Sympathetic skin response in psoriasis and vitiligo.

The sympathetic skin response (SSR) which is considered to be one of the indexes of peripheral autonomic nerve function, especially evaluates sudomotor function of unmyelinated sympathetic fibers. This noninvasive technique has been studied in various neurological disorders particularly in peripheral neuropathies and also in some dermatological disorders associated with nervous system involvement. However, literature lacks sufficient data regarding SSR in immunologically mediated skin disorders. We enrolled patients with vitiligo and psoriasis to determine the possible effects of these disorders on SSR. Examination of SSR was performed in 30 patients with psoriasis and 15 patients with vitiligo as well as in 23 healthy volunteers as controls. Right and left median nerves were stimulated successively and responses were recorded from the palms simultaneously. SSR could be obtained from every subject. The groups were not statistically different for the values of the latency, the amplitude, and the area under the negative component of SSR. Our results indicated that vitiligo and psoriasis did not have any significant effects on SSR.     

Cardiovascular autonomic function and sympathetic skin response in chronic inflammatory demyelinating polyradiculoneuropathy

Quantitative cardiovascular autonomic function tests (AFTs) and sympathetic skin response (SSR) were performed in 12 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Parasympathetic autonomic function was examined by Valsalva ratio and R-R interval variation during rest and deep breathing. Sympathetic autonomic function was evaluated by blood pressure responses to sustained handgrip and active standing. Using quantitative AFTs, subclinical autonomic dysfunction was demonstrated in three (25%) patients. Abnormal SSR was seen in six (50%) patients. Thus, mild autonomic dysfunction is present in many CIDP patients. The autonomic abnormalities involve parasympathetic or sympathetic components; in the sympathetic nervous system, both vasomotor and sudomotor fibers may be involved.     

Stroke induces disturbances of autonomic system function

BACKGROUND AND PURPOSE: Autonomic dysfunction in patients with stroke worsens their health status and can induce life-threatening complications. The purpose of the study was to evaluate the prevalence of autonomic disturbances in post-stroke patients using selected methods and to analyse the correlation between their results. MATERIAL AND METHODS: The examined group comprised 22 patients (mean age 64.6+/-8 years) with ischaemic stroke treated at the Department of Neurology in Zabrze. The evaluation of the autonomic nervous system was conducted using a questionnaire, cardiovascular reflex tests (Ewing battery) and a neurophysiological method (sympathetic skin response, SSR). RESULTS: All the tests demonstrated coexistence of dysautonomia in most patients. Abnormal score of the questionnaire was present in 72.7% of patients with ischaemic stroke. Cardiovascular autonomic dysfunction (>or=2 abnormal cardiovascular tests) was diagnosed in 31.8% of patients. Abnormal SSR was found in 81.8% of patients. No association was found among results of the autonomic tests and age, sex, disease duration, aetiology and localization of the stroke focus. The results of the Ewing battery significantly correlated with the questionnaire (p=0.05) and SSR (p=0.03). CONCLUSIONS: The study confirmed the presence of autonomic disturbances of both the sympathetic and parasympathetic system in post-stroke patients. SSR is the most sensitive method and is useful in patients with various degrees of disability. The observed correlation between SSR and Ewing battery confirms the clinical usefulness of the neurophysiological method for the evaluation of the autonomic nervous system.     

The sympathetic skin response in peripheral autonomic failure — evaluation in pure autonomic failure, pure cholinergic dysautonomia and dopamine-beta-hydroxylase deficiency

The sympathetic skin response (SSR) detects changes in the electrical potential in the skin in response to physiological and electrical stimuli and, therefore, may indicate the integrity of sympathetic cholinergic neural pathways to sweat glands. This has been evaluated in 21 patients with three different forms of peripheral autonomic failure. Of these, 15 had pure autonomic failure (PAF) without additional neurological features; investigations indicated both sympathetic and parasympathetic failure. Four patients had pure cholinergic dysautonomia (PCD), with clinical and laboratory features indicating only cholinergic failure. Two siblings had dopamine-betahydroxylase (DBH) deficiency with only sympathetic adrenergic failure. None was on drugs affecting cholinergic function. Ten normal individuals were aged-matched with PAF patients and studied as controls. The SSR was recorded from the palmar hand and plantar foot surfaces, using previously described techniques, in response to physiological (auditory, cough and inspiratory gasp) and electrical stimuli. Nerve conduction studies excluded an associated motor or sensory neuropathy.The SSR was present in all normal individuals, and in both patients with DBH deficiency who had preserved cholinergic and subdomotor function. It was absent in all 15 PAF and all four PCD patients with impaired cholimergic function. Therefore, we conclude that the SSR reflected sympathetic cholinergic function in these three different groups with peripheral autonomic failure. Clin Auton Res 8:133–138     

Subtle involvement of the sympathetic nervous system in amyotrophic lateral sclerosis

The literature on the involvement of the autonomic nervous system (ANS) in amyotrophic lateral sclerosis (ALS) is conflicting. We therefore investigated several aspects of autonomic function, namely muscle sympathetic nerve activity (MSNA), blood pressure, cardiac function (electrocardiogram; ECG), and respiration in 16 patients with sporadic ALS and in 12 age-matched healthy volunteers, both at rest and during sympathoexcitatory stimulation. We measured MSNA by provoking venous pooling during short-lasting lower body negative pressure (LBNP) and during the cold pressor test (CPT). To assess the vagal (baroreflex) control of heart rate (HR), we measured spontaneous baroreflex sensitivity (BRS). To assess the involvement of the ANS beyond the cardiovascular system, we measured the sympathetic skin response (SSR). The stand-up test showed that none of the subjects had orthostatic intolerance. In comparison with the control group, the ALS patients had an increased HR and a decreased BRS at rest, and a reduced MSNA response to LBNP. The CPT response was normal and the total MSNA at rest did not differ significantly from that of controls. The latencies of the palmar and plantar SSR were prolonged, and in 3 ALS patients there was no plantar SSR. The results indicate that the sympathetic nervous system shows subtle abnormalities in ALS, predominantly sympathetic overactivity. They also point to the involvement of the preganglionic sympathetic column as the cause of the higher sympathetic activity and the absence of SSR. The higher sympathetic activity is postulated to be due to changes in modulation of the sympathetic system, whereas the absence of the SSR is probably caused by disruption of the reflex pathway.     

Autonomic dysfunction in Wilson's disease – a clinical and electrophysiological study

Wilson's disease is known for its protean manifestations; however involvement of the autonomic nervous system has not received much attention. Fifty patients with varying duration and severity of illness were evaluated for autonomic dysfunction clinically and electrophysiologically, using sympathetic skin response (SSR) and RR interval variability (RRIV) on deep breathing. The change in heart rate (AHR) was calculated from RRIV. Five patients had at least one autonomic symptom and one asymptomatic patient had significant postural hypotension. Absent SSR and abnormal AHR were noted in seven patients each. Overall, 13 patients had electrophysiological dysautonomia and an additional six had clinical dysautonomia. All had normal peripheral conductions and all but one had normal hepatic functions. Dysautonomia was more common among patients with neurological presentation (12/32) than non-neurological (1/18) (p = .012). Dysautonomia, often subclinical is common in Wilson's disease and is probably of central origin. It is more frequent among those with neurological presentation. Sympathetic and parasympathetic functions are equally affected.     

Sympathetic skin response abnormalities in amyotrophic lateral sclerosis

The sympathetic skin response (SSR) was evaluated in 25 patients with amyotrophic lateral sclerosis (ALS) to assess for involvement of the autonomic nervous system. Twenty-two age-matched normals and 6 patients with muscular dystrophy served as controls. The SSR was intact in all normal volunteers and all patients with muscular dystrophy. The mean SSR latency in the ALS patients was prolonged compared to that of normals (2.29 ± 0.28 versus 2.13 ± 0.16 s, P > 0.05). The SSR was absent in one or both legs of 10 ALS patients (40%). Absence or abnormal latency of SSR in patients with ALS without clinical findings of autonomic failure suggests involvement of the autonomic nervous system in addition to the motor system. © 1993 John Wiley & Sons, Inc.     

DYSAUTONOMIA IN CRYOGLOBULINEMIC AND ALCOHOLIC NEUROPATHIES

Sympathetic Skin Response (SSR) can evaluate the activity of both sensory afferent and sudomotor sympathetic efferent fibres in peripheral neuropathy (PN). This electrophysiological test was performed in two groups of patients: one with HCV-related mixed cryoglobulinemia (MC) and the other with chronic alcoholism (CA). Thirty consecutive HCV-related MC patients, 25 female and 5 male, aged 35–74 years and thirty-three consecutive CA patients, 8 female and 25 male, aged 24–69 years were studied. In all cases, neurological exam, peroneal, sural and ulnar nerve conduction velocity, standardised test battery for autonomic disorder (defined according to Bellavere, 1990) and SSR (recorded with electrodes attached to the palm and sole and considered abnormal if no response was recorded) were performed.
PN was found in 27 MC patients (90%) and in 23 CA patients (69.6%). Autonomic dysfunction, shown by cardiovascular tests, was found in 3 MC patients, all with PN and in 6 CA subjects, all but one with PN. SSR resulted absent in 12 MC patients (40%): three of them with and 9 without dysautonomia; SSR was also absent in 9 CA patients (27.2%) (1 with and 8 without dysautonomia).
In MC and CA patients, autonomic dysfunction frequency increases when SSR is studied together with standard cardiovascular tests. SSR provides further information about sympathetic autonomic system activity and therefore it is advisable to add this investigation to tests usually utilized in functional evaluation of autonomic nervous system.     

Clinical versus electrophysiological assessment of dysautonomia in obstructive sleep apnea syndrome.

To assess the autonomic system in obstructive sleep apnea syndrome (OSAS), the sympathetic skin response (SSR) and the R-R interval variation (RRIV) tests were studied in 34 OSAS patients and in 32 healthy controls. The aim of the study was to evaluate the sympathetic and parasympathetic system function in OSAS, to define the pattern of autonomic abnormalities found in SSR and RRIV in patients, and to analyze the usefulness of both tests in paraclinical assessment of the dysautonomia, compared with clinical symptoms and signs of autonomic nervous system involvement. The correlations between both autonomic tests results were also studied. In OSAS patients, SSR test results were abnormal in about 44% and RRIV results were abnormal in about 21% of patients. The mean values of parameters studied in SSR were significantly different in OSAS patients and controls (P < 0.05), whereas the differences between RRIV results were less important. The SSR and RRIV results in patients with mild apnea (Apnea/ Hypopnea Index (AHI) < 15) were more frequently within normal limits if compared with those of patients with severe apnea, but without reaching statistical significance. The clinical studies results (according to the Autonomic Symptoms Questionnaire) were related to the SSR results (p < 0.05 on chi and Fisher exact test). According to these results, SSR and RRIV are simple paraclinical electrophysiologic tests that confirm clinical dysautonomia. They may be useful as screening tests for assessment of dysautonomia in OSAS.     

Autonomic diabetic neuropathy: skin sympathetic response and neurovegetative cardiovascular functionality tests.

One hundred and twelve diabetic patients were submitted to several tests for evaluation of autonomic cardiovascular and sudomotor function. It was found that a patient could be positive to one test and negative to others, thus confirming the presence of sectorial lesions which do not affect the autonomic nervous system uniformly. The parasympathetic system is more frequently and precociously affected than the sympathetic system. The tests used for investigating the sympathetic component, the sympathetic skin response (SSR) gives results which are more frequently and precociously altered.     

Autonomic dysfunction in patients with essential tremor

The aim of this study was to evaluate the autonomic function in patients with essential tremor (ET). Thirty-one adult patients with ET and 26 healthy controls were enrolled in the study. The electrophysiological evaluations of the autonomic nervous system function were performed by sympathetic skin response (SSR) and R–R interval variation (RRIV) tests. The mean latency of SSR in ET patients was significantly delayed compared with the controls (P = 0.01). The mean amplitude of sympathetic skin response was significantly lower in ET patients in comparison to the controls (P = 0.001). No differences were found in mean RRIV values in both group subjects. Sympathetic dysfunction may occur in patients with ET. This may be easily demonstrated by SSR tests.     

Are electrophysiological autonomic tests useful in the assessment of dysautonomia in Parkinson's disease?

To assess the autonomic system in Parkinson's disease (PD), the sympathetic skin response (SSR) and the R-R interval variation (RRIV) tests were studied in 26 PD patients and in 24 healthy controls. The aim of the study was to evaluate the sympathetic and parasympathetic system function in PD, to define the pattern of autonomic abnormalities found in SSR and RRIV in parkinsonian patients as well as to analyze the usefulness of both tests in paraclinical assessment of the dysautonomia, compared with clinical symptoms and signs of the autonomic nervous system involvement. The corrrelations between both autonomic tests results were also studied. In PD patients SSR test was abnormal in about 35% and RRIV was abnormal in about 54% of patients. SSR and RRIV were both abnormal in about 27% of PD patients whereas at least one of electrophysiological autonomic tests was abnormal in about 62% of PD patients. Clinical and paraclinical signs of dysautonomia occurred in a similar proportion of patients (i.e. in about 62%). A weak correlation was found between the latency of SSR from upper limbs and the value of RRIV during deep breathing (p=0.063). Our results show that SSR and RRIV are non-invasive paraclinical electrophysiological tests that confirm clinical dysautonomia in PD and can supplement the clinical differentiation of Parkinsonian syndromes.     

Is pruritus in chronic uremic patients related to peripheral somatic and autonomic neuropathy? Study by R-R interval variation test (RRIV) and by sympathetic skin response (SSR).

The problem of pruritus in uremic dialysed patients remains unsolved. The etiology of pruritus has not been precisely explained, and sometimes no efficient treatment is available. The aim of this study was to analyse the relationship between somatic neuropathy and pruritus as well as the relationship between pruritus and dysautonomia. Fifty-one patients with end-stage renal failure underwent basic neurological examination, nerve conduction velocity studies, and pruritus assessment by means of a questionnaire. Two tests were used to assess the autonomic nervous system, namely the R-R interval variation test in basal and profound breath conditions (RRIV) and the sympathetic skin response (SSR). Pruritus was found in 63% patients of the sample. Most of them had clinical symptoms and signs of peripheral sensorimotor neuropathy and dysautonomia. About 59% of uremic patients revealed abnormally reduced RRIV. About 45% of patients had abnormal (delayed or absent) SSR. The pruritus in uremic patients occurred significantly more frequently (P < 0.01) in patients with paresthesia. A nonsignificant but sizeable trend towards a relationship of pruritus with hypohidrosis and pathological SSR results was also observed. There was no relationship between the pruritus presence and RRIV results. According to our results the activity of the nervous system might play an important role in the mechanism of uremic pruritus, but paradoxically this latter appeared more tightly related to somatic neuropathy than to autonomic dysfunction. Our results also suggest that SSR may become a useful technique for the assessment of autonomic dysfunction in uremic patients.     

Sympathetic skin response and cardiovascular autonomic function tests in Parkinson's disease and multiple system atrophy with autonomic failure.

The relationship between sympathetic skin response (SSR) and cardiovascular autonomic function tests (CVTs) was investigated in 15 patients with idiopathic Parkinson's disease (PD), 15 patients with clinical evidence of multiple system atrophy (MSA) with autonomic failure, and in 15 healthy control subjects. SSR was elicited by electrical stimulation of the right and left median nerves and simultaneously recorded on the palms of both hands. CVTs included the following sympathetic and parasympathetic tests: orthostatism, head-up tilt, cold pressor test, deep breathing, Valsalva maneuver, and hyperventilation. The SSR was normal in all patients with PD and control subjects but was abnormal or absent in all patients with MSA. For patients with MSA, SSR latency was significantly longer and amplitude was significantly smaller than that of patients with PD and control subjects. For patients with PD, SSR did not differ from that of control subjects. In these patients, SSR latency was significantly longer and SSR amplitude was smaller when the side with more marked motor symptoms was stimulated, both ipsilaterally and contralaterally to the side of stimulation. A statistically significant difference in SSR latencies and amplitudes was found between patients with PD and control subjects only when motor asymmetries were considered. CVTs showed severe sympathetic and parasympathetic hypofunction in patients with MSA, but not in patients with PD or control subjects. No correlation was found between SSR and CVTs that assess sympathetic function in patients and control subjects. SSR is indicated as an additional test for the evaluation of sympathetic degeneration in patients with MSA.     

Imaging of the autonomic nervous system: focus on cardiac sympathetic innervation

Symptoms or signs of abnormal autonomic nervous system function occur commonly in several neurological disorders. Clinical evaluations have depended on physiological, pharmacological, and neurochemical approaches. Recently, imaging of sympathetic noradrenergic innervation has been introduced and applied especially in the heart. Most studies have used the radiolabeled sympathomimetic amine, (123)I-metaiodobenzylguanidine. Decreased uptake or increased "washout" of (123)I-metaiodobenzylguanidine-derived radioactivity is associated with worse prognosis or more severe disease in hypertension, congestive heart failure, arrhythmias, and diabetes mellitus. This pattern may reflect a high rate of postganglionic sympathetic nerve traffic to the heart. Many recent studies have agreed on the remarkable finding that all patients with Parkinson's disease and orthostatic hypotension have a loss of cardiac sympathetic innervation, whereas all patients with multiple system atrophy, often difficult to distinguish clinically from Parkinson's disease, have intact cardiac sympathetic innervation. Because Parkinson's disease entails a postganglionic sympathetic noradrenergic lesion, the disease appears to be not only a movement disorder, with dopamine loss in the nigrostriatal system of the brain, but also a dysautonomia, with noradrenaline loss in the sympathetic nervous system of the heart. As new ligands are developed, one may predict further discoveries of involvement of components of the autonomic nervous system in neurological diseases.     

Effects of epilepsy on autonomic nervous system and respiratory function tests

We have investigated autonomic nervous system function during the interictal period in epileptic patients and the possible effects of autonomic dysfunction on respiratory functions. A total of 32 epileptic patients (23 generalized, 9 partial epilepsy) and 32 healthy volunteers were involved. Sympathetic skin response (SSR), for evaluating the sympathetic nervous system, and RR interval variation (RRIV) were measured at the beginning and third month of antiepileptic treatment, and respiratory function tests (RFTs) were performed. In patients with partial epilepsy, SSR latency in the upper extremity (1.3+/-0.2 s) was longer than that of controls (1.2+/-0.3 s) at baseline (P=0.05), and was significantly reduced (1.1+/-0.3 s) after treatment (P<0.05). RRIV values of patients with generalized epilepsy were statistically significantly lower than those of controls (P<0.01). However, deep breathing RRIV values (32.6+/-15.3%) of patients were lower than those (43.0+/-18.2%) of controls (P<0.05). Sympathetic dysfunction was determined in patients with partial epilepsy and parasympathetic dysfunction in patients with generalized epilepsy. No abnormality was observed on RFTs for both patients with partial epilepsy and patients with generalized epilepsy.     

Central conduction and autonomic nervous function in HMSN I.

CNS conduction and autonomic nervous function were investigated in 15 patients with HMSN I. Central motor conduction time (CMCT) was estimated with magnetic brain stimulation and electrical nerve root stimulation. Somatosensory evoked potential (SEP) and visual evoked potential (VEP) were used for assessment of central sensory and visual conduction. Autonomic effector organ functions were assessed with the R-R variation test for parasympathetic function, and the sympathetic skin response test (SSR) for skin sympathetic sudomotor activity. Five of the patients had prolonged CMCT. Central sensory conduction was normal in 3, and slightly prolonged in 1 of the patients, but could not be estimated in 11 due to lack of response from the cervical recording. VEP was abnormal in 2 patients. R-R variations during normal breathing were low in 8 of 15 patients, and low also during deep breathing in 1 of 15. The SSR test was pathological in 5 of 15 patients. Thus, impaired central conduction and/or autonomic dysfunction was not an uncommon finding in patients with HMSN I.     

多发性硬化患者神经系统损害程度与自主神经症状量表评分和交感神经皮肤反应异常率的关系

目的探讨多发性硬化(MS)患者神经系统损害程度与自主神经症状量表(ASP)评分和交感神经皮肤反应(SSR)异常率的关系。方法 62例MS患者(MS组)和36例健康对照者(对照组)分别进行ASP问卷调查并记录各子项目分值。MS组根据扩展致残量表评分分为轻度损害组(0~4分)和重度损害组(4.5~9.5分),分别进行SSR检测。结果 MS组与对照组ASP评分的差异有统计学意义(t=7.962,P0.001)。两组ASP评分各子项目中差异有统计学意义的子项目为直立不耐受、分泌功能障碍、男性功能障碍、排尿障碍、胃轻瘫、便秘、瞳孔运动障碍、血管舒缩功能障碍、反射性晕厥(均P0.05)。MS组患者中,轻度损害组ASP评分及SSR异常率均明显低于重度损害组(t=9.069,P0.001;χ2=16.16,P0.001)。结论ASP可用于评估MS自主神经系统损害的临床特征和全貌。MS患者神经系统损害程度与其ASP评分及SSR异常率均有关。     

Evaluation of autonomic nervous system function with spectral analysis of heart rate variability in a case of tetanus

The autonomic nervous system is affected in a wide variety of neurological disorders. Its dysfunction may play an important role in the clinical course and may result in serious complications, such as cardiac arrest. We report a case of tetanus who presented with severe autonomic nervous system dysfunction which was detected by spectral analysis of heart rate variability monitored over 24 h. This is a semi-quantitative method for evaluation of the status of the autonomic nervous system. In the present case, the analysis revealed profoundly decreased activity of both sympathetic and parasympathetic nervous system modulation of cardiac rhythm. The parasympathetic nervous system activity was more severely impaired than that of the sympathetic nervous system. The relative predominance of the sympathetic nervous system in the present case may have resulted in unopposed sympathetic nervous system hyperactivity manifested in this patient by tachycardia and excessive sweating. We further infer that the documented diminished buffering capacity of the autonomic nervous system may have lead to a sudden cardiac arrest in our case. Thus, spectral analysis of heart rate variability is a non-invasive and sensitive method for evaluating the status of the autonomic nervous system of critically ill patients in the hospital setting.     

123I-metaiodobenzylguanidine myocardial scintigraphy in Parkinson's disease

OBJECTIVES: (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is clinically used to estimate local myocardial sympathetic nerve damage in some forms of heart disease, autonomic nerve disturbance in diabetic neuropathy, and disturbance of the autonomic nervous system in neurodegenerative disease. In the present study, examinations were performed to clarify (1) the proportion of cardiac sympathetic nerve disturbance in Parkinson's disease, (2) the usefulness of (123)I-MIBG myocardial scintigraphy to detect sympathetic nerve disturbances compared with autonomic function tests, (3) cardiac function in patients who have a decreased MIBG uptake in (123)I-MIBG myocardial scintigraphy, (4) the usefulness of (123)I-MIBG myocardial scintigraphy to differentiate Parkinson's disease from the other neurological diseases mimicking it. METHODS: (123)I-MIBG myocardial scintigraphy was performed, together with autonomic function tests and cardiac examinations in 46 patients with Parkinson's disease and 25 patients with vascular parkinsonism, essential tremor, or multiple system atrophy. RESULTS: In an anterior image study, the average count per pixel in heart to mediastinum (H/M) ratio decreased in 80% of the patients with Parkinson's disease in the early phase and 84% in the late phase. The mean H/M ratio in Parkinson's disease was significantly lower than that in controls and the other diseases. The H/M ratio tended to decrease with the disease progression. In almost half of the patients in Hoehn and Yahr stage I, the H/M ratio was already decreased. The sympathetic skin response in upper and lower limbs, head up tilt test, and coefficient of variation of R-R interval were abnormal in 17%, 31%, 30%, and 17% of the patients, respectively. All the patients with abnormal autonomic functions were in Hoehn and Yahr stage III, IV, or V. Echocardiography showed normal left ventricular function. Twenty four hour Holter electrocardiography detected no serious arrhythmias except for one patient with non-sustained ventricular tachycardia. CONCLUSION: (123)I-MIBG myocardial scintigraphy might detect early disturbances of the sympathetic nervous system in Parkinson's disease and might give useful diagnostic information to differentiate vascular parkinsonism, essential tremor, and multiple system atrophy from Parkinson's disease.