Naturopaths and Western herbalists' attitudes to evidence, regulation, information sources and knowledge about popular complementary medicines.

BACKGROUND: The practice of naturopathy and Western herbal medicine (WHM) was built on traditional evidence but may be undergoing change with the advent of scientific evidence. The aims of this research were to provide a better understanding of practitioners' attitudes towards evidence, information sources, professional regulation and their knowledge about the evidence of commonly used complementary medicines (CMs). METHOD: Naturopaths and WHM practitioners were invited to participate in an anonymous, self-administered, on-line survey. Participants were recruited using the mailing lists and websites of CM manufacturers and professional associations. RESULTS: Four hundred and seventy nine practitioners participated; 95% currently in practice. The majority (99%) thought well documented traditional evidence was essential or important, 97% patient reports and feedback, 97% personal experience, 94% controlled randomised trials and 89% published case reports. Significantly more recent graduates (less than 5 years) rated randomised trials as essential compared to others. Most (82%) respondents want information sources containing both traditional and scientific evidence. They currently use several resources; 74% CM textbooks, 67% conferences/seminars, 57% CM journals, 48% databases and 40% manufacturers' information. The mean knowledge score was 61.5% with no significant differences between respondents with diploma or degree level education or by graduating year. Eighty-five percent of practitioners strongly agreed or agreed that practitioners should be formally registered to safeguard the public, 8% were unsure and 8% disagreed or strongly disagreed. CONCLUSION: Naturopaths and WHM practitioners accept the importance of scientific evidence whilst maintaining the importance and use of traditional evidence. The majority are in favour of professional registration.

The effects of dimenhydrinate, cinnarizine and transdermal scopolamine on performance.

We assessed the influence of dimenhydrinate, cinnarizine and transdermal scopolamine on the ability to perform simulated naval crew tasks. The effect of single doses of dimenhydrinate, 100 mg, cinnarizine, 50 mg, and one transdermal scopolamine patch on psychomotor performance was evaluated using a double-blind, placebo-controlled, randomized, crossover design in three separate studies. A total of 60 young naval crew (20 for dimenhydrinate, 15 for cinnarizine and 25 for transdermal scopolamine) underwent a battery of computerized and paper and pencil performance tests, and filled out a questionnaire on side-effects and well-being self-assessment. Dimenhydrinate significantly impaired decision reaction time and auditory digit span. Most of the subjects who took dimenhydrinate also reported a subjective decrease in well-being and general performance abilities. Cinnarizine and transdermal scopolamine did not affect performance abilities. Cinnarizine was free of significant side-effects. Dry mouth was the only significant side-effect of transdermal scopolamine. These findings could be explained by the well-known sedative properties of dimenhydrinate and not by a specific effect on any particular cognitive or motor function. Our results suggest that dimenhydrinate, 100 mg, adversely affects psychomotor function, whereas single doses of cinnarizine, 50 mg, and transdermal scopolamine appear to be free of side-effects on performance and seem to be a preferable anti-seasickness drug for use by a naval crew.

Inner ear decompression sickness in sport compressed-air diving.

OBJECTIVE: We report our experience over the past 12 years with recreational diving-related inner ear decompression sickness (IEDCS). STUDY DESIGN: Retrospective, consecutive case series. METHODS: Twenty-four divers, representing 29 cases of IEDCS, are presented with regard to evaluation, treatment, and follow-up. RESULTS: These 29 cases represent 26% of the severe decompression sickness (DCS) cases treated in that period. The patient group includes 22 divers who had a single event of IEDCS, one diver who had two events, and one with five repeated episodes. The cause of injury in 23 cases (79%) was violation of the decompression schedule. The mean time from surfacing to appearance of symptoms was 47 +/- 65 minutes. In 83%, symptoms appeared within 1 hour of ascent, in 97% within 2 hours, and in only one diver after 5.5 hours. Ten divers (34%) had pure vestibular involvement, 4 (14%) had cochlear insult alone, and 15 (52%) had combined vestibulo-cochlear injury. Except for one patient who had central as well as peripheral vestibulo-cochlear DCS, all the remaining patients had end organ involvement only, as demonstrated by physical examination and laboratory test results. Fifteen (52%) had isolated IEDCS, whereas 14 had additional symptoms of DCS. Twenty-six cases were treated by hyperbaric oxygenation with supplementary daily hyperbaric sessions. Of the 25 cases with vestibular injury and the 19 with cochlear damage, only 7 (28%) and 6 (32%), respectively, made a full recovery, whereas the others remained with residual damage. Of the 17 treated within 6 hours of symptom appearance, 9 (53%) were cured, compared with one of the 9 treated later (P <.05). CONCLUSIONS: IEDCS related to compressed-air recreational diving is more common than previously thought, and might occur even when no decompression schedule violation took place. Prompt diagnosis leading to the early commencement of hyperbaric oxygen recompression therapy is the key to complete recovery of cochlear and vestibular function.

Vestibular findings in professional divers.

The purpose of the present study was to investigate possible inner ear changes related to professional diving, by the documentation of auditory and vestibular function in 13 asymptomatic professional divers and 12 nondiver controls. A higher average pure tone hearing threshold, although of no clinical significance, was found in the study group (8.53 +/- 4.85 versus 6.67 +/- 3.54 dB hearing level, p = .04). In the vestibular evaluation, the smooth harmonic acceleration test phase leads for 0.01, 0.02, and 0.04 Hz were significantly lower in the divers (0.01 Hz, 38.46 degrees +/- 7.15 degrees versus 45.83 degrees +/- 9.02 degrees, p = .02; 0.02 Hz, 21.08 degrees +/- 5.19 +/- versus 25.17 degrees +/- 5.78 degrees, p = .05: 0.04 Hz, 12.38 degrees +/- 3.69 degrees versus 14.25 degrees +/- 3.14 degrees, p = .05). We suggest that the lower smooth harmonic acceleration phase values found in the professional divers, reflecting longer vestibulo-ocular reflex primary time constants and enhancement of the velocity storage mechanism, are the result of a habituation process that augments the low-frequency response of the canal-ocular system.

Scopolamine bioavailability in combined oral and transdermal delivery.

Transdermal therapeutic system scopolamine (TTS-S) is effective in preventing motion sickness for 72 h. However, by this route a prophylactic effect is obtained 6 to 8 h postapplication. By the oral route, scopolamine is effective within 0.5 h for a period of 6 h. To achieve safe as well as effective protection against seasickness during the first hours of a voyage until the TTS-S patch takes effect, the pharmacokinetics of scopolamine was investigated after patch application in combination with oral tablets, 0.6 mg, 0. 3 mg, or placebo. Subjects were 25 naval-crew volunteers, randomly divided into three groups: group 1 (n = 9), TTS-S patch + 0.6 mg of scopolamine per os (p.o.); group 2 (n = 8), TTS-S patch + 0.3 mg of scopolamine p.o.; and group 3 (n = 8), TTS-S patch + placebo tablet. Blood samples were collected before treatment and 0.5, 1, 1.5, 2.5, 3.5, 6, 8, and 22 h post-treatment, and were analyzed for scopolamine levels using radioreceptor assay. Significantly higher plasma scopolamine levels were found in group 1 at 0.5, 1, 1.5, and 2.5 h, and in group 2 at 1 and 1.5 h post-treatment, compared with group 3. Thereafter, plasma levels did not differ significantly between the groups. In all subjects of group 1 and seven subjects (88%) of group 2, therapeutic levels (>50 pg/ml) were measured during the first 2.5 h, compared with only two subjects (25%) of group 3 (P < 0.05). Heart rate, blood pressure, visual accommodation, performance test results, and subjective complaints of adverse effects did not differ significantly. The combination of transdermal and oral scopolamine (0.3 or 0.6 mg) provides the required plasma levels to prevent seasickness, starting as early as 0.5 h post-treatment, with no significant adverse effects.

Computerized dynamic posturography and seasickness susceptibility.

OBJECTIVE/HYPOTHESIS: The neural mismatch theory emphasizes the role of conflicting multimodal sensory interactions in producing both motion sickness and the rearrangement process that finally leads to habituation to the adverse motion conditions. If this theory is, indeed, correct, the patterns of the response to the integrated signal from simultaneous multisensory stimulation, characterized by unusual relationships between the senses responsible for spatial orientation, should differ according to motion sickness susceptibility. Computerized dynamic posturography (CDP) provides the opportunity to simultaneously change the interactions between visual, somatosensory, and vestibular inputs, thus giving an indication of the relative importance of these senses in maintaining balance. The objective was to investigate balance strategies in naval crew members with differing susceptibility to sea conditions using CDP. STUDY DESIGN: Cross-sectional, parallel-group design. METHODS: Twenty subjects susceptible to seasickness (SS) and 20 nonsusceptible subjects (NSS), healthy male volunteers aged 18 to 25, were tested using the EquiTest system (NeuroCom, Inc., Clackamas, OR). RESULTS: The SS group exhibited significantly less stability than the NSS group in condition 5 of the sensory organization test (SOT). The ratio of the SOT scores of conditions 5 to 1 (the vestibular organization pattern) was also found to be significantly lower in the SS group. CONCLUSIONS: The results suggest that SS might be more dependent on somatosensory and visual inputs and less on vestibular inputs for maintenance of balance compared with NSS. Higher susceptibility to seasickness might reflect abnormal weighting of sensory modalities during the integration process. This would result in disruption of the integration process required to maintain balance and a sense of orientation in space in conditions producing conflicting sensory inputs.

Inner ear decompression sickness following altitude chamber operation.

Decompression sickness (DCS) is a known hazard of altitude chamber operation. The musculoskeletal, dermal, neurological and pulmonary manifestations of DCS are well recognized, but inner ear injury has not been reported. We present the unusual case of a medical corpsman suffering from vestibular DCS after an altitude chamber exposure to 25,000 ft. The patient had a good clinical response to hyperbaric treatment, but there was laboratory evidence of mild residual vestibular damage with full compensation. This case suggests that aviation medical personnel should be more aware of the possible occurrence of inner ear DCS among subjects exposed to altitude.

Alterations in R-R variability associated with experimental motion sickness.

Motion sickness is a complex integration of responses from multiple physiological systems. Whether the changes that occur during the time course of motion sickness are mediated by the sympathetic or parasympathetic systems is still controversial. The present study evaluates alterations in R-R variability during experimental motion sickness in motion sick and non-motion sick subjects. Ten motion sick subjects and 7 non-motion sick subjects participated in the study. Power spectrum analysis of R-R variation was conducted for all subjects 10 min before a brief vestibular disorientation test (BVDT), for 5-10 min of the test, and 10 min after the test. Subjects were also asked to report their symptoms during the test. The motion sick group showed a significant reduction in the power spectrum density of the R-R interval at the mid and high frequencies during the BVDT test period (BVDT), in comparison with the rest period (Rest). These changes probably indicate a decrease in parasympathetic activity during the time course of motion sickness. The non-motion sick group did not show significant differences at any of the frequencies during BVDT. Power spectrum analysis of the R-R interval provides an objective measure of the autonomic response to experimental motion sickness.

Nonspecific vertigo with normal otoneurological examination. The role of vestibular laboratory tests.

Vestibular laboratory tests are not generally necessary in the diagnosis of patients with a clear description of vertigo accompanied by positive otoneurological examination findings. The purpose of the study was to investigate the role of conventional vestibular laboratory tests in the diagnosis of patients complaining of nonspecific vertigo, despite their having a documented normal otoneurological examination. The results of the standard electronystagmography (ENG) and sinusoidal harmonic acceleration (SHA) tests of 52 patients referred for ambulatory vestibular laboratory tests due to a nonspecific illusion of movement, but with a normal otoneurological examination, were reviewed. Abnormalities were found in the vestibular tests of 35 patients (67 per cent), 22 of whom (63 per cent) were finally diagnosed as having a unilateral peripheral vestibular lesion, and 13 (37 per cent) benign positional vertigo. These results suggest that a high percentage of patients with nonspecific vertigo and a normal otoneurological examination probably suffer from peripheral vestibular dysfunction, which can be objectively documented by the ENG and SHA tests.

The vestibulo-ocular reflex and seasickness susceptibility.

VOR parameters were compared in subjects at the extremes of the seasickness susceptibility scale. Thirty-nine subjects highly susceptible to seasickness and 30 nonsusceptible subjects participated in the study. The VOR was evaluated by the Sinusoidal Harmonic Acceleration (SHA) test at frequencies of 0.01, 0.02, 0.04, 0.08, and 0.16 Hz. In subjects susceptible to seasickness, VOR gain was significantly higher at 0.02 and 0.04 Hz, and phase lead was significantly lower at 0.01, 0.02, 0.04, and 0.08 Hz, than in nonsusceptible subjects. Our findings are in agreement with the notion that the vestibular response will be more intense in subjects susceptible to motion sickness. The present results support the contention that a natural insusceptibility, or increased resistance to seasickness produced by adaptive responses to repeated sea exposures, may be reflected by lower VOR gain and higher phase lead.

Clinical features of mal de debarquement: adaptation and habituation to sea conditions.

A survey conducted among 116 crew members of seagoing vessels confirmed that mal de debarquement (M-D) is a transient feeling of swinging, swaying, unsteadiness, and disequilibrium. None of the subjects requested medical attention, although there were isolated cases in which a strong sensation of swinging and unsteadiness caused transient postural instability and impaired the ability to drive. In most cases, the sensation of M-D appeared immediately on disembarking and generally lasted a few hours. In addition, subjects usually described bouts or attacks of M-D associated with changes in body posture, head position, or with closing of the eyes. M-D was reported by 72% of our subjects. Sixty-six percent of subjects reported a high incidence following their first voyages. A significant positive correlation was found between M-D and seasickness susceptibility. The nature of M-D may be explained within the framework of multisensorimotor adaptation and habituation to a new or abnormal motion environment. It is suggested that M-D represents a dynamic, multisensorimotor form of CNS adaptive plasticity.

[Vestibular function in acoustic trauma].

Histological and functional derangement of the vestibular system has been reported in laboratory animals exposed to high levels of noise. However, reports of clinical series give contradictory results with regard to vestibular disturbances in industrial workers and military personnel suffering from noise-induced hearing loss (NIHL). This study evaluates vestibular function in 22 men with documented NIHL and in 21 matched controls, using electro-nystagmography (ENG) and the smooth harmonic acceleration (SHA) test. There was a significantly lower vestibulo-ocular reflex gain (p = 0.05), and a tendency towards decreased caloric response in the patients. There were no differences between patient and control groups in: incidence of vertigo and of spontaneous, positional and positioning nystagmus; directional preponderance and canal paresis in the ENG; or in phase and asymmetry parameters in the SHA test. These results demonstrated a symmetrical, centrally compensated decrease in vestibular end-organ response associated with symmetrical hearing loss in the patients. Statistically significant correlations were found between average hearing loss, and decrease in average vestibulo-ocular reflex gain (p = 0.01) and ENG caloric lateralization (p = 0.02). These correlations might indicate a single mechanism for both cochlear and vestibular NIHL. The results imply subclinical, well compensated malfunction of the vestibular system associated with NIHL.

Vestibular findings associated with chronic noise induced hearing impairment.

Histological and functional derangements of the vestibular system have been reported in laboratory animals exposed to high levels of noise. However, clinical series describe contradictory results with regard to vestibular disturbances in industrial workers and military personnel suffering from noise induced hearing loss (NIHL). The purpose of the present study was to evaluate vestibular function in a group of subjects with documented NIHL, employing electronystagmography (ENG) and the smooth harmonic acceleration (SHA) test. Subjects were 22 men suffering from NIHL and 21 matched controls. Significantly lower vestibulo-ocular reflex gain (p = 0.05), and a tendency towards decreased caloric responses were found in the study group. No differences in the incidence of vertigo symptoms, spontaneous, positional and positioning nystagmus, directional preponderance and canal paresis in the ENG, or the SHA test phase and asymmetry parameters were observed between the groups. These results demonstrated a symmetrical centrally compensated decrease in the vestibular end organ response which is associated with the symmetrical hearing loss measured in the study group. Statistically significant correlations were found between the average hearing loss, the decrement in the average vestibulo-ocular reflex gain (p = 0.01), and ENG caloric lateralization (p = 0.02). These correlations might indicate a single mechanism for both cochlear and vestibular noise-induced injury. The results imply subclinical, well compensated malfunction of the vestibular system associated with NIHL.

Effect of cinnarizine in the prevention of seasickness.

In a double-blind, placebo-controlled study, we evaluated the effect of two different doses of cinnarizine in the prevention of seasickness in very rough seas. We divided 95 healthy male subjects into 3 groups which received: cinnarizine 50 mg, cinnarizine 25 mg, and placebo. Seasickness susceptibility and severity were evaluated by a standard questionnaire concerning the subject's condition on previous voyages (seasickness susceptibility), and the subject's condition immediately after a 4-6-h voyage in very rough seas with 3.5 m waves (seasickness severity). Possible side effects of the drug were also evaluated by filling in a further questionnaire. Of the 31 subjects who received cinnarizine 50 mg, 65% felt better during the present voyage than on previous voyages, compared to 41% of the 32 subjects who received cinnarizine 25 mg and 31% of the 32 who received placebo. A significant difference (p < 0.05) was found between the cinnarizine 50 mg and placebo groups, while cinnarizine 25 mg was no more effective than placebo. No notable side effects were found for any drug group. In conclusion, cinnarizine 50 mg was found to be effective in the prevention of seasickness in rough seas.

Seasickness susceptibility, personality factors, and salivation.

The present study investigates the possible relationship between motion sickness susceptibility, personality factors and salivation. Personality factors, as evaluated by the Eysenck Personality Questionnaire, and salivary composition and flow were measured in a group of 29 subjects highly susceptible to seasickness and in a group of 25 non-susceptible subjects. The non-susceptible group had significantly higher psychoticism scores and significantly lower salivary amylase levels compared to the highly susceptible group. A significant positive correlation was found between psychoticism scores and the amount of the increase in salivary flow in response to gustatory stimulation. These results provide more data in support of a connection between motion sickness susceptibility, personality, and the autonomic nervous system.

Cinnarizine in the prophylaxis of seasickness: laboratory vestibular evaluation and sea study.

Cinnarizine was evaluated for the prevention of seasickness in a laboratory and sea study. The effects of 25 mg cinnarizine on the vestibulo-ocular reflex were investigated in 13 subjects. Significant reduction of the gain in response to sinusoidal oscillations at 0.02, 0.08, and 0.16 Hz (p < 0.05) and increased phase lead at 0.16 Hz (p < 0.01) were observed. The effect of 25 and 50 mg cinnarizine on seasickness severity was examined in 95 subjects during a voyage in rough seas. Seasickness symptoms were improved in 69% of the subjects by 50 mg cinnarizine versus 35% and 31% in the groups receiving 25 mg cinnarizine and placebo (p < 0.05 and p < 0.01, respectively). The percentage of vomiting protection provided by 50 mg cinnarizine was 63% (p < 0.05). We conclude that 50 mg cinnarizine is an effective drug for the prevention of seasickness. The reduction in vestibular sensitivity observed even after administration of 25 mg cinnarizine may explain the potency of cinnarizine in the prevention of seasickness.

The vestibulo-ocular reflex (VOR) under the influence of cinnarizine.

In a double-blind, placebo controlled, crossover study, we evaluated the effects of cinnarizine on the VOR of 55 healthy young subjects. VOR was evaluated by the Sinusoidal Harmonic Acceleration (SHA) test at frequencies of 0.01, 0.02, 0.04, 0.08 and 0.16 Hz. There was a reduction in VOR gain in 16 of the 20 SHA trials performed under the influence of cinnarizine alone (25 mg and 50 mg) and cinnarizine 25 mg in combination with 10 mg domperidone or 1 transdermal scopolamine patch. This decrease in VOR gain was significant in only a few SHA trials. Phase lead was not consistently affected by cinnarizine. No notable side effects were found for any of the drug groups. Our findings are in accord with the contention that increased resistance to seasickness produced either by drugs, or by the natural process of habituation to sea conditions, may be reflected by a decrease in VOR gain.

Vestibulo-ocular reflex in migraine patients: the effect of sodium valproate.

We studied vestibulo-ocular reflex measurements in a group of 12 patients suffering from migraine without aura and evaluated the effect of sodium valproate given as prophylactic migraine therapy. The study was randomized, double blind and placebo controlled, with a crossover design. The horizontal vestibulo-ocular reflex was evaluated by the Sinusoidal Harmonic Acceleration test at 0.01, 0.02, 0.04, 0.08 and 0.16 Hz using a computerized rotatory chair system. No abnormalities were found for the vestibulo-ocular reflex gain, phase and asymmetry at each of the frequencies examined during the placebo treatment. These normal vestibulo-ocular reflex measurements contrasted with the repeated complaints of dizziness, vertigo and unsteadiness reported by 7 patients (58%). Sodium valproate affected neither vestibulo-ocular responses nor vestibular complaints but was effective in reducing migraine attacks in 8 of the 12 patients. These results demonstrate that the low frequency vestibulo-ocular reflex measurements are normal in patients suffering from migraine without aura.

Salivary secretion and seasickness susceptibility.

The salivary flow rate and composition of 2 groups of 31 subjects, one group at each extreme of the seasickness susceptibility scale, were compared. No significant differences were found between the two groups in flow rates and electrolyte concentrations of whole resting and stimulated saliva. Amylase activity and rate of secretion in resting saliva were significantly higher in subjects susceptible to seasickness as compared with nonsusceptible subjects. Also, the total protein rate of secretion in resting saliva was significantly higher in the susceptible group. The present findings could be explained in terms of higher sympathetic tone in subjects susceptible to seasickness, and salivary amylase levels might be recommended as an additional parameter in the evaluation of seasickness susceptibility.