Structural connectivity mediates the relationship between blood oxygenation and cognitive function in sickle cell anemia.

In sickle cell disease, the relative importance of reduced hemoglobin (Hb) and peripheral oxygen saturation on brain structure remains uncertain. We applied graph-theoretical analysis to diffusion magnetic resonance imaging data to investigate the effect of structural brain connectivity on cognitive function, alongside the presence or absence, number, and volume of silent cerebral infarction. In patients, we investigated the relationships between network properties, blood oxygenation, and cognition (working memory and processing speed indices).

Quantification of Silent Cerebral Infarction on High-Resolution FLAIR and Cognition in Sickle Cell Anemia.

Research in sickle cell anemia (SCA) has used, with limited race-matched control data, binary categorization of patients according to the presence or absence of silent cerebral infarction (SCI). SCI have primarily been identified using low-resolution MRI, with radiological definitions varying in lesion length and the requirement for abnormality on both fluid attenuated inversion recovery (FLAIR) and T1-weighted images. We aimed to assess the effect of published SCI definitions on global, regional, and lobar lesion metrics and their value in predicting cognition.

Individual Watershed Areas in Sickle Cell Anemia: An Arterial Spin Labeling Study.

Previous studies have pointed to a role for regional cerebral hemodynamic stress in neurological complications in patients with sickle cell anemia (SCA), with watershed regions identified as particularly at risk of ischemic tissue injury. Using single- and multi-inflow time (TI) arterial spin labeling sequences (ASL) in 94 patients with SCA and 42 controls, the present study sought to investigate cerebral blood flow (CBF) and bolus arrival times (BAT) across gray matter, white matter with early arrival times, and in individual watershed areas (iWSAs). In iWSAs, associations between hemodynamic parameters, lesion burden, white matter integrity, and general cognitive performance were also explored.

Venous cerebral blood flow quantification and cognition in patients with sickle cell anemia.

Prior studies have described high venous signal qualitatively using arterial spin labelling (ASL) in patients with sickle cell anemia (SCA), consistent with arteriovenous shunting. We aimed to quantify the effect and explored cross-sectional associations with arterial oxygen content (CaO), disease-modifying treatments, silent cerebral infarction (SCI), and cognitive performance. 94 patients with SCA and 42 controls underwent cognitive assessment and MRI with single- and multi- inflow time (TI) ASL sequences.

Study of montelukast in children with sickle cell disease (SMILES): a study protocol for a randomised controlled trial.

Background: Young children with sickle cell anaemia (SCA) often have slowed processing speed associated with reduced brain white matter integrity, low oxygen saturation, and sleep-disordered breathing (SDB), related in part to enlarged adenoids and tonsils. Common treatments for SDB include adenotonsillectomy and nocturnal continuous positive airway pressure (CPAP), but adenotonsillectomy is an invasive surgical procedure, and CPAP is rarely well-tolerated. Further, there is no current consensus on the ability of these treatments to improve cognitive function.

White matter integrity and processing speed in sickle cell anemia.

Objective: The purpose of this retrospective cross-sectional study was to investigate whether changes in white matter integrity are related to slower processing speed in sickle cell anemia.

Methods: Thirty-seven patients with silent cerebral infarction, 46 patients with normal MRI, and 32 sibling controls (age range 8-37 years) underwent cognitive assessment using the Wechsler scales and 3-tesla MRI. Tract-based spatial statistics analyses of diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) parameters were performed.

White Matter Damage Relates to Oxygen Saturation in Children With Sickle Cell Anemia Without Silent Cerebral Infarcts.

Background And Purpose: Sickle cell anemia is associated with compromised oxygen-carrying capability of hemoglobin and a high incidence of overt and silent stroke. However, in children with no evidence of cerebral infarction, there are changes in brain morphometry relative to healthy controls, which may be related to chronic anemia and oxygen desaturation.

Methods: A whole-brain tract-based spatial statistics analysis was carried out in 25 children with sickle cell anemia with no evidence of abnormality on T2-weighted magnetic resonance imaging (13 male, age range: 8-18 years) and 14 age- and race-matched controls (7 male, age range: 10-19 years) to determine the extent of white matter injury.

Factors predicting future ACS episodes in children with sickle cell anemia.

While a doctor-diagnosis of asthma is associated with an increased risk of pain and acute chest syndrome (ACS) in children with sickle cell anemia (SCA), little is known about the relationship between specific asthma characteristics and clinical factors and future morbidity in children with SCA. We evaluated the relationship between (i) asthma risk factors at the time of a clinical visit (respiratory symptoms, maternal history of asthma, allergy skin tests, spirometry results) and (ii) the known risk factor of ACS early in life, on prospective pain and ACS episodes in a cohort of 159 children with SCA followed from birth to a median of 14.7 years.

Obstructive sleep apnea and sickle cell anemia.

Objective: To ascertain the prevalence of and risk factors for obstructive sleep apnea syndrome (OSAS) in children with sickle cell anemia (SCA).

Methods: Cross-sectional baseline data were analyzed from the Sleep and Asthma Cohort Study, a multicenter prospective study designed to evaluate the contribution of sleep and breathing abnormalities to SCA-related morbidity in children ages 4 to 18 years, unselected for OSAS symptoms or asthma. Multivariable logistic regression assessed the relationships between OSAS status on the basis of overnight in-laboratory polysomnography and putative risk factors obtained from questionnaires and direct measurements.

Enuresis associated with sleep disordered breathing in children with sickle cell anemia.

Purpose: Enuresis and sleep disordered breathing are common among children with sickle cell anemia. We evaluated whether enuresis is associated with sleep disordered breathing in children with sickle cell anemia.

Materials And Methods: Baseline data were used from a multicenter prospective cohort study of 221 unselected children with sickle cell anemia.

Clinical outcomes in children with sickle cell disease living in England: a neonatal cohort in East London.

Background And Objectives: We investigated outcomes in a UK neonatal cohort as a benchmark for care of children with sickle cell disease (SCD).

Design And Methods: Two-hundred and fifty-two children (180 with hemoglobin [Hb] SS, 64 with HbSC, and 8 with HbS/beta thalassemia), identified during 1983-2005 by universal birth screening in East London, were followed in a hospital and community-based program which included penicillin V prophylaxis from 3 months of age, 23-valent pneumococcal polysaccharide vaccine from 1993, conjugate pneumococcal vaccine from 2002 and transcranial Doppler screening from 1991.

Results: At the end of 2005, there were 2158 patient years of observation.