Maria Matteis

Effect of Collateral Blood Flow and Cerebral Vasomotor Reactivity on the Outcome of Carotid Artery Occlusion

Background and Purpose— Evidence suggests that an alteration in cerebral hemodynamics plays a relevant role in the occurrence of stroke in patients with carotid occlusion. The purpose of the present study was to evaluate the relationships among baseline characteristics, type and number of collateral pathways, cerebral vasomotor reactivity (VMR), and outcome of patients with carotid occlusion. Methods— One hundred four patients with symptomatic or asymptomatic internal carotid artery occlusion were followed up prospectively for a median period of 24 months. Cerebral VMR to apnea was calculated with transcranial Doppler ultrasonography by means of the breath-holding index (BHI) in the middle cerebral arteries. The patency of the 3 major intracranial collateral vessels was also evaluated. Results— During the follow-up period, 18 patients experienced an ischemic stroke ipsilateral to internal carotid artery occlusion. Among factors considered, only older age, number of collateral pathways, and BHI values in the middle cerebral artery ipsilateral to the occluded side were significantly associated with the risk of ipsilateral stroke (P <0.001, P =0.008, and P <0.001, respectively; multiple Cox regression analysis). A normal VMR and favorable prognosis characterized patients with full collateral development; in this group, no patient experienced an ischemic event. On the other hand, an impaired VMR and increased probability of experiencing a stroke were found in patients without collateral pathways; the annual risk of ipsilateral stroke in this group was 32.7%. Patients with 1 or 2 collateral pathways showed a different VMR ranging from normal to strongly reduced BHI values. The ipsilateral stroke event risk was 17.5% in patients with 1 collateral vessel and 2.7% in patients with 2 collateral pathways. In this case, the risk of cerebrovascular events occurring during the follow-up period was significantly related to VMR. Conclusions— These data suggest that cerebral hemodynamic status in patients with carotid occlusive disease is influenced by both individual anatomic and functional characteristics. The planning of strategies to define the risk profile and any attempt to influence patients’ outcome should be based on the evaluation of the intracranial hemodynamic adaptive status, with particular attention to the number of collateral vessels and the related VMR.

Cerebrovascular Reactivity and Cognitive Decline in Patients With Alzheimer Disease

Background and Purpose— The aim of this study was to explore the possible contribution of alterations in cerebral hemodynamics to the evolution of cognitive impairment in patients with Alzheimer disease (AD). Method— Fifty-three patients with AD were investigated. The evolution of cognitive decline over 12 months was evaluated by means of changes in Mini Mental State Examination (MMSE) and AD Assessment Scale for Cognition (ADAS-Cog) scores. Demographic characteristics, vascular risk profile, pharmacological treatment, and presence of white matter lesions were assessed at entry. Further, a basal evaluation of cerebrovascular reactivity to hypercapnia was measured with transcranial Doppler ultrasonography using the breath-holding index (BHI). Results— Of all the variables considered, both MMSE and ADAS-Cog changes had the highest correlation with BHI, followed by age and diabetes. After subdividing both cognitive measures reductions into bigger and smaller-than-average decline (2 points for MMSE; 5 points for ADAS-Cog), multiple logistic regression indicated BHI as the sole significant predictor of cognitive decline. Conclusions— These results show an association between impaired cerebral microvessels functionality and unfavorable evolution of cognitive function in patients with AD. Further research is needed to fully establish whether altered cerebral hemodynamics may be considered an independent factor in sustaining cognitive decline progression or an effect of pathological processes involved in AD.

Sex-Hormone-Related Events in Migrainous Females. A Clinical Comparative Study between Migraine with Aura and Migraine without Aura

In this study, the relationship between hormonal-related events and migraine with aura (MA) and without aura (MO) was investigated. Subjects included 268 women suffering from MA (88) and MO (180). Data were collected on the relationship between sex-hormone-related events and migraine. Migraine during menses was observed in a significantly higher percentage of MO than MA patients (p < 0.03). Menstrual migraine was significantly more common in MO than in MA patients (p < 0.01). Migraine began during pregnancy in a significantly higher percentage of MA than of MO patients (p < 0.01). No significant difference was observed between the two groups of patients regarding the onset of migraine at menarche, after menopause, in the postpartum period or during the early cycles of oral contraceptives. Also, both groups of patients showed a similar migraine course during pregnancy, oral contraceptive use and menopause. Eight patients with coexisting migraine with aura and migraine without aura attacks reported the appearance of the aura symptom for the first time in the early cycles of oral contraceptive intake. These findings suggest that gonadal hormone fluctuation may influence both types of migraine.

Age and Sex Differences in Cerebral Hemodynamics: A Transcranial Doppler Study

BACKGROUND AND PURPOSE Hemodynamic factors seem to play an important role in the pathogenesis of cerebral ischemic events. The aim of this study was to evaluate whether changes in cerebrovascular reactivity occur in women after menopause. METHODS Using transcranial Doppler ultrasonography, we studied the changes of flow velocity after hypercapnia in the middle cerebral arteries of 45 healthy premenopausal women (mean age, 32.3 years; range, 20 to 47 years) and 40 postmenopausal women (mean age, 54.4 years; range, 48 to 64 years). The same measurements were recorded in two groups of healthy male subjects age matched with premenopausal (45 subjects) and postmenopausal women (40 subjects). Moreover, a subgroup of postmenopausal women aged 48 to 53 years (15 subjects) were compared with a group of 15 premenopausal women of the same age. We obtained hypercapnia with breath holding and evaluated cerebrovascular reactivity with the breath-holding index (BHI). RESULTS BHI was significantly lower in postmenopausal women (0.89+/-0.3) than in premenopausal women (1.59+/-0.3; P<0.0001) and in young (1.34+/-0.5; P<0.001) and old men (1.20+/-0.4; P<0.04). In the latter group, BHI was significantly lower than in premenopausal women (P<.0001). BHI values were also significantly lower in postmenopausal than in premenopausal women of the same age (0.81+/-0.1 versus 1.34+/-0.1; P<0.0001). CONCLUSIONS These findings suggest that the large reduction of cerebrovascular reactivity in postmenopausal women cannot be considered a simple factor related to aging but is probably influenced by hormonal changes. The alteration in cerebrovascular regulation could be involved in the increase of cerebrovascular disease in postmenopausal women.

Transcranial Doppler Assessment of Cerebrovascular Reactivity in Symptomatic and Asymptomatic Severe Carotid Stenosis

BACKGROUND AND PURPOSE Some studies have suggested a link between impaired cerebral hemodynamics and stroke in patients with carotid stenosis. The aim of this study was to assess the effects of severe carotid stenosis on cerebrovascular reactivity and the possible changes after endarterectomy. METHODS Using bilateral transcranial Doppler ultrasound, we studied the changes of flow velocity after hypercapnia in the middle cerebral arteries of 10 control subjects and 24 patients (13 symptomatic and 11 asymptomatic) with unilateral severe carotid stenosis before and after endarterectomy. Cerebrovascular reactivity was evaluated with the breath-holding index (BHI). RESULTS Before endarterectomy, BHI (mean value +/- SD) was significantly lower (P < .001) in the stenotic side of symptomatic patients (0.40 +/- 0.2) than in control subjects (1.12 +/- 0.3), the stenotic side of asymptomatic patients (0.80 +/- 0.4), and the normal side of both symptomatic (0.93 +/- 0.3) and asymptomatic ultrasonics (1.03 +/- 0.2) patients. On the other hand, no significant difference in BHI was detected in control subjects, on the normal side of symptomatic and asymptomatic patients, and the stenotic side of asymptomatic patients. After endarterectomy, BHI significantly increased (P < .0001) on the stenotic side of symptomatic patients (1.06 +/- 0.2) while remaining substantially stable on the normal side of both symptomatic and asymptomatic patients and on the stenotic side of asymptomatic patients. CONCLUSIONS These findings suggest that the study of cerebrovascular reactivity to hypercapnia may be relevant in evaluating the functional effects of carotid stenosis. Further investigations are needed to confirm the reliability of the breath-holding method in the selection of patients who might benefit most from carotid endarterectomy.

Effect of Smoking on Cerebrovascular Reactivity

Current smoking is a risk factor for stroke. The aim of this study was to evaluate the effect of smoking one cigarette on cerebral hemodynamics. Using transcranial Doppler ultrasound, we studied the changes of flow velocity after hypercapnia in the middle cerebral arteries (MCAs) of 24 healthy young smokers and 24 healthy controls matched for age and sex. We obtained hypercapnia with breath-holding and evaluated cerebrovascular reactivity with the breath-holding index. In smokers, the evaluation was performed during basal condition, immediately after smoking one cigarette, and at 10-, 20-, and 30-min intervals thereafter. In controls, the evaluation was performed at corresponding time intervals. Breath-holding index (BHI) values at rest were similar for both controls and smokers. In the former, breath-holding index values remained constant for each of the different evaluations. On the contrary, in smokers, breath-holding index values were significantly lower immediately (p < 0.0001), at 10 min (p < 0.001), and at 20 min (p < 0.0001) after smoking with respect to baseline values. Smoking also caused more short-lasting changes, in this case increases in mean flow velocity (MFV), heart rate (HR), and mean blood pressure (MBP). These results suggest that a failure of cerebrovascular regulation occurs after smoking. This phenomenon might contribute to the increased risk of cerebrovascular disease in current smokers.

Bilateral Simultaneous Assessment of Cerebral Flow Velocity during Mental Activity

The purpose of this study was to assess the potential of transcranial Doppler (TCD) ultrasonography for detecting selective changes in cerebral blood flow velocity during mental activity. Mean flow velocity was continuously and simultaneously measured in the right and left middle cerebral arteries in 26 healthy right-handed young subjects at rest and during performance of verbal and visual-imaging mental tasks. These two mental tasks produced significantly different effects on the right and left sides: the verbal task produced a higher increase of flow velocity (mean absolute difference above baseline ± SD) with respect to the basal values in the left than in the right middle cerebral artery (5.56 ±3.8 cm/s vs 1.25 ± 3.1 cm/s); the visual-imaging task was accompanied by a higher increase in the right than in the left middle cerebral artery (3.92 ± 3.3 cm/s vs 1.52 ± 3.1 cm/s)—analysis of variance (ANOVA) three-fold interaction side of recording × task × condition, F = 25.67, p < .0001). Heart rate, blood pressure, and skin conductance showed comparable increases during performance of both mental tasks. Respiratory activity showed no modification during the mental activity with respect to the rest phase. These results demonstrate the possibility of delivering specific functional information via bilateral TCD and suggest wider utilization of this noninvasive technique in neuropsychological studies.

Involvement of the healthy hemisphere in recovery from aphasia and motor deficit in patients with cortical ischemic infarction A transcranial Doppler study

Activation of areas of the healthy hemisphere seems to play a role in functional recovery from stroke.We studied cerebral blood flow changes during motor and mental activity in patients with cortical ischemic lesions. We simultaneously measured blood flow velocity in the two middle cerebral arteries of 45 patients with single cortical ischemic lesions and good functional recovery and of 16 healthy controls by means of bilateral transcranial Doppler ultrasonography during a 2-minute sequential thumb-to-finger opposition task, alternately performed with the right and left hands, and during a 1-minute word-fluency task. Twenty-five patients had left cortical lesions, 12 with previous motor deficit alone and 13 with associated motor deficit and Brocas aphasia. Twenty patients had right cortical lesions with previous motor deficit. With respect to baseline values, the increase of flow velocity in the middle cerebral artery contralateral to the hand performing the motor task was comparable in controls and patients, regardless of the side of the lesion and the hand (normal or recovered) involved in the task. During movement of the recovered hand, the increase of flow velocity in the ipsilateral middle cerebral artery was significantly greater (p less than 0.001, two-way ANOVA) than the increase during movement of the normal hand in both controls and patients. During performance of the word-fluency task, the increase of flow velocity in the left middle cerebral artery was comparable in controls and patients. In patients with left lesions and previous aphasia, the increase of flow velocity in the right middle cerebral artery was significantly higher than in controls (p equals 0.02, one-way ANOVA), patients with right cortical lesions (p equals 0.01), and patients with left lesions but no previous aphasic problem (p equals 0.001). These data suggest a contribution of the undamaged hemisphere to the functional recovery of patients with cortical ischemic lesions. NEUROLOGY 1995;45: 1815-1820

Basilar and middle cerebral artery reactivity in patients with migraine.

Background.—Migraine has been reported as a possible risk factor for ischemic stroke. The mechanisms underlying this association are unknown.

Migrainous stroke and the antiphospholipid antibodies

The pathogenesis of migrainous stroke is controversial. The possibility that a number of migraine-related strokes is associated with the presence of antiphospholipid antibodies, a condition predisposing to coagulopathy, has been suggested. We investigated the prevalence of lupus anticoagulant and anticardiolipin antibodies in patients with migrainous stroke. In 6 out of 16 patients with migrainous cerebral infarction, the presence of antiphospholipids antibodies was detected. In such patients, the presence of other risk factors for stroke was significantly lower (chi 2 = 5.6; p = 0.01) with respect to patients with negative results for antiphospholipid antibodies. These results suggest that antiphospholipid antibodies associated with migraine may be an important marker for ischemic stroke.