Attenuation of spatial attentional asymmetries with poor sustained attention

The co-existence of deficits in sustained and spatial attention in patients with acquired damage to the right cerebral hemisphere has led to the proposition that sustained attention could be a marker for left spatial inattention, or neglect. We investigated the possibility that reductions in leftward spatial attentional asymmetries could arise from individual differences in the capacity for sustained attention even within healthy adult populations. We observed that healthy participants who performed poorly on a test of sustained attention had a significantly attenuated left spatial bias, relative to those with good sustained attention capacity, on a free-viewing spatial attention test. Our results provide further support for the notion that sustained attention may exert a modulatory influence on spatial attention.     

Daytime sleepiness and its evaluation

Basic models of sleepiness, focusing on the homeostatic and circadian components of sleepiness, are able to predict important fluctuations of sleepiness. However, they fail in explaining certain sleepiness phenomena, as for instance in insomnia patients. To meet this shortcoming, modern models incorporate the arousal component of sleepiness, in addition to the sleep drive. While these models mainly concentrate on short-term changes in sleepiness, "state" sleepiness, there are indications that a stable characteristic level of sleepiness, "trait" sleepiness, is also an important determinant of a person's level of sleepiness. This leads to a conceptualization of sleepiness in which situational factors modify a basal level of sleep drive and arousal. It implies that sleepiness is not a unitary concept and can reflect essentially different states. Multiple sleepiness assessment tools have been proposed in the past. The majority of them offer valuable information, but they do not grasp all aspects of sleepiness. We should bear in mind that tools for assessing sleepiness are always operationalizations reflecting the theoretical framework the investigator has on sleepiness. Hence, rather than searching for a gold standard for the measurement of sleepiness, future research effort should be aimed at linking the various measurement techniques with the hypothesized underlying components of sleepiness on a sound empirical basis.     

Daytime sleepiness and academic performance in medical students

This report presents an analysis of the complaints of increasing daytime sleepiness as well as a study on their possible effects on the academic performance of medical students at the University of Brasilia. The Epworth Sleepiness Scale was applied to 172 medical students, at the beginning of August 1997 and at the end of November 1997. Academic performance was measured by analyzing the number of SS grades (from 9.0 to 10 over ten) and MM grades (from 5.0 to 6.9) attained in exams at the end of that school period. The results showed that at the beginning of the semester, 68 (39.53%) of these 172 students already presented with excessive daytime sleepiness, and that of the 104 remaining students, 38 (22%) developed daytime sleepiness by the end of the semester. Furthermore, it was observed that the sleepier students did not achieve as well as the others on their final examinations.     

老年帕金森病患者日间过度思睡的临床调查及相关因素分析

目的了解老年帕金病(PD)患者日间过度思睡(EDS)的临床情况及相关因素。方法收集北京医院老年PD患者80例和年龄、性别相匹配的健康对照者50名,采用爱泼沃斯思睡量表(ESS)评定EDS,简易精神状态量表(MMSE)评定智能状况,比较PD患者和健康对照的EDS情况,同时对PD患者进行改良Webster评分、Hoehn-Yahr(H-Y)分期、Hamilton抑郁和焦虑量表调查,并询问是否具有夜间易醒、疲倦、不宁腿综合征、日间睡眠发作、夜间入睡困难、是否应用多巴受体激动剂及多巴胺药物的用量。根据ESS评分情况将PD患者分为EDS组(ESS≥10)和非EDS组(ESS<10分),并对两组间的上述调查项目进行比较。同时以ESS总分为因变量,以计量资料年龄、Hoehn-Yahr分级、左旋多巴用量、Webster评分、病程、Hamilton抑郁和焦虑评分及睡眠时间为自变量进行多元逐步回归分析,分析ESS评分与以上各因素的相关性。结果 80例PD患者中23例(28.8%)ESS≥10分,健康对照组5名(10.0%)ESS≥10分,两组有差异有统计学意义(χ2=6.40,P=0.01)。EDS组23例(男10例、女13例),年龄(72.26±5.94)岁,日间疲倦18例(78.26%),Hamilton抑郁量表评分(13.57±3.31)分,Hamilton焦虑量表评分(19.13±5.38)分,病程(7.65±4.12)年,非EDS组57例(男40例、女17例),年龄(68.58±5.27)岁,日间疲倦18例(31.58%),Hamilton抑郁量表评分(7.32±2.71)分,Hamilton焦虑量表评分(13.25±5.12)分,病程(5.55±3.40)年,两组间比较有统计学差异(均P<0.05);两组患者Hoe-hn-Yahr分级、改良Webster评分、应用左旋多巴剂量、是否应用多巴受体激动剂、夜间睡眠时间、入睡困难、不宁腿综合征、夜间易醒均无统计学差异(均P>0.05)。多元逐步回归分析结果显示,PD患者年龄和抑郁程度与ESS评分相关(分别回归系数=0.10,标准偏回归系数=0.16,P=0.04;回归系数=0.59,标准偏回归系数=0.66,P=0.00),抑郁程度相关性更强。结论老年PD患者EDS较为常见,可能受年龄和抑郁情绪的影响,但与疾病严重程度可能不存在相关性。     

Individual differences in sustained attention are associated with cortical thickness

Several studies have examined how individual differences in sustained attention relate to functional brain measures (e.g., functional connectivity), but far fewer studies relate sustained attention ability, or cognition in general, to individual differences in cortical structure. Functional magnetic resonance imaging meta‐analyses and patient work have highlighted that frontoparietal regions, lateralized to the right hemisphere, are critical for sustained attention, though recent work implicates a broader expanse of brain regions. The current study sought to determine if and where variation in cortical thickness is significantly associated with sustained attention performance. Sustained attention was measured using the gradual onset continuous performance task and the Test of Variables of Attention in 125 adult Veteran participants after acquiring two high‐resolution structural MRI scans. Whole‐brain vertex‐wise analyses of the cortex demonstrated that better sustained attention was associated with increased thickness in visual, somatomotor, frontal, and parietal cortices, especially in the right hemisphere. Network‐based analyses revealed relationships between sustained attention and cortical thickness in the dorsal attention, ventral attention, somatomotor, and visual networks. These results indicate cortical thickness in multiple regions and networks is associated with sustained attention, and add to the growing knowledge of how structural MRI can help explain individual differences in cognition.     

Daytime sleepiness is associated with dementia and cognitive decline in older Italian adults: A population-based study

ObjectiveThe occurrence of dementia among the elderly has been associated with several, often not modifiable, risk factors. Recent epidemiological studies focused their interest on a possible association between cognitive decline and sleep, a potentially modifiable risk factor. Due to controversial results and limitations of the previous studies, we decided to reexamine the relationship between disturbed sleep and cognitive impairment in the elderly.MethodsSeven hundred fifty subjects aged 65 years or older were recruited. The Mini-Mental State Examination (MMSE) and the Global Deterioration Scale (GDS) scores were used to evaluate the severity of cognitive decline. Diagnosis of dementia was made by means of the DSM-IV criteria. The older adults were interviewed in order to assess the presence of several sleep complaints (insomnia, snoring and/or witnessed sleep apneas, restlessness and/or leg jerks, sleepwalking and nightmares). Excessive daytime sleepiness was evaluated by means of a validated questionnaire. The principal caregiver of each older adult took part in the interview, providing the information if the subject was unable to answer because of mental impairment.ResultsEighty-six individuals were diagnosed as demented; a large part of them (47.8%), in particular, were recognized as being affected by Alzheimer’s disease. The prevalence of each sleep complaint in the older adults was as follows: insomnia 84.7%, snoring and/or witnessed sleep apneas 26.2%, restlessness and/or jerks in the legs 25.7%, sleepwalking 0.5%, nightmares 6.4% and daytime somnolence 30.6%. Among sleep disturbances, excessive daytime sleepiness was independently associated with the presence of dementia in the elderly. In addition, the frequency of excessive daytime sleepiness increased progressively across the different categories of cognitive decline, as measured by means of MMSE and GDS scores.ConclusionsInsomnia, the most common sleep complaint in our sample, was not associated with the presence of cognitive decline. As opposed to insomnia, excessive daytime sleepiness was significantly related to dementia. Further studies are needed in order to investigate the direction of this association and to evaluate the possible role of daytime somnolence as an early marker of neurodegenerative disease, particularly Alzheimer’s disease, in some older adults.     

Daytime sleepiness and polysomnography in obstructive sleep apnea patients

BackgroundExcessive daytime sleepiness (EDS) is the major complaint in subjects with obstructive sleep apnea syndrome (OSAS). However, EDS is not universally present in all patients with OSAS. The mechanisms explaining why some patients with OSAS complain of EDS whereas others do not are unknown.ObjectiveTo investigate polysomnographic determinants of excessive daytime sleepiness (EDS) in a large multicenter cohort of patients with obstructive sleep apnea (OSAS).MethodsAll consecutive patients with an apnea–hypopnea index greater than 5 h⁻¹ who were evaluated between 2003 and 2005. EDS was assessed using the Epworth Sleepiness Scale (ESS), and patients were considered to have EDS if the ESS was >10.ResultsA total of 1649 patients with EDS ((mean [±SD] Epworth 15 ± 3) and 1233 without EDS (Epworth 7 ± 3) were studied. Patients with EDS were slightly younger than patients without EDS (51 ± 12 vs 54 ± 13 years, p < 0.0001), had longer total sleep time (p < 0.007), shorter sleep latency (p < 0001), greater sleep efficiency (p < 0.0001) and less NREM sleep in stages 1 and 2 (p < 0.007) than those without EDS. Furthermore, patients with EDS had slightly higher AHI (p < 0.005) and arousal index (p < 0.001) and lower nadir oxygen saturation (p < 0.01).ConclusionsPatients with OSAS and EDS are characterized by longer sleep duration and increased slow wave sleep compared to those without EDS. Although patients with EDS showed a mild worsening of respiratory disturbance and sleep fragmentation, these results suggest that sleep apnea and sleep disruption are not the primary determinants of EDS in all of these patients.     

Daytime sleepiness and functional impairment in Alzheimer disease.

OBJECTIVE: Daytime sleep has been noted to accompany dementing illness and is more pronounced as dementia severity increases. Although acknowledged by caregivers, sleepiness during the daytime is among the least troublesome of sleep behaviors described in Alzheimer Disease (AD) patients. The purpose of this study was to examine whether patient and spouse/caregiver reports of daytime sleepiness in AD were associated with lower functional status in those patients. METHODS: The authors utilized the Epworth Sleepiness Scale to assess reported daytime sleepiness and a modification of the Lawton and Brody scale to assess functional status in a group of 137 AD patients. The authors also examined typical bedtimes and wakeup times via questionnaire. RESULTS: Higher levels of daytime sleepiness were associated with greater impairments in functional status. These results were independent of level of cognitive impairment, as assessed with Mini-Mental State Exam, and they were also detectable when the authors limited analyses to data reported only by spouse/caregiver. Findings were not associated with medication use. AD patients also had earlier bedtimes and later wake-up times than a comparison group. CONCLUSION: Even apart from its association with impaired cognition, daytime sleepiness was associated with functional impairment in AD patients. Although daytime sleep may represent a welcome relief for caregivers, its presence may be associated with greater impairment in instrumental activities and may warrant intervention.     

Daytime sleepiness in epilepsy patients receiving topiramate monotherapy

Summary: Purpose: Limited research has focused to date on objective neurophysiological evaluation of daytime sleepiness in patients treated with newer antiepileptic drugs (AEDs), especially when used as monotherapy. This study was aimed at assessing occurrence of daytime sleepiness in newly diagnosed, drug‐naïve patients with partial epilepsy receiving initial topiramate (TPM) monotherapy. Methods: Daytime vigilance was assessed in 14 consecutive, newly diagnosed and never medicated adult patients with focal epilepsy, receiving monotherapy with TPM. At baseline and 2 months after slowly titrated therapy with TPM, 200 mg/day, patients underwent the Multiple Sleep Latency Test (MSLT), visual simple and choice reaction times (VRT), and self‐rated their own degree of sleepiness with the Epworth Sleepiness Scale. A group of 14 age‐ and gender‐matched healthy volunteers served as controls. Results: At baseline, mean daytime sleep latencies on the MSLT were comparable in patients and in controls. Two months after TPM monotherapy, MSLT scores did not significantly change in patients as compared with pretreatment values. Accordingly, subjective daytime sleepiness and VRTs, which were comparable in controls and in untreated patients at baseline, did not change in patients after TPM monotherapy. Conclusions: Study results suggest that an initial short‐course monotherapy with TPM, 200 mg/day, does not impair daytime vigilance in newly diagnosed adult patients with partial seizures.     

Reduced electrodermal response to errors predicts poor sustained attention performance in attention deficit hyperactivity disorder

Research into attention deficit hyperactivity disorder (ADHD) has indicated abnormalities in electrodermal system activity (EDA) and separately, deficits in sustained attention. Here we asked whether reduced EDA in ADHD was consequential for the attention problems associated with this disorder. On a sustained attention task ADHD participants had higher overall error rates and exhibited a marked decrease in skin conductance responses (SCRs) to errors, relative to control children. Further, sustained attention errors were predicted by SCR amplitudes. Evidence of post-error slowing in both groups suggested comparable error awareness. It is proposed that attenuation of the normal autonomic response to errors reflects impairment in ADHD participants' psychological response to error significance and results in decreased behavioural correction and hence poorer sustained attention.     

Daytime sleepiness and automobile accidents in patients with obstructive sleep apnea syndrome

Abstract We evaluated the rate of automobile accidents and daytime sleepiness using the Epworth sleepiness scale (ESS) in 44 patients with obstructive sleep apnea syndrome (OSAS). We defined the automobile accident score as a sum of two points for every one automobile accident and one point for every near-miss accident. Automobile accidents and near-misses were found in 54.5% and 50.0% in patients with OSAS. Automobile accident score was significantly correlated with the ESS score ( r = 0.56, P < 0.01). Our findings suggest that ESS score may be useful in detecting patients with the potential risk of automobile accidents associated with daytime sleepiness.     

Daytime sleepiness and other sleep disorders in Parkinson's disease.

BACKGROUND: PD is associated with a variety of sleep problems. The dopamine agonists (DA) pramipexole and ropinirole were recently implicated in causing "sleep attacks" and motor vehicle accidents. METHODS: In order to determine the overall rate of subjective sleep problems in PD and to determine if any factors, including specific medications, correlate with sleep pathology, the authors surveyed consecutive patients with PD seen over a 3-month period in a Movement Disorders Clinic. The authors collected demographic and medication data, and the patients completed the Epworth Sleepiness Scale (ESS), questions assessing the presence of restless legs syndrome (RLS), a modified National Sleep Foundation sleep survey, and specific questions regarding falling asleep while driving. RESULTS: A total of 320 patients completed the questionnaire. The authors eliminated 17, six for incomplete data and 11 for having a primary diagnosis other than PD. The mean age of the remaining 303 patients was 67.1 +/- 10.7 years, and the mean duration of PD was 9.1 +/- 5.7 years. The ESS scores averaged 11.1 +/- 5.9, and in 50.2% of patients the score was abnormally high (>10). Stepwise regression analysis found that sleepiness correlated with longer duration of PD (p < 0.001), more advanced PD (p < 0.004), male sex (p < 0.001), and the use of any DA (p < 0.003). The soporific effects of the three most common DA (pramipexole, ropinirole, and pergolide) were similar. Falling asleep while driving was reported by 63/279 (22.6%) of current drivers and correlated with higher ESS scores (p < 0.05). Other sleep disorders, including RLS, were also frequently reported. CONCLUSION: Daytime sleepiness is common in PD and correlates with more advanced and longer duration of PD, and male sex. The DA were also independently associated with daytime sleepiness, but in this group, no single DA was more culpable than the others.     

Daytime sleepiness: a risk factor in community life

The prevalence of daytime sleepiness and background factors associated with it were investigated in a study carried out at the UKK Institute. The inquiry took the form of a questionnaire mailed to 1600 people of middle age. Daytime sleepiness was found to be associated with disturbed night sleep. Women were more tired than men, but men slept more frequently during the day. Those suffering from tiredness complained of poor health more than other respondents. Traffic accidents and other mishaps attributable to tiredness had occurred in 1.3% of cases, and almost 5% of male respondents had dozed off while driving at least five times in their lives. The findings indicate a need for increased attention to disturbance of sleep and daytime sleepiness in routine health screening.     

Effects of modafinil on sustained attention performance and quality of life in OSA patients with residual sleepiness while being treated with nCPAP

BACKGROUND: Some patients with obstructive sleep apnea/hypopnea syndrome (OSA/HS) who are regular users of nasal continuous positive airway pressure (nCPAP) therapy continue to experience daytime sleepiness that impairs performance and quality of life. A randomized, double-blind, placebo-controlled, parallel-group study was conducted to determine the effect of modafinil on sustained attention performance and functional quality of life in OSA/HS patients with residual daytime sleepiness, who were regular users of nCPAP therapy. METHODS: Seventy-seven patients received modafinil (200 mg/day, week 1; 400 mg/day, weeks 2-4) and 80 patients received matching placebo once daily for 4 weeks. Sustained attention performance on the psychomotor vigilance task (PVT) and functional status and quality of life using the Functional Outcomes of Sleep Questionnaire (FOSQ) were measured. RESULTS: The frequency of lapses of attention during PVT performance was significantly decreased, and both the median and slowest reaction times were significantly improved in patients receiving nCPAP plus modafinil compared with those receiving nCPAP plus placebo (P=0.010 for the number of lapses [transformed], P=0.023 for the median reaction time, and P=0.014 for the reciprocal of the 10% slowest reaction times). Treatment with nCPAP plus modafinil significantly improved the FOSQ total score (weeks 1 and 4), the vigilance subscale score (weeks 1 and 4), and the activity level subscale score (week 4) compared with treatment with nCPAP plus placebo (all P<0.05). CONCLUSIONS: Consistent with previous results for objective and subjective measures of sleepiness, modafinil used adjunctively improved performance on a test of behavioral alertness and reduced functional impairments in patients with OSA/HS who were regular users of nCPAP therapy but still experiencing sleepiness.