In vitro susceptibility of Brazilian Pythium insidiosum isolates to essential oils of some Lamiaceae family species.

The present study aimed to evaluate the in vitro antimicrobial action of Origanum vulgare, Origanum majorana, Mentha piperita and Rosmarinus officinalis on Pythium insidiosum oomycete zoospores. The antimicrobial activity evaluation was performed by the broth microdilution method according to CSLI M38-A2 documentation adapted to phytopharmaceuticals. Twenty-two P. insidiosum isolates were evaluated, and the minimum inhibitory concentration was determined at 100% growth inhibition. All P. insidiosum isolates evaluated showed a minimum inhibitory concentration ranging from 0.05 to 1.75 mg/mL when O. vulgare oil was used and from 0.11 to 3.5 mg/mL for O. majorana, M. piperita and R. officinalis oils. The results obtained indicate that the essential oils tested showed antimicrobial activity on P. insidiosum, with O. vulgare essential oil showing the best performance. These findings emphasize the potential use of plant essential oils as control agents in P. insidiosum infections; further research, however, is needed so as the in vivo activity of these oils can also be evaluated.

[Validation of the French version of the situational characteristics questionnaire in the measurement of space and motion discomfort]. / Validation de la version française du questionnaire des caractéristiques situationnelles dans la mesure de l'inconfort spatio-moteur.

INTRODUCTION: Space and motion discomfort (SMD) refers to various symptoms that occur in environments with unreliable visual and kinesthetic information that do not permit adequate spatial orientation. Some studies have demonstrated that there is a stable and predictable relationship between vestibular dysfunction and anxiety disorders. Further, vestibular dysfunction can predispose or trigger the development of panic disorder with or without agoraphobia (PD/A) or reinforce phobic avoidance. It therefore seems clinically useful to develop and validate instruments for evaluating SMD in various populations. Measuring SMD could facilitate identification of individuals with PD/A who present comorbid vestibular dysfunction. Jacob et al. developed and validated such a questionnaire: the Situational characteristics questionnaire (SitQ). This questionnaire evaluates the presence of symptoms such as dizziness, vertigo, and instability under specific conditions. The SitQ comprises two subscales that measure SMD and one subscale (agoraphobia) that measures agoraphobic avoidance behaviours. The instrument has two sections. The first section is composed of the SMD-I and agoraphobia subscales, containing 19 and seven items, respectively. Each item consists of two contrasting descriptors of a specific situation or environment. The respondent is required to indicate to what extent the two described situations or environments cause discomfort. Each item includes a "criterion" descriptor for the situation (i.e., a descriptor that is presumed to engender SMD) and an alternative (non-criterion) descriptor. The second section comprises the SMD-II scale; this scale is composed of nine criterion situations, for which non-criterion situations are not supplied. The instrument takes approximately 20 minutes to complete. OBJECTIVE: The present study focuses on the validation of the French-language version of the SitQ: the questionnaire des caractéristiques situationnelles (QCS). METHOD: The sample was composed of French Canadians recruited across Quebec from an anxiety disorders treatment clinic, general psychiatric care clinics, a community organization for individuals with anxiety disorders, advertisements in local newspapers, and ads posted in various public locations. The sample included 141 participants who met the criteria for lifetime PD/A. Participants reported current PD/A (n=73) or PD/A in remission (n=68). The control sample was recruited from undergraduate courses in various disciplines. Two hundred and thirty-five (n=235) students completed the questionnaires. Data from 63 (26.8%) participants were excluded from the analyses due to failure to complete all of the research questionnaires. RESULTS: Analysis of the global descriptive data and the descriptive data for each dependent variable revealed that the data were independent of sociodemographic variables and respected the assumptions of normal distribution (skewness and kurtosis). Parametric tests were subsequently conducted. Using the combined data from the control and clinical groups, the internal consistency of the scales was analyzed using Cronbach's alpha. The SMD-I and SMD-II scales demonstrated good homogeneity. The results were comparable or superior to those obtained with the English-language version of the questionnaire. The agoraphobia scale demonstrated weaker internal consistency and corresponding weaker homogeneity. This result was consistent with that of the original version of the agoraphobia scale; this scale was eliminated for the subsequent analyses. Construct validity was analyzed via t-tests comparing clinical and control groups. Effect sizes were estimated using percentage of variance explained. The SMD-I scale demonstrated weak construct validity and was also eliminated from subsequent analyses. The SMD-II scale demonstrated good construct validity and provided an adequate measure of the theoretical construct of SMD. This scale permitted discrimination of participants according to the presence or absence of PD/A. It is therefore possible to identify participants with PD/A by their level of SMD. This result is comparable to that of Jacob et al. CONCLUSION: The results of the present study are generally consistent with the results of the validation of the original version of the questionnaire. However, the SMD-I and agoraphobia scales in the French-language version of the measure did not achieve a level of significance sufficient to definitively establish validity.

Space and motion discomfort and abnormal balance control in patients with anxiety disorders.

OBJECTIVE: Previous research suggested that panic disorder with agoraphobia is associated with abnormalities on vestibular and balance function tests. The purpose of this study was to further examine psychiatric correlates of vestibular/balance dysfunction in patients with anxiety disorders and the specific nature of the correlated vestibular abnormalities. The psychiatric variables considered included anxiety disorder versus normal control status, panic disorder versus non-panic anxiety disorder diagnosis, presence or absence of comorbid fear of heights, and degree of space and motion discomfort (SMD). The role of anxiety responses to vestibular testing was also re-examined. METHODS: 104 subjects were recruited: 29 psychiatrically normal individuals and 75 psychiatric patients with anxiety disorders. Anxiety patients were assigned to four subgroups depending on whether or not they had panic disorder and comorbid fear of heights. SMD and anxiety responses were measured by questionnaires. Subjects were examined for abnormal unilateral vestibular hypofunction on caloric testing indicative of peripheral vestibular dysfunction, asymmetric responses on rotational testing as an indicator of an ongoing vestibular imbalance and balance function using Equitest dynamic posturography as an indicator of balance control. Logistic regression was used to establish the association between the psychiatric variables and vestibular or balance test abnormalities. RESULTS: Rotational test results were not significantly related to any of the psychiatric variables. The presence of either panic attacks or fear of heights increased the probability of having caloric hypofunction in a non-additive fashion. SMD and anxiety responses were independently associated with abnormal balance. Among specific posturography conditions, the association with SMD was significant for a condition that involved the balance platform tilting codirectionally with body sway, suggesting an abnormal dependence on somatosensory cues in the control of balance. CONCLUSION: In patients with anxiety disorders, higher SMD is indicative of somatosensory dependence in the control of balance. The absence of both panic and fear of heights reduces the probability of having peripheral vestibular dysfunction. Future research should examine if vestibular rehabilitation can be of value for patients with anxiety disorders complicated by SMD.

Vestibular rehabilitation for patients with agoraphobia and vestibular dysfunction: a pilot study.

This study examined whether physical therapy with vestibular rehabilitation exercises would benefit patients with agoraphobia and vestibular dysfunction. Nine patients went through a 2-week no-treatment baseline phase, a 4-week behavioral treatment phase focusing on self-directed exposure, and an 8-12-week vestibular rehabilitation phase (weekly sessions). On the main outcome measure, clinical global impressions (CGI) ratings of severity, behavioral treatment was accompanied by a reduction in severity (effect size d=0.8; P<.10). On the supplementary measures, the Hamilton Anxiety Scale (Hamilton-A) and the Chambless Mobility Inventory (MI), no significant improvements were noted. After vestibular rehabilitation therapy, further improvement occurred in CGI severity (d=0.65; two-tailed P<.10), and significant improvements occurred in the supplementary measures. The physical therapist identified motion-induced dizziness and disturbances in balance in most patients. These improved with rehabilitation. Although the results can be attributed to other explanations, they are not inconsistent with the hypothesis that vestibular dysfunction maintains agoraphobic symptoms in some patients.

Background and history of the interface between anxiety and vertigo.

The comorbidity of vertigo and anxiety has been an integral component of the medical literature since antiquity. In the works of Plato, the same terms were used in the context of vertigo, inebriation, height vertigo, disorientation, and mental confusion. In classical medicine, vertigo had the ambiguous status of being both a disease per se and a symptom of other diseases such as hypochondriacal melancholy. Further, two etiologies were described for vertigo: an origin in the head (brain) and an origin in the hypochondria (abdominal viscera). In the course of the development of a detailed neurologic taxonomy of vertigo in the latter half of the nineteenth century, a debate ensued whether agoraphobia was a form of vertigo or a distinct psychiatric condition. Elucidation of this forgotten debate, within its historical context, provides insights into the recent rediscovery of the balance-anxiety interface.

A clinical taxonomy of dizziness and anxiety in the otoneurological setting.

Dizziness can be associated with otologic, neurologic, medical, and psychiatric conditions. This paper focuses on the interface between otologic and psychiatric conditions. Because dizziness often is situation specific, concepts of space and motion sensitivity (SMS), space and motion discomfort (SMD), and space and motion phobia (SMP) are needed to understand the interface. We present a framework involving several categories of interactions between balance and psychiatric disorders. The first category is that of dizziness caused by psychiatric disorder (psychiatric dizziness), including hyperventilation-induced dizziness during panic attacks. The second category involves chance cooccurrence of a psychiatric disorder and a balance disorder in the same patient. The third category involves problematic coping with balance symptoms (psychiatric overlay). The fourth category provides psychological explanations for the relationship between anxiety and balance disorders, including somatopsychic and psychosomatic relationships. The final category, neurological linkage, focuses on the overlap in the neurological circuitry involved in balance disorders and anxiety disorders.

Psychiatric consequences of vestibular dysfunction.

Anxiety and dizziness are co-morbid symptoms in a larger percentage of patients than would be expected from chance alone. Such patients have an increased handicap and poorer prognosis. In this review, we discuss the interface between vestibular disorders and anxiety disorders. The two conditions are functionally related via both somatopsychic and psychosomatic mechanisms, and are linked via overlapping neural circuits that include monoaminergic pathways and the parabrachial nucleus network. An alternative conceptualization to the common notion of 'psychogenic' dizziness is presented. Implications for patient management are discussed.

The Raynaud's Treatment Study: biofeedback protocols and acquisition of temperature biofeedback skills.

The Raynaud's Treatment Study (RTS) compared temperature biofeedback training and a behavioral control procedure (frontalis EMG biofeedback) with nifedipine-XL and a medication placebo for treatment of primary Raynaud's phenomenon (RP) in a large (N = 313) multicenter trial. The present study describes the RTS biofeedback protocols and presents data on the acquisition of digital skin temperature and frontalis EMG responses in the RTS. The findings point to substantial problems with acquisition of physiological self-regulation skills in the RTS. Only 34.6% of the Temperature Biofeedback group (N = 81) and 55.4% of the EMG Biofeedback group (N = 74) successfully learned the desired physiological response. In contrast, 67.4% of a Normal Temperature Biofeedback group (N = 46) learned hand warming. Multivariate analysis found that coping strategies, anxiety, gender, and clinic site predicted acquisition of hand-warming skills whereas variables related to RP disease severity did not. Physiological data showed vasoconstriction in response to the onset of biofeedback and also found that performance in the initial sessions was critical for successful acquisition. These findings indicate that attention to the emotional and cognitive aspects of biofeedback training, and a degree of success in the initial biofeedback sessions, are important for acquisition.

Ambulatory blood pressure responses and the circumplex model of mood: a 4-day study.

BACKGROUND: The relation between mood or emotions and concurrent ambulatory blood pressure responses holds both fundamental and clinical interest. METHODS: The primary sample consisted of 69 normotensive or borderline hypertensive but otherwise healthy adult males. The validation sample consisted of 85 healthy male undergraduate college students. Both samples underwent half-hourly 24-hour ambulatory blood pressure measurements on four separate workdays, 1 week apart. At each ambulatory measurement, subjects recorded their behavior, environment, and mood. The circular mood scale, a circular visual analogue scale based on the circumplex model of mood, was used to reflect the totality of a participant's affective state space. Longitudinal random effects regression models were applied in the data analysis. RESULTS: The results for both samples were quite similar. Sleep and posture had the greatest influence on ambulatory blood pressure and heart rate. The effects of the environmental setting, social setting, and consumption were modest but statistically significant. Independent of these covariates, mood exerted a significant effect on blood pressure and heart rate. Relative to the "mellow" default category, blood pressure increased both for "anxious/annoyed" and "elated/happy" and decreased during "disengaged/sleepy" mood. The range of mood-related blood pressure estimates was 6.0/3.7 mm Hg. CONCLUSIONS: The pattern of blood pressure responses suggests that they were related to the degree of engagement of a mood rather than the degree of unpleasantness. The hypothesis that posits that negative affect-related cardiovascular reactivity mediates the observed correlation between negative affect and disease risk should be reconsidered.

Behavioral and pharmacologic interventions: the Raynaud's Treatment Study.

The Raynaud's Treatment Study (RTS) exemplified clinical trials with treatments that differ qualitatively both in their modes and in their methods of delivery. The RTS compared finger-temperature biofeedback to slow-release nifedipine, a calcium channel blocker, in patients with primary Raynaud's disease. Factors influencing the study design were the nature of the interventions and control measures of the protocol, the possibility of perceived differences by the patients between the treatments once the final protocol was developed, and concern on the part of the investigators over the fact that the primary endpoint was self-reported. This paper presents the final statistical model: a double parallel design with both a placebo group and a nonspecific behavioral control group.

Déjà vu all over again: critical misunderstandings concerning anxiety sensitivity and constructive suggestions for future research.

The debate concerning the relation between anxiety sensitivity (AS) and trait anxiety has been constructive for the field and has suggested a number of important directions for future research. Reiss' (1997) commentary on AS and trait anxiety in this journal, however, contains several serious factual mis-statements and logical errors that confuse, rather than clarify, many of the central issues in this debate. These misunderstandings are corrected and the implications of the issues raised by Reiss are addressed here. The authors suggest that future research on AS (a) embed this construct within the context of broader temperamental and personality variables and (b) explicitly recognize the biodirectionality of emotional and cognitive influences.

Clinical evidence that the vestibular system participates in autonomic control.

The vestibular system, including both the peripheral vestibular system, that is, the labyrinth, and the central vestibular system, is known to influence autonomic function in several ways that have clinical implications. This paper discusses evidence for vestibular influences on autonomic control from normal human subjects, evidence for vestibular influences on autonomic control from patients, clinical implications of vestibulo-autonomic regulation, and speculations regarding possible clinical implications of vestibulo-autonomic control. Situations that provoke vestibular-induced autonomic responses in normal subjects include vestibular laboratory testing, vehicular motion, simulators, and, possibly, exposure to microgravity. Patients with peripheral and central vestibular abnormalities manifest both symptoms and signs of autonomic dysfunction presumably via vestibulo-autonomic connections. Vestibulo-autonomic regulation impacts vestibular diagnostic testing, clinical diagnosis of balance disorders, and treatment of balance disorders. In addition to well-recognized peripheral and central vestibular disorders, anxiety disorders have recently been linked to vestibular dysfunction in a subset of patients. In particular, vestibular dysfunction has been linked to panic disorder and agoraphobia. Vestibular-autonomic connections may form a basis for an association between vestibular dysfunction and panic attacks. The importance of vestibulo-autonomic regulation in the clinical arena is not fully known. Two speculative areas discussed in this paper include vestibular-induced orthostatic intolerance and the role of vestibular-respiratory pathways on sleep apnea.

Surface dependence: a balance control strategy in panic disorder with agoraphobia.

OBJECTIVE: Previous studies have reported vestibular dysfunction and impaired balance in patients with agoraphobia. Vestibular dysfunction may lead to an information processing strategy focusing on spatial stimuli from two nonvestibular sensory channels, vision and proprioception. This nonvestibular balance control strategy may in turn lead to discomfort in situations involving inadequate visual or proprioceptive spatial cues (space and motion discomfort). The objective of this study was to examine sensory integration of spatial information in agoraphobia. Because of previous findings that space and motion discomfort and vestibular dysfunction are common in agoraphobia, we hypothesized that agoraphobics would use a nonvestibular balance control strategy. METHOD: Using computerized dynamic posturography, we examined balance performance in patients with panic disorder with agoraphobia, uncomplicated panic disorder, nonpanic anxiety disorders, and depression without anxiety, as well as healthy subjects for comparison. The posturography procedure included six sensory conditions in which visual and proprioceptive balance information was manipulated experimentally by permutations of sway-referencing the support surface or the visual surround or by having patients close their eyes. RESULTS: The agoraphobics had impaired balance when proprioceptive balance information was minimized by sway-referencing the support surface (p < 0.02). This pattern, called surface dependence, tended to be more pronounced in agoraphobics who reported space and motion discomfort, including fear of heights or boats. CONCLUSION: Agoraphobics rely on proprioceptive cues for maintenance of upright balance. This strategy may lead to intolerance of situations characterized by unstable support.

Space and motion discomfort in Brazilian versus American patients with anxiety disorders.

Space and motion discomfort (SMD) was studied in 38 Brazilian and 50 U.S. patients belonging to one of three diagnostic groups: (a) panic disorder with agoraphobia, (b) panic disorder without agoraphobia, and (3) other nonpanic anxiety disorders. A group of 30 U.S. normal controls was also included. SMD was assessed by the Situational Characteristics Questionnaire (SitQ), which includes two scales for SMD--the Smd1 and the Smd2, and one scale for non-space-related agoraphobic discomfort, the Ag1. The score in the Smd2 is based on the sum of Likert style items, while the scores of the Smd1 and Ag1 are based on differences between contrasting subitems. A significant diagnosis effect was observed in all scales, with the highest scores in the agoraphobia group. A country effect was found only in the Smd2. A country effect was also observed when all subitems of the Smd1 and Ag1 were added rather than subtracted, suggesting that this country bias is related to a tendency of Brazilian patients to endorse symptoms. Implications of these findings to the trans-cultural validation of rating scales are discussed.

Clinical features affecting treatment outcome in social phobia.

Characteristics of social phobics were examined to determine their effect on treatment acceptance, drop-out rate and amount of improvement at post-treatment. The rate of treatment non-acceptance was low and those who entered treatment differed from those who did not only on ratings of social phobia severity. The drop-out rate also was relatively low, and there were no differences between those who dropped out and those who completed treatment. When patients were divided on the specific versus generalized subtype dichotomy, a number of interesting findings emerged. Response to treatment was similar, but the specific subtype was significantly more improved at post-treatment than the generalized subtype. When compared on composite indexes of overall improvement and endstate functioning, there was no difference between the number of specific and generalized social phobics achieving significant or moderate improvement. However, a greater number of the specific subtype were judged to have high or moderate endstate status than the generalized subtype. A similar outcome was found when social phobics with comorbid disorders were compared with those who were non-comorbid. The results are discussed in terms of factors affecting outcome in social phobia treatment.

Panic, agoraphobia, and vestibular dysfunction.

OBJECTIVE: Otoneurological abnormalities have been reported in panic disorder. The purpose of this investigation was to determine the prevalence of such findings in panic disorder with and without agoraphobia and to discern whether vestibular dysfunction was associated with specific symptoms. METHOD: Clinical audiological and vestibular tests were administered to 30 patients with uncomplicated panic disorder (without agoraphobia or with only mild agoraphobia), 29 patients with panic disorder with moderate to severe agoraphobia, 27 patients with anxiety but no history of panic attacks, 13 patients with depressive disorders but no history of anxiety or panic attacks, and 45 normal comparison subjects. Evaluators were blind to subjects' diagnostic group. Quantitative measures of subjects' discomfort with space and motion and of the frequency of certain symptoms between and during panic attacks were obtained. Anxiety state levels were measured during the vestibular tests. RESULTS: Vestibular abnormalities were common in all the groups but most prevalent in the patients with panic disorder with moderate to severe agoraphobia. Vestibular dysfunction was associated with space and motion discomfort and with frequency of vestibular symptoms between, but not during, panic attacks. There were no major differences between the two panic groups in anxiety levels during vestibular testing. There were no significant differences between groups on the audiological component of the test battery. Exploratory data analysis indicated that the constellation of vestibular tests most specific for agoraphobia was one indicating compensated peripheral vestibular dysfunction. CONCLUSIONS: Subclinical vestibular dysfunction, as identified by clinical tests, may contribute to the phenomenology of panic disorder, particularly to the development of agoraphobia in panic disorder patients.