technetium-tc-99m-exametazime and Hypertension

Focal cerebral hypoperfusion is a common finding in uncomplicated hypertensives even in the absence of large vessel atherosclerosis, and neuropsychological deficits correlate with cerebral hypoperfusion in hypertensive patients with cerebral microangiopathy. We investigated the effects on cerebral perfusion of the dihydropiridine calcium antagonist lacidipine and of hydrochlorothiazide (HCTZ) in asymptomatic hypertensive patients with concomitant atherosclerosis of the carotid arteries. Fifteen essential hypertensives (including 13 males, aged 55-75 years) with at least one 30-60% stenosis of the internal carotid artery at echo-color Doppler examination were treated in a double-blind, randomized, parallel study with lacidipine (4-6 mg od) or HCTZ (25-50 mg od) for 3 months after a 4-week single-blind placebo period. Regional cerebral perfusion was assessed at baseline and at the end of the treatment period with HMPAO-SPECT. Relative perfusion of cortical and subcortical areas was calculated as the ratio between their tracer activity and that of the cerebellum. At baseline, mean relative perfusion (MRP) of the cortical and subcortical areas was similar in the stenotic and the contralateral side. Despite the fall in pressure, lacidipine increased MRP both in the cortical and in the subcortical areas, whereas HCTZ increased MRP only in the cortical areas. The mean change in local vascular resistance, adjusted for initial perfusion value, was -20 A.U. (arbitrary unit) with lacidipine and -12 A.U. with HCTZ (p < 0.001). These differential effects of antihypertensive drugs on subcortical perfusion may be of benefit in the long-term prevention of vascular dementia in hypertensive patients.

Topics: Aged; Antihypertensive Agents; Blood Pressure; Carotid Stenosis; Cerebrovascular Circulation; Dihydropyridines; Diuretics; Double-Blind Method; Female; Humans; Hydrochlorothiazide; Hypertension; Intracranial Arteriosclerosis; Male; Middle Aged; Sodium Chloride Symporter Inhibitors; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Vascular Resistance

Previous studies have shown areas of cerebral hypoperfusion in the frontal and parietal lobes of asymptomatic hypertensives, in the absence of extracranial carotid artery stenosis. The aims of the present study were: (a) to correlate the presence of focal cortical hypoperfusion with the presence of white matter lesions (WML), lacunae and extracranial carotid artery stenosis; and (b) to compare the effects on cerebral perfusion of the dihydropyridine calcium entry blocker lacidipine and of hydrochlorothiazide (HCTZ) in hypertensive patients with carotid artery stenosis. Forty-one patients (30 males, aged 40-75) with mild to moderate essential hypertension and with negative history for cerebrovascular diseases were investigated. Twenty-four had normal extracranial carotid arteries at echo-colourDoppler examination, while 17 had at least one 50-70% stenosis of the internal carotid artery (ICA). At computed tomography (CT) scan, five patients had one or more lacunar infarctions, four WML, three lacunar infarctions and WML, and 26 a normal CT scan. Three, with old cortical infarctions, were excluded from further analysis. The prevalence of lesions was significantly higher among the patients with carotid artery stenosis (44% vs. 29%; p < 0.05). Distribution of mean relative cortical perfusion (MRCP) of regions of interest [hexamethyl-propileneamine oxime-single photon emission tomography (SPET)] was not normal, with a negative skewness in patients with lacunae. MRCP was slightly but significantly reduced in patients with lacunae in comparison with hypertensives with normal CT scan and with WML. The asymmetry index of tracer distribution was significantly greater in the patients with lacunar infarctions and WML than in the hypertensive patients with normal CT scan, irrespective of the presence of internal carotid artery stenosis. Fifteen hypertensives (13 males, aged 55-75 years) with at least one moderate stenosis of ICA at duplex scanning were treated in a double-blind, randomised, parallel study with lacidipine (4-6 mg o.d.) or HCTZ (25-50 mg o.d.) for 3 months after a 4-week single-blind placebo period. At baseline, perfusion of the cortical and basal areas was similar in the stenotic and the contralateral side. Despite the fall in pressure, both treatments increased MRCP in the stenotic side and in the contralateral side. The lower the baseline perfusion, the larger its increase with treatment. The decrease of local cerebral vascular resistance was signific

Topics: Adult; Aged; Antihypertensive Agents; Carotid Stenosis; Cerebrovascular Circulation; Dihydropyridines; Diuretics; Double-Blind Method; Echoencephalography; Female; Humans; Hydrochlorothiazide; Hypertension; Male; Middle Aged; Radiopharmaceuticals; Sodium Chloride Symporter Inhibitors; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Topics: Blood Pressure; Cerebrovascular Circulation; Double-Blind Method; Female; Fosinopril; Humans; Hydrochlorothiazide; Hypertension; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Cerebral SPECT with 99mTc-HM-PAO allows a semiquantitative evaluation of regional cerebral blood flow (rCBF). Using this method we studied 25 patients affected by slight-to-moderate degree hypertension, in effective pharmacological treatment, and a control group of normotensives. On the cross-sections symmetrical ROIs were traced at the level of the cerebral lobes and the cerebellum. From the counts obtained on the ROIs the rCBF values were calculated in percentage units with Lassen's algorithm. We found no significant differences between the rCBF values of the two groups. In 5 hypertensive patients, however, focal areas of hypoperfusion were evidenced. These patients did not differ from the other hypertensives by pressure levels or other risk factors. Neurological, tomographic and flowmeter examinations of the supraaortic arteries proved to be normal. It is possible that SPECT with 99mTc-HM-PAO identifies a subgroup of hypertensives at risk of future cerebrovascular pathology despite the setting up of an effective antihypertensive therapy.

Topics: Adult; Cerebrovascular Circulation; Female; Humans; Hypertension; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

In cerebrovascular diseases pefuzionnaya single photon emission computed tomography with lipophilic amines used for the diagnosis of functional disorders of cerebral blood flow. Quantitative calculations helps clarify the nature of vascular disease and clarify the adequacy and effectiveness of the treatment. In this modern program for SPECT ensure conduct not only as to the calculation of blood flow, but also make it possible to compute also the absolute values of cerebral blood flow.

Topics: Adult; Case-Control Studies; Cerebrovascular Circulation; Female; Humans; Hypertension; Hypertensive Encephalopathy; Male; Middle Aged; Perfusion Imaging; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The aim of our study was to estimate brain perfusion and cognitive function (CF) in patients with arterial hypertension (AH) before and after hypotensive therapy. The study included 15 patients (mean age, 53.0+/-5.7 years) with previously untreated or ineffectively treated essential hypertension of the second degree. All patients underwent brain single photon emission computed tomography (SPECT) scanning with 99mTc-hexamethylpropylene amine oxime (99mTc-HMPAO) and comprehensive neuropsychological testing before and after 24 weeks of hypotensive therapy (angiotensin-converting enzyme [ACE] inhibitor or diuretics). The brain perfusion was significantly lower (15-22%) in all regions of AH patients. These patients showed a 25% decrease in attention and psychomotor speed as well as a 14% decrease in mentation. Six months of hypotensive therapy led to an increase in brain perfusion by an average of 7-11% in all brain regions. After treatment these patients demonstrated an average 11-18% improvements in attention and psychomotor speed, as well as an average 10% improvement in abstract mentation. Marked signs of brain hypoperfusion and impaired CF: decrease in attention, slowing psychomotor speed and mentation was found in hypertensive patients even without focal neurological symptomatology. Twenty-four weeks of hypotensive treatment with ACE inhibitors or diuretics had a positive effect on cerebral perfusion and led to CF improvement.

Topics: Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Cerebrovascular Circulation; Cognition Disorders; Diuretics; Female; Humans; Hypertension; Male; Middle Aged; Neuropsychological Tests; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The aim of the study was to assess cerebral perfusion (CP) in patients with arterial hypertension in combination with type II diabetes. The subjects were 57 patients with stage II AH (mean age 51.6 +/- 5.7 years), among who there were 33 patients without disturbances in carbohydrate exchange and 24 patients with compensated or subcompensated type II diabetes. All the patients underwent single-photon emission computed tomography of the brain with 99m Tchexamethylpropyleneamineoxime. The study showed that patients suffering from AH with or without type II diabetes had signs of cerebral hypoperfusion and lowered cerebrovascular reserve even in the absence of focal neurological symptoms. Disturbances in cerebral perfusion were more prominent in patients suffering from AH with type II diabetes vs. patients without carbohydrate exchange disorder.

Topics: Adult; Arteries; Brain; Carbohydrate Metabolism; Cerebrovascular Circulation; Diabetes Mellitus, Type 2; Female; Humans; Hypertension; Male; Middle Aged; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The purpose of the study was to examine cerebral microcirculatory and structural changes in 32 patients (20 males and 12 females whose age varied from 37 to 63 years) with moderate arterial hypertension (AH). All the patients underwent single-photon emission computed tomography of the brain, using (99m)Tc-hexamethylpropyleneaminoxylfor the evaluation of perfusion, as well as magnetic resonance imaging for the examination of cerebral structures. Cerebral structural changes and perfusion impairments were detected in patients with AH, even if they had no clinical signs of cerebrovascular insufficiency. Inadequate blood flow most frequently occurred in the parietal and temporal regions of the brain. There was a reduction in the cerebrovascular reserve in the frontal lobes in AH.

Topics: Adult; Brain; Cerebrovascular Circulation; Female; Humans; Hypertension; Magnetic Resonance Imaging; Male; Microcirculation; Middle Aged; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The cases of three children, 16, 12, and 12 years of age, who suffered sudden confusional state and cortical blindness lasting 12 to 30 minutes while under treatment with high-dose methotrexate, cyclophosphamide, and dactinomycin for a lower limb osteosarcoma are reported. Transient neuropsychologic deficits arose after the acute phase of treatment: left hemispatial neglect and constructive apraxia (Patient 1); constructive apraxia (Patient 2); and constructive apraxia and alexia without aphasia (Patient 3). The three patients recovered completely from all their deficits within the time frame of 3 hours to 2 weeks. Arterial hypertension and hypomagnesemia were found during the acute phase in all patients. In Patients 2 and 3, magnetic resonance imaging revealed increased parieto-occipital T(2) signal involving gray and white matter. In Patients 1 and 2, HmPAO-SPECT revealed parieto-occipital hypoperfusion that resolved a few days later. The alterations detected by neuroimaging were concurrent with the appearance and disappearance of the clinical symptoms. Such transient acute episodes have been named occipital-parietal encephalopathy. On the basis of our clinical, laboratory, and neuroimaging findings, an explanation for the origin of this syndrome, a migrainelike mechanism, triggered by chemotherapy-induced hypomagnesemia, is proposed.

Topics: Acute Disease; Adolescent; Antineoplastic Combined Chemotherapy Protocols; Brain; Child; Cyclophosphamide; Dactinomycin; Female; Humans; Hypertension; Magnesium Deficiency; Male; Methotrexate; Neurotoxicity Syndromes; Osteosarcoma; Radiopharmaceuticals; Remission Induction; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We studied risk factors for cerebral vascular disease (blood pressure and hypertension, factor VIIc, factor VIIIc, fibrinogen), indicators of atherosclerosis (intima-media thickness and plaques in the carotid artery) and cerebral white matter lesions in relation to regional cerebral blood flow (rCBF) in 60 persons (aged 65-85 years) recruited from a population-based study. rCBF was assessed with single-photon emission tomography using technetium-99m d, l-hexamethylpropylene amine oxime (99mTc-HMPAO). Statistical analysis was performed with multiple linear regression with adjustment for age, sex and ventricle-to-brain ratio. A significant positive association was found between systolic and diastolic blood pressure and temporo-parietal rCBF. In analysis with quartiles of the distribution, we found a threshold effect for the relation of low diastolic blood pressure (3.2 g/l) and low rCBF. Increased atherosclerosis was related to low rCBF in all cortical regions, but these associations were not significant. No consistent relation was observed between severity of cerebral white matter lesions and rCBF. Our results may have implications for blood pressure control in the elderly population.

Topics: Aged; Aged, 80 and over; Antigens; Brain; Brain Diseases; Carotid Arteries; Cerebrovascular Circulation; Factor VII; Factor VIII; Female; Fibrinogen; Humans; Hypertension; Intracranial Arteriosclerosis; Linear Models; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Risk Factors; Sampling Studies; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Ultrasonography