Evaluation of Neurophysiological Parameters: Autonomic Status and Acute Pain Perception in Migraneurs.

Introduction: Painful conditions are associated with autonomic dysfunction and altered pain perception. However, data regarding autonomic status in migraineurs is not conclusive and there are few studies regarding acute pain perception in these cases. Aims: This study was conducted to assess various neurophysiological parameters namely autonomic functions using the autonomic function tests and acute pain perception using the cold pressor test in migraneurs. Material and methods: 60 migraineurs and 30 age and gender matched control subjects were included in this study after screening for the exclusion criteria and following a written consent. Diagnosis of migraine was made according to the International Classification of Headache Disorders(ICHD) – 2 Criteria. In the pain free state of the subjects, autonomic function tests including basal heart rate variability, E:I ratio, 30:15 ratio, postural challenge test and sustained handgrip test were carried out together with the cold pressor test. Unpaired t-test was used for analysing the data. Result: Migraineurs showed a trend towards increased parasympathetic tone, as compared to the control subjects, though the p-values were not significant. The pain threshold was lower while the pain tolerance was significantly lower in migraineurs as compared to controls (p= 0.00).Conclusion: In our study we observed an increased vagal tone together with lower values of pain threshold and pain tolerance in migraineurs, indicating that certain neurophysiological parameters are affected in painful conditions like migraine.

Efficacy of two commercially available dentifrices in reducing dentinal hypersensitivity.

Objective: A parallel design clinical study evaluated reduction in hypersensitivity after brushing for 12 weeks with Anchor toothpaste (containing potassium citrate, zinc citrate, triclosan and sodium monofluorophosphate) (test) and Colgate Total (sodium fluoride, silica, triclosan and copolymer) (control) dentifrices. Materials and Methods: Sixty adults with sensitivity to hot and cold stimulus in at least two tooth surfaces were stratified at the baseline examination by tactile, hot and cold stimuli scores in two balanced groups. Subjects were randomly allocated the test and control dentifrices and evaluated after 6 and 12 weeks of dentifrice use for hypersensitivity. Results: The two teeth that were selected in each patient were designated as two different sets. The 12 th -week scores as compared to baseline scores for tactile, heat and cold tests in the test group showed a reduction in tooth hypersensitivity by 36.67% (P < 0.01), 20.35% (P < 0.01) and 53.64 % (P < 0.01), respectively, in the first set of teeth and 43.75% (P < 0.01), 24.48% (P < 0.01) and 59.78% (P < 0.01), respectively, in the second set of teeth. The 12 th -week scores as compared to baseline scores for tactile, heat and cold tests in the control group showed a reduction in tooth hypersensitivity by 42.86% (P < 0.01), 13.02% (P < 0.01) and 45.14% (P < 0.01), respectively, in the first set of teeth and 40% (P < 0.01), 16.59% (P < 0.01) and 44.16% (P < 0.01), respectively, in the second set of teeth. Conclusions: Both the products reduced dentinal hypersensitivity in the study subjects at the end of the 12-week period. However, there was no statistically significant difference in reduction in hypersensitivity between the two products.

Detection of individuals prone to develop hypertension in their future life.

Hypertension is a global burning health problem. Early detection of proneness to hypertension may help an individual to lead a healthy life by altering the life style (by diet restriction, exercise etc.). Subjects at high risk of future hypertension e.g. the persons of hypertensive family and/or having high resting heart rate etc. show blood pressure hyper-responsiveness to stress. Elevated blood pressure due to sympathetic stimulation prevailed longer time in susceptible persons. In the present study sympathetic stimulation exerted through cold pressor test (hand immersion up to the wrist in 4 degrees C water) resulted in elevation of blood pressure and heart rate in all young male normotensive individuals (age 18-35 years, n=72). Nevertheless, blood pressure and heart rate returned to baseline, following 5 minutes of withdrawal of the stressor, in case of volunteers from normotensive families. On the other hand, the subjects whose parents, either or both were reported to be hypertensive showed elevated diastolic blood pressure even after 5 minutes of withdrawal of the said stressor- indicating that the autonomic nervous system in them was not competent enough for lowering the diastolic pressure quickly to baseline as observed in the volunteers from the normotensive families. The present study revealed that the young subjects who showed greater and prolonged responsiveness to diastolic blood pressure due to sympathetic stimulation through cold pressor test are prone to develop hypertension in future.

Blood pressure response to cold pressor test in siblings of hypertensives.

One hundred and five female and thirty-four male student volunteers were divided into three groups. Each group was again divided into siblings of hypertensives (SH) and siblings of normotensives (C). SH group had higher basal seated and supine Systolic and Diastolic Blood Pressures (SBPs and DBPs, respectively). During cold pressor test (CPT), the SH group showed higher rise of SBPs and DBPs. All the volunteers were again regrouped as hyperreactors (HR) (the criteria of a rise of more than 22 mmHg systolic and 18 mmHg diastolic blood pressure during (CPT) and normoreactors (NR). HR showed higher resting seated SBPs and DBPs, and higher rise of SBPs & DBPs during CPT as compared to control groups. The rise in SBPs and DBPs in hyperreactors was significantly higher than SH groups only in 16-19 years female group. The rise of SBPs and DBPs during CPT were also higher in HR as compared to NR of all age groups. The rise of SBPs and DBPs during CPT was significantly higher in controls than in NR in the two female groups. The study suggests that identification of hyperreactors in population gives a better indication of potential hypertensives of future than the children of hypertensives.

Ice test for ocular myasthenia gravis.

A prospective, non randomized comparative study was conducted to examine the efficacy of the ice test in differentiating myasthenia gravis (MG) ptosis from non MG. Twenty patients with MG ptosis and 20 with non MG ptosis were evaluated by measuring the palpebral fissures pre and post ice test applied on the eyelids for 2 minutes. The difference in widening of palpebral fissure 2 mm or more was considered as a positive ice test. The results showed that 19 from 20 MG patients had positive ice test, whereas, all non MG patients had negative results. The sensitivity and specificity of the test were 95.0 per cent and 100 per cent, respectively while the accuracy or efficacy of the test was 97.5 per cent. In conclusion, the ice test is a useful, simple, safe, fast, cheap, and easy to perform for the screening and diagnosis MG patients with ocular ptosis.

Effect of cold pressor test and a high-chilli diet on rectosigmoid motility in irritable bowel syndrome.

AIM: Visceral hypersensitivity characterizes the irritable bowel syndrome (IBS). We evaluated the effect of a cold pressor test (CPT)--hand immersion in ice water for 1 minute, which evokes a sympathetic response--on rectosigmoid motility in patients with IBS and normal volunteers. Since many Indian patients with IBS complain of worsening of symptoms following a spicy meal, we also evaluated whether a high-chilli diet affects symptoms or changes rectosigmoid motility. METHODS: Fifteen men with IBS and 13 normal volunteers (all men) were studied. Baseline rectosigmoid manometry was done for 2 h, i.e., 1 h pre- and 1 h post-CPT. The subjects were then kept in hospital on a regular diet (approximately 5 g chilli daily) for 3 days, following which symptoms were reassessed and manometry repeated for 1 h. This was followed by a high-chilli diet (approximately 15 g/day) for 3 days, after which symptoms were reassessed and manometry repeated for 1 h. RESULTS: There was no difference in the baseline study in the pre-CPT period between patients and control subjects. CPT did not change rectosigmoid motility in either group. IBS patients had varied effect on symptoms but no change in rectosigmoid motility after the high-chilli diet. In the normal volunteers, there was increased activity in the low rectum after the high-chilli diet. CONCLUSIONS: Cold pressor test does not affect rectosigmoid motility in patients with IBS or normal subjects. A high-chilli diet has varied effect on symptoms in patients with IBS and does not affect rectosigmoid motility.

Behavioural parameters in hypertensives on atenolol therapy.

Behavioural responses which included psychological tests and cold pressor test as a stress test were studied in 20 mild to moderate hypertensives of both sexes, excluding smokers, alcoholics, secondary hypertensives and patients of chronic obstructive pulmonary diseases. Subjects were put on 2 weeks of placebo washout period followed by 6 weeks of treatment with atenolol. Following treatment with atenolol they showed no significant alteration in the scores of psychological tests which included Weschler adult intelligence scale for orientation, while showing significant depression in the rise of heart rate, systolic blood pressure and diastolic blood pressure following cold pressor test. On further analysis, the results showed that hypertensives on placebo had lower scores of memory and attention test as compared to normotensive controls. Besides this, hypertensives on placebo had higher rise of heart rate and systolic blood pressure as compared to normotensive controls after cold pressor test.

Cardiovascular reactivity to cold pressor test in offspring of normotensive & hypertensive parents.

A study was undertaken to assess the potential hypertensive status of the offspring of normotensive and hypertensive parents. The volunteers were divided into two groups based on the family history of hypertension. Heart rate and blood pressure recordings were made before and after the cold pressor test. Higher basal values of blood pressure and a significant rise in systolic and diastolic blood pressure in the offspring of hypertensive parents were observed indicating that they have an increased cardiovascular reactivity which was attributed to increased sympathetic activity. Excretion of urinary catecholamines was also found to be significantly higher in about 33 per cent of the offspring of hypertensive parents.

Cardiovascular responses to cold pressor test: a test for autonomic functions.

Circulatory dynamics during the cold pressor test, done by immersing the hand in water at 5 degrees C for one minute, were studied in 30 male healthy volunteers. All the subjects responded to the test with statistically significant increase in blood pressure (22.04%, p less than 0.001), heart rate (11.21%, p less than 0.001), galvanic skin resistance (36.17%, p less than 0.001) and decrease in forearm blood flow (40.85%, P less than 0.001). The measurement of cardiovascular responses following cold pressor test constitutes another test which can be used to test the efficiency of the autonomic nervous system in various autonomic neuropathies.

Beta-adrenoceptor blockade and cardiovascular response to the cold pressor test.

Seven healthy subjects immersed a hand in random order in either warm water or in cold water at 5 degrees C for 2 min, after taking orally a single dose of 120 mg of propranolol or a placebo in a double blind fashion. The cold stress resulted in a significant increase in blood pressure and the rate pressure product without a change in heart rate. Beta-adrenoceptor blockade did not affect the pressor response the cold. The changes induced by the cold stress in the cardiovascular variables in the placebo and propranolol experiments were not statistically different. The highest rate pressure product during the cold pressor test was about 109 units. This was well below the pain threshold value of about 200 found during exercise in patients with ischaemic heart disease. In the recovery phase, the cardiovascular variables reverted to pre-immersion values within 1 min inspite of continued low hand skin temperature.