Yawning in acute anterior circulation stroke.

Pathological yawning can be a clinical sign in disorders affecting the brainstem. Here we describe seven patients with pathological yawning caused by acute middle cerebral artery stroke, indicating that pathological yawning also occurs in supratentorial stroke. We hypothesise that excessive yawning is a consequence of lesions in cortical or subcortical areas, which physiologically control diencephalic yawning centres.

Conjugate eye deviation in acute stroke: incidence, hemispheric asymmetry, and lesion pattern.

BACKGROUND AND PURPOSE: The authors studied clinical features and lesion patterns associated with conjugate eye deviation (CED) in acute stroke. METHODS: Consecutive patients with supratentorial stroke (<6 hours after symptom onset) were prospectively recruited. CED was classified according to the National Institute of Health Stroke Scale (NIHSS) item "gaze palsy" as being forced, partial, or absent. Lesion patterns on diffusion-weighted images (DWI) were analyzed in 46 patients using a normalization procedure for direct comparisons between patients. Perfusion data were analyzed for a subset of patients. RESULTS: Partial CED was found in 7 (6%) and forced CED in 31 (26.7%) of 116 patients. Forced and partial CED were associated with higher initial NIHSS scores compared with patients without CED (16 and 10 versus 5; P<0.05). DWI lesion volume was larger in patients with CED (103.24+/-102.4 mL, mean+/-SD) as compared with patients without CED (17+/-34.98 mL, P<0.001). CED was more frequent in right hemispheric stroke (44.6% versus 23%, P<0.02). DWI pattern analysis in patients with CED with right hemispheric stroke revealed a network of affected regions, including basal ganglia and temporoparietal cortex. In left hemispheric CED, lesions were larger than in patients without CED, but no consistent pattern could be established. In a subset of selected patients with CED, a small temporoparietal perfusion deficit was sufficient to elicit CED. CONCLUSIONS: Selective dysfunction of cortical areas involved in spatial attention and control of eye movements is sufficient to cause CED in patients with acute stroke. However, in the majority of cases, CED is an indicator of large infarcts involving more than one area, including both cortical and subcortical structures.

Effects of balloon angioplasty on perfusion- and diffusion-weighted magnetic resonance imaging results and outcome in patients with cerebral vasospasm.

OBJECT: The aim of this study was to analyze the effects and outcome of transluminal balloon angioplasty (TBA) on brain tissue perfusion by using combined perfusion- and diffusion-weighted (PW/DW) magnetic resonance (MR) imaging in patients with cerebral vasospasm after subarachnoid hemorrhage. METHODS: Ten consecutive patients with cerebral vasospasm treated using TBA were included in this prospective study. Hemodynamically relevant vasospasm was diagnosed using a standardized PW/DW MR imaging protocol. Digital subtraction angiography was used to confirm vasospasm, and TBA was performed to dilate vasospastic arteries. The PW/DW imaging protocol was repeated after TBA. The evaluation of the passage of contrast medium after standardized application using the bolus tracking method allowed for the calculation of the time to peak (TTP) before and after TBA. Tissue at risk was defined based on perfusion delays in individual vessel territories compared with those in reference territories. In cases with proximal focal vasospasm, TBA could dilate spastic arteries. Follow-up PW/DW MR imaging showed the disappearance of, or a decrease in, the mismatch. A TBA-induced reduction in the perfusion delay of 6.2 +/- 1 seconds (mean +/- standard error of the mean) to 1.5 +/- 0.45 seconds resulted in the complete prevention of infarction; a reduction in the delay of 6.2 +/- 2.7 to 4.1 +/- 1.9 seconds resulted in the preservation of those brain tissue parts having only small infarcts in the vessel territories. Without TBA, however, the perfusion delay remained or even increased (11.1 +/- 3.7 seconds), and the complete infarction of a territory occurred. CONCLUSIONS: Angioplasty of vasospastic arteries leads to hemodynamic effects that can be quantified using PW/DW MR imaging. In cases of a severe PW/DW imaging mismatch successful TBA improved tissue perfusion and prevented cerebral infarction. The clinical significance of PW/DW MR imaging and the concept of tissue at risk is shown by cerebral infarction in vessels not accessible by TBA.

A simple 3-item stroke scale: comparison with the National Institutes of Health Stroke Scale and prediction of middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: The purpose of the study was to design a simple stroke scale that requires minimal training but reflects initial stroke severity and is predictive of middle cerebral artery (MCA) occlusion. METHODS: The new stroke scale assessed 3 parameters: (1) level of consciousness, (2) gaze, and (3) motor function. Each item was graded 0 to 2, where 0 indicated normal findings and 2 severe abnormalities (ie, profound drowsiness or worse, forced gaze deviation, and severe hemiparesis, respectively). During a study period of 11 months, patients presenting with acute stroke symptoms (onset < or =6 hours) were examined by a stroke neurologist assessing the new scale as well as the National Institutes of Health Stroke Scale (NIHSS). In addition, 83 patients received acute magnetic resonance angiography (MRA; as part of an acute stroke protocol). RESULTS: The new stroke scale was strongly associated with the NIHSS. Interobserver reliability of the new scale was high (intraclass correlation coefficient 0.947). Using post hoc analysis, a score of > or =4 predicted proximal vessel occlusion (T-segment or M1-segment occlusion of the MCA on MRA) almost as accurately (overall accuracy 0.86) as an NIHSS score of >or =14 (overall accuracy 0.93). CONCLUSIONS: The new stroke scale reflects acute stroke severity well and predicts proximal MCA occlusion with reasonable accuracy. However, the clinical scale needs further evaluation before it can be recommended as a tool for the triage of acute stroke patients.

Relation between relative cerebral blood flow, relative cerebral blood volume, and mean transit time in patients with acute ischemic stroke determined by perfusion-weighted MRI.

The relation between relative cerebral blood flow (relCBF), relative cerebral blood volume (relCBV), and mean transit time (MTT) changes was examined in 20 patients with acute cerebral ischemia (<6 h) using perfusion-weighted magnetic resonance imaging. Regions of interest (ROI) were selected on MTT maps covering the entire MTT abnormal cortical area. These ROIs were transferred to the relCBF and relCBV maps to analyze the relation between relCBF, relCBV, and MTT on a voxel-by-voxel basis. On the unaffected side, a tight coupling of relCBF and relCBV was found with little variation of MTT. In hypoperfused cortex, relCBV was increased at all investigated relCBF categories, and there was greater relCBV variability than on the unaffected side. Only a severe decrease of relCBF, to less than 0.3, in comparison with the unaffected side was associated with a reduction of relCBV less than 1.0. In contrast to the unaffected side, a power law function (relCBV = 2.283 x relCBF0.549) resulted in a better fit than using a linear function for the correlation of relCBF and relCBV. MTT ratios increased steadily with decreasing CBF values. In conclusion, there is a clear relation between different perfusion-weighted magnetic resonance imaging parameters in acute ischemia, reflecting both the degree of hemodynamic failure as well as compensatory mechanisms including vasodilation.

Prognostic value of choline and creatine in WHO grade II gliomas.

INTRODUCTION: The purpose of this study was to evaluate whether proton magnetic resonance spectroscopy ((1)H-MRS) predicts survival time, tumor progression, and malignant transformation in patients with WHO grade II gliomas. MATERIALS AND METHODS: (1)H-MRS and MR imaging (MRI) were performed before surgery in 45 patients with histologically proven WHO grade II gliomas. Metabolite concentrations of choline-containing compounds (Cho) and creatine/phosphocreatine (tCr) were normalized to contralateral brain tissue. Spectroscopic data as well as the extent of tumor resection, contrast enhancement, size and histopatholocical type of the tumor, age, sex, and first neurological symptoms of the patients were analyzed for survival, tumor progression, and malignant transformation for a follow-up period of 1 to 5 years. RESULTS: The normalized tCr of WHO grade II gliomas was a significant predictor for tumor progression (p = 0.011) and for malignant tumor transformation (p = 0.016). Further, contrast enhancement of the tumor (p = 0.014) at the time of diagnosis was significant for malignant tumor transformation and extent of tumor resection for the tumor progression (p = 0.007). All other parameters failed to predict any of the three endpoints. CONCLUSION: Normalized values of tCr in WHO grade II gliomas may have prognostic implications for this group of gliomas. As a rule of the thumb, low-grade gliomas with decreased tCr (relative tCr values below 1.0) may show longer progression-free times and later malignant transformation than low-grade gliomas with regular or increased tCr values.

Postictal spectroscopy and imaging findings mimicking brain tumor recurrence.

(1)H magnetic resonance spectroscopic imaging (MRSI) was performed on a patient with an admission diagnosis of recurrent astrocytoma. The patient had undergone surgical resection and radiation therapy for a left occipital astrocytoma WHO grade III 12 years previously, and presented with aphasia, right-sided hemiparesis, and severe headache. Postcontrast T1-weighted images showed cortical enhancement of the left parietotemporal lobe near the post-resection cavity. MRSI revealed a marked increase of trimethylamines (TMA), elevated creatine/creatinephosphate (tCr), and reduced N-acetyl-aspartate (tNAA) in the same brain region. The spectroscopic data were consistent with tumor recurrence. However, the pattern of contrast enhancement on magnetic resonance imaging (MRI), evidence of an epileptic focus on electroencephalography (EEG), and spontaneous regression of the symptoms argued against tumor recurrence. In a 4-week follow-up, the contrast enhancement disappeared on MRI and the EEG abnormalities and neurological symptoms resolved. Follow-up spectroscopic data showed a decrease in TMA compared to normal values. The tCr signal remained elevated but returned to normal values after 5 months. In conclusion, postictal neurological deficits with a temporary increase in TMA and tCr were diagnosed. This is the first report of seizure-induced MRS abnormalities mimicking tumor recurrence.

Effect of early and delayed recanalization on infarct pattern in proximal middle cerebral artery occlusion.

BACKGROUND: To investigate the effect of early (<6 h) versus delayed (>6 h) recanalization on infarct pattern in acute middle cerebral artery (MCA) occlusion. METHODS: 35 patients with acute MCA occlusion (M1 segment; symptom onset <6 h) were analyzed. Stroke MRI was performed immediately after admission (day 0), and on days 1 and 7. In addition, vessel status was assessed within 6 h, at 24 h and on day 7. Patients were grouped according to early (

Early functional recovery and the fate of the diffusion/perfusion mismatch in patients with proximal middle cerebral artery occlusion.

BACKGROUND: The relationship between early neurological recovery, time to recanalization and the salvage of hypoperfused, but not diffusion-restricted tissue was investigated. METHODS: In 17 patients with acute middle cerebral artery occlusion, a multiparametric stroke MRI protocol was performed < 6 h after symptom onset, as well as at day 2 and 7. Recanalization was monitored with transcranial Doppler or with conventional angiography (during local thrombolysis). Functional improvement was defined as a change of > or = 4 points on the National Institutes of Health Stroke Scale score. RESULTS: In patients with functional improvement, 78% (median, range 66-95%) of the acute mean transit time (MTT) lesion escaped infarction compared with 28% (median, range -13 to 78%) in patients without neurological improvement (p < 0.01). Similarly, the percentage of tissue with a time-to-peak (TTP) delay of > or = 2 s not progressing to infarction was 80 and 4% in the groups with and without improvement, respectively (p < 0.01). Neurological improvement was more frequent in patients with early (< or = 3 h after presentation) recanalization, due to the salvage of larger areas of initially hypoperfused tissue. CONCLUSIONS: The salvage of hypoperfused tissue is a major factor influencing early neurological improvement.