SEARCH · PubMed Health

Results for “Autonomic dysfunction”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources

PubMed1991

[Pupillometry in Menière's disease].

The autonomic dysfunction is one of the etiopathogenetic hypothesis of Ménière's disease. We have already described the presence of an anomalous pupillary contraction, induced by methacholine, during the attack stage of Ménière's disease, without cardio-vascular reflexes involving. We have now employed, in a larger number of cases, a new digital equipment with infrared lighting system, built by us. The pupillary area was measured in darkness by a personal computer in basal condition (time 0) and 10, 20, 30, 45, 60 minutes after methacholine instillation. We have observed 16 cases of Ménière's disease (during attack stage and free stage), 23 cases of other vertiginous disorders (during attack stage and free strage), 10 normal subjects (5 cases of these also during a caloric test). The pupillary contraction was always highest at 30 minutes after methacholine administration. Normal subjects didn't show anisocoria and the contraction was weak and symmetric. Caloric test modified only a little the pupillary response. We observed the same results in other vertiginous disorders. During free stage of Ménière's disease there was little basal anisocoria but the contraction was normal and symmetric. During attack stage of Ménière's disease the contraction was much more evident and higher on the affected side. Ménière's disease crisis is characterized by cholinergic pupillary hyperreactivity, that is not caused by labyrinthic reflexes. We suppose this autonomic dysfunction of central origin.

Autonomic Nervous System Diseases↗

PubMed2003

Allgrove or 4 "A" syndrome: an autosomal recessive syndrome causing multisystem neurological disease.

Allgrove's or "4 A" syndrome is a rare autosomal recessive condition with alacrima, achalasia, autonomic disturbance, and ACTH insensitivity among other features. Recent studies have identified mutations in the AAAS, a candidate gene on chromosome 12q13 in such patients. Manifestations in adult patients are rarely reported. The syndrome usually presents during the first decade of life with dysphagia or severe (occasionally fatal) hypoglycaemic or hypotensive attacks, related to adrenocortical insufficiency. Onset of adrenal insufficiency or other features may be delayed to adulthood. In contrast with paediatric patients, adult patients with Allgrove's syndrome may present with multisystem neurological disease; the childhood history of achalasia or alacrima may be overlooked. The authors describe two families with two affected siblings and a further unrelated patient with typical clinical features of Allgrove's syndrome, who exhibit signs of multisystem neurological disease including hyperreflexia, muscle wasting, dysarthria, ataxia, optic atrophy, and intellectual impairment. None of the cases have developed adrenal insufficiency but all have progressive neurological disability. Autonomic dysfunction was a significant cause of morbidity in two cases. The three index cases represent the longest described follow up of Allgrove's syndrome into adulthood. It is speculated that they represent a subgroup of patients who follow an often undiagnosed chronic neurological course. Recognition of the syndrome presenting in adult life permits treatment of unrecognised autonomic dysfunction, adrenal insufficiency and dysphagia, and appropriate genetic advice.

Adrenal Cortex Diseases↗

PubMed2006

Hypoxemia and autonomic nervous dysfunction in patients with chronic obstructive pulmonary disease.

OBJECTIVE: Hypoxemia is known to be associated with abnormal heart rate variability (HRV) that can reflect the severity of the illness and may have prognostic value in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to examine the relationship between the derangements in cardiac autonomic nervous function and the oxygenation status or degree of airflow obstruction in COPD patients by using HRV analysis. METHODS: Thirty clinically stable COPD patients and 18 age-matched normal subjects were included in this study. The normalized high-frequency power (nHFP) and the low-/high-frequency power ratio (LFP/HFP) were used as indices of vagal activity and sympathovagal balance, respectively. RESULTS: Although global HRV measures were all significantly decreased, the nHFP and LFP/HFP of COPD patients were not significantly different from those of normal controls. There was a negative correlation between nHFP and arterial partial pressure of O2 (PaO2) and a positive correlation between LFP/HFP and PaO2 in COPD patients. No correlation existed between forced expiratory volume in 1.0 s/forced vital capacity (FEV1/FVC), % predicted of FEV1 (%FEV1) and nHFP or LFP/HFP in COPD patients. CONCLUSIONS: The resting autonomic nervous function of COPD patients is not different from that of normal controls. Though the degree of airway narrowing is not related to the cardiac autonomic nervous function, chronic hypoxemia can lead to enhanced cardiac vagal activity and depressed sympathetic activity in COPD patients. A worse oxygenation status is associated with increased cardiac vagal and decreased cardiac sympathetic activities in COPD patients.

Aged↗

PubMed1996

Assessment of baroreceptor-cardiac reflex sensitivity using time domain analysis in patients with IDDM and the relation to left ventricular mass index.

Autonomic dysfunction in insulin-dependent diabetic (IDDM) patients has been associated with abnormalities of left ventricular function and an increased risk of sudden death. A group of 30 patients with IDDM and 30 age, sex and blood pressure matched control subjects underwent traditional tests of autonomic function. In addition, baroreceptor-cardiac reflex sensitivity (BRS) was assessed using time domain (sequence) analysis of systolic blood pressure and pulse interval data recorded non-invasively using the Finapres beat-to-beat blood pressure recording system. 'Up BRS' sequences-increases in systolic blood pressure associated with lengthening of R-R interval, and 'down BRS' sequences-decreases in systolic blood pressure associated with shortening of R-R interval were identified and BRS calculated from the regression of systolic blood pressure on R-R interval for all sequences. We also assessed heart rate variability using power spectral analysis and, after expressing components of the spectrum in normalised units, assessed sympathovagal balance from the ratio of low to high frequency powers. IDDM subjects underwent 2-D echocardiography to assess left ventricular mass index. Standard tests of autonomic function revealed no differences between IDDM patients and control subjects, but dramatic reductions in baroreceptor-cardiac reflex sensitivity were detected in IDDM patients. 'Up BRS' when supine was 11.2 +/- 1.5 ms/mmHg (mean +/- SEM) compared with 20.4 +/- 1.95 in control subjects (p < 0.003) and when standing was 4.1 +/- 1.9 vs 7.6 +/- 2.7 ms/mmHg (p < 0.001). Down BRS when supine was 11.5 +/- 1.2 vs 22 +/- 2.6 (p < 0.001) and standing was 4.4 +/- 1.9 vs 7.3 +/- 2.5 ms/mmHg (p < 0.003). There were significant relations between impairment of the baroreflex and duration of diabetes (p < 0.001) and poor glycaemic control (p < 0.001). From a fast Fourier transformation of supine heart rate data and using a band width of 0.05-0.15 Hz as low-frequency and 0.2-0.35 Hz as high frequency total spectral power of R-R interval variability was significantly reduced in the IDDM group for both low-frequency (473 +/- 62.8 vs 746.6 +/- 77.6 ms2 p = 0.002) and high frequency bands 125.2 +/- 12.9 vs 459.3 +/- 89.8 ms2 p < 0.0001. When the absolute powers were expressed in normalised units the ratio of low frequency to high frequency power (a measure of sympathovagal balance) was significantly increased in the IDDM group (2.9 +/- 0.53 vs 4.6 +/- 0.55, p < 0.002 supine: 3.8 +/- 0.49 vs 6.6 +/- 0.55, p < 0.001 standing). Thus, time domain analysis of baroreceptor-cardiac reflex sensitivity detects autonomic dysfunction more frequently in IDDM patients than conventional tests. Impaired BRS is associated with an increased left ventricular mass index and this abnormality may have a role in the increased incidence of sudden death seen in young IDDM patients.

Adult↗

PubMed2003

[Efficacy of acupressure therapy in combined treatment of psycho-autonomic neurotic disorders in children].

The aim of the study was to evaluate the efficacy of acupuncture in combined treatment of psychoautonomic neurotic disorders in children. 163 children, mean age 12.5 years, were included in the study. Autonomic dysfunction score, clinoorthostatic test, sinocarotid test and heart rate variability analysis were used to assess the efficacy of different therapeutic strategies applied: complex (acupuncture + conventional drug treatment)--group 1; acupuncture treatment--group 2, and conventional drug treatment--group 3. After 2 months of treatment, a reduction of autonomic dysfunction score and an increase of percentage of patients with normal clinoorthostatic and sinocarotid tests were revealed in all the groups, being most evident in group 1. Heart rate spectral variability changed in patients given acupuncture treatment (groups 1 and 2). Relative augmentation of sympathetic activity was observed in patients with initial vagotonia, while those with initial symphaticotonia exhibited a relative parasympathetic activity increase. Thus, acupuncture exerts beneficial effects on functioning of autonomic nervous system. The method may be used either independently, or in addition to conventional drug treatment of psychoautonomic neurotic disorders in children.

Acupressure↗

PubMed1995

Cardiac autonomic function in obese patients.

OBJECTIVE: The aim of this work was to determine the presence and prevalence of alterations in cardiac autonomic function in obese, non-diabetic subjects. SUBJECTS: These were 121 obese people, 15 with glucose intolerance and none with diabetes, and a group of 40 healthy people. MEASUREMENTS: A series of five standardized tests was carried out, three of which were based mainly on parasympathetic control (heart rate response to Valsalva, deep breathing and lying-to-standing) and two on cardiovascular sympathetic function (blood pressure response to standing and to handgrip). RESULTS: The response to the deep breathing test correlated negatively with age, as it did in control subjects. At least one parasympathetic test, age-adjusted, was abnormal in 49 patients (40.5%). Five other patients had an abnormal handgrip test, and no patient had orthostatic hypotension. No correlation was found between the parasympathetic test results and sex or body mass index. Prevalence of cardiac autonomic dysfunction, considered to be present when at least one parasympathetic test was abnormal, did not differ according to a gynoid or android type of obesity. A significant negative correlation was found between heart rate response to deep breathing and fasting glycemia. CONCLUSION: It was concluded that cardiac autonomic dysfunction evidenced by means of simple, reliable, reproducible tests is frequent in the non-diabetic obese subject. This disorder could explain the poor cardiovascular prognosis associated with obesity. Whether it is a complication of obesity or a marker associated with certain kinds of obesity (of hypothalamic origin) remains to be clarified.

Adolescent↗

PubMed1982

Selective loss of small myelinated and unmyelinated fibers in Shy-Drager syndrome.

The number and sizes of myelinated and unmyelinated fibers in biopsied sural nerves in cases with Shy-Drager syndrome were studied in comparison with cases with olivopontocerebellar degeneration not having autonomic dysfunction. In Shy-Drager syndrome there was a tendency for both small myelinated and unmyelinated fiber densities to be reduced in comparison with cases with olivopontocerebellar degeneration. Unmyelinated fibers more than 0.5 micrometers in diameter were significantly reduced in Shy-Drager syndrome, a fact suggesting myelinated fiber degeneration. Multilamellated Schwann cell processes, isolated Schwann cell processes, and collagen pockets were more numerous and conspicuous in cases with Shy-Drager syndrome. It was concluded that unmyelinated fibers and small myelinated fibers in the peripheral nerves were involved selectively in Shy-Drager syndrome. The significance of the findings was discussed in terms of autonomic dysfunction observed clinically.

Aged↗

PubMed2003

[Prolonged Guillain-Barré syndrome].

Outcome in Guillain-Barré syndrome (GBS) in childhood is usually favorable although prolonged and severe forms may develop. We report the case of a 12-year-old boy with rapidly ascending, slowly-progressive GBS with severe cranial nerve and autonomic dysfunction. Diagnosis was based on clinical presentation, electromyography, cerebrospinal fluid analysis and plasmatic antiganglioside GM1 antibodies. Early treatment with an initial loading dose of 2 g/kg of intravenous gammaglobulins over 5 days was given with a significant but slow clinical improvement. A repeat infusion of gammaglobulins was given two months later. Response was satisfactory with motor, sensory and autonomic dysfunction recovery. A third course of immunoglobulins 28 days later produced little benefit. At the present time, 5 months after the onset of the disease, flaccid paralysis of the lower limbs and the distal portion of the upper limbs persists but autonomic instability has disappeared. The patient has been decannulated and is following an ambulatory rehabilitation program. Although repeated intravenous immunoglobulins may be useful in the treatment of prolonged GBS, the key issue is excellent intensive care unit management. Further research examining potentially more effective treatment such as beta-interferon and immunosuppressive agents is required.

Child↗

PubMed1994

Silent exertional myocardial ischemia in the elderly: a quantitative analysis of anginal perceptual threshold and the influence of autonomic function.

OBJECTIVE: To assess the perception of angina in the elderly and its relationship to autonomic function. DESIGN: Prospective cohort study of patients with exertional ischemia. SETTING: Medical, geriatric and cardiac outpatient clinics in two centers. PARTICIPANTS: All subjects had ischemic heart disease as evidenced by positive treadmill stress tests and, in some, diagnostic angiography and/or documented Q wave infarction. In the first study (I), 37 older patients (range 70-82 years) and 39 younger patients (range 42-59 years) were studied. In a subsequent study (II), a further 49 patients were divided into 2 groups: those with good perception of angina (Anginal Perception Threshold < 15 seconds, group A, 26 patients) and those with no angina despite ischemia (group B, 23 patients). MEASUREMENTS: Anginal perceptual threshold (APT), age, cardiovascular autonomic function, and blood pressure were measured. APT was defined as the time between onset of 1 mm ST depression to the onset of angina during treadmill stress testing. Autonomic function was studied using heart rate ratios before and after the valsalva maneuver, heart rate responses to deep breathing, and heart rate and blood pressure responses to standing. RESULTS: In study I, APT in the older patients was delayed by a median value of 49 seconds [79 (range 15-188) versus 30 (-99 to 97) seconds in the younger patients, P < 0.001]. There was no significant correlation between prolonged APT and autonomic dysfunction when younger and older groups were analyzed independently or together. When, however, the high APT subgroup (APT > 30 seconds) was analyzed separately, there was a significant correlation between APT prolongation and impaired valsalva response (r = -0.4; P < 0.005). In study II, 21 of 23 patients (91.3%) with positive exercise test but with no angina (group B) had at least one abnormal autonomic function test compared with 5 of 26 (19%) patients with good anginal perception (group A). Of note, group A was significantly younger than group B [60 (53-63) years vs 66 (62-70 years, P < 0.001]. CONCLUSION: Elevation of APT in the elderly suggests that warning of critical myocardial ischemia is delayed. Autonomic dysfunction may be one of the underlying mechanisms.

Adult↗

PubMed2000

Limits of the sympathetic skin response in patients with diabetic polyneuropathy.

We performed upper- and lower-limb sympathetic skin responses (SSRs) in a series of 337 diabetic patients with and without peripheral polyneuropathy and 38 reference subjects. We did not find any correlations between SSRs and symptoms of pain or autonomic dysfunction. The SSR correlated more strongly with vibration perception threshold (VPT) and sural nerve amplitude than with cooling detection threshold (CDT) or clinical symptoms. We conclude that current limitations inherent in SSR testing preclude its use as a reliable and consistent index of the autonomic dysfunction commonly encountered in diabetic patients.

Adolescent↗

PubMed2003

Autonomic nervous dysfunction in patients with liver cirrhosis using 123I-metaiodobenzylguanidine myocardial scintigraphy and spectrum analysis of heart-rate variability.

BACKGROUND: It has been reported that nitric oxide (NO) synthase is induced in patients with liver cirrhosis (LC), and that an excessive production of NO enhances sympathetic nervous function. The present report describes a study of the feasibility of evaluation of abnormalities of autonomic nervous function by 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy and heart-rate variability in patients with LC. METHODS: Low-frequency (LF) power, high-frequency (HF) power, LF/HF, and 1/f fluctuations of heart rate variability were examined in 50 patients with LC (LC group), and 50 normal subjects (N group). Echocardiogram, urinary nitrite and nitrate, and cathecholamines were examined. RESULTS: Fractional shortening was observed for the hyperdynamic state of patients in the LC group according to Child's A-C classification. Washout rate of MIBG, LF/HF, and blood levels of norepinephrine increased and HF power decreased with the progression of LC. However, the urinary secretion of nitrite and nitrate were significantly increased only in cirrhotic patients with Child C. CONCLUSIONS: The present results indicate that autonomic abnormalities appear early in LC, and that these abnormalities can be detected by MIBG myocardial scintigraphy and analysis of heart-rate variability. We consider these methods to be clinically useful for the quantitative detection of hyperdynamic circulation of liver cirrhosis.

3-Iodobenzylguanidine↗

PubMed2002

Review: small-fiber neuropathy.

BACKGROUND: Most peripheral neuropathies involve large as well as small-fiber dysfunction. A small subset of neuropathies present with restricted or predominant small-fiber involvement. REVIEW SUMMARY: In this review, we discuss the differential diagnosis, clinical presentation, evaluation, and treatment of small-fiber neuropathies. Although these neuropathies are rare, their differential diagnosis is broad, and includes many disorders, including metabolic, toxic, inflammatory, infectious, and genetic etiologies. As small fibers subserve pain and autonomic functions, these neuropathies usually present with pain and temperature loss, painful dysesthesias, autonomic dysfunction, or a combination. These neuropathies are especially challenging as nerve conductions and EMG, which help guide the evaluation of most peripheral neuropathies, may have normal findings in patients with small-fiber neuropathies. Other specialized studies, including tests of autonomic function, intraepidermal nerve fiber analysis, and quantitative sensory testing, are often required to confirm the presence of a small-fiber neuropathy. In some cases, the underlying etiology can be directly treated. In most, management is limited to symptomatic treatment of sensory and autonomic dysfunction. CONCLUSION: Small-fiber neuropathies are a heterogeneous group of disorders. They vary in etiologies and require special attention, as many disorders are rare and the differential diagnosis is broad. Evaluation is often extensive and may need pathologic specimen. Many patients respond to symptomatic therapy, but some are difficult to treat.

Journal Article↗

PubMed2005

Estrogen synthesis in the central nucleus of the amygdala following middle cerebral artery occlusion: role in modulating neurotransmission.

Stroke-induced lesions of the insular cortex in the brain have been linked to autonomic dysfunction (sympathoexcitation) leading to arrhythmogenesis and sudden cardiac death. In experimental models, systemic estrogen administration in male rats has been shown to reduce stroke-induced cell death in the insular cortex as well as prevent sympathoexcitation. The central nucleus of the amygdala has been postulated to mediate sympathoexcitatory output from the insular cortex. We therefore set out to determine if endogenous estrogen levels within the central nucleus of the amygdala are altered following stroke and if microinjection of estrogen into the central nucleus of the amygdala modulates autonomic tone. Plasma estrogen concentrations were not altered by middle cerebral artery occlusion (22.86+/-0.14 pg/ml vs. 21.24+/-0.33 pg/ml; P>0.05). In contrast, estrogen concentrations in the central nucleus of the amygdala increased significantly following middle cerebral artery occlusion (from 20.83+/-0.54 pg/ml to 76.67+/-1.59 pg/ml; P<0.05). Local infusion of an aromatase inhibitor, letrozole, into the central nucleus of the amygdala at the time of middle cerebral artery occlusion prevented the increase in estrogen concentration suggesting that this increase was dependent on aromatization from testosterone. Furthermore, bilateral microinjection of estrogen (0.5 microM in 200 nl) directly into the central nucleus of the amygdala significantly decreased arterial pressure and sympathetic tone and increased baroreflex sensitivity, and these effects were enhanced following co-injection with either an N-methyl-D-aspartate or non-N-methyl-D-aspartate receptor antagonist. Taken together, the results suggest that middle cerebral artery occlusion resulted in synthesis of estrogen within the central nucleus of the amygdala and that this enhanced estrogen level may act to attenuate overstimulation of central nucleus of the amygdala neurons to prevent middle cerebral artery occlusion-induced autonomic dysfunction.

Amygdala↗

PubMed2006

Postnatal hypokinesia and the delayed time frame of sudden infant death syndrome.

The sudden infant death syndrome peaks in the second and third month of life. This is the period of the "two-month transformation of the central nervous system" in the human infant. Studies of 120 days of imposed hypokinesia in man demonstrated that the maximum period of autonomic dysfunction was delayed until the beginning of the second month through to the fourth month of the experiment. Hypokinesia also impaired sleep mechanisms and induced polymorphic changes in almost all systems of the human body. These studies suggest that prolonged postnatal hypokinesia in infants may induce autonomic dysfunction in the CNS, especially during the "two-month transformation period" of major postnatal neural development.

Central Nervous System↗

PubMed1998

Effect of sertraline hydrochloride on dialysis hypotension.

Hemodialysis hypotension (HH) is a very common disorder and has a multifactorial etiology. Autonomic dysfunction occurs in up to 50% of patients with end-stage renal disease (ESRD) and plays a key role in HH in some patients. Sertraline hydrochloride, a central nervous system serotonin reuptake inhibitor, has been shown to be an effective treatment of hypotension caused by autonomic dysfunction in disorders such as neurocardiogenic syncope and idiopathic orthostatic hypotension. This study sought to determine whether sertraline was effective in ameliorating HH. A retrospective chart analysis was performed that included nine consecutive patients (aged > or = 54 years, time on hemodialysis > or = 2.2 years) placed on sertraline (50 to 100 mg/d) for depression who also had HH (defined as prehemodialysis systolic blood pressure [SBP] < or = 100 mm Hg, > or = 40 mm Hg decrease in SBP during hemodialysis, SBP <90 mm Hg, any diastolic blood pressure <40 mm Hg, or a decrease in blood pressure-causing symptoms) before treatment with sertraline. The data from a 6-week pre-sertraline period were compared with the data from a 6-week sertraline period (defined as 6 weeks after drug begun). Blood pressure medications were unchanged during the trial period of sertraline. However, nadir mean arterial pressure recorded during a given dialysis session in the pre-sertraline period (55+/-4 mm Hg) was significantly lower than that recorded in the sertraline period (68+/-5 mm Hg; P < 0.05). In addition, the number of hypotensive episodes (same definition as HH) per dialysis session during the sertraline period was significantly lower than that during the pre-sertraline period (mean, 0.6+/-0.2 episodes per session v 1.4+/-0.3 episodes per session; P < 0.005). The number of therapeutic interventions required for hypotension during the sertraline period was also significantly less than that during the pre-sertraline period (mean, 1.7+/-0.8 interventions v 11.0+/-3.0 interventions; P < 0.005). The urea reduction ratio (62.7%+/-4.7% v 63.1%+/-9.3%; P = NS) and hematocrit (28.9%+/-0.8% v 29.5%+/-1.0%; P = NS) did not change significantly. It is concluded that the short-term (6 weeks) use of sertraline hydrochloride reduces HH in some patients with ESRD. A possible mechanism for this effect is sertraline-induced attenuation of the paradoxical sympathetic withdrawal that may underlie HH in some patients with ESRD.

1-Naphthylamine↗

PubMed1989

Autonomic neuropathy and the pathogenesis of glaucoma in diabetes mellitus.

In order to determine whether ocular hypertension and glaucoma may be a complication of autonomic neuropathy in diabetes mellitus, 30 asymptomatic diabetic patient volunteers were studied. A correlation was sought between reduced anterior chamber depth which is thought to predispose to the development of glaucoma, and two markers of autonomic dysfunction, loss of sinus arrhythmia and reduced diameter of dark adapted pupils. A significant correlation was found between reduced chamber depth and pupil diameter arrhythmia (r = 0.36, p = 0.025) and between chamber depth and pupil diameter (r = 0.45, p = 0.006). As expected, there was also a significant correlation between sinus arrhythmia and pupil diameter (r = 0.68, p less than 0.001). The correlation between pupil diameter and sinus arrhythmia, and between pupil diameter and chamber depth was preserved after the data were adjusted for age (r = 0.54, p less than 0.001 and r = 0.35, p = 0.03, respectively), while that between sinus arrhythmia and chamber depth was lost (r = 0.23, NS). No association was found between intraocular pressure and either marker of autonomic dysfunction, but intraocular pressure was not abnormal (less than 22 mmHg) in any individual case. These data suggest that autonomic denervation of the eye in diabetes may be associated with alteration of anterior chamber depth.

Adult↗

PubMed1988

The effect of intracerebroventricular D-ALA2 methionine enkephalinamide and naloxone on cardiovascular parameters in the cat.

Lathers and Schraeder (1) have shown that autonomic dysfunction is associated with epileptogenic activity induced by pentylenetetrazol while Vindrola et al (2) found increased D-ALA2 methionine-enkephalinamide (DAME) levels in the rat brain after pentylenetetrazol-induced epileptogenic activity. Thus, this study was designed to determine whether DAME could have contributed, at least in part, to the autonomic dysfunction associated with pentylenetetrazol-induced epileptogenic activity in the study of Lathers and Schraeder (1). DAME (500 micrograms/kg, icv) was given to 9 cats anesthetized with alpha chloralose. Epileptogenic activity and hypotension occurred in all cats (maximum fall ranging from 6 to 46 mmHg; duration of 6 to 35 min). In 6 cats the heart rate decreased, in 2 it increased, and in 1 it showed little or no change. The duration of heart rate changes varied from 18 to 76 min. Naloxone (100 micrograms/kg, iv) was given to 6 cats after DAME. Naloxone suppressed or abolished the epileptogenic activity in all 6 cats, reversed the DAME-induced hypotension and increased the heart rate in 3 cats, decreased it in 2, and produced no change in 1. These results indicate that DAME may produce epileptogenic activity and cardiovascular changes through an action on central opiate receptors. It is hypothesized that: 1) increased levels of DAME inhibit the release of gamma aminobutyric acid; 2) this then increases vagal bradycardia and hypotension; and 3) step 2 causes an imbalance in peripheral autonomic cardiac neural discharge which may cause arrhythmias and/or sudden unexplained death in the epileptic person.

Animals↗

PubMed2005

[Cardiovascular events in the course of tetanus: a prospective study on 30 cases in the infectious diseases clinic, in the Fann teaching hospital, Dakar].

OBJECTIVES: This prospective study had for aim to determine the frequency and characteristics of cardiovascular events in the course of tetanus. PATIENTS AND METHODS: From September to December 2002, we studied all patients over 4 years of age presenting with tetanus without any documented underlying disease. RESULTS: Thirty cases were included (mean age 36+/-20 years; sex-ratio 2.3). Seventy-three per cent had a mild-gravity tetanus (stage II of Mollaret) upon admission. One hundred and seventeen ECG were recorded and 93.3% of the patients had more than one abnormality: arrhythmia (24 cases), prolonged QT interval (23 cases), ventricular hypertrophia (17 cases), and atrial hypertrophia (4 cases) especially left (3 cases), failure of AV conduction (3 cases), ST segment depression (3 cases), left and right axis deviation (3 cases), baseline undulation (3 cases) and repolarization disturbances (1 case). All patients had a normal Doppler echocardiographic examination. The mean hospitalization stay was 11.6+/-1.4 days and complications were noted in 60%; sinus tachycardia in apyrexia (5 cases), instable BP (5 cases), excessive sweatiness in apyrexia (1 case), and access of bradycardia with sudden cardiac arrest (2 cases). 8 patients died (26.7%). Six patients with cardiac autonomic dysfunction died, the case fatality rate being statistically higher in this group (P=0.007). A prolonged QT interval, sinus tachycardia and left ventricular hypertrophia were statistically more frequent at the acute phase of the illness. CONCLUSION: The case fatality rate of tetanus is still high, due among others to autonomic dysfunctions.

Adolescent↗