Prediction of infarct growth and neurologic deterioration in patients with positive perfusion-diffusion mismatch

Background

To assess the value of baseline clinical severity and perfusion–diffusion mismatch as predictors for further infarct growth and clinical outcome.

Methods

Patients with acute ischemic stroke and initial perfusion–diffusion mismatch within 72 h were enrolled. Baseline perfusion defects on time-to-peak (TTP) and cerebral blood volume (CBV) maps were measured. Infarct volume and stroke severity were assessed by diffusion-weighted image (DWI) and NIHSS, and were repeatedly assessed 7 days later. The predictive value of baseline NIHSS and perfusion defects on further infarct growth and neurologic deterioration was determined.

Results

Fifty-two patients (mean age 68.3 ± 12.8 years, 42% women) were enrolled. CBV defects were significantly associated with infarct growth (CBV, p = 0.02). Initial stroke severity, but not TTP and CBV mismatch (p = 0.65 and 0.76, respectively), significantly inversely correlated with neurologic deterioration (p = 0.001).

Conclusions

In patients with mismatch, those with severe symptoms initially are more likely to have infarct growth, while those with minor symptoms tend to suffer from larger extent of neurologic deterioration within 1 week. CBV is associated with further infarct growth but not clinical deterioration.     

Association between metabolic syndrome and previous ischemic lesions in patients with intracranial atherosclerotic stroke

Objectives

To elucidate the relationship between MetS and ischemic stroke, we evaluated the association of MetS and individual components with frequency of ischemic stroke lesions and investigated the independent associations between them in acute ischemic stroke patients.

Patients and methods

We evaluated 370 acute ischemic stroke patients who underwent brain magnetic resonance (MR) imaging and MR angiography. The stroke subgroups were categorized as intracranial large artery atherosclerosis (IC-LAA, n = 151), extracranial large artery atherosclerosis (EC-LAA, n = 35), and nonatherosclerosis (NA, n = 184). MetS was defined using the criteria of the International Diabetes Federation.

Results

Patients with IC-LAA group showed a higher rate of MetS and previous ischemic lesions (predominantly deep gray/white matter) than those with EC-LAA and NA (all P < 0.001). The number of previous ischemic lesions showed a tendency to increase as the number of MetS components increased in the IC-LAA group (P = 0.004). In the IC-LAA group, age (OR, 1.04) and MetS (OR, 3.28) were independently associated with previous ischemic lesions (all P < 0.001), which was prominent with more severe MetS components after adjustment for risk factors (P < 0.001). Among the component conditions, high blood pressure, impaired fasting glucose, and abdominal obesity were more associated with previous ischemic lesions (all P < 0.001) than low high-density lipoprotein and high triglyceride levels (P = 0.010 and 0.028, respectively).

Conclusion

Our study showed a strong association between MetS and previous ischemic lesions, more in patients with IC-LAA.     

Outcome of Chlamydia pneumoniae associated acute ischemic stroke in elderly patients: a case-control study

Background

Limited data exists about the role of Chlamydia pneumoniae elderly patients with acute ischemic stroke.

Objective

To study the role of C. pneumoniae in elderly patients (age more than 65 years) with acute ischemic stroke and its impact on stroke out come.

Methods

We recruited 100 elderly patients with acute ischemic stroke and 100 age and sex matched controls over a period of 2 years. IgG and IgA anti C. pneumoniae antibodies were measured by microimmunofluorescence technique in patients and controls. Good outcome was defined as a Modified Rankin score (mRS) of ≤2.

Results

We found C. pneumoniae antibodies in 35% stroke patients and in 18% control subjects (p = 0.01). Good out come at 90 days follow up was found in 20/35(57.1%) seropositive stroke patients compared to 37/65(56.9%) seronegative stroke patients (p = 0.9).

Conclusions

C. pneumoniae antibody positivity was independently associated with ischemic stroke in elderly patients and its presence does not alter the stroke outcome.     

Carboxypeptidase U (TAFIa) decreases the efficacy of thrombolytic therapy in ischemic stroke patients

Introduction

Thrombolytic therapy improves clinical outcome in patients with acute ischemic stroke but is compromised by symptomatic intracranial hemorrhage and an unpredictable therapeutic response. In vitro and in vivo data suggest that activation of procarboxypeptidase U (proCPU) inhibits fibrinolysis.

Aims

To investigate whether the extent of proCPU activation is related to efficacy and safety of thrombolytic therapy in ischemic stroke patients.

Methods

In twelve patients with ischemic stroke who were treated with intravenous (n = 7) or intra-arterial (n = 5) thrombolysis, venous blood samples were taken at different time points before, during and after thrombolytic therapy. ProCPU and carboxypeptidase U (CPU, TAFIa) plasma concentrations were determined by HPLC. The maximal CPU activity (CPU_max) and the percentage of proCPU consumption during thrombolytic therapy were calculated. The efficacy and safety of the thrombolytic therapy were assessed by evolution of the clinical deficit, recanalisation, final infarct volume, thrombolysis-induced intracranial hemorrhage and mortality.

Results

No correlations between CPU_max or proCPU consumption and patient or stroke characteristics were found. However, CPU_max is associated with evolution of the clinical deficit and achieved recanalisation. ProCPU consumption is related to the risk of intracranial hemorrhage, mortality and final infarct volume.

Conclusions

Irrespective of patient and stroke characteristics, CPU_max and proCPU consumption during thrombolytic treatment for ischemic stroke are parameters for therapeutic efficacy and safety. Further evaluation of the clinical applicability of these parameters and further investigation of the potential role for CPU inhibitors as adjunctive therapeutics during thrombolytic treatment may be of value.     

Cilostazol versus aspirin therapy in patients with chronic dizziness after ischemic stroke

Background

Chronic dizziness is frequently reported by patients in the chronic stage after ischemic stroke. The aim of this study was to determine the efficacy of cilostazol versus that of aspirin for the chronic dizziness that follows ischemic stroke.

Methods

We performed a prospective, randomized, open-label, blinded endpoint trial. One hundred six patients who suffered supratentorial ischemic stroke within the previous 1–6 months and subsequently complained of persistent dizziness without other obvious sequelae were enrolled. Patients were randomly given cilostazol (200 mg/day) or aspirin (100 mg/day) for 6 months. Rates of improvement in the dizziness were then evaluated. Changes in fixation suppression of the vestibulo-ocular reflex (an indicator of cerebral control over the brainstem reflex related to balance), regional cerebral blood flow (CBF) in the cerebrum, cerebellum, and brainstem; and the Zung Self-Rating Depression Scale (SDS) were also evaluated.

Results

Dizziness was significantly improved in the cilostazol group versus the aspirin group (P < 0.0001) after the 6-month therapy. The capacity for fixation suppression of the vestibulo-ocular reflex was improved (P < 0.0001), and regional CBF in the cerebrum (relative to that in the brainstem [P = 0.003] and to that in the cerebello-brainstem [P = 0.012]) was increased only in the cilostazol group. There was no statistical difference in the change in SDS scores between the two groups.

Conclusion

Cilostazol improves the chronic dizziness that follows ischemic stroke and increases supratentorial CBF and cerebral function for adaptation of the brainstem reflex related to the sense of balance.     

Effectiveness of home rehabilitation program for ischemic stroke upon disability and quality of life: a randomized controlled trial

Background

To develop and examine the effectiveness of individual 6-month home rehabilitation program in ischemic stroke patients upon disability and quality of life at 2 years.

Methods

This is a prospective randomized controlled trial (RCT) in 60 patients with recent ischemic stroke. They were randomly assigned to receive either home rehabilitation program once a month for 6 months with audiovisual materials (intervention group) or usual care (control group). We collected outcome data after discharge from the hospital until 2 years. The Barthel index (BI), the modified Rankin Scale (mRS) and utility index (EQ-5D) were measured for function, disability and quality of life respectively.

Results

At 2 years, the BI was significantly improved in the intervention group more than the control group: 97.2 ± 2.8 vs. 76.4 ± 9.4, p < 0.001. The good outcome, defined as BI 95–100, or mRS 0 or 1. For BI, there were 29 patients (96.7%) in intervention group vs 12 patients (42.9%) in usual care group (95% CI, 42.0, 85.0, p = 0.03). For mRS, there were 28 patients (93.3%) in intervention group vs 9 patients (32.1%) in usual care group (95% CI, 38.2, 87.0, p = 0.02). Number needed to treat for good outcome in mRS was 2.0 (95% CI: 1.0, 1.3). The mean (SD) of utility index in intervention group and control group were 0.9 ± 0.02 and 0.7 ± 0.04 respectively (p = 0.03). There was no significant interaction in baseline characteristics and treatment outcome.

Conclusions

Early home rehabilitation program in the first 6 months period after ischemic stroke leads to more rapid improvement in function, reducing disability and increase quality of life than usual care.     

Preliminary findings of the effects of autonomic dysfunction on functional outcome after acute ischemic stroke

Background and purpose

Impaired autonomic function is common in the acute poststroke phase but little is known about its effects on functional outcome after acute ischemic stroke. This study sought to investigate the impact of autonomic dysfunction by Ewing's classification on functional outcome 2 months after acute ischemic stroke.

Methods

34 consecutive acute ischemic stroke patients within 7 days after onset were enrolled. On admission, autonomic function was assessed by Ewing's battery tests. Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS), autonomy in activities of daily living by the Barthel Index (BI), and global disability by the modified Rankin Scale (mRS). BI and mRS were also evaluated 2 months after ischemic stroke onset.

Results

On admission, eight patients were diagnosed as minor autonomic dysfunction and 26 patients as relatively severe autonomic dysfunction. The prevalence of relatively severe autonomic dysfunction in ischemic stroke patients was 76.5%. There were no significant differences in baseline characteristics between the minor and severe autonomic dysfunction groups. 2 months after stroke onset, the mean BI score of patients with minor autonomic dysfunction and severe autonomic dysfunction increased from 76.3 ± 15.3 on admission to 95.0 ± 7.1, 66.5 ± 15.2 on admission to 74.8 ± 15.9 respectively. The mean BI score after 2-month stroke onset and the change in BI from admission to 2-month outcome (delta BI) in patients with severe autonomic dysfunction were lower than those in patients with minor autonomic dysfunction (all P < 0.05).

Conclusions

Autonomic dysfunction occurs in acute stroke patients. Relatively severe autonomic dysfunction is related to an unfavorable functional outcome in patients with acute ischemic stroke.     

The effects of wide pulse neuromuscular electrical stimulation on elbow flexion torque in individuals with chronic hemiparetic stroke

Objective

Neuromuscular electrical stimulation that incorporates wide pulse widths (1 ms) and high frequencies (100 Hz; wide pulse-NMES (WP-NMES)) augments contractions through an increased reflexive recruitment of motoneurons in individuals without neurological impairments and those with spinal cord injury. The current study was designed to investigate whether WP-NMES also augments contractions after stroke. We hypothesized that WP-NMES would generate larger contractions in the paretic arm compared to the non-paretic arm due to increased reflex excitability for paretic muscles after stroke.

Methods

The biceps brachii muscles were stimulated bilaterally in 10 individuals with chronic hemiparetic stroke. Four stimulation patterns were delivered to explore the effects of pulse width and frequency on contraction amplitude: 20–100–20 Hz (4 s each phase, 1 ms pulse width); 20–100–20 Hz (4 s each phase, 0.1 ms); 20 Hz for 12 s (1 ms); and 100 Hz for 12 s (1 ms). Elbow flexion torque and electromyography were recorded.

Results

Stimulation that incorporated 1 ms pulses evoked more torque in the paretic arm than the non-paretic arm. When 0.1 ms pulses were used there was no difference in torque between arms. For both arms, torque declined significantly during the constant frequency 100 Hz stimulation and did not change during the constant frequency 20 Hz stimulation.

Conclusions

The larger contractions generated by WP-NMES are likely due to increased reflexive recruitment of motoneurons, resulting from increased reflex excitability on the paretic side.

Significance

NMES that elicits larger contractions may allow for development of more effective stroke rehabilitation paradigms and functional neural prostheses.     

Systemic arterial inflammation, measured with 18FDG-PET, is common amongst subjects with both recent and prior cerebrovascular disease

Objective

To compare systemic arterial inflammation in subjects with recent ischaemic stroke or TIA and controls with prior cerebrovascular disease.

Methods

Systemic arterial inflammation was prospectively measured by ¹⁸F-fluorodeoxygluose positron emission tomography in 11 cases with recent ischaemic stroke or TIA, and 11 sex matched controls with prior cerebrovascular disease.

Results

Hot spots (both carotid and non-carotid) of localised ¹⁸FDG uptake were found in more than half of all patients with either recent (n = 6) or prior (n = 8) cerebrovascular disease. There was no significant difference in the total number of hotspots, or hotspots at specific sites, in cases compared with controls. Mean standard uptake values (SUV) were similar in the carotid arteries and aorta of cases and controls, and showed a trend toward higher values in the femoral arteries of the controls (median 1.8; IQR 1.6–2.2) compared to cases (median 1.5; IQR 1.4–1.7).

Conclusion

Arterial inflammation was common, and appeared similar, in patients with recent stroke/TIA, and controls with stroke/TIA more than two years previously.     

Prevalence and risk factors for cerebrovascular disease in community-dwelling Latinos

Objectives

Surveys on stroke prevalence may provide valuable information for planning of healthcare services. Few such studies have been conducted in Latinos and none have been performed in Los Angeles, a County that contains the largest population of Latinos in the United States. We sought to assess the prevalence of self-reported stroke in a population-based sample of community-dwelling Latinos in Los Angeles.

Patients and methods

The group comprised of self-identified Latinos aged 40 years and older from six census tracts in Los Angeles participating in a population-based cross-sectional study of ocular disease in Latinos, The Los Angeles Latino Eye Study (LALES). The prevalence of stroke and its association with demographic, biological and behavioral risk factors was determined. Univariate and multiple stepwise logistic regression models were used to calculate odds ratios (ORs).

Results

The prevalence of self-reported stroke in 6954 community-dwelling Latinos in Los Angeles was 3.3%. Stroke prevalence increased with age (1.4% age 40–50, 3.3% age 50–65, 7.1% age >65), history of hypertension (OR 2.6, p < 0.001), heart disease (OR 4.8, p < 0.001) and diabetic retinopathy (OR 2.1, p = 0.01).

Conclusions

Renewed efforts directed at early identification and treatment of hypertension and heart disease within the Latino community will mitigate the burden of stroke.     

Bandpass filter settings differentially affect measurement of P50 sensory gating in children and adults

Objective

This study investigated the effect of four different bandpass filter settings on measures of the P50 component and the signal-to-noise ratios (SNR) of averaged ERPs obtained from a sensory gating paradigm employing paired-click stimuli.

Methods

Participants were adults (n = 18) 20–55 years old and children (n = 25) 5–10 years old who were free of neurological disorders.

Results

Results show that the filter settings (0.23–75 Hz, 10–50 Hz, 10–75 Hz, and 10–200 Hz) differentially affected the P50 amplitude, noise power and SNR measures of the conditioning and test clicks, and P50 T/C ratios.

Conclusions

The 10–50 Hz filter setting may be optimal in studies that include only adults as these settings resulted in the smallest mean P50 T/C ratio, a reasonable standard deviation (SD) for the ratio, and the highest SNRs. The 10–200 Hz filter may be the best for studying young children as this setting had the smallest mean and SD of P50 T/C ratios for these participants.

Significance

In studies that include both adults and children investigators are advised to use the 10–200 Hz filter setting because the smaller variability of sensory gating in the child group helps ensure better homogeneity of variance measures between the groups.     

Family history of hypertension is not an independent genetic factor predisposing to ischemic stroke subtypes

Objectives

The effect of family history of hypertension (FHx_HT), as a genetic factor predisposing to some ischemic stroke subtypes and independently of hypertension as risk factor, has never been studied.

Methods

A positive FHx_HT was searched in 472 patients (312 men, 160 women; mean [S.D.] age, 67.9 [11.4] years) consecutively admitted for a first-ever ischemic stroke (348) or transient ischemic attack (TIA) (124) due to small vessel disease (SVD, 180), large vessel disease (156), or cardioembolism (136). In this population and in three age bands, the genetically transmitted vascular risk factors, age, gender and the ischemic stroke subtypes were compared between those with and without a positive FHx_HT.

Results

None of the risk factors was associated with a positive FHx_HT, except for hypertension in the whole population (68.9% vs. 48.7%; p = 0.001) and in the <65 year-old patients (72.5% vs. 39.5%; p < 0.001). Regarding the stroke subtypes, a positive FHx_HT was only associated with SVD in the subgroup of <65 year-old patients (odd ratios (OR), 2.07; 95% confidence interval (CI), 1.01 to 4.25; p = 0.045). However, this finding disappeared in a logistic regression analysis, which only retained hypertension as independently associated with SVD.

Conclusions

FHx_HT is not an independent genetic factor predisposing to some aetiological stroke subtypes.     

Associations of cigarette smoking with intracranial atherosclerosis in the patients with acute ischemic stroke

Background

Although cigarette smoking has been established as an important risk factor for stroke, the effect on the atherosclerotic stenosis, which are based on observational studies, have been controversial. We set out to examine the differences in the risk factors between smokers and nonsmokers and to investigate the association of cigarette smoking with cerebral arterial stenosis.

Methods

A total of 989 consecutive patients with acute noncardioembolic ischemic stroke were prospectively enrolled from June 2004 to January 2010. The risk factor profiles were compared between smokers and nonsmokers. We analyzed the degree of stenosis in all MRA, and evaluated influencing factors in the patients with intracranial atherosclerosis (ICAS) and extracranial atherosclerosis (ECAS) who were randomly matched by age and sex.

Results

There were differences in the distribution of risk factors between the 467 (70.0%) nonsmokers and the 215 (30.0%) smokers. Nonsmokers were older (71.7 ± 11.0 versus 61.7 ± 12.0, p < 0.001) and had a higher frequency of hypertension than smokers had (75.4% versus 64.0%, p = 0.002). When smokers and nonsmokers were age- and sex-matched, smoking was more prevalent in patients with ICAS than with ECAS (32.9% versus 28.2%). Conditional regression analysis revealed that smoking and hypertension increased the odds of ICAS [smoking, odds ratio (OR): 1.83, p = 0.026; hypertension, OR: 1.84, p = 0.01], whereas hyperlipidemia increased the odds of ECAS (OR: 1.87, p = 0.034).

Conclusion

The distributions of the major risk factors for ischemic stroke were different between smokers and nonsmokers. Cigarette smoking may be more associated with ICAS than with ECAS after adjusting for potential risk factors.     

Effect of concentration and mode of intrathecal baclofen administration on soleus H-reflex in patients with muscle hypertonia

Objectives

Assess spinal reflex excitability after increasing intrathecal baclofen (ITB) flow by manipulation of drug concentration and mode of administration.

Methods

The effect of concentration was assessed by comparing changes in H-reflex (H/M ratio) 1–6 h after a 50 μg ITB bolus at 50 μg/ml concentration administered manually via lumbar puncture (LP, duration 1–2 min, n = 27) to a 50 μg bolus at 500 μg/ml concentration programmed through the pump and delivered via intrathecal catheter (IC, duration 10 min) above simple continuous dose (25–100 μg/day, n = 16). The effect of mode of administration was assessed by comparing peak changes in H/M ratio after 50 μg IC bolus above simple continuous dose (complex continuous mode, n = 27) to simple continuous mode only (n = 22) at equivalent daily doses (75–150 μg/day).

Results

H/M decrease was faster and overall greater after LP than IC bolus (mean 1-h 77% vs. 63%, p = 0.012; 1–6 h 91% vs. 82%, p < 0.001, respectively). H/M ratio also decreased significantly more with complex (91%) than simple continuous mode of administration (78%, p = 0.025).

Conclusions

Lower ITB concentration and complex continuous mode of administration lead to greater decrease in H/M ratio.

Significance

Decreased spinal reflex excitability after adjustment of drug and pump parameters to increase ITB flow may result in better clinical response.     

Non-cardioembolic Mechanisms in Cryptogenic Stroke: Clinical and Diffusion-weighted Imaging Features

Background

The role of several cardiogenic risk factors, including patent foramen ovale, in patients with cryptogenic stroke has been extensively studied. However, little attention has been paid to the role of non-cardioembolic causes of cryptogenic stroke. We therefore sought to identify the characteristics of cryptogenic stroke.

Methods

We studied 832 patients with acute infarction in the middle cerebral arterial territory. We divided the patients into four subtypes: 402 with large artery atherosclerosis (LAA), 133 with cardioembolism, 182 with small arterial occlusion (SAO), and 115 with cryptogenic stroke. We compared risk factors and lesion patterns observed by diffusion-weighted imaging (DWI) between patients with cryptogenic stroke and those with stroke of other subtypes.

Results

Both risk factors and DWI lesion patterns differed between the cryptogenic and cardioembolic groups (P<0.05). Risk factors for cryptogenic stroke were similar to those for the LAA and SAO groups. Similarly, DWI lesion patterns for cryptogenic stroke were similar to LAA patients. Large cortical infarcts on DWI were more common in the cardioembolic group than in the LAA or cryptogenic groups (P<0.001). In contrast, deep, non-lacunar (OR 5.02; 95% CI 2.68~9.40; P<0.001) and superficial perforator infarcts (OR 2.23; 95% CI 1.08~4.59; P=0.029) were independently associated with the cryptogenic group.

Conclusions

Our results indicate that non-cardioembolic causes, such as macro- and microangiopathy, are important mechanisms in the pathogenesis of cryptogenic stroke.     

颈内和大脑中动脉狭窄与闭塞的梗死类型及卒中机制的研究

目的 研究单侧动脉粥样硬化性MCA/ICA狭窄与闭塞的急性缺血性脑卒中患者在DWI上的梗死类型及发病机制.方法 起病48h内DWI诊断的急性脑梗死伴有动脉粥样硬化性MCA/ICA狭窄与闭塞的131例患者,有潜在心源性栓子患者除外.急性期DWI上梗死病灶分为：（1）单发病灶（小的穿动脉梗死灶;大的穿动脉梗死灶,皮层支梗死,大面积梗死,分水岭梗死）;（2）多发梗死病灶.结果 131例患者,ICA51例,MCA80例.ICA出现最多的梗死类型：穿支动脉伴分水岭梗死,但与MCA比较,皮层支伴分水岭梗死具有统计学意义（8/51,P=0.001）.MCA以穿支动脉伴皮层支梗死最多,且与ICA比较,具有统计学意义（12/80,P=0.003）.MCA中任何皮层支梗死与狭窄程度无关,ICA中任何分水岭梗死与狭窄程度相关.结论 颈内和大脑中动脉狭窄与闭塞在DWI上的梗死类型有明显的不同,提示有着不同的卒中发病机制.     

Factors affecting the diagnostic delay in amyotrophic lateral sclerosis

Background

Although amyotrophic lateral sclerosis (ALS) is a relentlessly progressive disorder, early diagnosis allows a prompt start with the specific drug riluzole and an accurate palliative care planning. ALS at onset may however mimic several disorders, some of them treatable (e.g., multifocal motor neuropathy) or epidemiologically more frequent (e.g., cervical myelopathy).

Objective

To study the delay from onset to diagnosis in a cohort of ALS patients and to the variables that may affect it.

Methods

We performed a retrospective analysis of the diagnostic delays in a cohort of 260 patients affected by ALS (M/F = 1.32) followed at our tertiary referral ALS Center between 2000 and 2007.

Results

The median time from onset to diagnosis was 11 months (range: 6–21) for the whole ALS cohort, 10 months (range: 6–15) in bulbar-onset (n = 65) and 12 months (range: 7–23) in spinal-onset (n = 195) patients (p = 0.3). 31.1% of patients received other diagnoses before ALS and this led to a significant delay of the correct diagnosis in this group (other diagnoses before ALS, n = 81: median delay, 15 months [9.75–24.25] vs ALS, n = 179, median delay, 9 months [6–15.25], p < 0.001).

Conclusions

The diagnostic delay in ALS is about one year, besides the growing number of tertiary centres and the spread of information about the disease through media and internet. Cognitive errors based on an incorrect use of heuristics might represent an important contributing factor. Furthermore, the length of the differential diagnosis from other disorders and delays in referral to the neurologist seems to be positively associated with the delay in diagnosis.     

Anti-aquaporin-4 antibody in Chinese patients with central nervous system inflammatory demyelinating disorders

Objective

To determine seroprevalence of aquaporin-4 (AQP4) antibody in Chinese patients with central nervous system (CNS) inflammatory demyelinating disorders.

Methods

AQP4 antibody was detected by anti-AQP4 antibody assay. We measured seroprevalence in 200 patients with neuromyelitis optica (NMO, n = 44), multiple sclerosis (MS, n = 46), transverse myelitis (TM, n = 44), optic neuritis (ON, n = 13), acute disseminated encephalomyelitis (ADEM, n = 2), and other neurological diseases (OND, n = 51).

Results

AQP4 antibody seropositivity was 88.6% in patients with NMO, 4.3% in patients with MS, 30.8% in patients with ON and 51.7% in patients with LETM (longitudinally extensive TM). No patients with acute partial TM, ADEM, OND were positive for AQP4 antibody. Sensitivity of the test was 88.6% (95% CI 80–95) in patients with NMO. Specificity is 97.9% (95% CI 95.1–100) in 46 MS patients, with 51 OND patients as the control group. If the patients with recurrent ON, LETM were considered high risk for NMO (n = 37) and the remaining patients (n = 119) were considered controls, the sensitivity of this assay would be 48.6% (95% CI 33.4–64.1) and the specificity 97.5% (95% CI 94.7–100).

Conclusion

This study confirms that AQP4 antibody is a sensitive and specific biomarker for discrimination between NMO and other CNS autoimmune diseases.     

Mismatch negativity and low frequency oscillations in schizophrenia families

Objective

Theta-alpha range oscillations have been associated with MMN in healthy controls. Our previous studies showed that theta-alpha activities are highly heritable in schizophrenia patients’ families. We aimed to test the hypothesis that theta-alpha activities may contribute to MMN in schizophrenia patients and their family members.

Methods

We compared MMN and single trial oscillations during MMN in 95 patients, 75 first-degree relatives, 87 controls, and 34 community subjects with schizophrenia spectrum personality (SSP) traits.

Results

We found that (1) MMN was reduced in patients (p < 0.001) and SSP subjects (p = 0.047) but not in relatives (p = 0.42); (2) there were augmented 1–20 Hz oscillations in patients (p = 0.02 to <0.001) during standard and deviant stimuli; (3) theta-alpha (5–12 Hz) oscillations had the strongest correlation to MMN in controls and relatives (ΔR² = 21.4–23.9%, all p < 0.001), while delta (<5 Hz) showed the strongest correlation to MMN in schizophrenia and SSP trait subjects; and, (4) MMN (h² = 0.56, p = 0.002) and theta-alpha (h² = 0.55, p = 0.004) were heritable traits.

Conclusions

Low frequency oscillations have a robust relationship with MMN and the relationship appears altered by schizophrenia; and schizophrenia patients showed augmented low frequency activities during the MMN paradigm.

Significance

The results encourage investigation of low frequency oscillations to elucidate the neurophysiological pathology underlying MMN abnormalities in schizophrenia.     

Topography of maturational changes in EEG burst spectral power of the preterm infant with a normal follow-up at 2years of age

Objective

To quantify the electroencephalography (EEG) burst frequency spectrum of preterm infants by automated analysis and to describe the topography of maturational change in spectral parameters.

Methods

Eighteen preterm infants <32 weeks gestation and normal neurological follow-up at 2 years underwent weekly 4-h EEG recordings (10–20 system). The recordings (n = 77) represent a large variability in postmenstrual age (PMA, 28–36 weeks). We applied an automated burst detection algorithm and performed spectral analysis. The frequency spectrum was divided into δ1 (0.5–1 Hz), δ2 (1–4 Hz), θ (4–8 Hz), α (8–13 Hz) and β (13–30 Hz) bands. Spectral parameters were evaluated as a function of PMA by regression analysis. Results were interpolated and topographically visualised.

Results

The majority of spectral parameters show significant change with PMA. Highest correlation is found for δ and θ band. Absolute band powers decrease with increasing PMA, while relative α and β powers increase. Maturational change is largest in frontal and temporal region.

Conclusions

Topographic distribution of maturational changes in spectral parameters corresponds with studies showing ongoing gyration and postnatal white matter maturation in frontal and temporal lobes.

Significance

Computer analysis of EEG may allow objective and reproducible analysis for long-term prognosis and/or stratification of clinical treatment.