Prevalence and characteristics of peripheral neuropathy in hepatitis C virus population

OBJECTIVE: To assess the prevalence of peripheral neuropathy (PN) and its correlation with cryoglobulinemia (CG) in an unselected, untreated referral hepatitis C virus (HCV) population. PATIENTS AND METHODS: Two hundred and thirty four patients (120 women and 114 men) with untreated HCV infection were consecutively enrolled by seven Italian centres. Clinical neuropathy was diagnosed when symptoms and signs of peripheral sensory or motor involvement were present. Median, ulnar, peroneal, and sural nerves were explored in all patients and distal symmetric polyneuropathy was diagnosed when all explored nerves or both lower limb nerves were affected. Mononeuropathy and mononeuropathy multiplex were diagnosed when one nerve or two non-contiguous nerves with asymmetrical distribution were affected. Screening for CG was done in 191 unselected patients. RESULTS: Clinical signs of PN were observed in 25 of the 234 patients (10.6%). Electrophysiological PN was found in 36 (15.3%). CG was present in 56/191 patients (29.3%). The prevalence of CG increased significantly with age (p<0.001) and disease duration (p<0.05). PN was present in 12/56 (21%) patients with CG and 18/135 (13%) without CG (p=NS). PN increased significantly with age (p<0.001) and logistic regression analysis confirmed age as the only independent predictor of PN (OR 1.10 for each year; 95% CI 1.04 to 1.15; p<0.001). CONCLUSIONS: Electrophysiological examination detected subclinical neuropathy in 11 patients (4.7%). Statistical analysis showed that CG was not a risk factor for PN whereas PN prevalence increased significantly with age.     

Clinical and electrophysiologic study of the peripheral nerve in 28 cases of mitochondrial disease]

Twenty-eight patients with mitochondrial disease were systematically investigated on clinical and electrophysiological grounds for peripheral neuropathy (PN): 25 had predominant ophthalmoplegia (including 4 with Kearns-Sayre syndrome) and 3 had predominant central nervous system involvement. There were 11 men and 17 women, mean age 43 years. Nine of the 28 patients had signs of sensory polyneuropathy involving mainly the lower limbs. These 9 patients and another asymptomatic patient had electrophysiological abnormalities: in the lower limbs, sensory potentials were absent or decreased in amplitude in all cases. In peroneal nerves, motor conduction nerve velocities were decreased in 4/10 cases. These data were consistent with an axonopathy. No correlation was found between the presence of PN and the clinical features of the mitochondrial diseases or with the respiratory chain defect (studied in 14 cases).     

Peripheral neuropathy in systemic lupus erythematosus.

The prevalence of clinically apparent peripheral neuropathy in systemic lupus erythematosus is reported to be between 2% to 18%. The purpose of this prospective case-control study was to determine the prevalence of peripheral neuropathy (PN) using electrodiagnostic criteria. Subgroup analysis was performed to determine whether PN correlated with disease activity, renal involvement, or serum immune markers. Fifty-four systemic lupus erythematosus patients and 30 controls were recruited in the study. The right median, ulnar, peroneal, tibial, and sural sensory and motor nerve conduction studies were obtained. PN in our study was defined as any abnormal values in motor and sensory distal latency, sensory action potential, motor action potential, or conduction velocity affecting 2 or more nerves. Of the 54 patients studied, PN was present in 15 patients (27.8%) of which 4 were symptomatic. There was a significant correlation between PN and anti-SM antibody, and there was a trend showing decreased motor and sensory action potential amplitudes in our systemic lupus erythematosus group compared to the controls. This observation was also seen in an active disease group when compared to those with inactive disease. The amplitude of the action potential was more often affected than the distal latency, and sensory nerves were more susceptible than motor nerves. The sural sensory action potential amplitude appears to be the most sensitive indicator of PN which may be used as an index to monitor disease activity.     

Peripheral nerve involvement in primary systemic AL amyloidosis: a clinical and electrophysiological study

Background: Involvement of visceral organs usually dominates the clinical picture of primary systemic AL amyloidosis, but some patients suffer from serious peripheral neuropathy. The aim of this study is to clinically and electrophysiologically investigate peripheral nerve involvement in AL amyloidosis patients. Patients and methods: We reviewed clinical manifestations, electrophysiological findings including nerve conduction velocities and treatments in 43 consecutive patients. Twenty age‐matched healthy subjects were employed as controls. Results: Fifteen patients (34.9%) showed apparent neuropathic symptoms, which consisted of polyneuropathy in 11 (25.6%), bilateral carpal tunnel syndrome in 4 (9.3%), and autonomic dysfunction in 8 (18.6%). Polyneuropathy in this disease was characterized by symmetrical and sensory‐dominant impairment, early involvement of the lower limbs, loss of all sensations, rarity of motor weakness, and painful paresthesia in the legs predominant at an early stage. Autonomic dysfunction including orthostatic hypotension was frequently associated with polyneuropathy at an advanced stage. On electrophysiological studies, motor conduction velocity and compound muscle action potential of both median and tibial nerves were significantly decreased in the patients with polyneuropathy but also in those without any signs of neuropathy. Only four of 15 patients with neuropathy were able to receive intensive but promising chemotherapy with a large dose of melphalan for plasma cell dyscrasia. Conclusions: Peripheral nerves in primary systemic AL amyloidosis patients seem to be involved more extensively than clinical manifestations might suggest. The clinical picture of polyneuropathy in this disease closely resembles that in transthyretin‐type familial amyloid polyneuropathy patients with a late age at onset, particularly those originating from sporadic kindreds.     

Human neurolymphomatosis in a patient with chronic lymphatic leukemia

A 62-year-old woman with chronic lymphatic leukemia (CLL) (RAI stage IV) with multiple organ involvement and diabetes mellitus, three months prior to death presented with a symmetrical sensory neuropathy of the upper extremities with little motor impairment and, two months later, sensory atactic neuropathy of the lower limbs. No cranial nerve or CNS impairment was noted. Clinical diagnosis was predominantly sensory neuropathy, but nerve conduction velocities were normal on upper limbs and moderately abnormal on lower limbs, the latter attributing to long lasting diabetes mellitus. The women died from acute subarachnoid hemorrhage. Autopsy revealed CLL of B-cell type with generalized organ involvement and acute craniospinal subarachnoid hemorrhage from ruptured cerebral aneurysm. There was selective neoplastic infiltration of the dorsal root ganglia and peripheral nerves, particularly the median nerve. Although selective infiltration of peripheral nerves by B-cell lymphoma cells was not associated with myelo-axonal degeneration, the relationship of this case to human neurolymphomatosis is discussed.     

Medial plantar and dorsal sural nerve conduction studies increase the sensitivity in the detection of neuropathy in diabetic patients.

OBJECTIVE: Clinical utility of nerve conduction studies (NCS) of the medial plantar and dorsal sural nerves in the early detection of polyneuropathy have already been shown separately. However, at present, there is no data about the combined assessment of these two nerves in distal sensory neuropathy. In the present study, we aimed to evaluate the medial plantar and dorsal sural NCS in a group of diabetic patients with distal sensory neuropathy (DSN) and in healthy controls. METHODS: Thirty healthy and 30 diabetic adult patients were included. In all subjects, peripheral motor and sensory NCS were performed bilaterally with surface electrodes on the lower limbs including medial plantar and dorsal sural nerves. In addition, motor and sensory nerves were studied unilaterally on the upper limb. RESULTS: In all patients, nerve action potential (NAP) amplitudes of sural and superficial peroneal nerves were within normal ranges, but in the patient group mean value was significantly lower than in the controls. Among clinically defined 30 DSN patients, medial plantar NAP amplitude was abnormal in 18 (60%) and dorsal sural nerve amplitude was abnormal in 13 (40%) of the patients bilaterally. Additionally, the onset NCV of the dorsal sural nerve was significantly slower in patients than controls (P=0.038). Evaluation of both of these nerves increased the sensitivity up to 70% in the detection of neuropathy. CONCLUSIONS: Bilateral NCS assessment of both of the medial plantar and dorsal sural nerves together increases the rate of diagnosis of diabetic distal sensory neuropathy compared to assessment of either of these nerves. SIGNIFICANCE: Assessment of medial plantar in addition to dorsal sural NCS together increases the sensitivity in the detection of neuropathy and allows earlier diagnosis, especially when routine NCS are normal.     

Can electrophysiology differentiate polyneuropathy with anti-MAG/SGPG antibodies from chronic inflammatory demyelinating polyneuropathy?

OBJECTIVES: Patients with polyneuropathy and antibodies to myelin-associated glycoprotein (MAG) and sulphated glucuronyl paragloboside (SGPG) differ from chronic inflammatory demyelinating polyneuropathy (CIDP) because of a slower, progressive course, symmetrical and predominantly sensory involvement of legs, predominantly distal slowing of motor conductions, and poorer response to therapy. We studied whether a wide set of electrophysiologic parameters may differentiate these two neuropathies. METHODS: We reviewed the electrophysiological studies of 10 patients with anti-MAG/SGPG antibodies and 22 with CIDP examining: (1) motor conduction velocity and distal compound muscle action potential amplitude; (2) conduction block (CB) and temporal dispersion; (3) distal motor latency and terminal latency index (TLI); (4) F wave and proximal conduction time; and (5) sensory conduction and occurrence of abnormal median with normal sural sensory potential. RESULTS: Anti-MAG/SGPG neuropathies showed: (1) more severe involvement of peroneal nerves; (2) more frequent disproportionate distal slowing of motor conductions (TLI< or =0.25) and absent sural potential, and (3) no CB. However 3/22 CIDP patients also had at least two nerves with TLI< or =0.25 and no CB. CONCLUSIONS: Electrophysiologic findings suggest in anti-MAG/SGPG neuropathy a length-dependent process with a likely centripetal evolution. A disproportionate slowing of conduction in distal segments of motor nerves suggests the diagnosis of anti-MAG/SGPG neuropathy, although it is not pathognomonic.     

COLD PRESSOR TEST DEMONSTRATES RESIDUAL SYMPATHETIC CARDIOVASCULAR ACTIVATION IN FAMILIAL DYSAUTONOMIA

Objectives: Patients with polyneuropathy and antibodies to myelin-associated glycoprotein (MAG) and sulphated glucuronyl paragloboside (SGPG) differ from chronic inflammatory demyelinating polyneuropathy (CIDP) because of a slower, progressive course, symmetrical and predominantly sensory involvement of legs, predominantly distal slowing of motor conductions, and poorer response to therapy. We studied whether a wide set of electrophysiologic parameters may differentiate these two neuropathies. Methods: We reviewed the electrophysiological studies of 10 patients with anti-MAG/SGPG antibodies and 22 with CIDP examining: (1) motor conduction velocity and distal compound muscle action potential amplitude; (2) conduction block (CB) and temporal dispersion; (3) distal motor latency and terminal latency index (TLI); (4) F wave and proximal conduction time; and (5) sensory conduction and occurrence of abnormal median with normal sural sensory potential. Results: Anti-MAG/SGPG neuropathies showed: (1) more severe involvement of peroneal nerves; (2) more frequent disproportionate distal slowing of motor conductions (TLI less than or equal to 0.25) and absent sural potential; and (3) no CB. However 3/22 CIDP patients also had at least two nerves with TLI 0.25 and no CB. Conclusions: Electrophysiologic findings suggest in anti-MAG/SGPG neuropathy a length-dependent process with a likely centripetal evolution. A disproportionate slowing of conduction in distal segments of motor nerves suggests the diagnosis of anti-MAG/SGPG neuropathy, although it is not pathognomonic.     

Proximal femoral conductions in patients with lumbosacral radiculoplexus neuropathy

OBJECTIVES: Lumbosacral radiculoplexus neuropathy (DLRPN) is a rare form of neuropathy observed in diabetic and rarely non-diabetic patients. Pathophysiology and lesion location are not clearly understood. Our aim was to analyze proximal and distal femoral conductions in patients with DLRPN. METHODS: Six patients with DLRPN, 14 patients with diabetic polyneuropathy and 25 healthy subjects were included in the study. We performed L3 monopolar root stimulation and femoral nerve trunk stimulation at the inguinal region and calculated lumbar plexus conduction time by subtracting the latency of compound muscle action potential (CMAP) of the vastus medialis evoked by femoral nerve stimulation from the latency of CMAP of vastus medialis evoked by L3 root stimulation. Additionally peak to peak amplitudes and areas of CMAPs were analyzed. RESULTS: Electrophysiological examination showed that there was an axonal involvement in all patients with DLRPN. Prolonged lumbar plexus conduction time (in five extremities), and prolonged distal latency of the femoral nerve (in five extremities) probably due to secondary demyelination were also observed. Similar abnormalities were not observed in the diabetic polyneuropathy group. CONCLUSIONS: DLRPN may affect different localizations on the peripheral nerves. L3 root stimulation may have an important role in the electrodiagnosis of DLRPN.     

An electrophysiological study of the deep peroneal sensory nerve

The electrodiagnosis of peripheral neuropathy is often based on nerve conduction abnormalities in sensory nerves of the lower extremities. We performed nerve conduction studies of the deep peroneal sensory nerve prospectively in 63 limbs of 38 normal subjects. The sensory amplitudes showed a decreasing trend with increasing age. 21% of subjects had absent sensory potentials, especially those in the older age groups. This was seen in contrast with superficial peroneal and sural potentials, which were universally present. Although the deep peroneal sensory nerve is located in the distal lower limb, it should be used with caution in evaluating peripheral neuropathy, in view of the frequent occurrence of absent potentials even in asymptomatic normal subjects.     

Facial nerve conduction in diabetic neuropathy

Diabetes mellitus (DM) has a severe influence on the nervous system and it is more likely to occur on the nerves of the upper and lower extremities than on the cranial nerves. According to the statistics, the incidence of cranial nerve involvement ranges anywhere from 3% to 14%. The aim of this study is to perform facial nerve conduction studies in diabetic patients with peripheral neuropathy, confirmed by electrophysiological methods, to determine the frequency of affection of a cranial nerve conduction in a neuropathy which mainly occurs in a distal, symmetric fashion. The study was conducted in a group of 20 diabetics who had electrophysiologically confirmed polyneuropathy. All of the patients had type 2 DM. Sixteen of the patients were receiving insulin therapy and 4 were treated with oral hypoglycaemic agents only. We found prolonged facial nerve distal latency at least on one tested side in 70% of patients. Distal latency and amplitudes of muscle responses to facial nerve stimulation showed a statistically significant difference from controls (p < 0.001). This study has shown that proximal nerves like cranial nerves are affected in a high proportion of cases in a neuropathy which mainly occurs in a distal symmetric fashion. The facial nerve is one of the most easily accessible nerves in the proximal part of the body (head-face) and makes it suitable for routine evaluation. We believe this conduction abnormality may give us the chance to classify these neuropathies as more severe than the ones that only have limb conduction abnormalities. Further studies should be performed in order to confirm these findings.     

Electrophysiological evaluation of peripheral and autonomic involvement in leprosy

OBJECTIVE: Motor and sensory nerve conductions, F responses, sympathetic skin responses and R-R interval variations (RRIV) were studied to determine the type of peripheral neuropathy among patients with leprosy. METHODS: Twenty-nine consecutive patients with leprosy (25 male, 4 female) hospitalized in the "Istanbul Leprosy Hospital" between January - December, 1999 were included in this study. Ten patients had borderline lepromatous leprosy, and 19 had lepromatous leprosy. None of the patients studied had the tuberculoid form. The mean age was 55 +/- 12 years. The control group consisted of 30 (26 male, 4 female) healthy volunteers (mean age: 58.1 +/- 7.8 years). All subjects included in the study underwent neurological examination and electrophysiological evaluation. Standard procedures were performed for evaluating sensory and motor conduction studies. Motor studies were carried out on both left and right median, ulnar, tibial and common peroneal nerves while median, ulnar, sural and superficial peroneal nerves were examined for sensory studies. Sympathetic skin response recordings on both hands and RRIV recordings on precordial region were done in order to evaluate the autonomic involvement. RESULTS: The lower extremity was found to be more severely affected than the upper, and sensory impairment predominated over motor. Of 58 upper limbs examined, no sympathetic skin responses was recorded in 46 (79.3%). Compared with the controls, the RRIVs of the leprosy patients were found to be reduced during both resting and deep forced hyperventilation. CONCLUSION: Our results indicate that leprosy causes a predominantly axonal polyneuropathy that is more severe in the lower extremities. Sensory nerve damage is accompanied by autonomic involvement.     

Sural nerve conduction velocity in peripheral neuropathies and subacute myelo-optico-neuropathies (SMON)

Sensory conduction velocity in the sural nerve (S-SCV) was measured in 10 cases of motor neuropathy, 35 cases of neuropathy with sensory symptoms and in 16 cases of subacute myelo-optico-neuropathy (SMON).In 2 cases of Friedreich's ataxis and 1 case of Charcot-Marie-Tooth disease, evoked sensory action potentials could not be recorded or S-SCV was reduced though sensation was normal; this finding suggests latent or subclinical involvement of the sensory nerves in these cases. In the other 7 cases of motor neuropathy, S-SCV was normal.In the cases of polyneuropathy with sensory symptoms, S-SCV was abnormal in 5 of 11 cases with subjective sensory complaints and in 6 of 10 cases with mild impairment of superficial sensation. No nerve potential could be evoked in 2 cases with severe impairment of superficial sensation, in 7 of 8 cases with mild impairment of deep sensation, and in 4 cases with severe impairment of deep sensation. These data suggest that S-SCV may be useful in confirming the extent of sensory nerve involvement in mildly-affected cases.In the case of SMON, though the S-SCVs could generally be correlated with the severity of the sensory symptoms, the degree of decrease in S-SCV was far less than in the cases of sensory neuropathy with similar symptoms. This discrepancy suggests that myelopathy in addition to peripheral neuropathy plays an important part in causing the sensory symptoms of SMON.     

Multifocal inflammatory demyelinating neuropathy: a distinct clinical entity?

BACKGROUND: Several patients have been reported with an asymmetric sensory or sensorimotor demyelinating neuropathy not fulfilling the diagnostic criteria for chronic inflammatory demyelinating polyneuropathy or multifocal motor neuropathy. OBJECTIVE: To present the clinical, electrophysiologic, radiologic, and pathologic features of six patients with an asymmetric sensory or sensorimotor demyelinating neuropathy. RESULTS: All six patients were initially affected in only one limb; in four patients the neuropathy progressed to other limbs in an asymmetric fashion during several years. On electrophysiologic examination, evidence of multifocal demyelination and conduction block in motor and sensory nerves was found in all patients. MRI of the brachial plexus revealed swollen nerves and an increased signal intensity on T2-weighted imaging in four patients. A biopsy sample taken from the brachial plexus of one patient revealed evidence of inflammation. All patients showed a beneficial response to IV immunoglobulin treatment. Thirty-four similar patients have been reported previously, many of whom were initially diagnosed as having various other (nontreatable) diseases. CONCLUSIONS: The authors propose calling this neuropathy "multifocal inflammatory demyelinating neuropathy" and considering it as a distinct clinical entity to facilitate early diagnosis of this treatable disorder.     

磁刺激运动诱发电位在多发性周围神经病中的诊断价值

对１２例多发性周围神经病患者进行磁刺激运动诱发电位（ＭＥＰ）测定，同时测定感觉神经传导速度（ＳＣＶ）、运动神经传导速度（ＭＣＶ）及Ｆ波。结果发现，ＭＥＰ潜伏期异常率为７５％，高于ＳＣＶ（６６．７％）和ＭＣＶ（５８．２％）及Ｆ波（６０％）；至少有１项ＭＥＰ指标异常者１１例，占９１．７％。分析认为，ＭＥＰ异常率较高的原因在于它可以对包括神经根在内的周围神经全长进行测定。将ＭＥＰ各项指标综合分析可提高ＭＥＰ的阳性率。ＭＥＰ对周围神经病是一项有较大价值的辅助检查手段。     

变应性肉芽肿性血管炎的神经系统表现

目的研究变应性肉芽肿性血管炎(AGA,亦称ChurgStrauss综合征,CSS)相关神经病的发病率、临床类型、发病机制、诊断和治疗。方法14例确诊为CSS的患者从临床表现、实验室检查、神经电生理检查和活检病理检查等方面予以分析,并观察治疗效果。结果14例CSS患者中有12例累及周围神经系统,其中5例以周围神经病为首发症状。12例周围神经受累的患者中5例表现为多发性单神经病,4例表现为远端不对称的多发性神经病,2例表现为对称的多发性神经病。腓肠神经活检可见有髓神经纤维丢失,轴索变性。电生理检查发现感觉和运动传导波幅显著降低或消失。CSS的诊断应结合临床与病理所见。除1例患者外,激素治疗对CSS相关神经病有效。结论CSS患者中周围神经病很常见,早期诊断可改善预后。     

Errors in diagnosis of polyneuropathy: three cases of chronic lumbosacral root impairment

In the last years very precise diagnostic investigations have been introduced to allow accurate diagnosis of pathologies affecting the major part of peripheral nerves; nevertheless, some avoidable misdiagnosis still occurs. For instance, the neurophysiological pattern observed in chronic compression of nerve roots may mimic an axonal polyneuropathy, especially when compression occurs in post-ganglionic tract of dorsal root (in this case sensory nerve conduction studies show decreased or absent response). A clinical-neurophysiological dissociation may be noted in cases with pre-ganglionic impairment of dorsal root (clinical sensory deficit in presence of normal amplitude of sensory response). During the past two years we observed 3 cases with diagnosis of polyneuropathy that, after further studies, appeared affected by severe chronic compression of lumbo-sacral nerve roots. Our data suggest that in those cases with suspected polyneuropathy, in which the neurophysiological picture is characterized by the exclusive axonal (and myelinic) involvement of motor and/or sensory peripheral nerve of lower limbs, neuroimaging of radicular structures must be performed. These further investigations may avoid severe and irreversible damage to neural tissues.     

Axonal sensorimotor neuropathy in patients with beta-thalassaemia

OBJECTIVE: The purpose of this study was to investigate the prevalence of peripheral neuropathy in patients with beta-thalassaemia. METHODS: Thirty six patients with a mean age of 29.2+/-8.2 years and 17 healthy controls with a mean age of 27.6+/-9.1 were included in this study. Measurements included the neuropathy symptoms score (NSS), the neuropathy disability score (NDS) as well as nerve conduction studies of two motor (ulnar and peroneal) and two sensory (ulnar and sural) nerves of the right limbs. RESULTS: A mainly sensory axonal polyneuropathy was present in 19 out of 36 patients (52.7%). Eight out of these 19 patients also had abnormal NDS values. The neuropathy correlated significantly with the age of the patients and the hematocrit. However, it did not correlate with the presence of antibodies against HCV, the ferritin levels, or with a history of transfusions, desferrioxamine treatment, or splenectomy. CONCLUSIONS: This study showed a high prevalence of a predominantly sensory neuropathy in patients with beta-thalassaemia. The electrophysiological data suggest that the underlying pathology is an axonopathy. Chronic hypoxia of the nerves resulting from severe anaemia may contribute to the pathogenesis of this neuropathy.     

Sensory nerve conduction in demyelinating and axonal Guillain-Barré syndromes

Guillain-Barré syndrome is divided into acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN) based on motor nerve conduction studies. We investigated whether sensory nerve conduction studies contribute to the electrodiagnosis of AIDP and AMAN. In consecutive 59 patients with AIDP (n = 26) or AMAN (n = 33), results of sensory nerve conduction studies in the median, ulnar and sural nerves were reviewed. Sensory nerve conduction abnormalities were found for 85% of AIDP patients and for only 6% of AMAN patients. In AIDP patients, the abnormalities were present in 85% of patients in the median nerves, 85% in the ulnar nerves and 38% in the sural nerves. AMAN is very rarely associated with sensory nerve involvement. Abnormal sensory nerve conduction is supportive of AIDP and is more frequently found for the median and ulnar nerves than sural nerves.     

Neuropathy Associated With Anti-Chondroitin Sulfate C IgM Antibodies

Chondroitin Sulfate C (ChS-C), is a glycosaminoglycan present in the membranes of neurons and axons. Anti-ChS-C IgM antibodies have been reported in patients with predominantly sensory neuropathy (PN) often associated with IgM monoclonal gammopathy, but also in some neurological controls. In order to evaluate the frequency and clinical correlate of anti-ChS-C IgM antibodies, we tested them by a new Covalink ELISA technique in sera from 206 patients with IgM monoclonal gammopathy including 79 with PN (PN+IgM) with unknown IgM reactivity, 65 with PN with antibodies to the myelin-associated glycoprotein and 62 without PN, and from 33 patients with PN of other causes, 30 with other neurological and non-neurological diseases and 23 normal subjects. We only found high titers of anti-ChS-C IgM in two patients (1/128,000 and 1/256,000 respectively) with IgM monoclonal gammopathy: one had Waldenström Macroglobulinemia diagnosed seven years before and a 3 year history of slowly progressive limb weakness, finger paresthesias, unsteady gait and occasional nocturnal cramps. Neurological examination revealed a predominantly large-fiber sensory neuropathy with mild distal atrophy and weakness in upper and lower limbs. Electrophysiological and morphological studies were suggestive of a predominantly demyelinating neuropathy. The other patient had IgM MGUS without PN at the time of antibody testing but developed finger paresthesias seven years later, when he had decreased position sense and abnormal sensory nerve conduction studies. In conclusion high titers of anti-ChS-C IgM, though infrequent, were always associated with the presence or development of sensory PN in patients with IgM M-protein, supporting a possible role for these antibodies in the neuropathy.