Endothelium-dependent vasodilatation in forearm is impaired in stroke patients.

OBJECTIVES: To investigate endothelium-dependent vasodilatation (EDV) in stroke patients. DESIGN: Cross-sectional. SETTING: University referral hospital. SUBJECTS: We studied 23 stroke patients (65-75 years old) who did not have atrial fibrillation or Warfarin treatment. Forty-six age- and sex-matched healthy controls and another 32 controls matched also for hypertension and medication were used for comparisons. METHODS. Endothelium-dependent vasodilatation was measured with venous occlusive plethysmography of forearm blood flow during intra-brachial infusion of acetylcholine. Endothelium-independent vasodilatation (EIDV) was evaluated by infusion of sodium nitroprusside. RESULTS: Stroke patients showed significantly lower EDV (P < 0.001) compared with healthy controls when measured with acetylcholine-stimulated forearm blood flow. The difference between these groups remained significant also after correction for blood pressure, body mass index, blood glucose and cholesterol. There was also significant difference in EDV between hypertension-matched controls and healthy controls. However, EIDV was significantly reduced in stroke patients (P < 0.01), but not in the hypertensive group, when compared with healthy controls. CONCLUSION: An impaired EDV was seen in both stroke patients and hypertensive-matched controls, while an impaired EIDV was seen in the stroke patients only, suggesting a more severe vasodilatory dysfunction in stroke patients than could be explained by a high blood pressure only.

Detection and appearance of intraparenchymal haematomas of the brain at 1.5 T with spin-echo, FLAIR and GE sequences: poor relationship to the age of the haematoma.

The specific appearance of blood related to time at T1- and T2-weighted spin-echo (SE) sequences is generally accepted; thus, these sequences are classically used for estimating the age of haematomas. Magnetic resonance imaging at 1.5 T, including T1- and T2-weighted SE fluid-attenuated inversion recovery (FLAIR) and T2*-weighted gradient-echo (GE) sequences, was performed on 82 intraparenchymal haematomas (IPHs) and 15 haemorrhagic infarcts (HIs) in order to analyse the appearance at different stages and with different sequences, and to investigate how reliably the age of hematomas can be estimated. The IPHs had been previously detected by CT, were spontaneous ( n=72) or traumatic ( n=10) in origin and were of different sizes (2 mm to 7 cm) and ages (from 7.5 h to 4 years after acute haemorrhagic event). The age of the lesion was calculated from the moment when clinical symptoms started or the traumatic event occurred. The 15 patients with HIs were patients with ischaemic stroke in whom there was either a suspicion of haemorrhagic transformation on CT, or haemorrhage was detected as an additional finding on MR performed for other indications. Patients with conditions that could affect the SI of blood, such as anticoagulant therapy or severe anaemia, were excluded. The signal intensity pattern of the lesions was analysed and related to their ages without prior knowledge of the clinical data. All lesions were detected with T2*-weighted GE. T1-weighted SE missed 13 haematomas and T2-weighted SE and FLAIR sequences missed five. Haemorrhagic transformation was missed in three infarcts by T1-, T2-weighted SE and FLAIR. The signal pattern on FLAIR was identical to that on T2-weighted SE. For all sequences, a wide variety of signal patterns, without a clear relationship to the age of the haematomas, was observed. There was a poor relationship between the real MR appearance of IPHs and the theoretical appearance on SE sequences. T2*-weighted GE was effective for detecting small bleedings but was not useful for estimating the age of a lesion. The FLAIR does not provide any more information than T2-weighted SE.