Influence of atorvastatin treatment on L-arginine cerebrovascular reactivity and flow-mediated dilatation in patients with lacunar infarctions.

BACKGROUND AND PURPOSE: In our study we hypothesized that statins improve endothelial function in patients with lacunar infarctions (LI). Cerebral and systemic endothelial function was determined before and after 3-months treatment with atorvastatin. METHODS: Cerebral endothelial function was determined by L-arginine reactivity and systemic endothelial function by flow-mediated dilatation (FMD) in patients with LI (18 patients, aged 61.1+/-7.6 years), 20 age- and gender-matched patients with similar risk factors (SR) and 19 age- and gender-matched healthy controls. The mean arterial velocity (v(m)) in both middle cerebral arteries was measured by transcranial Doppler sonography before, during and after a 30-minute intravenous infusion of L-arginine. FMD of the brachial artery after hyperaemia was determined. The measurements were repeated after 3-months treatment with 40 mg of atorvastatin per day. RESULTS: L-arginine reactivity was decreased in LI patients (13.1+/-8.4%) and in patients with SR compared with healthy controls (P < or = 0.01). FMD was more impaired in patients with LI (0.06+/-4.9%) compared with patients with SR and healthy controls (P < or = 0.01). After atorvastatin treatment, L-arginine reactivity and FMD improved in both patients with LI (17.1+/-7.6%; 7.0+/-5.7%) and patients with SR (P < or = 0.01). Previously mildly increased cholesterol values normalized. CONCLUSIONS: The decreased L-arginine reactivity and FMD improve after atorvastatin treatment in both patients with LI and patients with SR.

Cerebrovascular reactivity to L-arginine in patients with lacunar infarctions.

BACKGROUND: It is well known that endothelial dysfunction plays an important role in the pathogenesis of many cardiovascular disorders. The aim of this study was to test the hypothesis that specific, marked endothelial dysfunction of cerebral arteries is present in patients with lacunar cerebral infarctions. METHODS: Cerebrovascular reactivity to L-arginine, which reveals the function of the cerebral endothelium, was investigated in patients with lacunar infarctions (20 patients, 11 male and 9 female, aged 60.9 +/- 7.3 years), 21 age- and gender-matched asymptomatic patients with similar cardiovascular risk factors (all patients had arterial hypertension) and 21 age- and gender-matched healthy controls. The mean arterial velocity (vm) in both middle cerebral arteries was measured by transcranial Doppler sonography during a 15-min baseline period, a 30-min intravenous infusion of L-arginine and a 15-min interval after L-arginine infusion. Arterial blood pressure, heart rate and CO2 were measured continuously. RESULTS: The measured vm increase during L-arginine infusion in the patients with lacunar infarctions (13.4 +/- 9.1%) was significantly lower compared to the healthy controls (20.5 +/- 9.9%) but similar to that obtained in the patients with cardiovascular risk factors (11.5 +/- 8.9%). CONCLUSIONS: Our results showed that cerebrovascular reactivity to L-arginine, which demonstrates cerebral endothelial function, is significantly impaired in patients with cardiovascular risk factors. Importantly, we found that patients with lacunar infarctions do not show any additional impairment of cerebral endothelial function.

Effects of visual contrast on visual evoked potentials and Doppler signal.

We studied visually evoked cerebral blood flow responses (VEFR) and visual evoked potentials (VEP) to different visual contrasts and analysed the relationship between them. The records were made from 35 healthy volunteers aged 38.6 +/- 10.1 years. The stimulus was a black-and-white checkerboard with visual contrasts (VC) of 1%, 10% and 100%. The VEFR were measured in the posterior cerebral artery using transcranial Doppler, and the VEP were recorded from the occipital leads. We found the relationship between visual contrast and VEFR (r = 0.79, P < 0.01) as well as between visual contrast and VEP (r = 0.71, P < 0.01). We also found moderate association between the VEP and the VEFR (r = 0.69, P < 0.01). The analysis of the regression slopes between two different age subgroups (P < 0.01) did not show a significant difference (P = 0.020). We concluded that a simultaneous recording of VEFR and VEP to visual contrasts could allow an assessment of neurovascular coupling in humans.

Hypertensive encephalopathy mimicking brainstem tumour in psychiatric patient.

Hypertensive encephalopathy is a syndrome consisting of headache, seizures, visual changes, and other neurologic disturbances in patients with elevated systemic blood pressure. Diagnosis based on clinical and radiological findings, which are not specific, may be difficult to establish. Furthermore, hypertensive encephalopathy may develop gradually even when blood pressure is lower than that of malignant hypertension. We present clinical, magnetic resonance imaging (MRI) and autopsy findings in a 43-year-old schizophrenic patient with unrecognised hypertensive encephalopathy, which was misinterpreted by MRI as a diffusely growing brain stem tumour. Increased blood pressure was recorded several times, but it was not properly controlled and treated either during his out-door psychiatric examinations or hospitalisation. At autopsy, generalised atherosclerosis, concentric hypertrophy of the left ventricle and arteriolonephrosclerosis were found in addition to microvascular fibrinoid necroses and thromboses in the brain and kidneys, which were almost certainly caused by arterial hypertension evolving from benign into malignant stage. We discuss the differential diagnosis and give a review of the literature.

An evaluation of the Extended Barthel Index with acute ischemic stroke patients.

OBJECTIVE: To evaluate the Extended Barthel Index with acute ischemic stroke patients. METHODS: This prospective 1- to 6-week poststroke follow-up study was carried out using 33 newly diagnosed acute ischemic stroke patients who were admitted to the University Medical Centre Ljubljana, Department of Neurology. Measures used were Barthel Index (BI), Extended Barthel Index (EBI), Fugl-Meyer Motor Impairment Scale, 1-5 Self-Assessment scale, Rivermead Behavioural Memory Test. RESULTS: The EBI is a reliable scale in terms of internal consistency. The cognitive part is less reliable than the physical part of the EBI. It is a 3-dimensional scale as calculated by factor analysis (factor 1 with eigen value 8.2, factor 2 with eigen value 2.7 and factor 3 with eigen value 0.9). Criterion validity to the BI and the Fugl-Meyer Motor Impairment Scale was supported (P=0.1-0.001). External validity to the Self-Assessment scale was also supported (P<0.001). It is more sensitive to the changes in functional status that occur in the 1st 6 weeks poststroke than the original BI, although the ceiling effect was not really explained in this follow-up period. CONCLUSION: The EBI is a valid, reliable, 2- to 3-dimensional outcome measure of disability/activity for stroke patients. To some extent, it also reveals the level of patients' perception of their functional status.

Multiple sclerosis with uncommon cerebrospinal fluid findings.

AIM: To determine the frequency and clinical and laboratory features of patients with multiple sclerosis characterized by uncommon cerebrospinal findings, ie, negative oligoclonal band or increased number of mononuclear cells in cerebrospinal fluid. METHODS: The retrospective analysis included medical records of 233 patients (158 women and 75 men) admitted to the Department of Neurology, Ljubljana Medical Center, between January 1, 1990, and December 31, 1999 and discharged with the diagnosis of multiple sclerosis. We determined clinical features and cerebrospinal fluid parameters of patients with oligoclonal band-negative multiple sclerosis and > or =15 mononuclear cells/mm( 3) in cerebrospinal fluid and compared them with patients with oligoclonal band-positive multiple sclerosis and expected number of mononuclear cells in cerebrospinal fluid, respectively. There were 26 patients with oligoclonal band-negative finding and 26 with > or =15 mononuclear cells/mm(3) in cerebrospinal fluid. The two groups of patients did not overlap, except for one patient, who had 19 mononuclear cells/mm(3) and was oligoclonal band-negative. RESULTS: The diagnosis was delayed in oligoclonal band-negative multiple sclerosis patients, their cerebrospinal fluid contained less leukocytes, and lower concentration of IgG. The patients with > or =15 leukocytes/mm( 3) in cerebrospinal fluid were diagnosed earlier and had increased cerebrospinal fluid protein and IgG concentrations. CONCLUSION: Multiple sclerosis with negative oligoclonal band or increased count of leukocytes in cerebrospinal fluid were found in approximately 10% of patients with the disease. Because of the absence of oligoclonal band and less active cerebrospinal fluid, the diagnosis in these patients may be delayed.

The middle cerebral artery flow velocities during head-up tilt testing in diabetic patients with autonomic nervous system dysfunction.

BACKGROUND: The goal of this study was to examine the effects of diabetes mellitus on the trend of mean arterial velocity (v(m)) in both middle cerebral arteries during head-up tilt (HUT). METHODS: The study was performed in 20 patients, 9 females and 11 males (mean age 51 +/- 12 years) with an average 17-year history of insulin-dependent diabetes mellitus type I or II and a dysfunction of the autonomic nervous system confirmed by cardiocirculatory tests [Valsalva maneuver, deep breathing test, handgrip test, orthostatic test and spectral analysis of heart rate (HR) variability], and 19 age-matched healthy volunteers, 9 females and 10 males (mean age 48 +/- 6.8 years). v(m) was measured by a transcranial Doppler monitoring system during a 5-min baseline period, followed by a 5-min HUT in the upright position (90 degrees ). Mean arterial blood pressure (MAP), HR and end-tidal CO(2) (Et-CO(2)) were monitored concomitantly. RESULTS: In healthy volunteers, v(m) decreased stepwise during the first minute of HUT, reaching a minimum during the last 2 min of the test (v(m): basal 63.0 +/- 11.7 cm/s, 1st min 57.6 +/- 12.2 cm/s, 2nd min 55.9 +/- 12.6 cm/s, 3rd min 53.4 +/- 12.6 cm/s, 4th min 52.1 +/- 12.7 cm/s, 5th min 51.3 +/- 13.5 cm/s). In the supine position, v(m) recovered and reached the resting v(m) values. It declined gradually during HUT and less steeply in diabetic (v(m): basal 54.4 +/- 10.1 cm/s, 1st min 51.96 +/- 9.3 cm/s, 2nd min 50.7 +/- 11.6 cm/s, 3rd min 50.5 +/- 11.4 cm/s, 4th min 49.5 +/- 10.7 cm/s, 5th min 48.8 +/- 11.5 cm/s) than in healthy subjects. v(m) differed significantly (p = 0.00) between rest and HUT in both groups. The differences in MAP, HR and Et-CO(2) during rest and HUT between the groups were not statistically significant (p DeltaMAP = 0.36, p DeltaHR = 0.86, p DeltaEt-CO(2) = 0.97). The results of the analysis of variance of v(m) for repeated measurements between the two groups of subjects were highly significant (p = 0.00). The model of linear regression analysis was significant (p = 0.007). Diabetes was significant in the model (p = 0.00), while DeltaMAP, DeltaHR and DeltaEt-CO(2) were not. CONCLUSIONS: These findings may indicate that vasomotor responses during HUT testing are decreased in diabetic patients.

The influence of brightness, colour and complexity on visual evoked doppler flow responses.

The purpose of this study was to evaluate specific influence of colour, brightness and complexity on visual evoked flow responses (VEFRs). A total of 31 healthy subjects aged 35.1 +/- 7.7 years participated in the study. Mean arterial velocity was measured in the right posterior cerebral artery (v(pca)) and in the left middle cerebral artery (v(mca)) by Multi-DopX4 (DWL). Simple-white (SW), red (R) and complex-checkerboard (C) stimuli were used. VEFRs were determined by the difference of the v(pca):v(mca) ratio before and after stimulation. The VEFRs of SW with brightness of 21.4 cd/m(2), 10.5 cd/m(2) and 2 cd/m(2) were 8.7 +/- 3.4%, 9.1 +/- 3.0% and 8.0 +/- 3.7%, respectively (p < 0.001). The VEFRs of R and C stimuli were 10.4 +/- 6.5% and 12.4 +/- 6.1%, respectively (p < 0.001). ANOVA for repeated measurements did not show significant variances (p = 0.295) between VEFRs of SW of different brightness, but variances between VEFRs of SW, R and C stimuli were significant (p < 0.001). We found significant differences between VEFRs of SW and of C stimuli (3.8 +/- 1.9%, p < 0.001), VEFRs of SW and of R stimuli (1.8 +/- 2.4%, p = 0.008) as well as between VEFRs of C and of R stimuli (2.0 +/- 2.5%, p = 0.010). We have concluded that SW, R and C stimuli have a specific influence on VEFRs. Brightness does not appear to affect VEFRs.

DD Genotype of the angiotensin - converting enzyme gene and stroke in Slovenian population.

The angiotensin-converting enzyme (ACE) is a rate-limiting enzyme in the renin angiotensin system, the enzyme is involved in the vascular remodelling and atherosclerosis. Its significance in pathogenesis of ischemic cerebrovascular insults (CVI) is not known. We analysed 124 Slovenian patients with CVI and compared them with 161 healthy controls for I/D polymorphism. Under a recessive model (χ2 = 1.76, p= 0.1, OR = 1.40, 95% CI: 0.85 - 2.34) we found no significant difference in I/D genotypes between patients with CVI and controls. This study shows that in a group of Slovenian CVI patients the DD genotype is not an important risk factor for the development of stroke.