Sleep and Stroke

Circadian variations in conjunction with sleep-related heart rhythm changes and sleepdisordered breathing (SDB) are contributing risk factors for stroke. Strong scientificevidence now exists indicating that SDB contributes to systemic hypertension, aprominent risk factor for stroke, and compelling circumstantial evidence is presentsuggesting that SDB raises the risk for development of stroke through other circulatorymechanisms as well. Preliminary evidence indicates that post-stroke patients have ahigher prevalence of SDB, which is likely to compromise their rehabilitation outcomes.Since SDB is modifiable with the application of CPAP and other treatment modalities,there is practical value in investigating patients at risk of stroke or post stroke forpresence of SDB. Successful application of CPAP or BiPAP therapy may improve theoutcome in both instances.Key words : Sleep, Stroke, SDB, CPA

Causes of Hypersomnia – Narcolepsy

The causes of hypersomnia or excessive daytime sleepiness (EDS) besides volitionalsleep deprivation and obstructive sleep apnea are principally due to primary centralnervous system abnormalities. Most common amongst these is Narcolepsy, a primarydisorder of the neural control of wakefulness and sleep. The recent discovery ofhypocretin/orexin deficiency as the main cause of narcolepsy will lead to importanttherapeutic advances for patients with narcolepsy and further to understanding of thecontrol of sleep and wakefulness in general. Importantly, the excessive daytimesleepiness is not due to psychiatric conditions, but rather is always due to sleepdeprivation or an underlying diagnosable and treatable sleep disorder.Key words : EDS, Sleep, Narcoleps

Causes of Hypersomnia – Narcolepsy

The causes of hypersomnia or excessive daytime sleepiness (EDS) besides volitionalsleep deprivation and obstructive sleep apnea are principally due to primary centralnervous system abnormalities. Most common amongst these is Narcolepsy, a primarydisorder of the neural control of wakefulness and sleep. The recent discovery ofhypocretin/orexin deficiency as the main cause of narcolepsy will lead to importanttherapeutic advances for patients with narcolepsy and further to understanding of thecontrol of sleep and wakefulness in general. Importantly, the excessive daytimesleepiness is not due to psychiatric conditions, but rather is always due to sleepdeprivation or an underlying diagnosable and treatable sleep disorder.Key words : EDS, Sleep, Narcoleps

North and South Indian populations share a common ancestral origin of Friedreich's ataxia but vary in age of GAA repeat expansion

Friedreich's ataxia (FRDA) is caused by expansion of GAA repeats in the frataxin (FXN) gene on chromosome 9q13-q21.1. We analysed the origin of FRDA in 21 North Indian (NI) and eight South Indian (SI) families using five single nucleotide polymorphisms (SNPs) and a microsatellite marker spanning the GAA repeats. The NI and SI families were derived from Indo-European and Dravidian linguistic backgrounds respectively. The frequency of large normal (LNs) alleles of the GAA repeat correlate with the overall lower prevalence of FRDA in India compared to the European population. All of the expanded alleles in the Indian population share a common core haplotype suggesting a founder effect. The expanded alleles in the NI population demonstrate more similarity to those of Europeans in terms of age of GAA repeat expansion (15975 ± 2850 years) and association of LNs with expanded alleles. FRDA seems to have been introduced recently in the South Indian population since the average estimated age of the mutation in SI is 5425 ± 1750 years and unlike NI some of the haplotypes of LNs are not associated with the expanded alleles