Sensory neuropathy associated with primary biliary cirrhosis. Histologic and morphometric studies

Autoantibodies Against Dihydrolipoamide S-Acetyltransferase in Immune-Mediated Neuropathies

BACKGROUND AND OBJECTIVES

This study aimed to identify disease-related autoantibodies in the serum of patients with immune-mediated neuropathies including chronic inflammatory demyelinating polyneuropathy (CIDP) and to investigate the clinical characteristics of patients with these antibodies.

METHODS

Proteins extracted from mouse brain tissue were used to react with sera from patients with CIDP by western blotting (WB) to determine the presence of common bands. Positive bands were then identified by mass spectrometry and confirmed for reactivity with patient sera using enzyme-linked immunosorbent assay (ELISA) and WB. Reactivity was further confirmed by cell-based and tissue-based indirect immunofluorescence assays. The clinical characteristics of patients with candidate autoantibody-positive CIDP were analyzed, and their association with other neurologic diseases was also investigated.

RESULTS

Screening of 78 CIDP patient sera by WB revealed a positive band around 60-70 kDa identified as dihydrolipoamide S-acetyltransferase (DLAT) by immunoprecipitation and mass spectrometry. Serum immunoglobulin G (IgG) and IgM antibodies' reactivity to recombinant DLAT was confirmed using ELISA and WB. A relatively high reactivity was observed in 29 of 160 (18%) patients with CIDP, followed by patients with sensory neuropathy (6/58, 10%) and patients with MS (2/47, 4%), but not in patients with Guillain-Barré syndrome (0/27), patients with hereditary neuropathy (0/40), and healthy controls (0/26). Both the cell-based and tissue-based assays confirmed reactivity in 26 of 33 patients with CIDP. Comparing the clinical characteristics of patients with CIDP with anti-DLAT antibodies (n = 29) with those of negative cases (n = 131), a higher percentage of patients had comorbid sensory ataxia (69% vs 37%), cranial nerve disorders (24% vs 9%), and malignancy (20% vs 5%). A high DLAT expression was observed in human autopsy dorsal root ganglia, confirming the reactivity of patient serum with mouse dorsal root ganglion cells.

DISCUSSION

Reactivity to DLAT was confirmed in patient sera, mainly in patients with CIDP. DLAT is highly expressed in the dorsal root ganglion cells, and anti-DLAT antibody may serve as a biomarker for sensory-dominant neuropathies.

Chronic inflammatory demyelinating polyneuropathy associated with primary biliary cirrhosis

We report a patient with chronic inflammatory demyelinating polyneuropathy associated with primary biliary cirrhosis (PBC). Except for minimal biochemical abnormalities, clinical symptoms of PBC were not observed, and we diagnosed our patient with asymptomatic PBC from the results of a liver biopsy. Although the patient noticed little muscle weakness, an electrophysiological study demonstrated slow conduction velocities and prolonged distal latencies, with definite conduction blocks in the median, ulnar, and tibial nerves. The disturbed sensory pattern was asymmetrical, and sensory nerve action potentials were not evoked. From these observations, we diagnosed this patient with chronic inflammatory demyelinating polyneuropathy. Neuropathy associated with PBC is very rare. We must differentiate demyelinating neuropathy with PBC in patients with asymmetrical sensory dominant neuropathy with high immunoglobulin M titers, and investigate for the presence of anti-mitochondrial antibodies to rule out a complication of asymptomatic PBC.

Peripheral neuropathy: clinical and electrophysiological considerations

This article is a primer on the pathophysiology and clinical evaluation of peripheral neuropathy for the radiologist. Magnetic resonance neurography has utility in the diagnosis of many focal peripheral nerve lesions. When combined with history, examination, electrophysiology, and laboratory data, future advancements in high-field magnetic resonance neurography may play an increasingly important role in the evaluation of patients with peripheral neuropathy.

Knockout of the neurokinin-1 receptor reduces cholangiocyte proliferation in bile duct-ligated mice

In bile duct-ligated (BDL) rats, cholangiocyte proliferation is regulated by neuroendocrine factors such as α-calcitonin gene-related peptide (α-CGRP). There is no evidence that the sensory neuropeptide substance P (SP) regulates cholangiocyte hyperplasia. Wild-type (WT, (+/+)) and NK-1 receptor (NK-1R) knockout (NK-1R(-/-)) mice underwent sham or BDL for 1 wk. Then we evaluated 1) NK-1R expression, transaminases, and bilirubin serum levels; 2) necrosis, hepatocyte apoptosis and steatosis, and the number of cholangiocytes positive by CK-19 and terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling in liver sections; 3) mRNA expression for collagen 1α and α-smooth muscle (α-SMA) actin in total liver samples; and 4) PCNA expression and PKA phosphorylation in cholangiocytes. In cholangiocyte lines, we determined the effects of SP on cAMP and D-myo-inositol 1,4,5-trisphosphate levels, proliferation, and PKA phosphorylation. Cholangiocytes express NK-1R with expression being upregulated following BDL. In normal NK-1R(-/-) mice, there was higher hepatocyte apoptosis and scattered hepatocyte steatosis compared with controls. In NK-1R (-)/(-) BDL mice, there was a decrease in serum transaminases and bilirubin levels and the number of CK-19-positive cholangiocytes and enhanced biliary apoptosis compared with controls. In total liver samples, the expression of collagen 1α and α-SMA increased in BDL compared with normal mice and decreased in BDL NK-1R(-/-) compared with BDL mice. In cholangiocytes from BDL NK-1R (-)/(-) mice there was decreased PCNA expression and PKA phosphorylation. In vitro, SP increased cAMP levels, proliferation, and PKA phosphorylation of cholangiocytes. Targeting of NK-1R may be important in the inhibition of biliary hyperplasia in cholangiopathies.

Regulation of biliary proliferation by neuroendocrine factors: implications for the pathogenesis of cholestatic liver diseases

The proliferation of cholangiocytes occurs during the progression of cholestatic liver diseases and is critical for the maintenance and/or restoration of biliary mass during bile duct damage. The ability of cholangiocytes to proliferate is important in many different human pathologic conditions. Recent studies have brought to light the concept that proliferating cholangiocytes serve as a unique neuroendocrine compartment in the liver. During extrahepatic cholestasis and other pathologic conditions that trigger ductular reaction, proliferating cholangiocytes acquire a neuroendocrine phenotype. Cholangiocytes have the capacity to secrete and respond to a variety of hormones, neuropeptides, and neurotransmitters, regulating their surrounding cell functions and proliferative activity. In this review, we discuss the regulation of cholangiocyte growth by neuroendocrine factors in animal models of cholestasis and liver injury, which includes a discussion of the acquisition of neuroendocrine phenotypes by proliferating cholangiocytes and how this relates to cholangiopathies. We also review what is currently known about the neuroendocrine phenotypes of cholangiocytes in human cholestatic liver diseases (ie, cholangiopathies) that are characterized by ductular reaction.

[A case of sensory ataxic neuropathy associated with asymptomatic primary biliary cirrhosis]

A 65-year-old woman showed progressive asymmetric sensory ataxic neuropathy (SAN) in upper limbs over 12 years, beginning with the onset of primary biliary cirrhosis (PBC). Nerve conduction study showed that sensory action potential was not evoked in upper limbs. Right superficial radial nerve biopsy showed the density of myelinated fibers was severely decreased with large-fiber predominance. Since Sjögren's syndrome (SjS) and paraneoplastic syndrome were denied, this type of neuropathy seems accompanied with asymptomatic PBC. Corticosteroid administration and intravenous immunoglobulin therapy failed to obtain any beneficial effect. The pathological mechanism is considered ganglionitis, which resembles that found in association with SjS. We should also consider PBC as the cause of SAN.

Conduction and excitability properties of peripheral nerves in end-stage liver disease

The pathophysiology of hepatic neuropathy is poorly understood, but membrane depolarization due to a toxic inhibition of oxidative metabolism has been proposed. We investigated the relationship between nerve excitability properties, nerve dysfunction, and liver function in 11 pretransplant patients, the majority of whom were oligo- or asymptomatic for peripheral neuropathy. Abnormalities were detected on clinical examination (6), large-fiber nerve conduction (4), and thermal quantitative sensory testing (10). Small-fiber involvement was characterized by elevation of warm more than cold detection thresholds. Autonomic dysfunction was less frequent (4). Nerve excitability parameters in both upper and lower limbs provided evidence of membrane depolarization compared with controls, even in those patients without a history of alcohol abuse. No clear correlation was found between neurophysiological indices and scores of hepatic reserve or various blood parameters including ammonia level. Although chronic membrane depolarization may be involved, the degree of depolarization in large fibers was small, and its role in the pathophysiology of neuropathy uncertain.

Autonomic dysfunction and gastroparesis in cirrhosis

BACKGROUND

Patients with cirrhosis of the liver frequently present with many gastrointestinal complaints that are most likely due to abnormal gastrointestinal motility. The cause of these motility disorders in cirrhotics is unknown, however, underlying autonomic dysfunction may play a role.

OBJECTIVE

To determine the association between autonomic dysfunction and delayed gastric emptying in cirrhotic patients.

METHODS

We prospectively studied 20 patients with cirrhosis of the liver and postprandial abdominal pain, nausea, and vomiting and 10 asymptomatic patients with Hepatitis C (HCV) and no evidence of cirrhosis. All patients underwent 5 standardized cardiovascular tests to assess autonomic function. Each test was scored on a continuum from 0 (normal) to 5 (severe disease), thus producing a composite score of 0 to 5 for each subject. A composite score of greater than 1.5 was considered abnormal, with 5 representing severe autonomic involvement. A solid phase gastric emptying study was performed in each patient and a gastric retention of greater than 50% at 100 minutes was considered abnormal.

RESULTS

The mean percent retention at 100 minutes was 70.7% in the cirrhotic group vs. 26.1% (P < 0.001) in the patients with HCV and no evidence of cirrhosis (controls). The composite autonomic score for the cirrhotic group was 3.4 vs. 1.2 (P < 0.001) in the controls.

CONCLUSIONS

Our results suggest that gastroparesis is common in patients with cirrhosis of the liver, and may account for gastrointestinal symptoms of postprandial abdominal pain, nausea, and vomiting. The presence of autonomic dysfunction correlates positively with underlying motility disorders, such as delayed gastric emptying.

Pediatric-onset primary biliary cirrhosis

Unlike other autoimmune liver diseases, primary biliary cirrhosis (PBC) has not been reported in childhood. We report 2 cases of PBC diagnosed at 16 and 15 years of age, respectively. The first girl was noted to have increased liver enzyme levels at 16 years of age. Antimitochondrial antibody (AMA) was strongly positive, and serum quantitative immunoglobulin M level was 8.26 g/L (normal, 0.6-3 g/L). A liver biopsy specimen showed stage II PBC. Despite treatment with ursodeoxycholic acid, she developed progressive cholestasis, intractable pruritus, and a significant sensory neuropathy and weight loss eventually requiring liver transplantation. Her mother had PBC/autoimmune overlap syndrome and underwent successful liver transplantation at 34 years of age. The second girl had persistently elevated liver enzyme levels following cholecystectomy at 15 years of age for symptomatic cholelithiasis. Endoscopic retrograde cholangiopancreatography showed no abnormalities. AMA was positive at 1:160, and serum quantitative immunoglobulin was 6.96 g/L. A liver biopsy specimen showed stage II PBC, and her liver enzyme levels almost normalized after starting treatment with ursodeoxycholic acid. In conclusion, we present 2 liver biopsy-confirmed cases of pediatric-onset AMA-positive PBC. With increased awareness of early-onset PBC, further pediatric cases may be discovered.

Neuromuscular diseases and disorders of the alimentary system

This review outlines the relationship and interaction between neuromuscular diseases and disorders of the alimentary system. Neuromuscular manifestations of gastrointestinal and hepatobiliary diseases are first considered. Such diseases may cause neuromuscular disorders by leading to nutritional deficiency or by more direct mechanisms. The pathogenesis, clinical features, and treatment of these various neuromuscular manifestations are discussed. The impact of disorders of nerve, neuromuscular transmission, and muscle on the alimentary system is then reviewed. The main sequelae are impaired deglutition and gastrointestinal dysmotility. The management of these complications is considered.

Autonomic and peripheral (sensorimotor) neuropathy in chronic liver disease: a clinical and electrophysiologic study

Peripheral neuropathy has been reported in association with chronic liver disease. However, the precise incidence, severity and characteristics of neuropathy, and the relationship of neuropathy to different etiologies of liver disease have not been defined. In this study, 58 patients with advanced liver disease were evaluated in detail for the presence of neuropathy. Peripheral (sensorimotor) neuropathy was found in 71% and autonomic neuropathy was found in 48% of the patients. Although the majority of patients were asymptomatic, neurological examination showed distal sensory loss to pain, or vibration or distal loss of reflexes in 17 patients (29%). Sensory neuropathy was seen more commonly than motor axonal polyneuropathy on nerve conduction studies. Quantitative sensory testing was frequently abnormal (62%) and cooling thresholds were more affected than vibration thresholds. Overall, the pattern of neuropathy in patients with liver disease conformed to the pattern expected in "dying back" or length-dependent neuropathy. The neuropathy was most severe in patients with advanced hepatic decompensation. Comparison of causes of liver disease showed no significant differences in the severity of neuropathy among the different etiologies. In conclusion, axonal sensory-motor polyneuropathy and autonomic neuropathy are commonly seen in patients with end-stage liver disease of different causes.

Postural adjustments associated with different unloadings of the forearm: effects of proprioceptive and cutaneous afferent deprivation

Postural adjustments to imposed (passive) and voluntary (active) unloading conditions of the forearm were studied in normal subjects and a deafferented patient. The latency of the postural behaviour (deactivation of the biceps supporting the weight) was linearly related to the displacement amplitude of the unloaded forearm, independent of the unloading conditions. The postural behaviour consisted of an anticipatory postural adjustment (APA) occurring prior to active unloading (in both normals and the patient) and conversely in an unloading reflex response following passive unloading (only in the normals). In both the deafferented and the normal subjects, the amplitudes of the displacement during active unloadings were much smaller (3x) than in the passive conditions and an APA was present in both the deafferented and the normal subjects. The APA could not be triggered by some types of active movement and was absent when the movement was not directly producing the unloading. The EMG latencies of the APA and of the contralateral muscles used to unload were tightly coupled. However, the latency would sometimes be decoupled, particularly when a temporal delay was introduced between the active movement and the unloading in normal subjects. In contrast to the normal subjects, who were able to adapt quickly to an unusual unloading condition (produced by voluntary knee flexion), the deafferented patient did not show an APA in this task. It was concluded that, although the APA is of central origin, it cannot be generated only on the basis of internal timing cues and must rely on afferent information for its generation during unfamiliar unloading conditions.

Autonomic and peripheral neuropathy in primary biliary cirrhosis

Autonomic and peripheral nerve function was examined in a group of patients with primary biliary cirrhosis using standard cardiovascular reflex tests and peripheral nerve conduction studies. Sixty-three percent had cardiovascular autonomic dysfunction with predominantly parasympathetic abnormalities. Symptoms of peripheral neuropathy were rarely volunteered spontaneously but occurred frequently when specifically sought; 40.7% had definite peripheral neuropathy, with symptoms and/or signs plus peripheral neurophysiological abnormalities. A close association between autonomic and peripheral nerve function was found with correlation between the heart rate variation on deep breathing and both peroneal nerve conduction velocity (r = 0.67, P < 0.001) and sural nerve conduction velocity (r = 0.52, P < 0.008). Correlations were also noted between other autonomic tests and peripheral nerve function. Both autonomic and peripheral nerve function correlated with serum bilirubin and albumin; no significant association was noted with vitamin E deficiency or hyperlipidaemia. A generalised neuropathy with peripheral and autonomic abnormalities is common in primary biliary cirrhosis and could be related to hepatic damage. Although rarely clinically disabling, the autonomic impairment associated with this neuropathy may be of prognostic significance.

[Acute idiopathic sensory neuropathy: a case report]

Pure sensory neuropathies are clinically characterized by paresthesias, sensory ataxia and areflexia without muscle weakness. We report the case of a 21 years-old female patient with acute onset of distal paresthesias, marked sensory ataxia and hyporeflexia. Motor strength was normal. Sensory nerve conduction was absent and motor nerve conduction slightly decreased. CSF showed 2 leucocytes/mm3 and 1.06 g/dL protein. Collagen disorder and neoplasia were not found. Type 2 fiber atrophy was observed on muscle biopsy, and axonal demyelination on sural nerve biopsy. The patient was treated with prednisone. After 1.5 years she was recovered, but a minor proprioceptive deficit persisted. A revision is made on the etiology, pathophysiology and clinical manifestations of the disease.

Autonomic dysfunction in chronic liver disease

Chronic liver disease is accompanied by a number of circulatory changes including impairment of cardiovascular autonomic reflexes. This occurs irrespective of the aetiology of liver disease, increases in prevalence and severity with worsening hepatic function, and is related at least in part to an autonomic neuropathy. Parasympathetic abnormalities predominate and, although largely subclinical, they may play a role in the altered fluid homeostasis and neurohumoral disturbances associated with cirrhosis. On prospective follow up, the presence of autonomic impairment was associated with a five-fold increased mortality, largely from sepsis and variceal haemorrhage. Defective responses to such stressful events as a result of an afferent defect could possibly explain these findings. Further studies are required to evaluate the natural history of this complication, and determine if it is reversible with improvement in hepatic function or after liver transplantation.

A clinical, electrophysiological, morphological and immunological study of chronic sensory neuropathy with ataxia and paraesthesia

We have observed 9 patients (8 men and 1 woman), 58 to 77 years of age with neuropathy with only sensory symptoms and insidious onset. Five of them (4 men and 1 woman) aged 65 to 77 years, had normal serum electrophoretic profiles, while the others (all men), 58 to 74 years, had IgM monoclonal gammopathy of undetermined significance (MGUS). Clinical data were consistent with a sensory neuropathy affecting predominantly the kinesthetic sense (position and vibration sensation). The electrophysiological data indicated predominant sensory axonal neuropathy. Morphological data confirmed the primary axonal damage. Western immunoblot showed that the IgG from a patient without MGUS reacted with a 55 kD protein of dorsal root ganglion homogenate. Three of four patients with IgM MGUS were serum reactive against chondroitin sulfate C (ChS-C) in double immunodiffusion. After absorption with ChS-C the monoclonal peak completely disappeared from two patients and was decreased in the third patient. Our data indicate that immunological abnormalities are part of the pathogenesis for a subgroup of chronic neuropathy with only sensory symptoms.

AAEM minimonograph #34: polyneuropathy: classification by nerve conduction studies and electromyography

Electrodiagnostic evaluation of patients with suspected polyneuropathy is useful for detecting and documenting peripheral abnormalities, identifying the predominant pathophysiology, and determining the prognosis for certain disorders. The electrodiagnostic classification of polyneuropathy is associated with morphologic correlates and is based upon determining involvement of sensory and motor fibers and distinguishing between predominantly axon loss and demyelinating lesions. Accurate electrodiagnostic classification leads to a more focused and expedient identification of the etiology of polyneuropathy in clinical situations.

Subacute progressive sensory ataxic neuronopathy after Rickettsia conorii infection

A case is presented in which sensory ataxic neuronopathy developed after serologically proven infection with Rickettsia conorii and continued to be progressive after appropriate antibiotic treatment. Electrophysiological studies showed decreasing sensory nerve conduction velocities ending with the absence of sensory nerve action potentials as well as peripheral and cortical somatosensory evoked potentials. Histological studies revealed a profound loss of myelinated fibres due to primarily axonal degeneration. The clinical course and the electrophysiological and histological findings suggest primary involvement of the dorsal root ganglion. Peripheral neuropathy due to infection with R. conorii is rare and usually of the mixed motor and sensory type. We believe this to be the first report of sensory ataxic neuronopathy associated with R. conorii infection.

Electrodiagnostic evolution of carcinomatous sensory neuronopathy

Sensory neuronopathy is a well-recognized remote effect of carcinoma. We report the clinical and electrodiagnostic evolution of a sensory neuronopathy in a patient with carcinoma of the lung. Serial electrophysiologic studies suggest transformation from normal peripheral nerve function through early posterior root involvement to absent sensory nerve function. Diffuse motor conduction abnormalities occurred late in the disease, perhaps reflecting motor axon changes associated with disuse.

Vitamin E deficiency and its clinical significance in adults with primary biliary cirrhosis and other forms of chronic liver disease

The vitamin E status of 146 adults with chronic liver disease was assessed by estimating both their serum vitamin E concentration and the ratio of serum vitamin E to serum cholesterol concentration. Low levels of vitamin E occurred most frequently in patients with primary biliary cirrhosis and other forms of chronic cholestatic liver disease. When a serum vitamin E concentration of 12.3 mumol/l (mean-2 SD of a control population) was taken as the lower limit of normal, 44% of patients with primary biliary cirrhosis and 32% with other chronic cholestatic liver disease had a reduced concentration, indicating a biochemical deficiency of vitamin E. If a vitamin E/total cholesterol ratio of 2.35 mumol/mmol was taken as the lower limit of normal, then 64% and 43% of patients with primary biliary cirrhosis and other chronic cholestatic liver disease, respectively, had a biochemical deficiency of vitamin E. Of the patients with chronic cholestasis and a serum bilirubin concentration greater than 100 mumol/l, 91% had a reduced vitamin E/cholesterol ratio. Twelve patients with primary biliary cirrhosis and severe vitamin E deficiency (serum vitamin E less than 5.0 mumol/l and a vitamin E/cholesterol ratio less than 1.0 mumol/mmol) underwent extensive neurological investigation. Five had a mild mixed sensorimotor peripheral neuropathy, which was not, however, typical of the neurological syndrome associated with vitamin E deficiency. In patients with severe biochemical deficiency of vitamin E (less than 5 mumol/l and less than 1 mumol/mmol total cholesterol), administration of large oral doses of vitamin E only increased serum concentrations to within the normal range in one patient; in the others even weekly parenteral administration over a 3-month period did not correct deficiency. In patients with less severe biochemical deficiency, the serum vitamin E concentration and vitamin E/total cholesterol ratio were restored to normal by oral or intramuscular supplements of the vitamin.

Neurologic syndrome associated with low levels of vitamin E in primary biliary cirrhosis

A 41-yr-old woman with primary biliary cirrhosis developed weakness and wasting in proximal muscles, areflexia, and decreased proprioceptive and vibratory sensation. Investigations revealed law serum levels of vitamin E and electromyographic and muscle biopsy changes consistent with a neuropathy. Sural nerve histology demonstrated axonal dystrophy with patchy demyelination. These features closely resemble a neurologic syndrome associated with chronic cholestatic liver disease and vitamin E deficiency in children. Adults with chronic cholestasis may also be susceptible to neurologic damage from prolonged malabsorption of vitamin E.

Chronic idiopathic ataxic neuropathy

Fifteen patients with chronic sensory ataxia caused by a large-fiber sensory neuropathy were studied and followed up for a period of 17.4 years (range, 4 to 41). When first seen, they had distal paresthesias and sensory ataxia of slow onset and progression, areflexia, normal strength, and a profound loss of proprioceptive and kinesthetic sensation extending up to the most proximal joints. Needle electromyogram and motor-nerve conduction velocity findings were normal in most of the patients and sensory potentials were absent in all. Nerve biopsy showed severe loss of the large myelinated fibers. Nine patients had a serum monoclonal or polyclonal gammopathy (3 with IgM kappa, 1 with IgA kappa, and 5 with a polyclonal increase of IgG, IgA, or IgM), and 8 had elevated cerebrospinal fluid gamma globulin levels in spite of low normal total cerebrospinal fluid protein levels. No circulating antibodies to ganglionic neurons were found. Therapy with immunosuppressants or plasmapheresis was unsuccessful. All patients are disabled and their conditions have continued to worsen without signs of malignancy or systemic illness during a mean follow-up period of 17.4 years. Chronic idiopathic ataxic neuropathy is a proprioceptive neuropathy, clinically indistinguishable from the one associated with carcinoma or pyridoxine abuse due to involvement of the dorsal root ganglia, and could represent a distinct form of an indolent, slowly progressive sensory neuronopathy (ganglionopathy). Although immunopathological mechanisms may play a role, especially in patients with an associated paraproteinemia, the resistance of such patients to therapy, the progressive course, and the resemblance of this disorder to other toxic neuronopathies associated with pyridoxine abuse or doxorubicin administration suggest a possible toxic etiopathogenesis.

Progressive sensory neuropathy in patients without carcinoma: a disorder with distinctive clinical and electrophysiological findings

Seven patients with severe progressive impairment of kinesthetic sense, mild dysfunction of cutaneous sense, and sparing of motor function were examined during a 3-year period. The clinical and electrophysiological findings are described in detail. None of these seven has had evidence of cancer despite a thorough investigation and a 3- to 16-year (average, 7 years) period of symptoms. These patients' symptoms were indistinguishable from those of patients with sensory neuropathy and coexistent carcinoma, suggesting that progressive sensory neuropathy is not invariably associated with carcinoma.