Autonomic and sensory nerve dysfunction in primary biliary cirrhosis

AIM:Cardiovascular autonomic and peripheral sensoryneuropathy is a known complication of chronic alcoholicand non-alcoholic liver diseases.We aimed to assess theprevalence and risk factors for peripheral sensory nerveand autonomic dysfunction using sensitive methods inpatients with primary biliary cirrhosis (PBC).METHODS:Twenty-four AMA M2 positive female patientswith clinical,biochemical and histological evidence of PBCand 20 age matched healthy female subjects were studied.Five standard cardiovascular reflex tests and 2d-h heartrate variability(HRV)analysis were performed to defineautonomic function.Peripheral sensory nerve function onmedian and peroneal nerves was characterized by currentperception threshold(CPT),measured by a neuroselectivediagnostic stimulator(Neurotron,Baltimore,MD).RESULTS:Fourteen of 24 patients(58%)had at least oneabnormal cardiovascular reflex test and thirteen(54%)had peripheral sensory neuropathy.Lower heart rateresponse to deep breathing(P=0.001),standing(P=0.03)and Valsalva manoeuvre(P=0.01),and more profounddecrease of blood pressure after standing(P=0.03)wasfound in PBC patients than in controls.As a novel findingwe proved that both time domain and frequency domainparameters of 24-h HRV were significantly reduced in PBCpatients compared to controls.Each patient had at leastone abnormal parameter of HRV.Lower CPT values indicatedhyperaesthesia as a characteristic feature at peronealnerve testing at three frequencies(2000 Hz:P=0.005;250 Hz:P=0.002;5 Hz:P=0.004)in PBC compared tocontrols.Correlation of autonomic dysfunction with theseverity and duration of the disease was observed.Lowertotal power of HRV correlated with lower CPT values atmedian nerve testing at 250 Hz(P=0.0001)and at 5 Hz(P=0.002),as well as with those at peroneal nerve testingat 2000 Hz(P=0.01).CONCLUSION:Autonomic and sensory nerve dysfunctionsare frequent in PBC.Twenty-four-hour HRV analysis is moresensitive than standard cardiovascular tests for detectingof both parasympathetic and sympathetic impairments.Ournovel data suggest that hyperaesthesia is a characteristicfeature of peripheral sensory neuropathy and mightcontribute to itching in PBC.Autonomic dysfunction is relatedto the duration and severity of PBC.

Assessment of autonomic function in untreated adult coeliac disease

AIM: Some recent studies showed that alteration of upper-gut motility in coeliac disease may be related to dysfunction of autonomic nervous system. The aim of our study was to investigate whether autonomic nervous system was altered in untreated and unselected coeliac disease patients.METHODS: We studied 8 untreated and consecutive coeliac disease patients (2 males and 6 females, age range 37±14.5 years). Histological evaluation of duodenal mucosa, anti-gliadin antibodies (AGA), antiendomysial antibodies (EMA) and anti-tTG antibodies and sorbitol H2 breath test were performed in all patients. Extrinsic autonomic neuropathy was assessed by the standardized measurement of cardiovascular reflexes (lying-to-standing,Valsalva manoeuvre, deep breathing, sustained handgrip).The results obtained were compared with a healthy,asymptomatic control group (6 males and 7females, age range 42.3±13.5 years).RESULTS: Coeliac patients exhibited a lower increase of PAS as a response to isometric effort, a reduction of spectral power LF as a response to clinostatic position,but without statistical significance. Also they showed a lower tolerance to orthostatic position, associated with a latent disequilibrium of sympathetic-vagal balance, a relative prevalence of parasympathetic component of the autonomic function. However, these results were not statistically significant when compared with control group(P = n.s.). And they were unchanged after 6 and 12 mo of gluten-free diet.CONCLUSION: This study failed to confirm a significant correlation between autonomic dysfunction and coeliac disease, yet we could not exclude a role of autonomic dysfunction in the genesis of systemic symptoms in some coeliacs.