METHODOLOGY/PRINCIPAL FINDINGS: This study was conducted using the motion analysis technique with the reflex responses measured in terms of knee angles. Forty healthy subjects were selected and categorized into three different age groups. Patellar reflexes were elicited from both the left and right patellar tendons of each subject at three different tapping angles and using the Jendrassik maneuver. The findings suggested that age has a significant effect on the magnitude of the reflex response. An angle of 45° may be the ideal tapping angle at which the reflex can be elicited to detect age-related differences in reflex response. The reflex responses were also not influenced by gender and were observed to be fairly symmetrical.
CONCLUSIONS/SIGNIFICANCE: Neurologically normal individuals will experience an age-dependent decline in patellar reflex response.
METHODS: Sixty healthy adult subjects aged 22-76-year-old (mean ± standard deviation=47.27 ± 18.29) participated in the head impulse paradigm and suppression head impulse paradigm using the video head impulse test. The Head impulse paradigm was used to assess all 6 semicircular canals, while suppression head impulse paradigm measured only the horizontal canals. Twenty subjects aged 22-40-year-old (25.25 ± 4.9) underwent a second session for the test-retest reliability.
RESULTS: There were good test-retest reliability for both measures (right horizontal head impulse paradigm, intraclass correlation coefficient=0.80; left horizontal head impulse paradigm, intraclass correlation coefficient=0.77; right anterior head impulse paradigm, intraclass correlation coefficient=0.86; left anterior head impulse paradigm, intraclass correlation coefficient=0.78; right posterior head impulse paradigm, intraclass correlation coefficient=0.78; left posterior head impulse paradigm, intraclass correlation coefficient=0.75; right horizontal suppression head impulse paradigm, intraclass correlation coefficient=0.76; left horizontal suppression head impulse paradigm, intraclass correlation coefficient=0.79). The test-retest reliability for suppression head impulse paradigmanti-compensatory saccade latency and amplitude were moderate (right latency, intraclass correlation coefficient=0.61; left latency, intraclass correlation coefficient=0.69; right amplitude, intraclass correlation coefficient=0.69; left amplitude, intraclass correlation coefficient=0.58). There were no significant effects of age on head impulse paradigm and suppression head impulse paradigm vestibulo-ocular reflex gain values and suppression head impulse paradigmsaccade latency. However, the saccade amplitude became smaller with increasing age, P < .001. The horizontal suppression head impulse paradigm vestibuloocular reflex gain values were significantly lower than the head impulse paradigm for both sides (right, P = .004; left, P = .004).
CONCLUSION: There was good test-retest reliability for both measures, and the gain values stabilized with age. However, suppression head impulse paradigm anti-compensatory saccade latency and amplitude had lower test-retest reliability than the gain. The suppression head impulse paradigm vestibulo-ocular reflex gain was lower than the head impulse paradigm and its anti-compensatory saccade amplitude reduced with increasing age.
MATERIAL AND METHODS: A prospective, quasi-experimental physiological study. Selected healthy subjects were observed electrocardiographically for 60 s continuously in three equal phases of 20 s each - baseline phase, nasoendoscopic phase, and recovery phase (post-nasoendoscopy). Heart rate fluctuations were charted, followed by identification of a positive nasocardiac reflex group of subjects and a negative group. Analyses against multiple variables were done.
RESULTS: A total of 53 subjects were analysed. Heart rate during the baseline phase was 81.0 ± 9.9, nasoendoscopic phase was 72.7 ± 10.1, and recovery phase was 75.2 ± 9.6. Sixteen subjects (30.2%) had a positive nasocardiac reflex, and they remained in sinus rhythm with no occurrences of skipped beats, atrioventricular blocks or asystoles. One subject (1.9%) developed temporary ectopic premature ventricular contractions after nasoendoscopy. No variables were found affecting the incidence of a nasocardiac reflex in our study.
CONCLUSIONS: The pattern of heart rate dynamics was consistent as heart rates drop rapidly upon endoscope insertion and recover in some measure after its withdrawal. Although all our subjects remained asymptomatic, clinicians should not overlook the risks of a severe nasocardiac reflex when performing nasoendoscopy. We recommend that electrical cardiac monitoring be part of the management of vasovagal responses during in-office endonasal procedures.