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System Dysfunction (system + dysfunction)

Distribution by Scientific Domains
Medical Sciences88%
Distribution within Medical Sciences
Neurology19%
Gastroenterology & Hepatology12%
8 Other Subdomains45%

Kinds of System Dysfunction

  • autonomic nervous system dysfunction
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  • nervous system dysfunction
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    Selected Abstracts

    Serum concentrations of high-mobility group box chromosomal protein 1 before and after exposure to the surgical stress of thoracic esophagectomy: a predictor of clinical course after surgery?

    DISEASES OF THE ESOPHAGUS, Issue 1 2006
    K. Suda
    SUMMARY., High-mobility group box chromosomal protein 1 (HMGB-1) has recently been shown as an important late mediator of endotoxin shock, intra-abdominal sepsis, and acute lung injury. However, its role in the systemic inflammatory response syndrome after major surgical stress, which may lead to multiple organ dysfunction syndrome, has not been thoroughly investigated. We hypothesized that serum HMGB-1 participates in the pathogenesis of postoperative organ system dysfunction after exposure to major surgical stress. A prospective clinical study was performed to consecutive patients (n = 24) with carcinoma of the thoracic esophagus who underwent transthoracic esophagectomy with three field lymph node resection between 1998 and 2003 at Keio University Hospital, Japan. Serum HMGB-1 concentrations were measured by enzyme-linked immunosorbent assay. Preoperative serum HMGB-1 levels correlated with postoperative duration of SIRS, mechanical ventilation, and intensive care unit stay. Three of the 24 patients had serious postoperative complications: sepsis in two, and acute lung injury in one. Serum HMGB-1 levels in patients without complications increased within the first 24 h postoperatively, remained high during postoperative days 2,3, and then decreased gradually by postoperative day 7. In patients with serious complications, serum HMGB-1 was significantly higher than that found in patients without postoperative complications at every time point except postoperative day 2. Preoperative serum HMGB-1 concentration seems to be an important predictor of the postoperative clinical course. Transthoracic esophagectomy induces an increase in HMGB-1 in serum even in patients without complications. Postoperative serum HMGB-1 concentrations were higher in patients who developed complications, and may be a predictive marker for complications in this setting. [source]

    Migraine: A Chronic Sympathetic Nervous System Disorder

    HEADACHE, Issue 1 2004
    Stephen J. Peroutka MD
    Objective.,To determine the degree of diagnostic and clinical similarity between chronic sympathetic nervous system disorders and migraine. Background.,Migraine is an episodic syndrome consisting of a variety of clinical features that result from dysfunction of the sympathetic nervous system. During headache-free periods, migraineurs have a reduction in sympathetic function compared to nonmigraineurs. Sympathetic nervous system dysfunction is also the major feature of rare neurological disorders such as pure autonomic failure and multiple system atrophy. There are no known reports in the medical literature, however, comparing sympathetic nervous system function in individuals with migraine, pure autonomic failure, and multiple system atrophy. Methods.,A detailed review of the literature was performed to compare the results of a wide variety of diagnostic tests and clinical signs that have been described in these 3 heretofore unrelated disorders. Results.,The data indicate that migraine shares significant diagnostic and clinical features with both pure autonomic failure and multiple system atrophy, yet represents a distinct subtype of chronic sympathetic dysfunction. Migraine is most similar to pure autonomic failure in terms of reduced supine plasma norepinephrine levels, peripheral adrenergic receptor supersensitivity, and clinical symptomatology directly related to sympathetic nervous system dysfunction. The peripheral sympathetic nervous system dysfunction is much more severe in pure autonomic failure than in migraine. Migraine differs from both pure autonomic failure and multiple system atrophy in that migraineurs retain the ability, although suboptimal, to increase plasma norepinephrine levels following physiological stressors. Conclusions.,The major finding of the present study is that migraine is a disorder of chronic sympathetic dysfunction, sharing many diagnostic and clinical characteristics with pure autonomic failure and multiple system atrophy. However, the sympathetic nervous system dysfunction in migraine differs from pure autonomic failure and multiple system atrophy in that occurs in an anatomically intact system. It is proposed that the sympathetic dysfunction in migraine relates to an imbalance of sympathetic co-transmitters. Specifically, it is suggested that a migraine attack is characterized by a relative depletion of sympathetic norepinephrine stores in conjunction with an increase in the release of other sympathetic cotransmitters such as dopamine, prostaglandins, adenosine triphosphate, and adenosine. An enhanced understanding of the sympathetic dysfunction in migraine may help to more effectively diagnose, prevent, and/or treat migraine and other types of headache. [source]

    Association between serotonin transporter gene polymorphism and eating disorders: A meta-analytic study

    INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 6 2010
    Yu Lee MD
    Abstract Objective Compelling evidence has suggested a role for serotonin system dysfunction in the pathogenesis of eating disorders (EDs), including anorexia nervosa (AN) and bulimia nervosa (BN). Studies have examined the association between EDs and a functional polymorphism of the serotonin transporter gene promoter (5-HTTLPR). These studies have yielded inconsistent results. The present study aimed to determine conclusively whether there is an association by using a meta-analytic method. Method Data of over 2,000 participants from eight independent case,controlassociation studies were pooled by using a random effects model. Results AN was found to be significantly associated with the S allele (p < .001) and S carrier (SS + LS) genotype (p = .007). However, BN was associated neither with the S allele (p = .49) nor with the S carrier genotype (p = .33). Discussion These results suggested that the genetic variance of the serotonin transporter gene promoter contributed to the susceptibility of AN. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010; 43:498,504 [source]

    Sinusoidal heart rate pattern: Reappraisal of its definition and clinical significance

    JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 3 2004
    Houchang D. Modanlou
    Abstract Objectives: To address the clinical significance of sinusoidal heart rate (SHR) pattern and review its occurrence, define its characteristics, and explain its physiopathology. Background: In 1972, Manseau et al. and Kubli et al. described an undulating wave form alternating with a flat or smooth baseline fetal heart rate (FHR) in severely affected, Rh-sensitized and dying fetuses. This FHR pattern was called ,sinusoidal' because of its sine waveform. Subsequently, Modanlou et al. described SHR pattern associated with fetal to maternal hemorrhage causing severe fetal anemia and hydrops fetalis. Both Manseau et al. and Kubli et al. stated that this particular FHR pattern, whatever its pathogenesis, was an extremely significant finding that implied severe fetal jeopardy and impending fetal death. Undulating FHR pattern: Undulating FHR pattern may be due to the following: (1) true SHR pattern; (2) drugs; (3) pre-mortem FHR pattern; (4) pseudo-SHR pattern; and (5) equivocal FHR patterns. Fetal conditions associated with SHR pattern: SHR pattern has been reported with the following fetal conditions: (1) severe fetal anemia of several etiologies; (2) effects of drugs, particularly narcotics; (3) fetal asphyxia/hypoxia; (4) fetal infection; (5) fetal cardiac anomalies; (6) fetal sleep cycles; and (7) sucking and rhythmic movements of fetal mouth. Definition of true SHR pattern: Modanlou and Freeman proposed the following definition for the interpretation of true SHR pattern: (a) stable baseline FHR of 120,160 bpm; (b) amplitude of 5,15 bpm, rarely greater; (c) frequency of 2,5 cycles per minute; (d) fixed or flat short-term variability; (e) oscillation of the sinusoidal wave from above and below a baseline; and (f) no areas of normal FHR variability or reactivity. Physiopathology: Since its early recognition, the physiopathology of SHR became a matter of debate. Murata et al. noted a rise of arginine vasopressin levels in the blood of posthemorrhagic/anemic fetal lamb. Further works by the same authors revealed that with chemical or surgical vagotomy, arginine vasopressin infusion produced SHR pattern, thus providing the role of autonomic nervous system dysfunction combined with the increase in arginine vasopressin as the etiology. Conclusion: SHR is a rare occurrence. A true SHR is an ominous sign of fetal jeopardy needing immediate intervention. The correct diagnosis of true SHR pattern should also include fetal biophysical profile and the absence of drugs such as narcotics. [source]

    Endocannabinoid control of gastric sensorimotor function in man

    ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 10 2010
    K. AMELOOT
    Aliment Pharmacol Ther,31, 1123,1131 Summary Background, Little is known about the physiological role of the endocannabinoid system in the regulation of the motility and the sensitivity of the stomach. Endocannabinoid system dysfunction has been hypothesized to contribute to the control of food intake and the pathogenesis of functional dyspepsia. Aim, To study the influence of rimonabant, the endocannabinoid 1 (CB1) receptor antagonist, on gastric sensorimotor function in healthy controls. Methods, After 4 days of pre-treatment with rimonabant 20 mg/day or placebo, 12 healthy volunteers (mean age 34 ± 12 years, six men) participated in a placebo-controlled, double-blind, randomized, crossover study with a gastric barostat assessment of gastric sensitivity to distension, gastric compliance, gastric accommodation and phasic motility on day 3 and a liquid nutrient challenge test on day 4. Results, Rimonabant did not influence gastric compliance and sensitivity to distension. The meal-induced gastric accommodation reflex was significantly inhibited by rimonabant (154.3 ± 30.9 vs. 64.3 ± 32.4 mL, P = 0.02). Rimonabant did not affect maximal nutrient tolerance or meal-related symptoms during the satiety drinking test. Conclusion, Endocannabinoids acting on the CB1 receptor are involved in the control of gastric accommodation in man. [source]

    Morvan's syndrome: Clinical, laboratory, and in vitro electrophysiological studies

    MUSCLE AND NERVE, Issue 2 2004
    Wolfgang N. Löscher MD
    Abstract Morvan's syndrome is a rare disorder characterized by neuromyotonia, hyperhidrosis, and central nervous system dysfunction. We report a patient with features of this syndrome, but who initially presented with breathing difficulties. Concentric needle electromyography showed an abundance of myokymic and neuromyotonic discharges. Exercise tests and repetitive nerve stimulation showed a decrement,increment response of compound muscle action potentials. Antibodies against voltage-gated potassium channels were not detected on repeated testing, but the presence of oligoclonal bands in the cerebrospinal fluid (CSF) suggested an autoimmune etiology. At follow-up over 3 years, no cancer was found. Electrophysiological in vitro studies of effects of patient serum and CSF on rat nerves provided no evidence of altered voltage-gated sodium or potassium conductances. We conclude that putative humoral factors do not block ion channels acutely but may cause channel dysfunction with chronic exposure. Muscle Nerve 30: 157,163, 2004 [source]

    Vagal dysfunction in irritable bowel syndrome assessed by rectal distension and baroreceptor sensitivity

    NEUROGASTROENTEROLOGY & MOTILITY, Issue 4 2008
    R. Spaziani
    Abstract, Autonomic nervous system dysfunction has been implicated in the pathophysiology of irritable bowel syndrome (IBS). This study characterized the autonomic response to rectal distension in IBS using baroreceptor sensitivity (BRS), a measure of autonomic function. Rectal bag pressure, discomfort, pain, ECG, blood pressure and BRS were continuously measured before, during and after rectal distension in 98 healthy volunteers (34 ± 12 years old, 52 females) and 39 IBS patients (39 ± 11 years old, 35 females). In comparison with the healthy volunteers, IBS patients experienced significantly more discomfort (69 ± 2.2% vs 56 ± 3.6%; P < 0.05), but not pain (9 ± 1.4% vs 6 ± 2.4%; ns) with rectal distension despite similar distension pressures (51 ± 1.4 vs 54 ± 2.4 mmHg; ns) and volumes (394 ± 10.9 vs 398 ± 21.5 mL; ns). With rectal distension, heart rate increased in both healthy volunteers (66 ± 1 to 71 ± 1 bpm; P < 0.05) and IBS patients (66 ± 2 to 74 ± 3 bpm; P < 0.05). Systolic blood pressure also increased in both healthy volunteers (121 ± 2 to 143 ± 2 mmHg; P < 0.05) and patients (126 ± 3 to 153 ± 4 mmHg (P < 0.05) as did diastolic blood pressure, 66 ± 2 to 80 ± 2 mmHg (P < 0.05), compared with 68 ± 3 to 84 ± 3 mmHg (P < 0.05) in IBS patients. The systolic blood pressure increase observed in IBS patients was greater than that seen in healthy volunteers and remained elevated in the post distension period (139 ± 3 mmHg vs 129 ± 2 mmHg; P < 0.05). IBS patients had lower BRS (7.85 ± 0.4 ms mmHg,1) compared with healthy volunteers (9.4 ± 0.3; P < 0.05) at rest and throughout rectal distension. Greater systolic blood pressure response to rectal distension and associated diminished BRS suggests a compromise of the autonomic nervous system in IBS patients. [source]

    Heart Rate Turbulence Impairment and Ventricular Arrhythmias in Patients with Systemic Sclerosis

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2010
    PIOTR BIENIAS M.D., Ph.D.
    Background:,Arrhythmias, conduction disturbances, and cardiac autonomic nervous system dysfunction are the most frequent cardiovascular complications in systemic sclerosis (scleroderma). The aim of the study was to assess heart rate turbulence (HRT) in systemic sclerosis patients and to identify the relationship between HRT and occurrence of arrhythmias. Methods:,Forty-five patients with scleroderma (aged 54.6 ± 14.7 years) and 30 healthy sex- and age-matched subjects were examined. In addition to routine studies, 24-hour Holter monitoring with assessment of HRT was performed. Results:,As compared to controls, HRT was significantly impaired in systemic sclerosis patients. Abnormal HRT defined as turbulence onset (TO) ,0.0% and/or turbulence slope (TS) ,2.5 ms/RR (ms/RR interval) was found in 19 (42%) scleroderma patients and in no members of the control group. Serious ventricular arrhythmias Lown class IV (VA-LownIV), for example, couplets and/or nonsustained ventricular tachycardias, were observed in 16 (36%) scleroderma patients. The median value of TS was significantly lower in systemic sclerosis patients with VA-LownIV than in patients without VA-LownIV (3.68 vs 7.00 ms/RR, P = 0.02). The area under curve of ROC analysis for prediction of VA-LownIV was 0.72 (95% confidence interval [CI] 0.56,0.87) and revealed that TS <9.0 ms/RR was associated with VA-Lown IV occurrence, with sensitivity of 93.7% and specificity of 44.8%. Univariate and multivariate analyses confirmed that lower values of TS were associated with VA-LownIV occurrence (odds ratio 1.52, 95% CI 1.09,2.12, P = 0.01). Conclusions:,Patients with systemic sclerosis are characterized by significant HRT impairment. Assessment of HRT and especially TS is useful in the identification of patients at risk for ventricular arrhythmias. (PACE 2010; 920,928) [source]

    Pulmonary hypertension does not affect the autonomic nervous system dysfunction of sickle cell disease

    AMERICAN JOURNAL OF HEMATOLOGY, Issue 5 2009
    Jocelyn Inamo
    No abstract is available for this article. [source]

    Autonomic Nervous System Evaluation of Patients With Vasomotor Rhinitis ,

    THE LARYNGOSCOPE, Issue 11 2000
    Safwan S. Jaradeh MD
    Abstract Objective To demonstrate the utility of quantitative neurological laboratory testing of autonomic nervous system dysfunction and to apply this methodology to further study the relation of chronic vasomotor (nonallergic) rhinitis to the autonomic nervous system. Methods It has been suspected that vasomotor rhinitis is due either to a hyperactive parasympathetic nervous system or an imbalance between it and the sympathetic nervous system. The exact relation has not been determined. Recently neurological laboratories have been developed in which a battery of tests can be performed to determine reactivity of the autonomic nervous system. Results Autonomic nervous system testing was performed on 19 patients with symptoms fulfilling the diagnostic criteria for vasomotor rhinitis and the results were compared with 75 sex- and age-matched control subjects. Patients with vasomotor rhinitis had significant abnormalities of their sudomotor, cardiovagal, and adrenergic subscores. Their composite autonomic scale score was significantly impaired at 2.43, as compared with 0.11 for controls (P < .005). Conclusion Autonomic nervous system dysfunction is significant in patients with vasomotor rhinitis. Possible factors that trigger this dysfunction including nasal trauma and extraesophageal manifestations of gastroesophageal reflux are discussed. [source]

    Dysautonomia in human T-cell lymphotrophic virus type I-associated myelopathy/tropical spastic paraparesis

    ANNALS OF NEUROLOGY, Issue 5 2001
    Alexandre H. Alamy MD
    The frequency and importance of dysautonomia in human T-cell lymphotrophic virus type I,associated myelopathy/tropical spastic paraparesis (HAM/TSP) have not been fully investigated. We describe the characteristics of dysautonomia in such patients in a case-control study. Our results indicate that autonomic disturbances are more frequent in HAM/TSP than has been previously suggested, with a predominance of sympathetic nervous system dysfunction. In some of these patients, the symptoms may be severe enough to warrant specific treatment. [source]

    Original Article: Audit of severe acute maternal morbidity describing reasons for transfer and potential preventability of admissions to ICU

    AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 4 2010
    Beverley A. LAWTON
    Background:, Maternal mortality is a rare event in the developed world. Assessment of severe acute maternal morbidity (SAMM) is therefore an appropriate measure of the quality of maternity care. Aims:, The aim of the study was to conduct a retrospective audit of SAMM cases (pregnant women admitted to a New Zealand Intensive Care Unit) to describe clinical, socio-demographic characteristics, pregnancy outcomes and preventability. Methods:, Severe acute maternal morbidity cases were reviewed by a multidisciplinary panel to determine reasons for admission to ICU, to classify organ-system dysfunction and to determine whether the SAMM case was preventable or not. Inclusion criteria were: admission to ICU between 2005 and 2007 during pregnancy or within 42 days of delivery. Results:, Twenty-nine SAMM cases were reviewed, of which 10 (35%) were deemed preventable. The most common reasons for transfer to ICU were: the need for invasive vascular monitoring, hypotension and disseminated intravascular coagulation. The most frequent types of preventable events were: inadequate diagnosis/recognition of high-risk status, inappropriate treatment, communication problems and inadequate documentation. All five SAMM cases of septicaemia were deemed preventable. Of the ten preventable cases, three were Maori (50% of the Maori in total audit), four were Pacific (67% of the Pacific in total audit) and three were women of ,other' ethnicities (17.6%, 3 of 17 in the audit). Conclusions:, An audit of SAMM cases describing reasons for transfer to ICU and preventability is feasible. We recommend that a prospective national SAMM audit process be introduced in New Zealand as a quality of care measure. [source]

    Self,other relations in social development and autism: multiple roles for mirror neurons and other brain bases

    AUTISM RESEARCH, Issue 2 2008
    Justin H.G. Williams
    Abstract Mirror neuron system dysfunction may underlie a self,other matching impairment, which has previously been suggested to account for autism. Embodied Cognition Theory, which proposes that action provides a foundation for cognition has lent further credence to these ideas. The hypotheses of a self,other matching deficit and impaired mirror neuron function in autism have now been well supported by studies employing a range of methodologies. However, underlying mechanisms require further exploration to explain how mirror neurons may be involved in attentional and mentalizing processes. Impairments in self,other matching and mirror neuron function are not necessarily inextricably linked and it seems possible that different sub-populations of mirror neurons, located in several regions, contribute differentially to social cognitive functions. It is hypothesized that mirror neuron coding for action,direction may be required for developing attentional sensitivity to self-directed actions, and consequently for person-oriented, stimulus-driven attention. Mirror neuron networks may vary for different types of social learning such as "automatic" imitation and imitation learning. Imitation learning may be more reliant on self,other comparison processes (based on mirror neurons) that identify differences as well as similarities between actions. Differential connectivity with the amygdala,orbitofrontal system may also be important. This could have implications for developing "theory of mind," with intentional self,other comparison being relevant to meta-representational abilities, and "automatic" imitation being more relevant to empathy. While it seems clear that autism is associated with impaired development of embodied aspects of cognition, the ways that mirror neurons contribute to these brain,behavior links are likely to be complex. [source]

    Bringing the brain into the test tube: an experiment illustrating the effect of ethanol on nerve terminal viability

    BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 3 2001
    Rodrigo A. Cunha
    Abstract Ethanol is primarily responsible for the behavioural effects of acute alcoholic beverage consumption, which involves central nervous system dysfunction. The mechanisms of ethanol action in the nervous system are poorly understood, particularly those related to the neurotoxicity of high acute ethanol consumption. We now describe a simple experiment showing that a concentration of ethanol, which is reached in the plasma after high acute ethanol intake, disrupts rat brain nerve terminals, as measured by the release of lactate dehydrogenase. This cytolytic action of ethanol was further enhanced upon depolarisation of the nerve terminals suggesting that the mechanism of action of ethanol might not be related to modification of lipid bilayer properties. © 2001 IUBMB. Published by Elsevier Science Ltd. All rights reserved. [source]

    4341: Are visual evoked potentials and pattern ERG useful in neuro-ophthalmology?

    ACTA OPHTHALMOLOGICA, Issue 2010
    GE HOLDER
    Purpose To describe the roles of VEP and PERG in clinical neuroophthalmology. Methods Case based examples. Results Objective visual system testing with electrophysiology allows the distinction between optic nerve and macular dysfunction, often difficult in clinical practice. Examples will be shown of the types of VEP abnormality that can occur in different disorders of optic nerve function. PERG should also be performed in the patient with visual symptoms; if the PERG suggests macular dysfunction, full-field ERG is indicated in order to determine whether that macular dysfunction is part of a generalised retinal process or is dysfunction localised to the macula. Electrophysiology further allows the diagnosis of non-organic visual loss and the quantification of visual system dysfunction. Conclusion The objective functional assessment with electrophysiology is an important part of the diagnostic armamentarium available to neuroophthalmologists. [source]

    The effect of ageing on macrophage Toll-like receptor-mediated responses in the fight against pathogens

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2010
    C. R. Dunston
    Summary The cellular changes during ageing are incompletely understood yet immune system dysfunction is implicated in the age-related decline in health. The acquired immune system shows a functional decline in ability to respond to new pathogens whereas serum levels of cytokines are elevated with age. Despite these age-associated increases in circulating cytokines, the function of aged macrophages is decreased. Pathogen-associated molecular pattern receptors such as Toll-like receptors (TLRs) are vital in the response of macrophages to pathological stimuli. Here we review the evidence for defective TLR signalling in normal ageing. Gene transcription, protein expression and cell surface expression of members of the TLR family of receptors and co-effector molecules do not show a consistent age-dependent change across model systems. However, there is evidence for impaired downstream signalling events, including inhibition of positive and activation of negative modulators of TLR induced signalling events. In this paper we hypothesize that despite a poor inflammatory response via TLR activation, the ineffective clearance of pathogens by macrophages increases the duration of their activation and contributes to perpetuation of inflammatory responses and ageing. [source]

    The effect of vestibular nerve section upon tinnitus

    CLINICAL OTOLARYNGOLOGY, Issue 4 2002
    D.M. Baguley
    This paper reviews the published evidence regarding the effect of vestibular nerve section upon tinnitus. This is of relevance not only for those performing and undergoing this procedure, but also for those considering the hypothesis that auditory efferent system dysfunction may be influential in tinnitus perception. The auditory medial efferent fibres within the internal auditory canal run within the inferior vestibular nerve, only joining the cochlear nerve at the anastomosis of Oort, a bundle of 1300 fibres running from the saccular branch of the inferior vestibular nerve to the cochlear nerve. Vestibular nerve section procedures therefore section this efferent olivocochlear pathway, and ablate efferent influence upon that cochlear. If auditory efferent dysfunction is involved in tinnitus perception, this ablation might influence the tinnitus status of that patient. A literature search identified 18 papers mentioning tinnitus status after vestibular nerve section, describing the experiences of a total of 1318 patients. The proportion of patients in whom tinnitus was said to be exacerbated postoperatively ranged from 0% to 60%, with a mean of 16.4% (standard deviation 14.0). The proportion of patients in whom tinnitus was unchanged was 17% to 72% (mean 38.5%, standard deviation 15.6), and in whom tinnitus was said to be improved was 6% to 61% (mean 37.2%, standard deviation 15.2). In the majority of patients undergoing this procedure, ablation of auditory efferent input (and thus total efferent dysfunction) to the cochlea was not associated with an exacerbation of tinnitus. The finding of this review is that efferent dysfunction after vestibular nerve section does not consistently worsen tinnitus. [source]