Abnormal sympathetic skin response in patients with autoimmune vitiligo and primary autoimmune hypothyroidism

The sympathetic skin response was studied in 21 patients with autoimmune vitiligo or hypothyroidism or both. No response to stimulation was found in 6 patients, but 4 with both diseases showed abnormal results. Sympathetic skin response is useful in evaluating sudo motor activity of the autonomic nervous system, and it is concluded that patients with autoimmune vitiligo, auto immune hypothyroidism and especially those with both diseases show evidence of sudomotor dysfunction.     

Differentiation of autonomic nervous activity in different stages of coma displayed by power spectrum analysis of heart rate variability

The analysis of heart rate (HR) variability offers a noninvasive method to investigate autonomic nervous system activity in comatose patients. We analyzed three components of the HR variability in a group of comatose patients: the low-frequency band (LF), representing mainly sympathetic influence, the mid-frequency band (MF), representing sympathetic and parasympathetic influence, and the high-frequency band (HF), representing the parasympathetic influence. A value for sympathovagal balance was defined as LF/HF and MF/HF ratio. Moreover, the skin conductance level (SCL) and the skin conductance resistance (SCR) variability were recorded. The patient group consisted of 22 patients with traumatic brain injuries. Coma depth was assessed by the Glacow Coma Scale and artifact-free HR, SCL, and SCR were measured 75 times in the patient group. The results documented a significant gain in sympathetic nervous system activity corresponding with the state of emerging from coma. This gain was most pronounced in the HF component of the HR and in the sympathovagal balance between LF/HF. The findings in SCL and SCR variability endorsed this result. It is concluded that emerging from coma is accompanied by an increasing influence of the sympathetic nervous system on HR control. This leads to a change in the sympathovagal balance, i.e., a reintegration of parasympathetic and sympathetic activity. Received: 7 February 1996 / Accepted: 8 October 1997     

Autonomic dysfunction in Machado-Joseph disease

OBJECTIVE: Machado-Joseph disease is an autosomal dominant spinocerebellar ataxia with expanded trinucleotide repeats. Although autonomic nervous system degeneration was documented in postmortem reports, the autonomic dysfunction in patients with Machado-Joseph disease, either in clinical analysis or electrophysiological investigations, has not yet been studied in detail. METHODS: Fifteen patients with genetically confirmed Machado-Joseph disease and 34 healthy subjects were studied. The study design included a detailed questionnaire, R-R interval variation on deep breathing or Valsalva maneuver, and sympathetic skin response evoked by electrical stimulation of the median nerve or magnetic stimulation of the neck. RESULTS: Sixty-seven percent of patients had at least 3 symptoms involving different aspects of autonomic functions. Voiding problems and thermoregulatory disturbance were the most common symptoms. Ten (71%) of 14 patients had abnormal R-R interval variation with a significant reduction of the mean ratio. Prolonged latency or absence of sympathetic skin response to electrical stimulation was identified in 73% of patients and to magnetic stimulation, in 53%. R-R interval variation and sympathetic skin response showed good correlation with the functional stage. Electrical stimulation revealed the highest sensitivity, specificity, and positive predictive value compared with other tests. CONCLUSION: The present investigation documents that autonomic dysfunction is not uncommon in patients with Machado-Joseph disease and might be related to the clinical progression.     

Autonomic reactivity to sensory stimulation is related to consciousness level after severe traumatic brain injury.

OBJECTIVE: To examine changes in the activity of the autonomic nervous system (ANS) that are related to recovery to consciousness in the post-acute phase after severe traumatic brain injury (sTBI). METHODS: Skin conductance and heart rate reactivity to sensory stimulation were recorded every 2 weeks for an average period of 3.5 months in 16 adolescent patients, during the assessment of their level of consciousness (LoC), and their cognitive and functional behaviour. RESULTS: Both heart rate variability (HRV) and skin conductance level (SCL) in reaction to sensory stimulation changed with recovery to consciousness. Indices of HRV and SCL that represent sympathetic activity of the autonomic nervous system (ANS) increased with recovery, whereas indices that represent parasympathetic activity decreased. In addition, we observed an increase in sympathovagal balance of the ANS with recovery. CONCLUSIONS: Recovery to consciousness determined by clinical observation in sTBI in the post-acute phase is related to changes in SCL and HRV during sensory stimulation. ANS reactivity to environmental stimulation can therefore give objective supplementary information about the clinical state of sTBI patients, and can contribute to decision-making in the treatment policy of unresponsive patients. SIGNIFICANCE: These findings demonstrate that autonomic reactivity can be informative concerning how a severely damaged nervous system reacts to environmental stimulation and how, in a recovering nervous system, this reactivity changes.     

EFFECT OF HYPERGLYCEMIA ON ELECTRODERMAL ACTIVITY IN DIABETIC RATS

This study investigated the relationship between hyperglycemia and electrodermal activity (EDA) parameters in streptozotocin (STZ) induced diabetic rats. The article evaluates the course of development of neurophysiological alterations in the peripheral nervous system in diabetic rats through EDA. Rats were made diabetic using a moderate dose of STZ (DI) and high dose (DII). The placebo group (P) was injected with physiological saline. EDA was recorded 1 h before the injection (beginning, 0, day), 1st day (one day after the injection) and 10th day. Skin conductance level (SCL) was lower in DII than P on the 1st and the 10th days. The SCL and SC fluctuation rate (SCFr) of DI were significantly lower on the 10th day compared to their first record. SC response rate (SCRr) was lower on the 10th day compared to the 1st day, in the DI. In the DI, SCL, SC fluctuation rate (SCFr) and SC response rate (SCRr) were lower on the 10th day compared to the 1st day. The DII was statistically higher in electrodermal non-responsiveness compared to other groups on the 1st day. The results obtained show that hyperglycemia affects the peripheral nervous system, and EDA parameters are affected by blood glucose level. It is suggested that EDA is a simple and non-invasive electrophysiological method in early diagnosis of diabetic neuropathy.     

Effect of hyperglycemia on electrodermal activity in diabetic rats

This study investigated the relationship between hyperglycemia and electrodermal activity (EDA) parameters in streptozotocin (STZ) induced diabetic rats. The article evaluates the course of development of neurophysiological alterations in the peripheral nervous system in diabetic rats through EDA. Rats were made diabetic using a moderate dose of STZ (DI) and high dose (DII). The placebo group (P) was injected with physiological saline. EDA was recorded 1 h before the injection (beginning, 0, day), 1st day (one day after the injection) and 10th day. Skin conductance level (SCL) was lower in DII than P on the 1st and the 10th days. The SCL and SC fluctuation rate (SCFr) of DI were significantly lower on the 10th day compared to their first record. SC response rate (SCRr) was lower on the 10th day compared to the 1st day, in the DI. In the DI, SCL, SC fluctuation rate (SCFr) and SC response rate (SCRr) were lower on the 10th day compared to the 1st day. The DII was statistically higher in electrodermal non-responsiveness compared to other groups on the 1st day. The results obtained show that hyperglycemia affects the peripheral nervous system, and EDA parameters are affected by blood glucose level. It is suggested that EDA is a simple and non-invasive electrophysiological method in early diagnosis of diabetic neuropathy.     

Sympathetic skin response in patients with severe motor and intellectual disabilities

To elucidate autonomic function in individuals with severe motor and intellectual disabilities, we evaluated sympathetic skin response in 14 patients with severe motor and intellectual disabilities. The results of sympathetic skin response were compared with those of patients with mild or moderate motor and intellectual disabilities who could walk and had an intelligence quotient > or = 35 (7 cases) and neuromuscular diseases (3 cases). No sympathetic skin response was recorded in patients with severe motor and intellectual disabilities, whereas all patients with mild or moderate motor and intellectual disabilities defined above and neuromuscular diseases showed sympathetic skin response. The results suggested that all patients with severe motor and intellectual disabilities had autonomic dysfunction, and sympathetic skin response can be a useful test that can evaluate autonomic function in patients with severe motor and intellectual disabilities.     

Determination of nerve conduction abnormalities in patients with impaired glucose tolerance

Recent studies have shown that impaired glucose tolerance (IGT) is associated with dysfunction in the peripheral and autonomic nerves. The aim of this study was to determine the electrophysiological abnormalities of IGT. To determine electrophysiological abnormality in the large sensorimotor and sudomotor autonomic nerves with IGT patients, 43 patients and 34 healthy subjects have been studied. Subjective neuropathy symptoms, neurological examination and the electrophysiological findings were evaluated. When conduction of large somatic fibers only was evaluated, the ratio of electrophysiological abnormality was found to be 21%. In addition, where sympathetic skin response was evaluated the sudomotor autonomic abnormality ratio was 28% in upper extremities, 53% in lower extremities, and 16% in upper and lower extremities together. The percentages of abnormal electrophysiological parameters in different motor and sensory nerves were 39.5% in the peroneal motor nerve, 20.9% in the median motor and sural sensory nerves, 18.6% in the median sensory nerve, 16.3% in the tibial motor nerve, 14% in the ulnar sensory nerve, and 2.3% in the ulnar motor nerve. While distal motor latency was the most frequent abnormal parameter in the median and tibial motor nerves, the amplitude changes in the peroneal and ulnar motor nerves were also prominent. In sensory evaluation, the onset latency in the median-ulnar sensory nerves and the amplitude in the sural sensory nerve were found to be evident abnormalities.     

Sexual dysfunction and sympathetic skin response recorded from the genital region in women with multiple sclerosis

Multiple Sclerosis is known to cause autonomic and sexual dysfunction. However, genitourinary and sexual problems in female multiple sclerosis patients are difficult to analyse. Therefore, it is an understudied field. As an attempt to fill this gap, we evaluated genital region autonomic dysfunction of female multiple sclerosis patients by using genital sympathetic skin response. Forty female patients with definite multiple sclerosis and twenty healthy female controls were included in the study. We examined hand, foot and genital sympathetic skin responses. Some genitourinary parameters were questioned by and results were compared with genital sympathetic skin response results. Among multiple sclerosis patients 42.5% of them had genitourinary and 75% had sexual problems clinically. Sympathetic skin response pathologies were distributed as following: 22.5% in hand, 20% in the foot, and 50% in genital region in the patient group. A statistically significant correlation between sexual dysfunction and genital sympathetic skin response could not been found. It is found that patients with multiple sclerosis have higher genital sympathetic skin response abnormalities than foot and hand sympathetic skin response abnormalities. This might be the early sign of autonomic dysfuntion in multiple sclerosis patients. Genital sympathetic skin response may be an easy and objective method to apply and helpful to evaluate genitourinary dysfunction in women in conjunction with female sexual dysfuntion index.     

Diagnostic utility of autonomic measures for major depressive disorders

The diagnostic utility (sensitivity, specificity, and overall efficiency) of autonomic nervous system measures in distinguishing hospitalized patients with unipolar depression from age-matched normal controls is reported. Tonic resting skin conductance level (SCL), tonic resting heart rate level (HRL), and the phasic skin conductance and heart rate responses (SCRs and HRRs) to task-related stimuli were used. The overall efficiency of SCL of 70% was generally consistent with previous research. The other measures yielded greater efficiency: 80% for SCR, 90% for HRL, and 83% for HRR. The possible role of autonomic measures in the diagnosis of major depressive episodes is discussed.     

Pathological Gambling in Parkinson's disease: Autonomic measures supporting impaired decision‐making

According to the somatic marker hypothesis, autonomic measures and arousal modulation can reveal a difference in subgroups of patients developing impaired decision‐making because of addictions. Previously, pathological gambling (PG) and Parkinson's disease (PD) have been associated with differential arousal levels during gambling behavior. However, no research considered the specific autonomic responses of Parkinson's disease patients with pathological gambling and with a previous history of gambling. Thus, this study investigated skin conductance responses (SCRs), skin conductance level (SCL) and heart rate (HR) during the Iowa Gambling Task (IGT) in two groups of PD patients with gambling disorder, active (PD Gamblers; n = 14) or remitted (PD Non‐Gamblers; n = 13) and a control group of patients with Parkinson's disease only (n = 13). Anticipatory autonomic responses to disadvantageous decks and advantageous decks during the Iowa Gambling Task were measured for each participant. The PD Gamblers group performed worse than the PD Non‐Gamblers and the control groups at the IGT task and exhibited lower SCRs, SCL, and HR during the decision‐making processing of cards belonging to disadvantageous decks. The role of autonomic and behavioral measures was considered.     

Autonomic dysfunction in multiple sclerosis: correlation with disease-related parameters

Cardiovascular autonomic functions were investigated in a prospective, controlled study of 22 consecutive relapsing-remitting multiple sclerosis (MS) patients and 22 healthy subjects using 5 simple noninvasive tests and sympathetic skin response testing. Tests included the heart rate response to deep breathing, valsalva maneuver and standing, blood pressure response to standing and sustained hand grip, and were graded according to the Ewing and Clark classification as early, definite or severe impairment. The relationship between autonomic dysfunction and disease-related parameters such as the expanded disability status scale (EDSS) and disease duration was studied. Ninety percent of the patients had symptoms related with autonomic dysfunction, and 45.5 % had abnormal results in cardiovascular autonomic function testing with 4 patients also having abnormal sympathetic skin responses. Statistical analysis indicated that patients with a long disease duration rather than high EDSS carried a risk of autonomic involvement in MS. Both parasympathetic and sympathetic functions were impaired and this could have been easily overlooked by a standard EDSS follow-up. In this regard, autonomic function testing seems necessary in order to detect subclinical changes in MS patients and should be considered in outcome measures.     

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.     

Alexithymia is no risk factor for exacerbation in spasmodic torticollis patients

OBJECTIVE: To assess whether alexithymia is a risk factor for exacerbation in spasmodic torticollis (ST). METHODS: ST patients (2 x 10) with high vs. low alexithymia scores (mean score on the 20-item Toronto Alexithymia Scale [TAS-20]=69.2 vs. 28.7) were compared on physiological, motor and subjective responses to a cognitive and an emotional laboratory stressor. Changes in sustained abnormal head/shoulder positions and maximum range of motion (ROM) of the cervical spine were kinematically quantified. Skin conductance level (SCL), nonspecific skin conductance fluctuations (NS.SCF), heart rate (HR) and skin temperature (T) were measured. RESULTS: High alexithymia had no effect on the abnormal head posture or movements, but high-alexithymic ST patients showed generally increased levels of autonomic arousal (more NS.SCF, higher SCL; analysis of variance [ANOVA]: P=.016 and P=.051, respectively) under all experimental conditions. When ST symptom severity (TSUI-score) was partialled out, these group differences were somewhat reduced (analysis of covariance [ANCOVA]: P=.052 and P=.143). CONCLUSIONS: High alexithymia did not lead to increased abnormal head movements to stressors, but may result in a subtle increase in tonic level of sympathetic activity.     

Investigation of the relationship between electrodermal and behavioural responses to executive tasks in Prader-Willi syndrome: An event-related experiment

BackgroundRecent work suggests that maladaptive behaviors in genetic developmental disorders may emerge from autonomic dysfunctions impacting higher order executive functions. In Prader-Willi syndrome (PWS), executive functions are not well understood and investigations of possible underlying causes at the autonomic level are lacking.AimsThis study aimed at clarifying the status of inhibition and working memory updating functions in PWS and searched for sympathetic signatures as well as to examine their links with executive performance.Methods and ProceduresThe performance of thirty adults with PWS was compared to that of thirty healthy adults on two tasks assessing inhibition and working memory updating while electrodermal activity (EDA) was recorded.Outcomes and ResultsPWS adults underperformed healthy adults in the inhibition and the working memory updating tasks and showed abnormal skin conductance responses. Distinct EDA have been found in PWS and healthy adults. Furthermore, while EDA reflected distinct cognitive processes, correlations between electrodermal and behavioural data were absent when examining the two groups separately.Conclusions and ImplicationsPWS is associated with a slight impairment of inhibition and a severe impairment of working memory updating. Furthermore, there are specific sympathetic autonomic signatures in PWS that do not present straightforward links with executive dysfunctions.     

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.     

Electrophysiological tests of autonomic function in patients with idiopathic autonomic failure syndromes

Three electrophysiological tests of autonomic function were performed in patients with autonomic nervous system dysfunction to define test sensitivities and specificities. The skin sympathetic response, Valsalva ratio, and heart rate variation with deep breathing were studied in 10 patients with multiple system atrophy (MSA) and in 7 patients with pure (also called progressive or primary) autonomic failure (PAF); control subjects were 17 normal individuals of similar age. Thirteen patients had abnormal skin sympathetic responses, and 16 had abnormal Valsalva ratios. Fourteen patients had an abnormal variation of the heart rate with deep breathing. Taking the three tests together, binary logistic regression for distinguishing between patients and normal subjects correctly classified 91% of the 33 individuals for whom there were complete data with sensitivity of 88% and specificity of 94%. However, only 69% of the patients could be correctly classified by a logistic regression for discriminating between MSA and PAF. Electromyography (EMG) studies showed that 7 of 8 patients with MSA but only 2 of 7 patients with PAF (both multiparous women) had denervation of the rectal sphincter muscle. The EMG study is, therefore, valuable in men, but has a high false positive rate in women, probably because of pudendal nerve injury from parturition. © 1996 John Wiley & Sons, Inc.     

Emotion and ocular responses in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disease that affects motor, cognitive, and emotional functioning. Previous studies reported reduced skin conductance responses in PD patients, compared to healthy older adults when viewing emotionally arousing pictures. Attenuated skin conductance changes in PD may reflect peripheral autonomic dysfunction (e.g., reduced nerve endings at the sweat gland) or, alternatively, a more central emotional deficit. The aim of the current study was to investigate a second measure of sympathetic arousal—change in pupil dilation. Eye movements, a motor-based correlate of emotional processing, were also assessed. Results indicated that pupil dilation was significantly greater when viewing emotional, compared to neutral pictures for both PD patients and controls. On the other hand, PD patients made fewer fixations with shorter scan paths, particularly when viewing pleasant pictures. These results suggest that PD patients show normal sympathetic arousal to affective stimuli (indexed by pupil diameter), but differences in motor correlates of emotion (eye movements).     

Sympathetic activation in broadly defined generalized anxiety disorder

The definition of generalized anxiety disorder (GAD) has been narrowed in successive editions of DSM by emphasizing intrusive worry and deemphasizing somatic symptoms of hyperarousal. We tried to determine the clinical characteristics of more broadly defined chronically anxious patients, and whether they would show physiological signs of sympathetic activation. A group whose chief complaint was frequent, unpleasant tension over at least the last six weeks for which they desired treatment, was compared with a group who described themselves as calm. Participants were assessed with structured interviews and questionnaires. Finger skin conductance, motor activity, and ambient temperature were measured for 24h. Results show that during waking and in bed at night, runs of continuous minute-by-minute skin conductance level (SCL) declines were skewed towards being shorter in the tense group than in the calm group. In addition, during waking, distributions of minute SCLs were skewed towards higher levels in the tense group, although overall mean SCL did not differ. Thus, the tense group showed a failure to periodically reduce sympathetic tone, presumably a corollary of failure to relax. We conclude that broader GAD criteria include a substantial number of chronically anxious and hyperaroused patients who do not fall within standard criteria. Such patients deserve attention by clinicians and researchers.