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G R de Freitas

Publications and source records attributed to G R de Freitas.

12 recordsLinked to original sources
PubMed2003

Persistence of isolated flow in the internal carotid artery in brain death.

The criteria for the confirmation of brain death (BD) using transcranial Doppler ultrasonography (TCD) state that flow should not be observed in the internal carotid artery (ICA). In 94 brain-dead patients examined by TCD, 19 (20%) had flow in the ICA despite cerebral circulatory arrest. There was no difference in the clinical characteristics of patients with or without isolated flow in the ICA. Shunting of blood from the ICA into the external carotid system or the arrest of blood flow at a higher level than the carotid siphon may explain our findings. Our results show that the current TCD criteria can result in a high rate of false negatives. We suggest that the TCD criteria for the diagnosis of brain death should be reviewed.

Adult↗
PubMed2003

Complex spinal reflexes during transcranial Doppler ultrasound examination for the confirmation of brain death.

OBJECTIVE: Complex sets of movements of the extremities can be seen in patients with brain death (BD), and are typically observed during apnea testing or removal of ventilatory support (also called the Lazarus sign). We here describe brain-dead patients who had not shown previous movements, even during apnea testing, but presented complex spinal reflexes during transcranial Doppler (TCD) examination elicited by neck flexion. METHODS: We performed a prospective TCD study of patients with the clinical diagnosis of BD. RESULTS: Four (2.5%) of 161 brain-dead patients presented complex spinal reflexes exclusively during TCD examination. TCD showed vertebro-basilar circulatory arrest in all four. Their systolic blood pressure was significantly lower than that of brain-dead patients not presenting movements during TCD examination. CONCLUSIONS: Hypotension and mechanical stimulation play a role in the pathophysiology of complex spinal reflexes present in BD, which are not exclusively seen in terminal hypoxia. Intensive care personnel and neurologists who perform TCD to confirm BD should be aware of these movements.

Adult↗
PubMed2001

A CADASIL case with normal skin biopsy and without mutations in exons 3 and 4 of the Notch3 gene.

The diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is usually confirmed by genetic testing or skin biopsy. We here report the case of a 69-year-old woman with recurrent transient ischemic attacks (TIAs) and strokes, seizures, and dementia without any mutations in exons 3 and 4 of the Notch3 gene and with a normal skin biopsy, but who showed characteristic CADASIL abnormalities on brain pathological examination. Our findings suggest that negative results in these two tests do not exclude the disease and a leptomeningeal biopsy or a second skin biopsy should be considered in such cases.

Aged↗
PubMed2001

Stroke with internal carotid artery stenosis.

BACKGROUND: Stroke patterns in patients with different degrees of carotid stenosis have not been systematically studied. OBJECTIVE: To determine first-ever stroke subtypes in nonselected patients with extracranial internal carotid artery (ICA) stenosis, based on a primary care hospital stroke registry. METHODS: One hundred seventy-three patients who experienced their first-ever stroke and who had 50% or greater (North American Symptomatic Carotid Endarterectomy Trial method) ipsilateral extracranial ICA stenosis, corresponding to 6.5% of 2649 patients with anterior circulation stroke included in the Lausanne Stroke Registry, were studied. All these patients underwent Doppler ultrasonography, carotid angiography (conventional or magnetic resonance angiography), neuroimaging (computed tomography or magnetic resonance imaging), and other investigations from the standard protocol of the Lausanne Stroke Registry. RESULTS: We found the following types of infarct in the middle cerebral artery territory: anterior pial in 54 (31%) of the patients; subcortical, 34 (20%); posterior pial, 32 (19%); large hemispheral, 20 (12%); and border zone, 17 (10%). There were multiple pial in 14 (8%) and multiple deep infarcts in 2 (1%) of the patients. Moderate (50%-69%) ICA stenosis was significantly associated with large hemispheral infarcts and a normal contralateral ICA (P =.04 and P =.02, respectively). Seventy percent to 89% of ICA stenosis was associated with prior transient ischemic attacks (P =.02). After adjusting for cardioembolism, border zone infarcts showed a strong trend to appear mostly in patients with 90% to 99% ICA stenosis (P =.06). CONCLUSIONS: The association of a large hemispheral infarct with moderate ICA stenosis suggests a large embolism and/or an inadequate collateral supply. While an embolism may also contribute, the association of border zone infarcts with 90% to 99% ICA stenosis emphasizes the significance of hemodynamic disturbance in the pathogenesis of these types of infarct.

Aged↗
PubMed2001

Primary stroke prevention.

Stroke is one of the leading causes of death and disability worldwide. Although important advances in therapeutic approaches have been made, treatment is still far from satisfactory. Thus, major efforts should be made on stroke prevention. We present evidence-based recommendations for primary stroke prevention. Changes to modifiable risk factors, the role of drugs and surgery are discussed. New markers may help identification of subjects at high risk.

Cost of Illness↗
PubMed2001

Massive haemorrhagic transformation in cardioembolic stroke: the role of arterial wall trauma and dissection.

The pathogenesis of massive haemorrhagic transformation is not well established. Fatal haemorrhagic transformation associated with in situ dissection after acute middle cerebral artery (MCA) occlusion in a patient with atrial fibrillation is reported. An 80 year old woman with atrial fibrillation developed mild hemiparesis and aphasia. Brain CT and MRI at 4 and 5 hours, respectively, of symptom onset showed proximal MCA trunk occlusion with developing striatocapsular infarct and hypoperfusion in the superficial MCA territory. A few hours later, she developed massive bleeding into the ischaemic area and died. Pathological examination showed MCA trunk dissection, surrounded by a subarachnoid clot which communicated with the cerebral haematoma. It is suggested that direct arterial wall trauma as a result of cardioembolic MCA occlusion caused bleeding into the infarct. Secondary in situ dissection may be an overlooked mechanism of haemorrhagic transformation.

Aged↗
PubMed2000

Do transient ischemic attacks have a neuroprotective effect?

OBJECTIVE: To determine whether TIAs have a neuroprotective effect. BACKGROUND: Ischemic tolerance or preconditioning, which protects the brain against stroke, has been demonstrated in animal models of cerebral ischemia. Because TIA may represent a clinical model of ischemic tolerance, patients with TIA before cerebral infarction (CI) may therefore have a better outcome than patients without TIA before CI. METHODS: A total of 2,490 patients admitted consecutively to a primary care center for first-ever CI in the anterior circulation were divided into two groups on the basis of the presence or absence of prior ipsilateral TIAs. Duration of TIA was classified into three groups (<10 minutes, 10 to 20 minutes, and >20 minutes). The severity of the neurologic picture on admission and functional disability after stroke were compared between patients with and without TIAs. RESULTS: A total of 293 (12%) of the 2,490 patients had prior ipsilateral TIAs before CI. Risk factors did not differ between patients with or without TIAs, whereas the topography and etiology of ischemic stroke did differ (p < 0.001). Patients without prior TIAs had a more severe clinical picture on admission, with a greater reduction of consciousness (p = 0.009). Patients with previous TIAs had a more favorable outcome than those without TIAs (67% versus 58%, p = 0.004). After adjustment for confounding variables, TIAs lasting 10 to 20 minutes were still associated with a favorable outcome (odds ratio, 1.98; 95% confidence interval, 1.27 to 3.08; p = 0.002). The interval between TIA and CI influenced the outcome (p = 0.007). CONCLUSIONS: This study suggests that ischemic tolerance may play a role in patients with ipsilateral TIAs before CI, allowing better recovery from a subsequent ischemic stroke.

Aged↗
PubMed2000

Better outcome after stroke with higher serum cholesterol levels.

OBJECTIVE: To examine whether serum cholesterol levels have any prognostic value in the first month following acute ischemic stroke. BACKGROUND: Although the association between serum cholesterol levels and cerebrovascular disorders has been extensively studied, the relationship between cholesterol levels and outcome following ischemic stroke has not been investigated. METHODS: Using data from 3,273 consecutive patients with first-ever ischemic stroke, the authors compared poor functional outcome (severe disability or death) at 1 month in patients with high cholesterol (total serum cholesterol greater than 6.5 mmol/L or 250 mg/dL) and normal cholesterol (level equal to or less than 6.5 mmol/L or 250 mg/dL). Data were analyzed by univariate and multivariate analysis. RESULTS: In comparison with patients with normal cholesterol levels, patients with high cholesterol levels had a 2.2-fold lower risk of death (p = 0.002) and a 2.1-fold lower risk of poor functional outcome at 1 month (p < 0.001). After adjustment for known confounding variables, multivariate analysis showed that higher cholesterol levels remained an independent predictor of better functional outcome (OR 0.48, CI 0. 34 to 0.69, p < 0.001). CONCLUSIONS: The authors' findings suggest that higher levels of cholesterol are associated with a better outcome in the early phase after ischemic stroke.

Aged↗
PubMed2000

Motor strokes sparing the leg: different lesions and causes.

BACKGROUND: A considerable number of patients develop stroke without involvement of the lower limb. However, there are few reports about the motor syndrome when the leg is spared. OBJECTIVE: To study clinical findings, causative factors, and lesion topography in stroke patients with a motor deficit sparing the leg. PATIENTS AND METHODS: We studied 895 patients with paresis sparing the leg from the 3,901 patients enrolled in the Lausanne Stroke Registry. They were compared with 1,644 stroke patients with paresis involving the leg, by means of univariate and multivariate analysis. RESULTS: Eight hundred forty-four infarcts (94.3%) and 51 hemorrhages (5.7%) led to weakness sparing the leg. Different sites of lesion were found, but the majority were caused by superficial infarcts. Almost half of the lesions were confined to superficial branches of the middle cerebral artery territory, with 276 (30.8%) in the anterior (superior) and 138 (15.4%) in the posterior (inferior) middle cerebral artery. More than half of the infarcts had a presumed embolic source from large-artery disease or from the heart. In comparison with patients with paresis involving the leg, patients without leg involvement had a lower prevalence of small-artery disease (P<.001), but a higher prevalence of migraine (P<.001), transient ischemic attack (P = .001), atherosclerosis without stenosis (P = .005), large-artery disease (P<.001), and left hemispheric strokes (P<.001). They also had a lower frequency of hemorrhagic stroke. CONCLUSIONS: Patients without leg involvement had different stroke lesions and causes and were characterized by more superficial infarcts mainly caused by emboli from large-artery disease and atherosclerosis without stenosis.

Cardiovascular Diseases↗
PubMed1995

[Charcot-Marie-Tooth disease. Clinical study in 45 patients].

Charcot-Marie-Tooth (CMT) disease is the commonest inherited peripheral neuropathy. The clinical study of 45 patients with CMT is presented. They were derived from Antonio Pedro Hospital of Universidade Federal Fluminense in Niteroi, RJ, Brazil. Such patients could be divided by the motor conduction velocity in two types: a demyelinating form or type I (11 cases) and an axonal form or type II (34 cases). The disease was inherited as an autosomal dominant trait in 23 patients and as an autosomal recessive trait in 7 cases. In 15 patients the disorder was sporadic. The age of onset was in most of our cases before the 20 years. All of them had distal weakness in lower limbs. 38.2% had also distal weakness in upper limbs. 80% had distal wasting of the lower limbs and 50% had distal wasting of upper limbs. The tendon reflexes were absent in 64% in lower limbs and in 28% in upper limbs. The sensitive impairment in the distal regions of the extremities was mild in most patients. We found enlargement of peripheral nerves in 7 patients of type I. Pes cavus was present in 21 cases and scoliosis in 7. We found postural tremor of hands in 6 patients. In 9 cases there were rare features as mental retardation, trigeminal nevralgia, optic atrophy, deafness and calf enlargement. In most of our cases the clinical course was very slow progressive. A greater severity was seen in our sporadic cases.

Adolescent↗
PubMed1995

[Charcot-Marie-Tooth disease. Study of sural nerve biopsy in 41 patients].

We studied the pathological findings of sural nerve biopsy in 41 patients with Charcot-Marie-Tooth (CMT) disease. They were previously classified by the median motor conduction velocity (MCV) in two types. Type I (demyelinating) with 9 patients and type II (axonal) with 32 cases. In type I we found loss of myelinated fibers (unimodal histogram), demyelinated and remyelinated axons with numerous onion bulb formations. In one case there was thickness of myelin with thin axons (axonal atrophy). In type II there were seven patients with normal sural nerve biopsy. In 25 cases there were mild to severe loss of myelinated fibers. In 5 patients the number of myelinated fibers was increased due to the great regeneration of the axons. The electron microscopic studies in type II showed in a few cases small onion bulbs and in one case axonal atrophy. In type I there was no correlation between clinical severity and the loss of myelinated fibers, but there was relationship between the low MCV and the intensity of myelinated fibers. In type II we did not found any correlation between clinical course, MCV and pathological findings.

Adult↗