Thrombolysis and adjunct anticoagulation in patients with acute basilar artery occlusion.

BACKGROUND AND PURPOSE: Patients suffering from basilar artery occlusion (BAO) and treated with intravenous thrombolysis are, in some centers, started on adjunct anticoagulation in hyperacute settings. We aimed to assess the outcome of such patients and to compare low-molecular weight heparin (LMWH) and unfractionated heparin (UFH) in this context. METHODS: We examined 211 patients with angiography-proven BAO treated with intravenous thrombolysis and either adjunct UFH or LMWH. Main outcome variables were rate of symptomatic intracranial hemorrhage (sICH) according to European Cooperative Acute Stroke Study II criteria and modified Rankin Scale (mRS) at 3 months. RESULTS: The overall rate of sICH was 11.4% and driven by the UFH group (13.3%). None of the LMWH group developed sICH. Recanalization rate did not significantly differ between the LMWH and UFH groups. An additional propensity analysis was made to balance anticoagulation groups regarding baseline characteristics. Propensity analysis showed a significant difference in sICH rate (0.0% vs. 14.8%, P = 0.044) in favor of LMWH. Independent outcome (mRS score 0-2) was achieved in a total of 31.0% and in 44.8% and 29.1% in the LMWH and UFH group, respectively (P = 0.09). Propensity analysis showed a significant difference in the risk of ending up bedridden or dead (mRS score 5-6; 34.5% vs. 63.0%, P = 0.033) in favor of LMWH. CONCLUSIONS: Our study showed a lower rate of sICH and a shift towards improved outcome in thrombolysed patients with BAO treated with LMWH as compared with UFH.

Media multitasking is associated with distractibility and increased prefrontal activity in adolescents and young adults.

The current generation of young people indulges in more media multitasking behavior (e.g., instant messaging while watching videos) in their everyday lives than older generations. Concerns have been raised about how this might affect their attentional functioning, as previous studies have indicated that extensive media multitasking in everyday life may be associated with decreased attentional control. In the current study, 149 adolescents and young adults (aged 13-24years) performed speech-listening and reading tasks that required maintaining attention in the presence of distractor stimuli in the other modality or dividing attention between two concurrent tasks. Brain activity during task performance was measured using functional magnetic resonance imaging (fMRI). We studied the relationship between self-reported daily media multitasking (MMT), task performance and brain activity during task performance. The results showed that in the presence of distractor stimuli, a higher MMT score was associated with worse performance and increased brain activity in right prefrontal regions. The level of performance during divided attention did not depend on MMT. This suggests that daily media multitasking is associated with behavioral distractibility and increased recruitment of brain areas involved in attentional and inhibitory control, and that media multitasking in everyday life does not translate to performance benefits in multitasking in laboratory settings.

Three-decade neurological and neurocognitive follow-up of HIV-1-infected patients on best-available antiretroviral therapy in Finland.

OBJECTIVES: Is it possible to live without neurocognitive or neurological symptoms after being infected with HIV for a very long time? These study patients with decades-long HIV infection in Finland were observed in this follow-up study during three time periods: 1986-1990, in 1997 and in 2013. SETTING: Patients from greater Helsinki area were selected from outpatient's unit of infectious diseases. PARTICIPANTS: The study included 80 HIV patients. Patients with heavy alcohol consumption, central nervous system disorder or psychiatric disease were excluded. PRIMARY AND SECONDARY OUTCOME MEASURES: The patients underwent neurological and neuropsychological examinations, MRI of the brain and laboratory tests, including blood CD4 cells and plasma HIV-1 RNA. Neuropsychological examination included several measures: subtests of Wechsler Adult Intelligence Scale, Wechsler Memory Scale-Revised, list learning, Stroop and Trail-Making-B test. The Beck Depression Inventory and Fatigue Severity Scale were also carried out. The obtained data from the three time periods were compared with each other. RESULTS: Owing to high mortality among the original 80 patients, eventually, 17 participated in all three examinations performed between 1986 and 2013. The time from the HIV diagnosis was 27 (23-30) years. Blood CD4 cells at the diagnosis were 610 (29-870) cells/mm(3), and the nadir CD4 168 (4-408) cells/mm(3). The time on combined antiretroviral treatment was 13 (5-17) years. 9 patients suffered from fatigue, 5 had polyneuropathy and 3 had lacunar cerebral infarcts. There was a subtle increase of brain atrophy in 2 patients. Mild depressive symptoms were common. The neuropsychological follow-up showed typical age-related cognitive changes. No HIV-associated dementia features were detected. CONCLUSIONS: Polyneuropathy, fatigue and mild depression were common, but more severe neurological abnormalities were absent. These long-term surviving HIV-seropositive patients, while on best-available treatment, showed no evidence of HIV-associated neurocognitive disorder in neuropsychological and neuroradiological evaluations.

Symptomatic intracranial haemorrhage after thrombolysis with adjuvant anticoagulation in basilar artery occlusion.

BACKGROUND AND PURPOSE: Our aim was to determine factors associated with symptomatic intracranial haemorrhage (sICH) in basilar artery occlusion patients treated with intravenous thrombolysis (IVT) and adjuvant anticoagulant therapy. METHODS: A registry of 176 consecutive patients with angiography-proven basilar artery occlusion who received IVT with alteplase and heparin between 1995 to 2013 was assessed. Post-treatment sICH was evaluated with the European Cooperative Acute Stroke Study II criteria. Unfavourable outcome was defined as a modified Rankin Scale score of 3-6 at 3 months. RESULTS: Twenty-four patients developed sICH (13.6%, sICH+), all of whom had unfavourable outcome and only two (8.3%) sICH+ patients survived. On admission, sICH+ patients more frequently had extensive ischaemic changes defined as posterior circulation Acute Stroke Prognosis Early CT Score (PC-ASPECTS) < 8 (50% vs. 27% in sICH-, P = 0.031) and lower platelet counts (183 vs. 218 E9/l; P = 0.011). They also had higher systolic blood pressure (SBP) (median 160 vs. 147 mmHg, P = 0.034) immediately after IVT. In multivariable regression analysis, lower platelet values [odds ratio (OR) 0.99, 95% confidence interval (CI) 0.97-0.996; P = 0.006], PC-ASPECTS < 8 on admission (OR 3.6, 95% CI 1.3-10.3; P = 0.017) and higher SBP after treatment (OR 1.03, 95% CI 1.01-1.05; P = 0.017) were independently associated with sICH. Ninety per cent of the sICHs occurred within 48 h from IVT/anticoagulation treatment. No differences in activated partial thrompoplastin times prior to or after the treatment were observed between sICH+ and sICH- patients. CONCLUSIONS: The risk of sICH was largely determined by extension of ischaemic changes on admission computed tomography. Clinically relevantly, also higher post-thrombolytic SBP as described earlier and lower perithrombolytic platelet counts do increase the risk, a finding requiring confirmation in other patient series.

Intravenous thrombolysis in ischemic stroke patients with isolated homonymous hemianopia.

BACKGROUND: Patients with posterior ischemic stroke were usually excluded from thrombolytic treatment in clinical trials and clinical practice, and little is known about effectiveness of thrombolysis treatment in such patients who may end up with severe disability. AIMS OF THE STUDY: We aimed to describe the outcome of acute ischemic stroke patients presenting with isolated homonymous hemianopia and treated with intravenous thrombolysis. METHODS: A case report of three patients presenting with homonymous hemianopia owing to posterior circulation stroke treated with intravenous thrombolysis at the Helsinki University Central Hospital. Main outcome measures were modified Rankin Scale and neuropsychological examination at 3 months after thrombolysis. We further evaluated Goldmann visual field examination at 6 months. RESULTS: No acute findings appeared on admission non-contrast head-computed tomography scan. All patients had a perfusion deficit on admission-computed tomography perfusion imaging. All patients scored 0 on 3-month modified Rankin Scale, and their neuropsychological evaluation was normal. Goldmann examination revealed no visual field deficit in both female patients, and a modest visual field defect was detected in the male patient. CONCLUSIONS: Our experience encourages application of intravenous thrombolytic treatment (especially when supported with multimodality neuroimaging) in patients with homonymous hemianopia, for which rehabilitation options are limited.

Patient outcomes from symptomatic intracerebral hemorrhage after stroke thrombolysis.

OBJECTIVES: To assess the impact of symptomatic intracerebral hemorrhage (sICH) on outcome of thrombolysis-treated ischemic stroke patients, as additional to recognized prognosticators. METHODS: The study cohort included 985 ischemic stroke patients treated with IV thrombolysis at the Helsinki University Central Hospital (1995-2008). In a multivariable model adjusted for baseline stroke severity, age, onset-to-treatment time, baseline glucose, hyperdense cerebral artery sign, and early infarct signs on baseline imaging, and prior modified Rankin Scale (mRS), we calculated risk ratios (RRs) of patients with sICH (separately per Safe Implementation of Thrombolysis in Stroke[SITS]-Monitoring Study, European Cooperative Acute Stroke Study II [ECASS-II], and National Institute of Neurological Disorders and Stroke [NINDS] definitions) for poor 3-month outcome (mRS 3-6) and mortality. Receiver operating characteristic (ROC) curve and integrated discrimination improvement (IDI) evaluated impact of sICH on outcome. Internal cross-validation of the model was done with bootstrap statistics. RESULTS: The frequency of sICH was 2.1% (SITS), 7.0% (ECASS-II), and 9.4% (NINDS). RRs for poor and fatal outcome, respectively, were 1.7 and 4.8 (SITS), 1.6 and 3.8 (ECASS-II), and 1.6 and 3.4 (NINDS). In IDI analyses, sICH improved prediction model for 3-month mRS of 3-6 and 4-6, respectively, by 1.4% and 3.0% (SITS), 4.0% and 5.9% (ECASS-II), and 4.7% and 6.1% (NINDS). In case of 3-month mRS 5-6 and mortality, it was 6.1% and 5.3% (SITS), 11.3% and 9.3% (ECASS-II), and 10.3% and 8.0% (NINDS). ROC analysis revealed similar results. CONCLUSIONS: Patients with sICH have increased risk of poor and fatal outcome. Compared with recognized stroke prognosticators, contribution of sICH is smaller. Definition-wise, ECASS-II- and NINDS-based sICH contribute relatively more; ECASS-II has the largest contribution to worst outcomes.

Silent brain infarcts, leukoaraiosis, and long-term prognosis in young ischemic stroke patients.

OBJECTIVE: To investigate prognostic relevance of silent brain infarcts (SBIs) and leukoaraiosis (LA) in young patients with ischemic stroke. METHODS: This observational cohort study included consecutive MRI-scanned patients aged 15 to 49 with first-ever ischemic stroke treated at Helsinki University Central Hospital (1994-2007) with long-term follow-up data available. Outcome measures were 1) nonfatal or fatal ischemic stroke, 2) composite vascular endpoint, and 3) death from any cause. Trial of ORG 10172 in Acute Stroke Treatment (TOAST) and Bamford criteria allowed for stroke subtyping. Number of SBIs was categorized into none, single, or multiple. LA fell into groups of none, mild, or moderate to severe (validated visual rating scale). RESULTS: The 655 patients (mean age 40.0 ± 8.0 years) included were followed for a mean 8.7 ± 3.8 years (survivors). Of the 86 (13.1%) patients with SBIs, 46 had single and 40 had multiple SBIs. In the 50 (7.6%) patients with LA, these changes were mild in 21 and moderate to severe in 29. In Cox regression analysis, multiple SBIs independently raised the risk for recurrent ischemic stroke (odds ratio 2.48; 95% confidence interval 1.24-4.94) adjusted for age, gender, risk factors, stroke etiology, and LA. After further adjustment for initial stroke severity, TOAST and Bamford subgroups, and presence of SBIs, moderate to severe LA increased the risk for death (3.43; 1.58-7.42). Neither SBIs nor LA associated with the composite vascular endpoint. CONCLUSIONS: MRI-defined SBIs and LA are prognostically valuable in young adults after their first-ever ischemic stroke.

Viral meningoencephalitis: a review of diagnostic methods and guidelines for management.

BACKGROUND: Viral encephalitis is a medical emergency. The prognosis depends mainly on the pathogen and host immunologic state. Correct immediate diagnosis and introduction of symptomatic and specific therapy has a dramatic influence upon survival and reduces the extent of permanent brain injury. METHODS: We searched the literature from 1966 to 2009. Recommendations were reached by consensus. Where there was lack of evidence but consensus was clear, we have stated our opinion as good practice points. RECOMMENDATIONS: Diagnosis should be based on medical history and examination followed by CSF analysis for protein and glucose levels, cellular analysis, and identification of the pathogen by polymerase chain reaction amplification (recommendation level A) and serology (level B). Neuroimaging, preferably by MRI, is essential (level B). Lumbar puncture can follow neuroimaging when immediately available, but if this cannot be performed immediately, LP should be delayed only under unusual circumstances. Brain biopsy should be reserved only for unusual and diagnostically difficult cases. Patients must be hospitalized with easy access to intensive care units. Specific, evidence-based, antiviral therapy, acyclovir, is available for herpes encephalitis (level A) and may also be effective for varicella-zoster virus encephalitis. Ganciclovir and foscarnet can be given to treat cytomegalovirus encephalitis, and pleconaril for enterovirus encephalitis (IV class evidence). Corticosteroids as an adjunct treatment for acute viral encephalitis are not generally considered to be effective, and their use is controversial, but this important issue is currently being evaluated in a large clinical trial. Surgical decompression is indicated for impending uncal herniation or increased intracranial pressure refractory to medical management.

HHV-6 infection in multiple sclerosis. A clinical and laboratory analysis.

BACKGROUND AND PURPOSE: To elucidate the role of human herpesvirus-6 (HHV-6) in the development of multiple sclerosis (MS). PATIENTS AND METHODS: Nine patients with MS and with acute or chronic HHV-6 infection were evaluated. RESULTS: Intrathecal antibody production to HHV-6 and oligoclonal IgG bands in the cerebrospinal fluid (CSF) was observed in two patients with a clinically definite MS and chronic HHV-6 infection (based on the presence of HHV-6 specific antibodies in the CSF). A temporal association between the symptoms of clinically possible MS and acute primary HHV-6A infection (based on avidity of HHV-6 specific antibodies) was observed in two patients. CONCLUSIONS: Human herpesvirus-6 infection may be an associated agent in some MS cases. Viral studies are needed to identify a possible viral etiology and give specific therapy.

Silent brain infarcts and leukoaraiosis in young adults with first-ever ischemic stroke.

BACKGROUND: We recently observed that 13% of 1,008 consecutive adults aged 15-49 years with first-ever ischemic stroke had one or more silent brain infarcts (SBIs), and more than 5% presented with leukoaraiosis on CT or MRI. We sought to investigate the features of and risk factors for magnetic resonance (MR)-defined SBIs and leukoaraiosis in these patients. METHODS: We analyzed the radiologic features of SBIs and leukoaraiosis in MR-scanned patients (n = 669) blinded to clinical data and examined their relation with subtype of the overt stroke. We used logistic regression to identify factors predisposing to SBIs and leukoaraiosis. RESULTS: Of the 669 patients included, 86 (13%) had SBIs, 50 (7%) had leukoaraiosis, 17 (3%) had both, and 550 had no SBIs or leukoaraiosis and served as controls. The majority (54%) had a single SBI, 20% had two SBIs, and 27% had three or more SBIs. Most SBIs were located in basal ganglia (39%) or subcortical regions (21%), but cerebellar SBIs also were rather frequent (15%). Leukoaraiosis was mainly mild to moderate. Independent risk factors for SBIs were type 1 diabetes (odds ratio [OR] 5.78, 95% confidence interval 2.37-14.10), obesity (OR 2.12, 1.07-4.19), smoking (OR 1.69, 1.05-2.72), and increasing age (OR 1.08, 1.04-1.13). Risk factors for leukoaraiosis were type 1 diabetes (OR 9.75, 3.39-28.04), obesity (OR 2.42, 1.04-5.68), female sex (OR 2.25, 1.16-4.34), and increasing age (OR 1.19, 1.10-1.29). Small-vessel disease was the predominant cause of stroke in both those with SBIs (31%) and leukoaraiosis (44%). CONCLUSIONS: Silent brain infarcts and leukoaraiosis are not uncommon among young stroke patients--type 1 diabetes being the strongest risk factor.

Adult cervicocerebral artery dissection: a single-center study of 301 Finnish patients.

BACKGROUND AND PURPOSE: There are only few small studies assessing potential risk factors, comorbidity, and prognostic factors in adult spontaneous cervicocerebral artery dissection (CAD). METHODS: We conducted a retrospective, hospital-based analysis on the prognostic factors and association of CAD with vascular risk factors in 301 consecutive Finnish patients, diagnosed from 1994 to 2007. RESULTS: Two thirds of the patients were men (68%). Women were younger than men. Migraine (36% of all patients), especially with visual aura (63% of all migraineurs), and smoking were more common in patients with CAD compared with the general Finnish population. At 3 months, 247 (83%) patients reached a favorable outcome. Occlusion of the dissected artery, internal carotid artery dissection (ICAD), and recent infection in infarction patients were associated with a poorer outcome. ICAD patients had less often brain infarction, but the strokes they had were more severe. Seven (2.3%) patients died during the follow-up (mean 4.0 years, 1186 patient years). Six (2%) patients had verified CAD recurrence. CONCLUSIONS: This study provides evidence for the association of CAD with male sex, and possible association with smoking and migraine. Occlusion of the dissected artery, ICAD, and infection appear to be associated with poorer outcome.

Magnetic resonance imaging of the brain used to detect early post-partum activation of multiple sclerosis.

Post-partum relapses are a frequent phenomenon in multiple sclerosis (MS). The purpose of this study was to evaluate the timing and extent of new or growing T2-lesions after delivery in a cohort of Finnish MS patients. In addition to serial magnetic resonance imaging (MRI), the patients were followed up clinically with determination of relapse rate and expanded disability status scale. The annualized relapse rate was decreased during the last trimester of pregnancy [mean 0.14, standard deviation (SD) 0.14] when compared with the time before pregnancy (mean 0.64, SD 0.14; P = 0.04) and to time post-partum (mean 1.50, SD 0.45; P = 0.0002). New or enlarging lesions were detected in the post-partum images in 14 of 28 patients. Gadolinium-enhancing lesions in post-partum MRI were present in eight of 13 patients. There was a significant increase in the number of T2-lesions (P = 0.0009), in the total volume of MS-lesions measured from fluid-attenuated inversion recovery images (P = 0.0126) and in the number of diffusion weighted imaging hyperintense lesions (P = 0.0098) in the post-partum images. The clinical results support the earlier findings of decreased disease activity in late pregnancy. The clinical and MRI findings indicate that post-partum activation is an early and common phenomenon amongst mothers with MS.

Subtle cognitive deficits after cerebellar infarcts.

The role of the cerebellum in cognitive functions has been under debate. We investigated the neuropsychological functioning of patients with cerebellar lesions (infarcts) and evaluated the significance of laterality in cognitive symptoms. Twenty-six patients with exclusive cerebellar lesions as verified by clinical and neuroradiological findings underwent a neuropsychological assessment at the acute stage and at 3 months. Their performance was compared with 14 controls, also assessed twice. The focus was on four domains: visuospatial/motor functions, episodic memory, working memory and attentional shifting/execution. Both groups improved over time. Statistical differences emerged in tests in the visuomotor domain as well as in the episodic and working memory domains. Patients with left cerebellar lesion were slow in a visuospatial task, whereas those with right cerebellar lesions had verbal memory difficulty compared with controls. By 3 months, 77% of the patients had returned to work, and only one had cognitive impairment and did not return to work. Our results indicate that cerebellar infarcts may result in subtle cognitive changes perhaps primarily related to working memory deficit. The symptoms may be mediated by the contralateral cortical hemisphere, left cerebellar infarcts producing mild right hemispheral dysfunction and right cerebellar infarct producing mild left hemispheral dysfunction.

Cognitive profile of subcortical ischaemic vascular disease.

OBJECTIVES: Subcortical ischaemic vascular disease (SIVD) is a subtype of vascular cognitive impairment characterised by extensive white matter lesions and multiple lacunar infarcts. Radiologically defined diagnostic criteria for SIVD have been introduced, but only a few studies have presented empirical data on its clinical and cognitive features. The aim of this study is to describe in detail the neuropsychological characteristics of patients with SIVD from a large well defined stroke cohort. METHODS: A sample of 323 consecutive patients with ischaemic stroke, aged 55-85 years, was investigated using neuropsychological examination and magnetic resonance imaging (MRI). Patients fulfilling the MRI criteria of SIVD (n = 85) were compared to the other stroke patients (n = 238) and to normal control subjects (n = 38). RESULTS: Cognitive performance of the SIVD group was inferior to that of the normal control group throughout all domains. As compared to the other stroke patients, the SIVD group performed significantly worse in tests measuring executive functions and delayed memory recall. Adjusting for depression had no effect on these results. Instead, after controlling for medial temporal lobe atrophy, the differences disappeared for delayed memory but remained significant for executive functions. CONCLUSION: Executive deficits are the most prominent cognitive characteristic associated with SIVD. Patients with SIVD also exhibit subtle deficits in delayed memory, which is explained in part by medial temporal lobe atrophy. Cognitive and mood changes seem to be parallel but independent processes related to SIVD. The results support the concept of SIVD as a separate clinical entity.

Viral encephalitis: a review of diagnostic methods and guidelines for management.

Viral encephalitis is a medical emergency. The spectrum of brain involvement and the prognosis are dependent mainly on the specific pathogen and the immunological state of the host. Although specific therapy is limited to only several viral agents, correct immediate diagnosis and introduction of symptomatic and specific therapy has a dramatic influence upon survival and reduces the extent of permanent brain injury in survivors. We searched MEDLINE (National Library of Medicine) for relevant literature from 1966 to May 2004. Review articles and book chapters were also included. Recommendations are based on this literature based on our judgment of the relevance of the references to the subject. Recommendations were reached by consensus. Where there was lack of evidence but consensus was clear we have stated our opinion as good practice points. Diagnosis should be based on medical history, examination followed by analysis of cerebrospinal fluid for protein and glucose contents, cellular analysis and identification of the pathogen by polymerase chain reaction (PCR) amplification (recommendation level A) and serology (recommendation level B). Neuroimaging, preferably by magnetic resonance imaging, is an essential aspect of evaluation (recommendation level B). Lumbar puncture can follow neuroimaging when immediately available, but if this cannot be obtained at the shortest span of time it should be delayed only in the presence of strict contraindications. Brain biopsy should be reserved only for unusual and diagnostically difficult cases. All encephalitis cases must be hospitalized with an access to intensive care units. Supportive therapy is an important basis of management. Specific, evidence-based, anti-viral therapy, acyclovir, is available for herpes encephalitis (recommendation level A). Acyclovir might also be effective for varicella-zoster virus encephalitis, gancyclovir and foscarnet for cytomegalovirus encephalitis and pleconaril for enterovirus encephalitis (IV class of evidence). Corticosteroids as an adjunct treatment for acute viral encephalitis are not generally considered to be effective and their use is controversial. Surgical decompression is indicated for impending uncal herniation or increased intracranial pressure refractory to medical management.

Poststroke depression and lesion location revisited.

Seventy patients with one brain infarct on magnetic resonance imaging (MRI) were studied 3 months after ischemic stroke by a standardized protocol to detail side, site, type, and extent of the brain infarct, as well as severity of white matter lesions and brain atrophy. Depression was diagnosed by DSM-III-R and DSM-IV criteria. The brain infarcts that affected structures of the frontal-subcortical circuits, (i.e., the pallidum and caudate, especially on the left side) predisposed stroke patients to depression. The size of the infarcts at these sites in the depressed patients was larger. Using a logistic regression analysis, the authors found that a brain infarct that affected pallidum was a strong independent MRI correlate for poststroke depression (odds ratio = 7.2).

Electromagnetic function of polymicrogyric cortex in congenital bilateral perisylvian syndrome.

BACKGROUND: Congenital bilateral perisylvian syndrome (CBPS) is characterised by bilateral perisylvian polymicrogyria and suprabulbar paresis. Mild tetraparesis, cognitive impairment, and epilepsy are frequently associated. Sensory deficits are surprisingly rare, even though polymicrogyria often extends to auditory and sensorimotor cortex. OBJECTIVES: To study the sensorimotor and auditory cortex function and location in CBPS patients. METHODS: We mapped the sensory and motor cortex function onto brain magnetic resonance images in six CBPS patients and seven control subjects using sources of somatosensory and auditory evoked magnetic fields, and of rhythmic magnetoencephalographic (MEG) activity phase-locked to surface electromyogram (EMG) during voluntary hand muscle contraction. RESULTS: MEG-EMG coherence in CBPS patients varied from normal (if normal central sulcus anatomy) to absent, and could occur at abnormally low frequency. Coherent MEG activity was generated at the central sulcus or in the polymicrogyric frontoparietal cortex. Somatosensory and auditory evoked responses were preserved and also originated within the polymicrogyric cortex, but the locations of some source components could be grossly shifted. CONCLUSION: Plastic changes of sensory and motor cortex location suggest disturbed cortex organisation in CBPS patients. Because the polymicrogyric cortex of CBPS patients may embed normal functions in unexpected locations, functional mapping should be considered before brain surgery.

MRI correlates of executive dysfunction in patients with ischaemic stroke.

Executive dysfunction (ED) may lead to problem behaviour and impaired activities of daily living in many neuropsychiatric disorders, but the neuroanatomical correlates of ED are still not well known. Different aspects of executive functions were studied by widely used neuropsychological tests in 214 elderly patients 3 months after ischaemic stroke, and a sum score of eight different measures was counted in each patient. The number and site of brain infarcts as well as severity and location of white matter lesions (WMLs) and brain atrophy on magnetic resonance imaging were recorded and compared between patients with and without ED. ED was present in 73 (34.1%) of the 214 patients. The mean frequency of brain infarcts in the brain and in the left hemisphere was higher in the patients with ED. Lesions affecting the frontal-subcortical circuits (e.g. pallidum, corona radiata or centrum semiovale) were more frequent in patients with ED than in those without. Also, patients with pontine brain infarcts frequently had ED, but this may have been due to more extensive ischaemic changes in these patients in general. Mean number of brain infarcts affecting the pons and posterior centrum semiovale on the left side, moderate to severe medial temporal atrophy, the Fazekas white matter score, the Mini-Mental State Examination score and low education were independent correlates of ED. Brain infarcts and WML affecting the frontal-subcortical circuits or the pons may increase risk for ED in stroke patients.

Brain diffusion changes in carotid occlusive disease treated with endarterectomy.

BACKGROUND: Patients with unilateral high-grade carotid stenosis or occlusion have been reported to have more leukoaraiosis and ischemic lesions in ipsilateral than in contralateral cerebral hemisphere. The lesions alter apparent diffusion coefficient (ADC) values in diffusion-weighted MRI (DWI). The overall effects of carotid endarterectomy on ADC values have not yet been explored. OBJECTIVE: S: To find out whether 1) average ADC (ADC(av)) values differed between hemispheres, 2) diffusion changes induced by carotid endarterectomy could be detected in brain tissue with serial DWI, and 3) patients with asymptomatic carotid stenosis differed from patients with a symptomatic stenosis. METHODS: Forty-five patients (22 with asymptomatic carotid stenosis and 23 with symptomatic carotid stenosis) with unilateral high-grade carotid stenosis underwent DWI before carotid endarterectomy and 3 and 100 days afterward, and 45 age- and sex-matched healthy control subjects were imaged once. We evaluated ADC(av) values in normal-appearing gray and white matter, watershed regions (WsR), and thalamus. RESULTS: ADC(av) values of ipsilateral white matter and WsR were higher than those of contralateral white matter and WsR, both being higher than in white matter and WsR of control subjects. After carotid endarterectomy, these differences were diminished, but the levels remained higher than in controls. ADC(av) values of gray matter and thalamus remained unaffected. Asymptomatic carotid stenosis and symptomatic carotid stenosis patient groups did not differ from each other. CONCLUSIONS: Carotid stenosis has an effect on diffusion in the white matter of the ipsilateral hemisphere, and it is partly reversible by carotid endarterectomy. The finding may be associated with leukoaraiotic development ("preleukoaraiosis").

Cerebral hemodynamics in a healthy population measured by dynamic susceptibility contrast MR imaging.

PURPOSE: To establish reference data and to study age-dependency for cerebral perfusion in various regions of the brain in a healthy population. MATERIAL AND METHODS: Eighty healthy subjects of both genders from 22 to 85 years of age were studied with spin echo echo-planar dynamic susceptibility contrast MR imaging (DSC MRI) at 1.5 T. Cerebral blood volume (CBV), cerebral blood flow (CBF), and contrast agent mean transit time (MTT) were calculated bilaterally for 20 distinct neuroanatomic structures. RESULTS: In gray matter, the following values were found (mean +/- SD): CBV (4.6 +/- 1.0 ml/100 g), CBF (94.2 +/- 23.0 ml/100 g/min), and MTT (3.0 +/- 0.6 s), and in white matter: CBV (1.3 +/- 0.4 ml/100 g), CBF (19.6 +/- 5.8 ml/100 g/min), and MTT (4.3 +/- 0.7 s). The perfusion parameters did not change with age, except for a tendency to an increase in gray matter MTT and CBV. Males exhibited higher MTT and CBV than females. No hemispheric difference was found in either gender. CONCLUSION: Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population.