Information processing speed in obstructive sleep apnea syndrome: a review.

To provide a comprehensive review of studies on information processing speed in patients with obstructive sleep apnea syndrome (OSAS) as compared to healthy controls and normative data, and to determine whether continuous positive airway pressure (CPAP) treatment improves information processing speed. A systematic review was performed on studies drawn from Medline and PsycINFO (January 1990-December 2011) and identified from lists of references in these studies. After inclusion criteria, 159 articles were left for abstract review, and after exclusion criteria 44 articles were fully reviewed. The number of patients in the studies reviewed ranged from 10 to 157 and the study samples consisted mainly of men. Half of the studies reported that patients with OSAS showed reduced information processing speed when compared to healthy controls. Reduced information processing speed was seen more often (75%) when compared to norm-referenced data. Psychomotor speed seemed to be particularly liable to change. CPAP treatment improved processing speed, but the improvement was marginal when compared to placebo or conservative treatment. Patients with OSAS are affected by reduced information processing speed, which may persist despite CPAP treatment. Information processing is usually assessed as part of other cognitive functioning, not as a cognitive domain per se. However, it is important to take account of information processing speed when assessing other aspects of cognitive functioning. This will make it possible to determine whether cognitive decline in patients with OSAS is based on lower-level or higher-level cognitive processes or both.

The presence of visual neglect after thrombolytic treatment in patients with right hemisphere stroke.

Visual neglect (VN) is a common consequence of right hemisphere (RH) stroke. The aims of this study were to explore the presence of VN after RH stroke in the patients with (T+) or without (T-) thrombolytic treatment, and to determine whether thrombolysis is a predictor of VN. The study group consisted of 77 RH infarct patients. VN was evaluated with six conventional subtests of the Behavioural Inattention Test (BIT). Stroke severity was assessed using the National Institute of Health Stroke Scale (NIHSS). In the neuropsychological examination, 22% of all RH stroke patients had VN. VN was present in 15% of the patients in the T+ group and in 28% of the patients in the T- group, but the difference was not statistically significant. Despite that, patients in the T- group had a higher risk of VN than patients in the T+ group. Our results suggest that thrombolysis independently predicted absence of VN.

Recovery from visual neglect after right hemisphere stroke: does starting point in cancellation tasks change after 6 months?

In the acute phase of stroke, patients with left visual neglect (VN) automatically orient to the right hemispace. This study examined the presence of rightward bias after right hemisphere stroke within 10 days of stroke onset and after 6 months. Our sample comprised 43 patients and 49 healthy controls. Presence of VN was evaluated with the six conventional subtests of the Behavioral Inattention Test (BITC). Starting points were determined in three BITC cancellation tasks by measuring the distance between the starting point and the median line of the stimulus sheet in centimeters. Activities of daily living (ADL) were assessed with the Barthel Index. At baseline VN patients showed more robust rightward bias than patients without VN. The magnitude of rightward bias decreased clearly in the VN patients at follow-up. A favorable ADL outcome was observed in 90% of the patients with VN and in all of the patients without VN. The magnitude of rightward bias differed clearly between the patient groups and controls. Our result implies that VN was likely to have improved as measured by BITC sum scores, but symptoms of rightward attention bias were still detected. We therefore suggest that, for clinical purposes, it is important that attention bias is measured accurately after right hemisphere stroke.

Rightward bias in right hemisphere infarct patients with or without thrombolytic treatment and in healthy controls.

Right hemisphere (RH) infarct patients have a tendency to begin visual scanning from the right side of a given stimulus. Our aim was to find out whether RH patients with (T+) or without (T-) thrombolytic treatment and healthy controls differ in their starting points in three cancellation tasks. Our sample comprised of 77 patients and 62 controls. Thirty-four patients received thrombolysis. Rightward orientation bias was more evident in the T- group than in the T+ group. The T+ group showed a robust tendency to start all cancellation tasks more often on the right side than the controls. Regardless of whether they had visual neglect, patients in the T+ group showed still defective rightward orienting, possibly indicating residual attentional problems. The analyses of starting points in visual cancellation tasks provide additional information on residual symptoms of attention difficulties after stroke.

Predictors of functional outcome after right hemisphere stroke in patients with or without thrombolytic treatment.

The purpose of this study was to assess the predictors of functional outcome after right hemisphere stroke at 6-month follow up in patients with or without thrombolytic treatment. Thrombolysis did not predict functional outcome in instrumental activities of daily living (IADL). Lower acute phase basic activities of daily living (ADL) measured by the Barthel Index was a statistically significant predictor of IADL when adjusted for age and education (p = .015) and had borderline significance (p = .076) as a predictor of functional outcome when adjusted for severity of stroke at admission. When stroke severity was taken into account also higher age became a statistically significant (p = .039) predictor of functional outcome. The acute phase neuropsychological symptoms predicted the functional outcome in unadjusted analyses but when adjusted for age, education, and severity of stroke no independent association was found.

Is persistent visual neglect associated with poor survival?

BACKGROUND: The association of visual neglect with survival after right hemisphere (RH) stroke has received only limited attention. OBJECTIVE: This study explores the relationship of visual neglect and its spontaneous recovery to survival in a homogenous patient group with first-ever RH stroke. METHODS: Fifty-one RH stroke patients who suffered an infarct between 1994 and 1997 were retrospectively followed for survival until August 31, 2009. Acute-phase neurological, neuropsychological and neuroradiological data were studied to identify predictors of survival. RESULTS: Twenty-eight patients died during the follow-up. Age, education, and poor recovery of visual neglect emerged as significant single predictors of death. The best set of predictors for poor survival in the multivariate model was poor recovery of visual neglect and low education. CONCLUSIONS: Poor recovery of visual neglect is associated with long-term mortality in RH infarct patients. The follow-up of RH patients' neuropsychological performance gives additional information about the prognosis.

Predictors of discharge to home after thrombolytic treatment in right hemisphere infarct patients.

BACKGROUND: The aim of the study was to assess the association between thrombolysis and length of hospital stay after right hemisphere (RH) infarct, and to identify which cognitive functions were predictive of discharge. METHODS: The study group consisted of 75 acute RH patients. Thirty-three patients had thrombolysis. Neuropsychological examinations were performed within 11 days of stroke onset. The cognitive predictors were visual neglect, visual memory, visual search and reasoning and visuoconstructive abilities. The outcome variable was time from stroke to discharge to home. RESULTS: Thrombolysis emerged as a statistically significant predictor of discharge time in patients with moderate/severe stroke (NIHSS ≥5). In the total series of patients and in patients with mild stroke (NIHSS <5), thrombolysis was not significantly associated with discharge time. Milder visuoconstructive defects shortened the hospital stay of the whole patient group and of patients with moderate/severe stroke. In all patient groups, independence in activities of daily living (ADL) was a significant single predictor of a shorter hospital stay. The best combination of predictors for discharge was independence in ADL in the total series of patients and in patients with mild stroke, and thrombolysis and independence in ADL in patients with moderate/severe stroke. CONCLUSIONS: Thrombolytic treatment was a significant predictor of earlier discharge to home in patients with moderate/severe RH infarct, while cognitive functions had less predictive power.

Fluctuation in spontaneous recovery of left visual neglect: a 1-year follow-up.

Spontaneous recovery and possible fluctuation in left visual neglect, and its relation to stroke severity, basic activities of daily living (ADL) and extended ADL were examined at 10 days, at 3, 6, and 12 months after onset. Twenty-one of 56 right hemisphere stroke patients had visual neglect. Three visual neglect recovery groups were identified: continuous, fluctuating and poor recovery. We concentrated on the comparison of the continuous and the fluctuating recovery groups. At the acute phase the fluctuating recovery group had larger infarcts, more severe neglect and stroke, and a lower level of basic ADL compared to the continuous recovery group. In the continuous recovery group stable recovery was detected up to 6 months, whereas in the fluctuating recovery group recovery was incoherent in neglect and in extended ADL. A minimum follow-up period of 6 months including the evaluation of extended ADL is recommended for neglect patients due to possible fluctuation in visual neglect.

Depression and anxiety in obstructive sleep apnea syndrome: a review.

OBJECTIVE - To provide an update on recent research on depression and anxiety in obstructive sleep apnea syndrome (OSAS). METHODS - A review was carried out on reports drawn from MEDLINE and PSYCHLIT (January 1995-June 2006) and identified from their list of references. The selection criteria were met by 55 articles. RESULTS - Sample sizes in the reviewed studies varied widely and consisted mainly of working age men. Depression and anxiety were mostly evaluated with commonly used mood scales; only a few studies provided a psychiatric diagnosis. Prevalence figures fluctuated considerably for both depression (7-63%) and anxiety (11-70%). The effect of the continuous positive airway pressure (CPAP) on mood was inconsistent. CONCLUSIONS - Variations in the prevalence of depression and anxiety are affected by patient characteristics, mood assessment methods, and overlap between mood alterations and OSAS-related symptoms. CPAP might improve mood alterations but more long-term follow-up studies are needed to verify the effectiveness.

A review of executive functions in obstructive sleep apnea syndrome.

OBJECTIVES: To provide an update on recent research concerning obstructive sleep apnea syndrome (OSAS) and executive functions. METHODS: A systematic review was carried out on reports drawn from MEDLINE and PSYCHLIT (January 1990-December 2005) and identified from lists of references in these reports. The selection criteria were met by 40 articles. RESULTS: The sample sizes in the reviewed studies varied widely and consisted mostly of selected groups. Most patient samples were heterogeneous in terms of the severity of OSAS. Executive functions were generally assessed with standardized test methods. Half of the studies assessed executive functions using only one or two tests. The most defected domains of executive functions were working memory, phonological fluency, cognitive flexibility, and planning. Continuous positive airway pressure (CPAP) treatment improved performance times, cognitive flexibility, and planning. Deficits in working memory and phonological fluency persisted. CONCLUSIONS: Executive functions are the most defected cognitive domain in OSAS. Previous studies are affected by the heterogeneity of patient samples and the definitions of the domains of executive functions. Executive functions in OSAS should be assessed with a standardized neuropsychological test battery including assessments of different domains of executive functions. More research is needed on the efficiency of CPAP treatment on executive dysfunctions.

Impact of neglect on functional outcome after stroke: a review of methodological issues and recent research findings.

PURPOSE: This study provides an update on recent research findings concerning neglect and its impact on functional outcome. The review covers studies published during the past ten years. METHODS: A systematic review was carried out on reports drawn from electronic databases (MEDLINE and PSYCHLIT, January 1996 - August 2005) and identified from the lists of references in these reports. Unpublished reports, articles in other than the English language, and studies with non-human and non-adult subjects were excluded. The selection criteria were met by 26 articles. RESULTS: 15 of the 26 studies recruited heterogeneous patient groups (patients with right and left and/or unspecified lesions). The results from homogeneous groups (right hemisphere patients) were more consistent, emphasizing neglect as an independent predictor of functional outcome. Studies with homogeneous patient groups used consecutive series of patients, standardized measures of neglect, and a broader concept of functional outcome (both motor and cognitive items) than those with heterogeneous patient groups. Follow-ups longer than one year were very rare. CONCLUSIONS: Neglect has a significant negative impact on functional outcome, either as an independent predictive factor or in connection with other variables. The results, however, are inevitably affected by differences in patient samples and in the methods used in assessing neglect and functional outcome. Research focusing on homogeneous patient groups and especially on left hemisphere patients is needed. Neglect should be assessed with a standardized test battery rather than a single test, and functional outcome should be measured with scales consisting of cognitive, social and motor items. Also longer follow-ups are needed to verify the long-term functional outcome of neglect patients.

Anosognosia after stroke: assessment, occurrence, subtypes and impact on functional outcome reviewed.

PURPOSE: This review provides an update on recent research findings concerning the methods used in the assessment of anosognosia, the occurrence and subtypes of anosognosia, the association between anosognosia and neglect, and the impact of anosognosias on functional outcome. METHODS: A systematic review covering the period from 1995 to 2005 was carried out on reports drawn from electronic databases (MEDLINE, PSYCHLIT) and identified from the references in these reports. Twenty-seven articles met the selection criteria. RESULTS: The results of this review are in line with previous findings in the following respects: anosognosia was more often associated with right hemisphere damage, neglect and anosognosia co-occurred, and anosognosia had predictive value on poor functional outcome. The variation in the methods used in the assessment of anosognosia, patient samples and assessment times influence the occurrence rates and the predictive value of anosognosia, which might undermine the generalizability of the results. CONCLUSIONS: More homogeneous patient samples and consistency in the assessment methods and evaluation times would facilitate comparisons of the occurrence and the impact of anosognosia on functional outcome. New methods need to be developed for the assessment of anosognosia. These new methods should take account of the subtypes of anosognosia both at verbal and at non-verbal levels.

Predictors of discharge to home during the first year after right hemisphere stroke.

OBJECTIVES: The aim of this study was to explore predictive factors of the length of hospital stay at the acute stage of right hemisphere stroke. Special attention was paid to the possible role of anosognosia for hemiparesis and anosognosia for neglect in this prediction. PATIENTS AND METHODS: A consecutive series of 57 patients having their first right hemisphere stroke were examined at the acute phase. Forty-nine patients were included in this study and followed-up for 12 months. The examinations were conducted within 2 weeks of onset. The outcome variable was the time (days) from stroke to discharge to home. The predictors were age, gender, size of infarct, neglect, hemiparesis, verbal memory, unawareness of illness, anosognosia for neglect, anosognosia for hemiparesis and presence of a relative at home. RESULTS: Hemiparesis and unawareness of illness lengthened the duration of the hospital stay, the presence of a relative reduced it. Neglect was the best single predictor of poor outcome, but it had no additional value in the combination of the three predictors above. Neither anosognosia for hemiparesis nor anosognosia for neglect were important predictors. CONCLUSION: Hemiparesis, unawareness of illness and presence of a relative at home were the best predictors of the time from right hemisphere stroke to discharge to home.

Unawareness of deficits after right hemisphere stroke: double-dissociations of anosognosias.

OBJECTIVES: The aim was to study whether anosognosia for hemiparesis, anosognosia for neglect and general unawareness of illness double-dissociate, indicating that anosognosias are specific and independent impairments of awareness. On the other hand, anosognosias may be associated with one another and with general cognitive dysfunction, which decreases awareness of deficits. The persistence and predictive value of anosognosias was examined during a 1-year follow-up. PATIENTS AND METHODS: Fifty-seven consecutive patients with acute right hemisphere infarction underwent neurological and neuroradiological examinations, neuropsychological testing and an interview 10 days, 3 months and 1 year after onset. RESULTS: Anosognosia for neglect and anosognosia for hemiparesis double-dissociated, as did unawareness of illness and anosognosia for neglect. Patients showing unawareness of illness or anosognosia for neglect and anosognosia for hemiparesis had poorer orientation and verbal memory than patients who were aware of these defects. Unawareness of illness and anosognosia for hemiparesis disappeared during 3-month follow-up. CONCLUSION: Double-dissociations demonstrate that anosognosias for different defects are independent and specific impairments of awareness, although general cognitive disorder may also reduce awareness of defects. Unawareness of illness and anosognosia for hemiparesis disappear rapidly and can hardly be direct causes of poor long-term recovery. However, transient anosognosia may be associated with persistent disorders which result in poor outcome.

Volumetric measurements of right cerebral hemisphere infarction: use of a semiautomatic MRI segmentation technique.

The applications of a new segmentation software, Anatomatic, in the evaluation of volumetric measurements of brain infarctions and the new Medimag 3D software in the evaluation of 3D image representation of infarctions are described. These programs are applied to magnetic resonance imaging. The aim of this study is to evaluate the use of these software packages in making accurate volumetric measurements in 40 patients with right cerebral infarctions, in determining the correlations between the quantitated lesions and neurological/neuropsychological dysfunctions and in creating realistic 3D views of the infarctions. Using Anatomatic, reproducible infarction volumes were achieved with ease and within a reasonably fast time. Medimag helped achieve realistic 3D representations of the infarctions. When compared, the semiautomatic segmentation proved to be much faster and yielded higher infarction volumes than the manual segmentation technique. Significantly positive correlations between the infarction volumes and neurological dysfunctions and neuropsychological deficit (neglect) helped to explain the effect of volumes on the clinical status of the patients.

Visual neglect as a predictor of functional outcome one year after stroke.

OBJECTIVE: The aim was to study the role of visual neglect in acute right hemisphere brain infarct as a predictor of poor functional outcome during the first year after stroke. In particular, we were interested in the additional value of neglect measures besides hemiparesis, hemianopia, cognitive deficits and age. PATIENTS AND METHODS: A consecutive series of 57 patients with a neuroradiologically verified right hemisphere infarct was examined within 10 days of the stroke. Fifty patients were followed up for 1 year. Neglect was measured with the Conventional and the Behavioural subtests of the Behavioural Inattention Test (BITC and BITB, respectively). The predictors were determined at the 10-day examination. Functional outcome was assessed 3, 6 and 12 months after the onset with the Frenchay Activities Index. RESULTS: Neglect in BITB was the best single predictor, which together with high age formed the best combination of predictors for poor functional outcome at each follow-up. Hemiparesis was also included in this prediction model at the 3-month follow-up, but hemianopia, BITC, or visuoconstructional and memory deficits showed no additional predictive value. However, neglect usually recovered soon. When neurological and cognitive deficits were assessed at the same time as the outcome, hemiparesis rather than neglect was the strongest correlate of poor outcome. CONCLUSION: Neglect in acute stroke is an important predictor of poor functional recovery. Residual neglect, which could be compensated in the follow-up tests, may nevertheless restrict patients' real-life activities and hobbies.

Low plasma antioxidant activity is associated with high lesion volume and neurological impairment in stroke.

BACKGROUND AND PURPOSE: Oxidative stress is probably involved in neuronal damage induced by ischemia-reperfusion. The purpose of this study was to assess the role of antioxidant activity in cerebral ischemic stroke. METHODS: Antioxidant activity of blood plasma and cerebrospinal fluid was assessed in 22 patients with cerebral hemisphere infarction that was verified and quantified by MRI. RESULTS: Low total peroxyl radical trapping potential of plasma, but not of cerebrospinal fluid, was associated with high lesion volume and high neurological impairment assessed by scores on NIH Stroke Scale, Barthel Index, and Hand Motor Score tests. The plasma concentrations of ascorbic acid, alpha-tocopherol, and protein thiols were also associated with the degree of neurological impairment. CONCLUSIONS: These data suggest that the antioxidant activity of plasma may be an important factor providing protection from neurological damage caused by stroke-associated oxidative stress.

Cortical silent period evoked by transcranial magnetic stimulation in ischemic stroke.

OBJECTIVES: Transcranial magnetic stimulation (TMS) of the motor cortex produces motor evoked potentials (MEPs). Besides this excitatory response, TMS has inhibitory effects. When TMS is performed during voluntary muscle contraction, the MEP is followed by a pause in electromyographic activity (cortical silent period, SP). The aim of this study was to evaluate the clinical usefulness of the SP. METHODS: We studied SP changes in 50 patients with acute hemispheric brain infarction. A stimulator with a round coil and a fixed intensity of 90% of maximum was used to evoke MEPs. RESULTS: SP was elicited on the affected side in 29 of the 50 patients. The mean SP duration was markedly longer on the affected side in the patient group. There were no significant differences between left and right sides in the means of the MEP amplitude ratio (amplitude related to corresponding amplitudes to peripheral electric stimulation) and MEP latencies in the patient group. Prolonged SP was found in 25 of the 29 patients (86%) whereas only 4 (14%) had abnormalities in MEP latency or amplitude ratio. The mean SP duration was significantly prolonged also in a subgroup of 14 patients with normal hand function. CONCLUSIONS: The SP measurement is an easily performed and sensitive method to detect even subclinical disturbances in motor system function in ischemic stroke.

Auditory sustained attention is a marker of unilateral spatial neglect.

The relationships between performance on a non-spatially-lateralized measure of sustained attention and spatial bias on tests sensitive to unilateral neglect were considered in a group of 44 patients with right hemisphere lesions following stroke. As predicted from earlier studies showing a strong association between unilateral spatial neglect and sustained attention, performance on a brief and monotonous tone-counting measure formed a significant predictor of spatial bias across a variety of measures of unilateral visual neglect. This study provides further evidence for a very close link between two attentional systems hitherto regarded as being quite separate, namely a spatial attention system implicated in unilateral neglect and a sustained attention system. A close connection between these two systems was predicted by Posner, who argued that the right hemisphere-dominant sustained attention system provides a strong modulatory influence on the functioning of the lateralized posterior attention system.