Impairment of C ognition in patients of B ipolar disorder in E uthymia in Indian population

Background: Bipolar disorder is one of the common mental disorders(CMD) in India. It leads to significant cognitive deficit even during the period of euthymia. So, it is important to identify the various cognitive deficits in euthymic bipolar disorder patients in Indian population. Methods: The study was conducted over a period of 2 years in AIIMS Jodhpur, Rajasthan. 30 cases and 30 controls were selected. Cases were selected by administering Hamilton dep ression rating scale (HAM - D) and Young mania rating scale (YMRS) to the bipolar disorder patient, recruited from Psychiatry OPD, to select the patients who were in euthymia. Cognitive domains such as attention, memory, fluency, language and Visuospatial we re tested in both the groups and compared. Kruskal - Wallis test was employed to compare the 2 sample groups for different variables. In this study we wanted to observe the decline in cognitive function in healthy vs euthymic bipolar disorder patients and to know the various domains of cognition that are affected. Results: This study shows a presence of cognitive decline in euthymic bipolar disorder patients as compared to controls. A significant difference was found in all the cognitive domains namely atte ntion, memory, fluency, language and visuospatial between cases and controls. Conclusion: This study shows a positive correlation between cognitive decline and bipolar patients during the period of euthymia. This suggests that even though the bipolar disor der patient is in remission, there is still a residual effect on cognition during euthymic state which can eventually affect the day to day life and can hamper the quality of life.

Peak Expiratory Flow Rate (PEFR) Corrected for Forced Expiratory Pressure

Traditionally, PEFR is a measure of airway resistance and estimate of bronchoconstriction. It is used as adiagnostic as well as prognostic marker for respiratory diseases, especially asthma. But PEFR is effortdependent parameter which not only depends upon the airway resistance but also the Forced ExpiratoryPressure (FEP) generated by the respiratory muscles. This expiratory force generated needs to be consideredwhen interpreting the results of PEFR. Therefore, present study was undertaken to explore relationshipbetween PEFR and FEP and to find corrected PEFR.A total of 56 physically fit volunteers were examinedfor PEFR using Wright’s peak flow meter and FEP was estimated using a mercury manometer connectedto a mouth piece with airtight seal. The results of multiple linear regression model suggested that FEP hasstatistically significant influence on PEFR (beta coefficient = 1.18, adjusted R20.699). The formula forcorrected PEFR was derived and the coefficient of variance before and after PEFR correction was 35.53%and 30.13% respectively, suggesting that for better clinical utility PEFR should be corrected for FEP. Toextrapolate the present study results to other age groups and diseased population further studies areneeded.

Sphygmomanometric Blood Pressure Drop on Consecutive Measurements : The Search for a Cause.

This study was inspired by our oft-noted observation that the first sphygmomanometric reading of blood pressure (BP) is invariably higher than the subsequent ones recorded immediately thereafter. The objectives of this study were to establish the statistical validity of this observation and further, to probe the possible causes of the same. The sphygmomanometric BP was recorded in 30 non-obese young adults using two different protocols. In protocol-1, BP in the left arm was repeated thrice in quick succession, both in standing and supine postures. In protocol-2, BP was recorded in the supine position six times in quick succession, thrice in the left arm and immediately thereafter, thrice in the right arm. Data was compiled and analysed using appropriate statistical tests. In protocol-1, a statistically-significant drop in the blood pressure was consistently noted between quickly consecutive measurements in both standing and supine postures. Importantly, this pressure drop was not significantly affected by posture. In protocol-2, significant pressure drop was recordable from both arms. These findings rule out baroreflex as a cause of the pressure-drop on consecutive measurements and suggest a likely role of tissue compaction in the same.

Post-task changes in visual P300 and their reversibility through brief hyperventilation.

Long hours of continuous, mental task reportedly increase the average auditory P3 latency of the normal subjects significantly, a change that is thought to be related to mental fatigue. We have tried out several protocols of varying task difficulty and duration in an effort to study the onset of the assumed fatigue-related changes. The present study shows that changes in visual event-related potential occur in less than two minutes if the task is sufficiently rigorous. The changes occur both in latency and in amplitude. Moreover, the changes are reversible with a brief (30 second) period of hyperventilation. The changes were most marked at Fz. Following the difficult task, the P3 amplitude at Fz decreased from 8.588 micro/V +/- 0.966 to 5.800 microV +/- 0.795 and the P3 latency increased from 368 +/- 4 ms to 380 +/- 3. Following hyperventilation, the P3 amplitude at Fz reverted to 8.457 +/- 5 and the P3 latency reverted to 371 +/- 5 ms. These observations call for further investigations on the cause of the post-task changes and their quick reversibility.

Post-task P3-changes following a brief, rigorous visual task indicate individual differences in the task-specific ability.

The P3 latency in an auditory oddball ERP paradigm is known to get prolonged after a few hours of mental task. The present study shows that it takes merely a few minutes of challenging visual mental activity to produce significant changes in P3 latency in the visual oddball ERP paradigm. However, the mental activity results in a shortening of P3-latency almost as often as it results in its prolongation. Similarly, the post-task P3 amplitude is higher or lower with nearly equal incidences. Following the task, the reaction time shortens as often as it prolongs. It seems that the P3 changes and their variations through electrode sites signify individual differences in the amount and extent of additional neuronal resources tapped by the subject in coping with the challenging task, and that it leaves an aftereffect for several minutes after the mental workload is withdrawn. These aftereffects get indexed in the P3 wave characteristics of a much simpler ERP paradigm with more change occurring in the better performers. In the clinical context, these observations raise doubts about the diagnostic value of P3 latency or amplitude without knowledge of the immediate history of mental workload.