor functions in FI. Methods: In 52 women with “idiopathic” FI and 21 age matched asymptomatic women, we assessed symptoms by standardised questionnaire, anal pressures by manometry, anal sphincter appearance by endoanal ultrasound and magnetic resonance imaging (MRI), pelvic floor motion by dynamic MRI, and rectal compliance and sensation by a barostat. Results: The prevalence of anal sphincter injury (by imaging), reduced anal resting pressure (35% of FI), and reduced squeeze pressures (73% of FI) was higher in FI compared with controls. Puborectalis atrophy (by MRI) was associated (p<0.05) with FI and with impaired anorectal motion during pelvic floor contraction. Volume and pressure thresholds for the desire to defecate were lower, indicating rectal hypersensitivity, in FI. The rectal volume at maximum tolerated pressure (that is, rectal capacity) was reduced in 25% of FI; this volume was associated with the symptom of urge FI (p<0.01) and rectal hypersensitivity (p = 0.02). A combination of predictors (age, body mass index, symptoms, obstetric history, and anal sphincter appearance) explained a substantial proportion of the interindividual variation in anal squeeze pressure (45%) and rectal capacity (35%). Conclusions: Idiopathic FI in women is a multifactorial disorder resulting from one or more of the following: a disordered pelvic barrier (anal sphincters and puborectalis), or rectal capacity or sensation.

Chronic immune sensory polyradiculopathy A possibly treatable sensory ataxia

Background: Chronic inflammatory neuropathies can present with a sensory ataxia due to involvement of dorsal root ganglia (DRG) or sensory nerves. Selective inflammatory involvement of sensory nerve roots proximal to the DRG has been postulated. Methods: The authors identified 15 patients with a sensory syndrome and normal nerve conduction studies. Sensory nerve root involvement was suggested by either somatosensory evoked potential (SSEP) or imaging abnormalities. CNS disease was excluded. Results: All patients had gait ataxia, large fiber sensory loss, and paresthesias, and nine had frequent falls. The disease course was chronic and progressive (median duration 5 years, range 3 months to 18 years). Sural sensory nerve action potential amplitudes were preserved and SSEP abnormalities were consistent with sensory nerve root involvement. Five patients had enlargement of lumbar nerve roots on MRI with enhancement in three. The CSF protein was elevated in 13 of 14 patients tested. Three patients had lumbar sensory rootlet biopsies that showed thickened rootlets, decreased density of large myelinated fibers, segmental demyelination, onion-bulb formation, and endoneurial inflammation. Six patients who required aids to walk were treated with immune modulating therapy and all had marked improvement with four returning to normal ambulation. Conclusion: Based on the described clinical features, normal nerve conduction studies, characteristic somatosensory evoked potential (SSEP) abnormality, enlarged nerve roots, elevated CSF protein, and inflammatory hypertrophic changes of sensory nerve rootlet tissue, we suggest the term chronic immune sensory polyradiculopathy (CISP) for this syndrome. This condition preferentially affects large myelinated fibers of the posterior roots, may respond favorably to treatment, and may be a restricted form of chronic inflammatory demyelinating polyradiculoneuropathy.

Near normoglycaemia improved nerve conduction and vibration sensation in diabetic neuropathy

SummaryTwelve C-peptide deficient Type 1 (insulin-dependent) diabetic patients with abnormal peripheral nerve function were randomly assigned to continuation of conventional insulin therapy (CIT) or to continuous subcutaneous insulin infusion (CSII). There were no statistically significant differences at entry to the study between the two treatment groups in nerve function assessed by neurologic disability score, computer assisted sensation examination and measurements of amplitudes, distal latencies, F-wave latencies and somatosensory evoked potential latencies over the spine and conduction velocities of motor and sensory fibers of ulnar, median, peroneal, tibial, plantar and sural nerves. In addition, mean plasma glucose from 24 h profiles (12.5 vs 10.6 mmol/l, respectively) and HbA1 (11.0 vs 11.6%, respectively) did not differ significantly between the two treatment groups at entry. Despite improved glycaemia from CSII in 5 patients (one dropped out of the study after 2 months) contrasted to CIT in 6 patients (5.3 vs 9.9 mmol/l, respectively, p=0.002) and HbA1 (8.5 vs 10.7%, respectively, p=0.002), there were no significant differences in measurements of peripheral nerve function after 4 months. After 8 months of improved glycaemia (4.4 vs 10.2 mmol/l, p=0.004) and improved HbA1, (8.3 vs 10.5%, p=0.002), nerve conduction (p=0.03) and vibratory sensation threshold (p=0.002) were significantly better in patients treated with CSII than those who received CIT. The improvements in nerve function, although small, provide further evidence that some clinical endpoints of neuropathy are favorably influenced by improved control of glycaemia.

Improved Preservation of Facial Nerve Function With Use of Electrical Monitoring During Removal of Acoustic Neuromas

Continuous spontaneous electromyographic activity and responses to electrical stimulation of the facial nerve in the surgical field were monitored in 48 patients undergoing primary removal of an acoustic neuroma. The operative and postoperative results in these patients were compared with the results in 48 patients who were matched for age and size of tumor and who underwent the same surgical procedure without intraoperative monitoring. Eighty-three percent of the patients had preoperative evidence of facial neuropathy, which was more severe with larger tumors. Postoperative facial nerve function was most accurately predicted on the basis of the extent of facial neuropathy on preoperative electrophysiologic testing. Anatomic preservation of the facial nerve in patients with large tumors was substantially improved in the monitored patients (67%) in comparison with those without monitoring (33%). No difference was noted in facial nerve function in the two groups of patients immediately postoperatively. By 3 months, the degree of improvement in the monitored group exceeded that in those who were not monitored, particularly in patients with medium-sized and large tumors.

Effects of Alterations in Pulmonary Function and Sleep Variables on Survival in Patients With Amyotrophic Lateral Sclerosis

Breathing abnormalities and nocturnal hypoventilation occur in patients with amyotrophic lateral sclerosis (ALS). A prospective study was undertaken to determine the relationship of pulmonary function test abnormalities with quality of sleep and survival in 21 patients with ALS. Results of spirometry including determination of maximal respiratory pressures and arterial blood gases were compared with several formal polysomnographic variables and then also with 18-month survival. The patients had mild to moderate pulmonary function deficits, but the quality of sleep was best related to age (mean age, 58.5 years). The results of pulmonary function tests and arterial blood gas measurements did not correlate well with the presence of nocturnal breathing events or survival time, but the maximal inspiratory pressure was 86% sensitive for predicting the presence of a nocturnal oxygen saturation nadir of 80% or less and 100% sensitive for predicting 18-month survival. Although obstructive breathing events occurred, the primary explanation for the decline in nocturnal oxygen saturation was hypoventilation. We conclude that routine pulmonary function tests may be useful for screening for reductions in nocturnal oxygen saturation and also may have prognostic value. Further studies may determine whether treatment of nocturnal hypoventilation will have an effect on survival in patients with ALS who have breathing impairment.

Neuropathy in the Miller Fisher syndrome Clinical and electrophysiologic findings

The clinical and electrophysiologic findings in 10 patients with Miller Fisher syndrome (ataxia, ophthalmoplegia, and areflexia) were reviewed. All patients had motor and sensory nerve conduction studies and EMG in the arm and the leg, and seven patients had cranial nerve conduction studies. Electrodiagnostic abnormalities were found in all patients and were characteristic of an axonal neuropathy or a neuronopathy with predominant sensory nerve changes in the limbs and motor damage in the cranial nerves. The pattern of abnormalities was distinct from the usual features seen in the major form of acute inflammatory polyneuropathy, the Guillain-Barrb syndrome.