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Biomedical subjects

J Matías-Guiu

Publications and source records attributed to J Matías-Guiu.

At least 19 recordsLinked to original sources

[Changes in the cerebral flow velocity induced in the middle cerebral artery by acute stress studied by transcranial Doppler ultrasonography].

BACKGROUND: The behavior of brain flow on acute stress has not been previously evaluated. Transcranial Doppler ultrasonography (TD) is a bloodless method to evaluate the speed of cerebral flow in the arteries of the Willis polygon. The present study was designed to analyze the changes which occur in the same during two situations of acute stress. METHODS: The mean speed of cerebral flow (MS) and the pulsation rate (PR) of the right and left middle cerebral artery (MCA) were measured basally and following a mental stress test (calculation) and physical stress (cold test) by TD and through the temporal window. Twenty-five healthy volunteers (18 women and 8 men) with a mean age of 27.8 +/- 7.3 years were studied. RESULTS: In response to mental stress an increase was observed in MS in both the right MCA (10 +/- 8.6 cm/sec) and the left MCA (10.4 +/- 8.7 cm/sec) with a decrease in the MCA (0.14 +/- 0.23 in the right MCA, 0.14 +/- 0.18 cm/sec in the left MCA). In response to the cold test an increase in MS (7.3 +/- 7.5 cm/sec in the right MCA, 14.8 +/- 14.7 cm/sec in the left MCA) was also observed with a decrease in the PR (0.2 +/- 0.2 in the right MCA and 0.2 +/- 0.16 in the left MCA). No significant differences were observed in the changes induced in the right or left artery or in those induced by the mental or cold tests. CONCLUSIONS: These results suggest that the acute stress produces an increase in cerebral flow in the arteries of the Willis polygon.

Adult

Cardiovascular reflexes in patients with vascular headache.

We have investigated the autonomic function of 75 patients with migraine by examining cardiovascular reflex function. The results were compared with those of 78 healthy volunteers. Measurements were made between attacks. Patients with migraine showed a smaller heart-rate response to deep breathing but a greater heart-rate response and higher blood pressure to standing when compared to controls. Migraine patients had a higher percentage of established sympathetic lesions (51% vs 17%) and severe (25% vs 5%) or atypical (24% vs 11.5%) global autonomic dysfunction. No significant differences were found among patients with migraine with aura, migraine without aura, and migraine with prolonged aura. Our findings indicate that patients with migraine have sympathetic hypofunction.

Adolescent

Placebo-controlled trial of nimodipine in the treatment of acute ischemic cerebral infarction.

Nimodipine is a 1,4-dihydropyridine derivative that shows a preferential cerebrovascular activity in experimental animals. Clinical data suggest that nimodipine has a beneficial effect on the neurologic outcome of patients suffering an acute ischemic stroke. Our double-blind placebo-controlled multicenter trial was designed to assess the effects of oral nimodipine on the mortality rate and neurologic outcome of patients with an acute ischemic stroke. One hundred sixty-four patients were randomly allocated to receive either nimodipine tablets (30 mg q.i.d.) or identical placebo tablets for 28 days. Treatment was always started less than or equal to 48 hours after the acute event. The Mathew Scale, slightly modified by Gelmers et al, was used for neurologic assessment. Mortality rate and neurologic outcome after 28 days were used as evaluation criteria. We considered 123 patients to be valid for the analysis of efficacy. Mortality rates did not differ significantly between groups. Neurologic outcome after 28 days of therapy did not differ between groups. However, when only those patients most likely to benefit from any intervention (Mathew Scale sum score of less than or equal to 65 at baseline) were analyzed separately in post hoc-defined subgroups, the nimodipine-treated subgroups showed a significantly better neurologic outcome. This result suggests that some patients with acute ischemic stroke will benefit from treatment with nimodipine tablets.

Adult

Computed tomography in reversible ischaemic attacks: clinical and prognostic correlations in a prospective study.

Two hundred and nineteen patients admitted with reversible atherothrombotic ischaemic attacks were prospectively evaluated by computed tomography. Of these patients, 122 were diagnosed as suffering from transient ischaemic attacks, 58 from reversible ischaemic neurological deficits and 39 from reversible ischaemic neurological deficits with incomplete resolution. In 133 cases the ischaemic event affected the carotid system, in 63 the vertebrobasilar system and in 23 cases the system could not be determined. Brain infarctions were observed in 64 patients (29.2%), cerebral atrophy in 96 (44.4%) and dilatation of a ventricle in 17 (7.8%). The frequency of brain infarction was related to the duration of the neurological deficit, being 20.5% in those with transient ischaemic attacks, 37.9% in those with reversible ischaemic neurological deficits and 43.6% in patients with reversible ischaemic neurological deficits with incomplete resolution (P = 0.005). Ischaemic lesions were closely correlated with abnormalities on supra-aortic trunk angiography or Doppler ultrasonography. During an average follow-up period of 21 months, a higher percentage of recurrence was found in those patients with CT infarctions, but the difference was not significant.

Cerebral Infarction

Low-dose acetylsalicylic acid (ASA) plus dipyridamole versus dipyridamole alone in the prevention of stroke in patients with reversible ischemic attacks.

A total of 243 patients who had reversible ischemic attacks (RIA) were submitted to clinical trial to determine whether dipyridamole (400 mg/day) (D) or aspirin (100 mg/48 hours) + dipyridamole (300 mg/day) (ASA + D) would produce significant reduction in the subsequent occurrence of RIA and completed stroke. One hundred and fifteen were selected for Group ASA + D and 71 were treated with dipyridamole only. The treatment groups were similar in relation to age, sex, risk factors, duration and presumed vascular territory of RIA, incidence of alterations of arterial supra-aortic trunks, cerebral infarct (CT scan), and platelet function. Patients were followed for a mean time of 21 months. At the end of the study, 21.7% of the ASA + D group and 19.7% in the D group had suffered new episodes of RIA or completed stroke (p = 0.88). Frequency of stroke (reversible ischemic neurologic deficit or completed stroke) was 7.8% in the ASA + D patients and 9.8% in the D patients (p = 0.83). Subgroup analysis did not show significant differences either. It is concluded that ASA + D has no significantly greater beneficial effect than that observed with D alone in the secondary prevention of atherothrombotic cerebral ischemia. However, a statistical Type II error cannot be excluded by the reduced number of recurrences.

Adult