Intracranial blood flow velocities in patients with sickle cell disease and β-thalassemia intermedia

Background: Sickle cell disease (SCD) is the most common cause of stroke in children. Impairment of vasodilatory capacity reflecting reduced cerebrovascular reserve was previously shown in adults with SCD and might play a role in the pathophysiology of stroke in such patients. We assessed the hypothesis that children with SCD would also have a higher frequency of impaired cerebral vasoreactivity when compared to healthy age-matched subjects. Patients and Methods: Patients were selected from the pediatric outpatient clinic of the Department of Hematology at our University Hospital. All those patients with SCD disease (diagnosis confirmed by hemoglobin electrophoresis on cellulose acetate) without a history of symptomatic stroke aged 10 to 18 years old were evaluated. Healthy children of similar age and gender were also studied. Transcranial Doppler (TCD) was performed in all patients and controls subjects, with breath-holding maneuver and calculation of the breath-holding index (BHI) to assess cerebral vasoreactivity. The BHI was obtained by dividing the percentage increase in mean flow velocity occurring during breath holding by the length of time (seconds) subjects hold their breath after a normal inspiration. BHI was considered abnormal if < 0.69. Results: TCD was performed in 42 patients (mean age 12.7 +/-2.2 years) and 20 controls (mean age 13.90 +/-3.04 years). Blood flow velocities were higher in patients with SCD than in healthy volunteers in all arteries evaluated (p<0.01). Cerebral blood flow velocities were negatively correlated with hemoglobin levels (p<0.05). BHI values in patients with SCD were significantly lower than in control subjects (1.27 +/-0.65 versus 1.74 +/- 0.15, p=0.01 at left and 1.16 +/- 0.45 versus 1.61 +/- 0.11, p<0.01 at right). BHI was abnormal in 19% of the patients and none of the healthy controls (p=0.04). Conclusions: In conclusion, children with SCD may have impaired cerebral vasoreactivity, with low BHI values suggesting a reduced autoregulation capacity in these patients.

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Intra-individual variation in blood flow velocities in cerebral arteries of children with sickle cell disease

Pediatric Blood & Cancer ◽

10.1002/pbc.21142 ◽

2007 ◽

Vol 49 (3) ◽

pp. 318-322 ◽

Cited By ~ 21

Author(s):

Donald J. Brambilla ◽

Scott T. Miller ◽

Robert J. Adams

Keyword(s):

Blood Flow ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Individual Variation ◽

Cerebral Arteries ◽

Cell Disease ◽

Blood Flow Velocities ◽

Flow Velocities

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Blood flow velocities of intracranial arteries in children with sickle cell disease seem to decrease with age

Tijdschrift voor kindergeneeskunde ◽

10.1007/s12456-013-0106-y ◽

2013 ◽

Vol 81 (S1) ◽

pp. 109-109

Author(s):

M.A.J. Smits ◽

V. van der Land ◽

H. Heijboer ◽

K Fijnvandraat

Keyword(s):

Blood Flow ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Cell Disease ◽

Intracranial Arteries ◽

Blood Flow Velocities ◽

Flow Velocities

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Hemodynamic Etiology of Elevated Flow Velocity and Stroke in Sickle-Cell Disease

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2009.6 ◽

2009 ◽

Vol 29 (4) ◽

pp. 803-810 ◽

Cited By ~ 85

Author(s):

Isak Prohovnik ◽

Anne Hurlet-Jensen ◽

Robert Adams ◽

Darryl De Vivo ◽

Steven G Pavlakis

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Sickle Cell Disease ◽

Flow Velocity ◽

Sickle Cell ◽

Prognostic Significance ◽

Cerebrovascular Reactivity ◽

Cell Disease ◽

Cerebrovascular Reserve ◽

Blood Flow Velocities

Elevation of blood flow velocity in the large cerebral vessels is known to be of substantial pathophysiologic and prognostic significance in sickle-cell disease (SCD). Its precise cause is not established, but the two obvious proximal mechanisms are obstructive vascular stenosis and hemodynamic dilatation. Here we revisit this distinction by analyzing cerebrovascular reserve capacity. Forty-two patients with SCD underwent measurements of global cerebral blood flow in grey matter by the 133Xe inhalation method during normocapnia and hypercapnia to quantify cerebrovascular reactivity. Cerebral blood flow was significantly higher in SCD patients (120±31 ml/100 g/min) than in controls (76±20 ml/100 g/min). Reactivity was significantly lower in SCD patients (1.06±1.92 versus 2.16±1.15%/mm Hg). Stepwise multiple regressions within the SCD sample determined that normocapnic cerebral blood flow was largely predicted by hematocrit ( r =–0.59; P > 0.0001), whereas hypercapnic reactivity was only predicted by normocapnic flow across all subjects ( r =–0.52; P > 0.0001). None of the controls, but 24% of the SCD patients showed ‘steal’ (negative reactivity, χ2 = 6.05; P > 0.02). This impairment of vasodilatory capacity, occurring at perfusion levels above 150 ml/100 g/min, may reflect intrinsic limitations of the human cerebrovascular system and can explain both the elevated blood flow velocities and the high risk of stroke observed in such patients.

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Migraine-Mimicking Headache and Sickle Cell Disease

Cephalalgia ◽

10.1111/j.1468-2982.2006.01092.x ◽

2006 ◽

Vol 26 (6) ◽

pp. 678-683 ◽

Cited By ~ 12

Author(s):

GS Silva ◽

P Vicari ◽

MS Figueiredo ◽

HC Junior ◽

MH Idagawa ◽

...

Keyword(s):

Blood Flow ◽

Sickle Cell Disease ◽

Sickle Cell ◽

International Headache Society ◽

Brain Mri ◽

Brain Magnetic Resonance Imaging ◽

Primary Headache ◽

Cell Disease ◽

Magnetic Resonance Imaging Mri ◽

Blood Flow Velocities

Headache occurs in sickle cell disease (SCD), but its characteristics and frequency have not previously been studied. Our aim was to study patterns of headache in adults with SCD and to correlate its presence with blood flow velocities measured by transcranial Doppler (TCD) and with brain magnetic resonance imaging (MRI) abnormalities. We studied 56 adults with SCD. Twenty-eight patients (50%) had severe and frequent headaches. In 20 patients (35.7%) the headache met the International Headache Society criteria for migraine without aura. Patients with frequent and severe headache presented TCD velocities significantly higher than those without headache, or with milder headache. No correlation was found between headache and abnormalities in brain MRI. A migraine-mimicking headache occurs in SCD but we should not understand it as a primary headache because the blood flow abnormalities secondary to SCD detected by TCD seem to play an important role in these patients.

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Is there a role for selective vasodilation in the management of sickle cell disease?

Blood ◽

10.1182/blood.v71.3.597.597 ◽

1988 ◽

Vol 71 (3) ◽

pp. 597-602 ◽

Cited By ~ 18

Author(s):

GP Rodgers ◽

MS Roy ◽

CT Noguchi ◽

AN Schechter

Keyword(s):

Blood Flow ◽

Steady State ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Microvascular Obstruction ◽

Controlled Study ◽

Control Group ◽

Cell Disease ◽

Retinal Arteriolar

Abstract To test the hypothesis that microvascular obstruction to blood flow at the level of the arteriole may be significant in individuals with sickle cell anemia, the ophthalmologic effects of orally administered nifedipine were monitored in 11 steady-state patients. Three patients with evidence of acute peripheral retinal arteriolar occlusion displayed a prompt reperfusion of the involved segment. Two other patients showed fading of retroequatorial red retinal lesions. Color vision performance was improved in six of the nine patients tested. The majority of patients also demonstrated a significant decrease in the amount of blanching of the conjunctiva which reflects improved blood flow to this frequently involved area. Such improvements were not observable in a control group of untreated stable sickle cell subjects. These findings support the hypothesis that inappropriate vasoconstriction or frank vasospasm may be a significant factor in the pathogenesis of the microvascular lesions of sickle cell disease and, further, that selective microvascular entrapment inhibition may offer an additional strategy to the management of this disorder. We believe a larger, placebo-controlled study with nifedipine and similar agents is warranted.

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