Evaluation of endothelial function and subclinical atherosclerosis in patients with HIV infection

The aim of this study was to analyse the association between human immunodeficiency virus (HIV) related clinical and analytical parameters and the presence of subclinical atherosclerosis as well as endothelial dysfunction. This was a prospective cohort study of HIV-positive patients who underwent intima media thickness (IMT) determination and coronary artery calcium scoring to determine subclinical atherosclerosis. To detect endothelial dysfunction, the breath holding index, flow-mediated dilation and the concentration of endothelial progenitor cells (EPCs) were measured. Patients with an IMT ≥ 0.9 mm had an average of 559.3 ± 283.34 CD4/μl, and those with an IMT < 0.9 mm had an average of 715.4 ± 389.92 CD4/μl (p = 0.04). Patients with a low calcium score had a significantly higher average CD4 cell value and lower zenith viral load (VL) than those with a higher score (707.7 ± 377.5 CD4/μl vs 477.23 ± 235.7 CD4/μl (p = 0.01) and 7 × 104 ± 5 × 104 copies/ml vs 23.4 × 104 ± 19 × 104 copies/ml (p = 0.02)). The number of early EPCs in patients with a CD4 nadir < 350/µl was lower than that in those with a CD4 nadir ≥ 350 (p = 0.03). In HIV-positive patients, low CD4 cell levels and high VL were associated with risk of developing subclinical atherosclerosis. HIV patients with CD4 cell nadir < 350/µl may have fewer early EPCs.

Erenumab does not alter cerebral hemodynamics and endothelial function in migraine without aura

Objective To assess whether erenumab influences cerebral vasomotor reactivity and flow-mediated dilation in migraine patients. Methods Consecutive migraineurs prescribed erenumab at our Headache Centre and age and sex-matching controls were invited to participate in this observational longitudinal study. Patients were evaluated for cerebral vasomotor reactivity to hypercapnia (breath-holding index) in middle and posterior cerebral arteries and for brachial corrected flow mediated dilation at baseline (T0), after 2 weeks from the first erenumab injection (T2) and after 2 weeks from the fourth Erenumab injection (T18). Patients displaying a reduction of at least 50% in monthly migraine days after completing the fourth month of therapy were classified as responders. Results Sixty patients and 25 controls agreed to participate. Middle and posterior cerebral artery mean flow velocities, breath-holding index and flow-mediated dilation did not differ at T0 and from T0 to T2 in patients and controls. In patients, we neither observed a variation of the explored variables from T0 to T18 nor an interaction between evaluation times (T0–T2 or T0–T18) and chronic condition at T0, responder state or erenumab fourth dose. Conclusions Our findings demonstrate that erenumab preserves cerebral vasomotor reactivity and flow-mediated dilation in migraineurs without aura.

Transcranial Doppler findings in antiphospholipid syndrome

Introduction Transcranial Doppler is a method that enables the assessment of different cerebral hemodynamic parameters. It also allows for the evaluation of the presence of right-to-left circulation shunts (RLS) and for the detection of microembolic signals (MESs), which might be associated with an increased risk of cerebrovascular events. For instance, the presence of MESs on transcranial Doppler in patients with systemic lupus erythematous (SLE) and antiphospholipid syndrome (APS) is associated with an increased risk of stroke. Therefore, transcranial Doppler could be a useful tool for stroke risk stratification in these patients. Objective Our objective was to evaluate transcranial Doppler cerebral mean blood flow velocities as well as the presence of MESs and RLS in patients with antiphospholipid syndrome and SLE. Patients and methods Twenty-two patients with primary APS (PAPS), 24 patients with secondary APS (SAPS), 27 patients with SLE without APS and 21 healthy controls were evaluated. Clinical and epidemiological data were compiled from medical charts, and all subjects underwent transcranial Doppler examination with breath-holding index calculation. Both middle cerebral arteries were monitored for 60 min for the detection of MESs. RLS was investigated with agitated saline injected as a bolus. Results There were no significant differences in mean blood flow velocities among the groups. MESs were more frequently found in patients with SLE when compared with controls and patients with APS (SLE: 17.4%, SAPS: 4.3%, PAPS: 0%, controls: 0%, p = 0.03). Anticoagulant therapy was more frequently used in the APS group (PAPS: 81.8%, SAPS: 75.2%, SLE: 1.7%, p < 0.001). Patients with APS had a higher frequency of RLS when compared with volunteers (63.6% versus 38.1%, p = 0.05). Breath-holding index values tended to be lower in patients with SAPS than in control subjects and patients with PAPS and SLE ( p = 0.06). Conclusions Patients with APS had a higher frequency of RLS than healthy controls. This finding alerts to the importance of cardiac investigation in patients with stroke and APS, because further therapies such as RLS occlusion might eventually add protection. The higher frequency of MES in patients with SLE could suggest an effect of anticoagulant therapy on MES prevention, more frequently used in patients with APS.

Breath holding index in episodic primary headaches

Background/Aim. Examination of cerebrovascular reactivity in patients with primary headaches is focused mainly on migraine, while the smaller number of studies deals with tensiontype and cluster headache, or comparison of cerebral haemodynamic in migraine and tension-type headache (TTH). In this study, we hypothesized that cerebrovascular reactivity differs among different types of episodic primary headaches. In order to prove that we aimed to compare the interictal cerebrovascular reactivity in patients with the episodic form of the three most common types of primary headaches using the breath holding test. Methods. Examination was performed in 243 patients, 100 migraineurs with aura (group I), 70 migraineurs without aura (group II), 38 patients with episodic tension-type headache (group III), 35 patients with episodic form of cluster headache (group IV) and 35 healthy controls (group V). The Doppler instrument was used for transcranial doppler (TCD) sonography and breath-holding test performance. Blood flow mean velocities (MV), pulsatility indices (PI) and breath-holding index (BHI) for middle cerebral artery among these groups were analyzed. Results. The mean velocities and pulsatility indices were not different in 4 groups of headache patients and controls. The BHI was found to be significantly greater in the migraineurs with aura (1.668 ? 0.269) compared with the patients with migraineurs without aura (1.411 ? 0.358, p = 0.005), tension type headache (1.401 ? 0.428, p = 0.035), cluster headache (1.203 ? 0.311, p < 0.01) and controls (1.195 ? 0.269, p < 0.01) showing an exaggerated reactivity to hypercapnia in patients with migraine with aura. Conclusion. In conclusion, our finding support the literature data that increased cerebrovascular reactivity is a feature of migraine with aura. Result of unchanged cerebrovascular reactivity in migraine without aura, cluster headache and tension-type headache is expected, still, it is possible that in future, using different technique, we will be able to put more light on vascular changes that are following different headache disorders.

Cerebral vasomotor reactivity in reversible cerebral vasoconstriction syndrome

Background Altered cerebrovascular tone is implicated in reversible cerebral vasoconstriction syndrome (RCVS). We evaluated vasomotor reactivity using bedside transcranial Doppler in RCVS patients. Methods In this retrospective case-control study, middle cerebral artery (MCA) blood flow velocities were compared at rest and in response to breath-hold in RCVS ( n = 8), Migraineurs ( n = 10), and non-headache Controls ( n = 10). Hyperventilation response was measured in RCVS. Results In RCVS, Breath Holding Index (BHI) was severely reduced in seven of eight patients and 14/16 MCAs; seven of 16 MCAs showed exhausted (BHI < 0.1) or inverted (BHI < 0) vasomotor reactivity. Mean BHI in RCVS (0.23 ± 0.5) was significantly lower than Migraine (1.52 ± 0.57) and Controls (1.51 ± 0.32), p < 0.001. Triphasic velocity responses were seen in all groups. The maximum Vmean decline during the middle negative phase was −15.5 ± 9.2% in RCVS, −15.4 ± 7% in Migraine, and −10.3 ± 5% in Controls ( p = 0.04). In the late positive phase, average Vmean increase was 6.2 ± 14% in RCVS, which was significantly lower ( p < 0.001) than Migraine (30.5 ± 11%) and Controls (30.2 ± 6%). With hyperventilation, RCVS patients showed 23% decrease in Vmean. Conclusion Cerebral arterial tone is abnormal in RCVS, with proximal vasoconstriction and abnormally reduced capacity for vasodilation. Further studies are needed to determine the utility of BHI to diagnose RCVS before angiographic reversibility is established, and to estimate prognosis.

Cerebral vasomotor reactivity and apnea test in symptomatic and asymptomatic high-grade carotid stenosis

Introduction. Cerebral vasomotor reactivity (VMR) represents an autoregulatory response of the arterial trunks on the specific vasoactive stimuli, most commonly CO2. Objective. The aim of this retrospective study was to compare VMR in high-grade symptomatic (SCAS) and asymptomatic carotid stenosis (ACAS), using the apnea test to evaluate the hemodynamic status. Methods. The study included 50 patients who were hospitalized at the neurology and vascular surgery departments as part of preparation for carotid endarterectomy. We evaluated VMR by calculating the breath holding index (BHI) in 34 patients with SCAS and 16 patients with ACAS, with isolated high-grade carotid stenosis. We evaluated the impact of risk factors and collateral circulation on BHI, as well as the correlation between the degree of carotid stenosis and BHI. Results. A pathological BHI was more frequent in the SCAS group (p<0.01). There was no difference in the range of BHI values between the groups, both ipsilaterally and contralaterally. Only male gender was associated with pathological BHI in both groups (p<0.05). Collateral circulation did not exist in over 60% of all subjects. We confirmed a negative correlation between the degree of carotid stenosis and BHI. Conclusion. SCAS and ACAS patients present with different hemodynamics. While ACAS patients have stable hemodynamics, combination of hemodynamic and thromboembolic effects is characteristic of SCAS patients.

Abnormal Cerebrovascular Reactivity in Patients with Parkinson’s Disease

Background. Orthostatic hypotension (OH) is an important nonmotor manifestation of Parkinson’s disease (PD). Changes in cerebrovascular reactivity may contribute to this manifestation and can be monitored using transcranial Doppler.Objective. To identify possible changes in cerebrovascular reactivity in patients with OH.Methods. Twenty-two individuals were selected and divided into three groups: with and without OH and controls. Transcranial Doppler was used to assess basal mean blood flow velocity, postapnea mean blood flow velocity, percentage increase in mean blood flow velocity, and cerebrovascular reactivity as measured by the breath-holding index.Results. PD patients had lower values of basal velocity (p=0.019), postapnea velocity (p=0.0015), percentage increase in velocity (p=0.039), and breath-holding index (p=0.04) than the controls. Patients with OH had higher values of basal velocity (p=0.09) and postapnea velocity (p=0.19) but lower values of percentage increase in velocity (p=0.22) and breath-holding index (p=0.32) than patients without OH.Conclusions. PD patients present with abnormalities in a compensatory mechanism that regulates cerebral blood flow. OH could be an indicator of these abnormalities.