Sympathetic Skin Response Recordings Research Articles

59. Can sacral SSR recordings be useful in the assessment of autonomic nervous dysfunction in patients with sacral-pudendal impairment?

While it is well know the usefulness of neurophysiological tests to investigate somatic nervous system of pelvic floor, it is not yet recognized the real efficacy of sympathetic skin response (SSR). In the last years we examined more than 1500 patients with different pelvic disorders (age range 7–85 years). All patients were studied with pudendal EMG, SEP, MEP, sacral reflexes. SSR was recorded from skin of sacral area (i.e. penis or mons pubis, perineal area, perianal area according to symptoms), applying random single square pulses at wrist or supraorbital region. SSR latency and amplitude were measured and the results were compared by mean age with those of control group. We observed alterations in latency and/or amplitude and in some cases SSR changes were the only present abnormality. We have also observed that it is important to differentiate anterior from posterior perineal area in SSR recording. SSR test may be a useful tool to investigate autonomic sacral involvement, because until now it is the only test to explore autonomic system. In our experience SSR is always present, in absence of pathology, so it could become a standard investigation for clinical routine of patients with sacral disorders.

P442: The value of SSR recordings in the assessment of autonomic nervous dysfunction in patients with sacral-pudendal impairment

P442: The value of SSR recordings in the assessment of autonomic nervous dysfunction in patients with sacral-pudendal impairment

What features differentiate unilateral from bilateral restless legs syndrome? A comparative observational study of 195 patients

ObjectiveRestless legs syndrome (RLS) is frequently misdiagnosed, mainly due to variability in the description of symptoms by patients. We observed some patients with classical RLS manifesting symptoms involving limbs on one side. This study was planned to evaluate various clinical and investigational parameters which might differentiate the profile of patients with unilateral versus bilateral RLS. MethodsAll patients diagnosed with RLS during an eight-year period, attending the Sleep Disorders Clinic, All India Institute of Medical Sciences, were studied. Clinical assessment was carried out from a pre-structured proforma, including details of the diagnostic criteria proposed by the International Restless Legs Syndrome Study Group of the National Institutes of Health. A detailed hemogram, serum ferritin, liver and kidney function tests, and nerve conduction studies with sympathetic skin response recording were obtained for all patients. To identify features, which differentiated patients with unilateral RLS versus those with bilateral RLS, various statistical tests of significance were used, as applicable. ResultsAmong 195 patients, 161 (69 male, 92 female) with bilateral and 34 (12 male, 22 female) with unilateral RLS (mean age of 42years±10–14), both with similar age and gender distribution, were enrolled. These could be further subdivided into those with strictly unilateral RLS and those with strictly unilateral onset (n=23), with later involvement of the opposite side, but with persistent asymmetry (n=11). Variables significantly differentiating unilateral from bilateral RLS group were: RLS being secondary versus primary (44% versus 55% in unilateral; 76% versus 23% in bilateral; OR, 4.2; CI, 2–9) and positive family history (36% in bilateral, 11% in unilateral; OR, 2.6; CI, 1.1–8). All other features were similar in both groups. ConclusionsUnilateral RLS is not rare (17%) and although similar to bilateral RLS in clinical features, this entity may more often be secondary and less often associated with a positive family history. These differences emerge from exploratory evaluations, however, and would need further confirmation through future studies.

Autonomic dysfunction in parkinsonian LRRK2 mutation carriers

IntroductionThe aim of this study was to compare autonomic function in PD symptomatic carriers of the LRRK2 mutations and idiopathic Parkinson's disease (iPD) patients. Material and methodsWe studied 25 PD patients: 12 with the LRRK2 mutation (6 G2019S and 6 R1441G), and 13 with iPD. All patients underwent blood pressure and heart rate monitoring during head up tilt, Valsalva maneuver and deep breathing, along with recording of sympathetic skin response (SSR) and cardiac MIBG scintigraphy. ResultsThree of the patients with iPD and one of the LRRK2 carriers had orthostatic hypotension. Arterial pressure “overshoot” during phase IV of Valsalva maneuver was less pronounced in patients with iPD. During passive tilt, LRRK2 carries had higher increase of blood pressure than iPD patients MIBG late myocardial/mediastinal uptake ratios were higher in LRRK2 mutation carriers (1.51 ± 0.28 vs 1.32 ± 0.25; p < 0.05). DiscussionCarriers of the LRRK2 mutation had less autonomic impairment than those with iPD as shown by higher cardiac MIBG uptake and a tendency to less impairment of autonomic non-invasive tests. It is important to carry out larger studies comparing the clinical, functional and pathological characteristics of these patients.

Sympathetic skin response in incomplete spinal cord injury with urinary incontinence

Objectives:Sympathetic skin response (SSR) is a test for evaluation of the sympathetic sweat gland pathways, and it has been used to study the central sympathetic pathways in spinal cord injury (SCI). This study aimed to assess the autonomic pathways according to normal or abnormal SSR in urinary incontinence patients due to incomplete spinal cord injury.Materials and Methods:Suprapubic, palmar, and plantar SSR to the peripheral nerve electrical stimulation were recorded in 16 urinary incontinence patients with incomplete spinal cord injury at various neurological levels and in 30 healthy control subjects.Results:All the recordings of SSR from the incomplete SCI patients with urinary incontinence as compared with their counterparts in the control group showed significantly reduced amplitudes with more prominent reduction in the suprapubic area recording site (P value < 0.0004). SSR with significantly prolonged latencies were recorded from palm and plantar areas in response to suprapubic area and tibial N stimuli, respectively (P value < 0.02). In this study, a significantly higher stimulus intensity (P value < 0.01) was needed to elicit SSR in the cases compared with the control group.Conclusion:This study showed abnormal SSR in urinary incontinence patients due to incomplete SCI. In addition, for the first time we have described recording of abnormal SSR from the suprapubic area as another way to show bladder sympathetic system involvement.

Cardiac sympathetic denervation in symptomatic and asymptomatic carriers of the E46K mutation in the α synuclein gene

ObjectiveThe aim of this study was to analyze autonomic function and cardiac sympathetic innervation in symptomatic and asymptomatic carriers of the E46K alpha-synuclein gene (SNCA) mutation. Patients and methodsAutonomic function tests were performed in six patients, four of whom were symptomatic carriers (ages: 46, 59, 52 and 28-years) and two who were asymptomatic carriers (ages: 52 and 29 years). Autopsy studies were performed on an additional two symptomatic carriers not eligible for autonomic testing.Patients completed the SCOPA autonomic questionnaire, and underwent the head-up tilt test accompanied by measurements of plasma norepinephrine. Valsalva maneuver and deep breathing tests, along with recording of sympathetic skin response (SSR) and cardiac MIBG scintigraphy were carried out. Myocardial tissue sections removed from the two autopsied cases were subjected to routine histological staining and immunohistochemical processing with monoclonal antibodies against tyrosine hydroxylase and alpha-synuclein. ResultsBoth the four symptomatic and the older asymptomatic carriers reported abnormalities in the SCOPA questionnaire and had markedly diminished cardiac MIBG uptake. Plasma norepinephrine in the supine and tilted positions was normal in all subjects. Only one patient had significant orthostatic hypotension. There was a complete absence of tyrosine hydroxylase immunostaining in the myocardium of the two autopsied cases. InterpretationWe have found imaging and histological evidence of cardiac sympathetic denervation in symptomatic and asymptomatic carriers of the E46K alpha-synuclein gene mutation. The sympathetic denervation appears to be organ-specific, with selective affectation of the heart given that plasma norepinephrine levels and blood pressure were normal.

Sympathetic skin response (SSR) in multiple sclerosis and clinically isolated syndrome: A case-control study

To compare the sympathetic skin responses (SSRs) in patients with multiple sclerosis (MS), clinically isolated syndrome (CIS), and healthy controls. SSR was recorded on both hands and feet in 30 patients and 20 healthy controls. SSR results (latency measurements) were compared in patients with normal or abnormal brainstem auditory evoked potentials (BAEPs), visual evoked potentials (VEPs) and somatosensory evoked potentials (SEPs). Twenty-three (76.6%) and sixteen patients (53.3%) with MS had abnormal SSR recordings based on 2-standard deviation (SD) or 3-SD (from the mean of the control group) abnormality criteria, respectively. Sixty-six percent and 40 percent of patients had abnormal (>2SD) SSR in at least one hand and one foot, respectively. Patients with absent SSR had more severe disease and higher Expanded Disability Status Scale (EDSS) scores. Fourteen patients had an EDSS of zero, of whom nine had abnormal SSR and others had at least one abnormal EP study. Patients with abnormal SSR had significantly more abnormal BAEPs and SEPs than patients with normal SSR. SSR latencies were significantly correlated with EDSS and disease duration (P<0.01). All patients had at least one abnormal electrophysiological study. ROC-curve analysis showed that a cut-off score of 7008 ms as the sum of all-4-limb SSR latencies had a 80% sensitivity and 95% specificity for differentiating MS patients from healthy controls. This study suggests that SSR is a useful tool for assessment of autonomic function and can be complementary to EDSS and other electrophysiological studies in patients with MS and CIS.

Effects of subthalamic nucleus deep brain stimulation on sweating function in Parkinson's disease

Purpose To assess the impact of subthalamic nucleus (STN) deep brain stimulation (DBS) on the sweating function in patients with advanced Parkinson's disease (PD). Methods Nineteen patients with idiopathic PD (mean age ± SD, 61.58 ± 9.47) were examined immediately before and 6 months after DBS. Each examination session included registration of autonomic symptoms by means of a semi-structural questionnaire and recording of sympathetic skin response (SSR) from both palms and one sole. The neurophysiological measurements were compared to those of 19 matched for sex and age healthy controls. Results Six months post-DBS motor improvement was amounted to 65.9% and the daily levodopa equivalent dose was decreased by 36.4%. Post-operatively, dyshidrosis manifestations were reduced by 66.7% (pre-DBS sudomotor dysfunction in 47.4% of patients and sudomotor fluctuation in 57.1% of the above patients). There were no significant differences in-between pre- and post-DBS results of SSR study. However, the number of patients with at least one abnormal SSR pre-operative was reduced from 6 to 3 post-operative. No correlation was found between this neurophysiological finding and the change of clinical symptoms of hyperhidrosis or the DBS motor improvement. Conclusions These results, although based on a small sample, suggest that STN DBS, in addition to the effect to the mobility, might also favorably regulate sweat in idiopathic PD.

Electrophysiological deterioration over time in patients with Huntington's disease

In recent studies aimed at assessing the effects of original therapeutic strategies applied to patients with Huntington's disease (HD), we observed informative changes in electrophysiological results that recovered normal values in coherence with clinical improvement. However, longitudinal studies were lacking for determining whether electrophysiological test results evolve in parallel with clinical markers of the natural course of the disease and could consequently provide objective quantifiable markers of disease progression. For this purpose, electrophysiological testing was performed annually in a cohort of 20 patients with HD over a 2-year period (three examinations). The study included the recording of sympathetic skin responses and blink reflexes (BRs) to supraorbital nerve stimulation, long latency reflexes (LLRs) and somatosensory evoked potentials (SEPs) to median nerve stimulation, and cortical silent periods (CSPs) to transcranial magnetic stimulation. Clinical evaluation was based on the Total Functional Capacity scale (TFC) and the Motor part of the Unified Huntington's Disease Rating Scale (UHDRS). A significant deterioration with time was found for BR latency, LLR presence, various SEP parameters (parietal N20 peak amplitude and frontal N30 presence) and CSP duration. Attenuation of the N20 peak and CSP shortening correlated with functional decline, as assessed by the TFC score, whereas delayed BR and LLR abolition correlated with UHDRS Motor score deterioration. This study shows that several electrophysiological parameters are closely associated with dysfunction of various neural circuits in HD and could be useful markers of disease progression.

The significance of intact sympathetic skin responses in carpal tunnel syndrome

The current study aimed to investigate the impact of carpal tunnel syndrome (CTS) on sympathetic skin response (SSR) recorded from the median and ulnar territory. Thirty patients were studied and idiopathic CTS was documented in a total of 46 hands. These were classified, according to electrophysiological criteria, into two groups; a group of 31 hands with severe CTS and a group of 15 hands with mild/moderate CTS, and were compared with a group of 30 hands of age-matched controls. SSR was recorded simultaneously from the median and ulnar side of the palm following electrical stimulation at the wrist, in a mid-point between median and ulnar nerve. Latency, amplitude, habituation and the median-to-ulnar ratio were estimated. In all controls clear recordings of SSR were obtained. In the patient groups, absence of SSR was never observed either in mild/moderate or in the severe CTS hands. The mean SSR latency and amplitude values recorded from both the median and ulnar nerves did not significantly differ between mild/moderate or severe CTS hands and controls. Likewise, the median-to-ulnar ratio and habituation of SSR latencies and amplitudes did not significantly differ between groups. SSR does not seem to be a sensitive method for evidence of autonomic involvement in CTS, even in patients manifesting sudomotor or other autonomic symptoms. In the present setting, SSR appeared to be independent of somatic afferent function and the corresponding sensory action potentials.

Sympathetic skin response in patients with peripheral arterial occlusive disease

Objective The current study aimed to assess the viability of sympathetic sudomotor fibers in patients suffering from mild peripheral arterial occlusive disease (PAD). Methods Sympathetic skin response (SSR) from the hand (electrical stimulation) and sole (electrical and magnetic stimulation) of 25 patients with PAD (19 males and 6 females with mean age 62.7±10.2 years) was recorded unilaterally depending on the side of the affected limb (18 right side, 7 left side). Electrophysiological data were also collected and correlated with the SSR results. Twenty-five, age- and gender-matched healthy volunteers served as controls. Results No evidence of nerve conduction abnormalities was recorded from the group of patients. Intact SSR recordings were obtained from the upper limb of patients. Nine patients (36%) had absent SSR in the lower limb following electrical stimulation, whilst the same 9 patients had absent SSR following magnetic stimulation. Significant differences occurred between groups in the SSR latency scores recorded from the lower limb. Following electrical stimulation the mean SSR latency in patients was significantly prolonged, compared to that of controls ( P=0.000), whilst the same applied following magnetic stimulation ( P=0.000). There was no correlation between SSR abnormalities and nerve conduction measurements. The manifestation of intermittent claudication at a walking distance of 250 m was strongly correlated with absent lower limb SSR ( r=0.71, P=0.035). Conclusions SSR abnormalities appeared to be an early and independent finding of neural impairment in our patients. Significance SSR study, performed at an early stage of PAD may prove useful in differentiating PAD-induced neuropathy from other neuropathic processes.

Caloric test and simultaneous recording of sympathetic skin response

Conclusions. It was found that there was a close correlation between sympathetic skin response (SSR) parameters and nystagmus parameters obtained in caloric tests. Further studies are needed to investigate the clinical correlation of these findings. Objectives. To investigate whether the caloric response creates a measurable SSR and, if so, to compare the SSR parameters with the nystagmus parameters and the feelings of the patient. Material and methods. Patients completed an autonomic symptom questionnaire (ASQ) regarding their past history of autonomic symptoms. They used a visual analog scale (VAS) to assess the severity of symptoms during simultaneous SSR and caloric tests. Symptoms were also noted separately by the investigator. Results. Eighteen patients were included in the study (13 females, 5 males). Eight of the patients had central and 10 had peripheral vertigo. The mean VAS score was 6.6±1.9 and the mean ASQ score was 7.2±3.6. In terms of the recorded parameters, there were no significant differences between patients with central and peripheral vertigo, males and females or warm and cold irrigation. The number of SSR waves increased significantly when the slow-phase velocity was > 26°/s (p<0.01) and the nystagmus latency was ≤27 s (p<0.05). The VAS score was also correlated with the number of SSR waves (p<0.01).

Neurophysiological testing in anorectal disorders

The neurophysiological techniques currently available to evaluate anorectal disorders include concentric needle electromyography (EMG) of the external anal sphincter, anal nerve terminal motor latency (TML) measurement in response to transrectal electrical stimulation or sacral magnetic stimulation, motor evoked potentials (MEPs) of the anal sphincter to transcranial magnetic cortical stimulation, cortical recording of somatosensory evoked potentials (SEPs) to anal nerve stimulation, quantification of electrical or thermal sensory thresholds (QSTs) within the anal canal, sacral anal reflex (SAR) latency measurement in response to pudendal nerve or perianal stimulation, and perianal recording of sympathetic skin responses (SSRs). In most cases, a comprehensive approach using several tests is helpful for diagnosis: needle EMG signs of sphincter denervation or prolonged TML give evidence for anal motor nerve lesion; SEP/QST or SSR abnormalities can suggest sensory or autonomic neuropathy; and in the absence of peripheral nerve disorder, MEPs, SEPs, SSRs, and SARs can assist in demonstrating and localizing spinal or supraspinal disease. Such techniques are complementary to other methods of investigation, such as pelvic floor imaging and anorectal manometry, to establish the diagnosis and guide therapeutic management of neurogenic anorectal disorders.

Electrophysiological evaluation of peripheral and autonomic involvement in leprosy.

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. 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. 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. 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.

Urethral Evoked Sympathetic Skin Responses and Viscerosensory Evoked Potentials as Diagnostic Tools to Evaluate Urogenital Autonomic Afferent Innervation in Spinal Cord Injured Patients

In most spinal cord injured (SCI) patients the objective assessment of afferent neuronal pathways from the lower urinary tract and the recording of a disturbed urethral sensation and/or desire to void are still difficult. Viscerosensory evoked potentials (VSEPs) might be helpful, but they remain technically difficult to obtain and interpretation is delicate. As a new approach, sympathetic skin response (SSR) of the hand and foot were recorded after electrical stimulation of the posterior urethral mucosa. This technique should allow assessment of the integrity or deterioration of the autonomic afferent pathway. A total of 20 males and 8 females with SCI somatosensory incomplete 15, somatosensory complete 13 and 6 healthy male volunteers were prospectively examined. During urodynamic examination electrical stimulation (single square pulses of 0.2 ms, 2 to 3-fold sensory threshold, 60 mA in complete SCI patients) of the posterior urethra/bladder neck was performed using a bipolar electrode inserted into a microtip pressure catheter. SSR recordings of the right palm and sole were simultaneously taken using surface electrodes and were analyzed by an electromyography unit. Patient reports on evoked urethral sensations at individual sensory thresholds were simultaneously noted. Additionally, well-known electrophysiological measurements such as pudendal sensory evoked potential and urethral VSEP were recorded to check clinical assessed somatosensory and viscerosensory status, and to compare SSR results with these conventional methods. Electrical stimulation of the posterior urethra evoked clear urethral sensation and SSRs in normal subjects. In 14 of 15 sensory incomplete SCI patients with disturbed urethral sensation SSRs could be recorded as well. Electrically evoked urethral sensations resembled the subjective desire to void at full bladder reported by controls and patients. In 13 sensory complete SCI patients with loss of any urethral sensation SSRs could not be recorded even at maximal electrical stimulation strength. All subjects with electrically induced urethral sensation had positive evoked (supralesional) SSRs of the hand. However, none of the patients with absent urethral sensation presented SSRs. Simultaneously recorded VSEPs could not be recorded clearly in 5 patients and 2 control subjects, whereas SSRs delivered clear results in all controls and patients, matching their reports. SSR recordings above a spinal lesion level after urethral electrostimulation might provide a useful and technically simple objective diagnostic tool to assess integrity of autonomic (visceral) afferent nerves from the lower urinary tract. Somatosensory deficits are not always paralleled by viscerosensory loss and vice versa. In this study SSRs were superior to VSEPs, the latter being more difficult to record. The subjective sensations reported by subjects during stimulation could be confirmed in an objective way in 100% of cases by positive/negative SSR findings.

Clinical application of laser evoked potentials using the Nd:YAG laser

The clinical interest of a new type of laser evoked potentials (LEPs) using Nd:YAG laser was assessed in the diagnosis of peripheral neuropathies affecting the small-diameter nerve fibres, and of spinal cord lesions, affecting the spinothalamic tract. Twelve patients aged from 26 to 79 years with sensory neuropathies ( n = 6) or spinal cord lesions ( n = 6) underwent neurophysiological examination of the lower limbs comprising quantitative sensory testing, i.e., the determination of vibratory and thermal thresholds (VT and TT), somatosensory evoked potentials (SEPs) to electrical stimulation and Nd:YAG LEPs. VT and SEPs were used to assess large-diameter afferent nerve fibres and the lemniscal pathways while TT and LEPs were used to assess small-diameter afferent nerve fibres and the spinothalamic tract. In addition, patients with peripheral neuropathy underwent also standard nerve conduction studies to explore large fibres and the recording of sympathetic skin responses (SSRs) to explore small fibres, whereas motor evoked potentials were performed in patients with spinal cord lesion. LEPs were absent bilaterally in all patients with polyneuropathy, even when TT remained within the normal limits and SSRs were present. LEPs were absent after stimulation of the affected limb in all patients with a spinal cord lesion, and allowed to detect subclinical contralateral lesion in two cases. LEPs following Nd:YAG laser stimulation are sensitive in the diagnosis of peripheral and/or central nervous system disorders and they give complementary information as compared to routine electrophysiological tests.

Afferent pathways of sympathetic skin response in spinal cord: a clinical and electrophysiological study

Background: Sympathetic skin response (SSR) recording is an established test of sudomotor autonomic functions. However, knowledge of its pathways in spinal cord is putative. Objective: This study involved subjects with isolated spinal cord lesions to evaluate the afferent pathways of SSR. Methods: Clinical examination was done according to standard neurological classification of spinal cord injury. Electrophysiological evaluation included: (1) conventional nerve conduction studies to exclude peripheral nerve lesions, (2) scalp somato-sensory-evoked potentials (SEP) with posterior tibial nerve (PTN) stimulation and (3) SSR recording from palm by stimulating supra orbital nerve (SON) at forehead, and PTN at ankle. Subjects with absent SSR in palm to SON stimulation were excluded. In such patients, the afferent tracts were considered abnormal when SSR was absent in palm on stimulation of PTN. Results: Among 37 subjects (age—28.1±12.8 years), the afferent tracts of SSR were affected in 13. Sparing of afferent SSR tracts correlated with preservation of bladder sensations ( P<0.01). There was no correlation between SSR and SEP. Conclusions: Spinal cord lesions frequently involve afferent tracts of SSR. Spinal afferents of SSR are closely related with tracts of bladder sensations and are different from pathways for SEP.

Die sympathische Hautreaktion (SSR) - Eine elektrophysiologische Methode zur Erfassung von Sympathikusläsionen

The sympathetic skin response (SSR), also known as electrodermal activity (EDA), can be used to quantitatively determine type and extent of damage in the autonomic nervous system. Three electrical and three acoustical stimuli are used to simultaneously obtain bilateral SSRs from both hands and feet (Fig. 2 and 3). Latencies and amplitudes for normal subjects are provided in Tables 1 and 2. Recording of SSRs may be of diagnostic value in polyneuropathies, diseases of the spinal cord, multiple sclerosis, Parkinson's disease and disturbances of consciousness and vigilance.

Modulation of cerebral cortex in acupuncture stimulation: a study using sympathetic skin response and somatosensory evoked potentials.

Although acupuncture has been widely used for treating disorders, its therapeutic mechanism remains unclear. In order to study the physiological mechanism of acupuncture stimulation, both palm recordings of sympathetic skin response (SSR) were evoked by electrical stimulation of the right median nerve on 13 normal adult volunteers. Median nerve evoked short-latency somatosensory evoked potential (SEPs) recordings were taken at least one week after SSR recording. The latencies and amplitudes were calculated. N13 component was obtained from Cv7, and N20 and P25 were from somatosensory cortex. The control did not receive acupuncture stimulation. Acupuncture needles were inserted into both Zusanli (St-36) acupoints as follows: 1) manual acupuncture (MA): using fingers to twist the acupuncture needle until so-called Der-Qi was obtained, 2) 2 Hz electroacupuncture (EA): 2 Hz square-wave electrical pulses were applied between the Zusanli needle and the Shangjuxu (St-37) needle bilaterally. Our results indicated that the mean latencies of SSR were largest during 2 Hz EA followed by MA stimulation, whereas the period of control exhibited the shortest mean latencies. In contrast, the mean amplitudes of SSR were smallest during the period of 2Hz EA, followed by the period of MA, and the period of control exhibited the largest mean amplitudes of SSR. The latencies of N13, N20 and P25 remained unchanged, but the amplitudes of P25 were largest during the period of 2Hz EA, followed by the period of MA; the period of control exhibited the smallest mean amplitudes of SEPs. The results suggest that acupuncture stimulation of both Zusanli acupoints inhibited SSR, which implies that the cerebral cortex contributed at least in part to this inhibition. The stimulation effect of 2Hz EA is stronger than MA.

The Value of Sympathetic Skin Response Recordings in the Assessment of the Vesicourethral Autonomic Nervous Dysfunction in Spinal Cord Injured Patients

The Value of Sympathetic Skin Response Recordings in the Assessment of the Vesicourethral Autonomic Nervous Dysfunction in Spinal Cord Injured Patients