Neurologic complications of sickle cell disease

Abnormal Neurologic Findings in Patients With Sickle Cell Disease Without a History of Major Neurologic Events

Background and Objectives

Patients with sickle cell disease (SCD) are prone to symptomatic neurologic complications. Previous studies reported accrual of neural injury starting at early age, even without having symptomatic neurologic events. The aim of this study was to assess the prevalence and risk factors of abnormal neurologic findings in patients with SCD with no history of major symptomatic neurologic events.

Methods

Our study extracted patients diagnosed with SCD from the Cooperative Study of Sickle Cell Disease. Patients who underwent a neurologic evaluation were included in our analysis. Patients with previous documented major symptomatic neurologic events were excluded. We compared patients with SCD with abnormal neurologic findings with those without in terms of clinical and laboratory parameters using multivariate binary logistic regression.

Results

A total of 3,573 patients with SCD were included (median age = 11 [IQR = 19] years, male = 1719 [48.1%]). 519 (14.5%) patients had at least one abnormal neurologic finding. The most common findings in descending order were abnormal reflexes, gait abnormalities, cerebellar dysfunction, language deficits, nystagmus, abnormal muscle tone and strength, Romberg sign, Horner syndrome, and intellectual impairment. History of eye disease (odds ratio [OR] = 2.76, 95% confidence interval [CI] = 1.63-4.68) and history of osteomyelitis (OR = 2.55, 95% CI 1.34-4.84) were the strongest predictors of abnormal neurologic findings, followed by smoking (OR = 1.59, 95% CI 1.08-2.33), aseptic necrosis (OR = 1.57, 95% CI 1.06-2.33), hand-foot syndrome (OR = 1.48, 95% CI 1.04-2.12), and male sex (OR = 1.42, 95% CI 1.01-2.02).

Discussion

Neurologic deficits are relatively common in patients with SCD, even without documented major neurologic insults. They range from peripheral and ophthalmic deficits to central and cognitive disabilities. Patients with SCD should have early regular neurologic evaluations and risk factor modification, particularly actively promoting smoking cessation.

Neurocognitive Changes in Sickle Cell Disease: A Comprehensive Review

Background:

Sickle cell disease (SCD) is a type of hemoglobinopathy characterized by abnormal hemoglobin molecules, which includes numerous acute and chronic complications. Ischemic stroke, silent cerebral infarction, headache, and neurocognitive impairment are the most common neurological complications associated with SCD.

Summary:

Acute anemia because of SCD can cause cognitive impairments because of cerebral hypoxia. Cognitive abnormalities in SCD manifest in various aspects such as working memory, verbal learning, executive functions, and attention. These neurocognitive impairments have been associated with poor functional results, such as transitioning from juvenile to adult care, adherence to medications, and unemployment.

Key message:

In this review, we focus on neurocognitive aspects of SCD patients based on different imaging techniques, psychological batteries, associated neuromarkers, and interventions for managing of cognitive deficiencies..

A case series of hemorrhagic neurological complications of sickle cell disease: Multiple faces of an underestimated problem!

Sickle cell disease (SCD) is a group of hemoglobinopathies that vary in severity, the most severe form, homozygous sickle cell anemia, is more commonly associated with neurologic complications. These are attributed to the vaso-occlusion and micro-obstruction in the circulation of the central nervous system. The incidence of various neurologic complications in SCD ranges from 6% to 30% in various series. The commonly reported in literature include silent cerebral infarction (SCI), ischemic stroke, transient ischemic attacks (TIAs), headaches, seizures and neurocognitive impairment. However, hemorrhagic complications like subarachnoid hemorrhage (SAH), hemorrhagic stroke, extradural and subdural hematomas, especially in absence of trauma are rarely thought of. We report three uncommon spontaneous hemorrhagic manifestations of sickle cell anemia – one case of parenchymal (intracerebral) bleed who presented with acute onset of parkinsonism and two cases of extradural hematoma (EDH) of which one patient had recurrent EDH at the same site which is hitherto not reported in the literature.

Role of age and neuroinflammation in the mechanism of cognitive deficits in sickle cell disease

IMPACT STATEMENT

This study provides crucial information that could be helpful in the development of new or repurposing of existing therapies for the treatment of cognitive deficit in individuals with sickle cell disease (SCD). Its impact is in demonstrating for the first time that neuroinflammation and along with abnormal neuroplasticity are among the underlying mechanism of cognitive and behavioral deficits in SCD and that drugs such as minocycline which targets these pathophysiological mechanisms could be repurposed for the treatment of this life altering complication of SCD.

Evaluation of hydroxyurea genotoxicity in patients with sickle cell disease

OBJECTIVE

To evaluate the induction of DNA damage in peripheral blood mononuclear cells of patients with sickle cell disease, SS and SC genotypes, treated with hydroxyurea.

METHODS

The study subjects were divided into two groups: one group of 22 patients with sickle cell disease, SS and SC genotypes, treated with hydroxyurea, and a Control Group composed of 24 patients with sickle cell disease who were not treated with hydroxyurea. Peripheral blood samples were submitted to peripheral blood mononuclear cell isolation to assess genotoxicity by the cytokinesis-block micronucleus cytome assay, in which DNA damage biomarkers - micronuclei, nucleoplasmic bridges and nuclear buds - were counted.

RESULTS

Patients with sickle cell disease treated with hydroxyurea had a mean age of 25.4 years, whereas patients with sickle cell disease not treated with hydroxyurea had a mean age of 17.6 years. The mean dose of hydroxyurea used by the patients was 12.8mg/kg/day, for a mean period of 44 months. The mean micronucleus frequency per 1,000 cells of 8.591±1.568 was observed in the Hydroxyurea Group and 10.040±1.003 in the Control Group. The mean frequency of nucleoplasmic bridges per 1,000 cells and nuclear buds per 1,000 cells for the hydroxyurea and Control Groups were 0.4545±0.1707 versus 0.5833±0.2078, and 0.8182±0.2430 versus 0.9583±0.1853, respectively. There was no statistically significant difference between groups.

CONCLUSION

In the study population, patients with sickle cell disease treated with the standard dose of hydroxyurea treatment did not show evidence of DNA damage induction.

Balance control is impaired in adults with sickle cell anaemia

BACKGROUND

Musculoskeletal involvement and cerebrovascular disease are common in sickle cell anaemia (SCA). These changes are potentially important factors that modify the control of balance in this population.

OBJECTIVE

To assess balance control in adults with SCA and investigate the associations among balance, posture and muscle function.

METHODS

Twenty neurologically intact (i.e. without previous episodes of overt stroke or transient ischaemic attack) adults with SCA and 18 controls were evaluated. All participants underwent static balance measurement through stabilometry, postural evaluation through photogrammetry and assessment of muscle function through handgrip and respiratory muscle strength.

RESULTS

Compared to the controls, the adults with SCA exhibited greater displacement of the centre of mass, particularly in the mediolateral direction. Moreover, the adults with SCA exhibited greater postural deviations for the following variables: angles of the right and left hip, horizontal asymmetry of the scapula in relation to T3, angles of the right and left leg-heel and horizontal alignment of the pelvis. Handgrip strength, respiratory muscle strength and haemoglobin (Hb) levels were significantly correlated with postural balance measurements. Significant correlations between balance and posture were only observed between the variables of balance and the postural parameters that involved the angulations calculated from the vertical alignment of the pelvis, hip and ankle.

CONCLUSIONS

Neurologically intact adults with SCA exhibit damage in static balance, particularly in the mediolateral direction. These patients present postural deviations due to changes in the hip and ankle joints. In addition, balance control is related to posture, Hb level and muscle function.

Neurologic complications of sickle cell disease in Africa: A systematic review and meta-analysis

Objective:

To summarize prevalence data on the neurologic complications of sickle cell disease (SCD) in Africa.

Methods:

We searched EMBASE, PubMed, and African Index Medicus to identify all relevant articles published from inception to May 31, 2016. Each study was reviewed for methodologic quality. A random-effects model was used to estimate the prevalence of neurologic complications of SCD across studies.

Results:

Thirty-one studies were included. Methodologic quality was high or moderate in 90% of studies. Stroke, conditional and abnormal cerebral blood flow, seizures, and headache were the complications most frequently reported, with overall prevalence rates of 4.2%, 10.6%, 6.1%, 4.4%, and 18.9%, respectively. Some complications, like silent brain infarcts, peripheral neuropathies, neurocognitive deficits, or moyamoya disease, have been rarely or not studied at all in the African setting. Incidence data were scarce and of poor quality.

Conclusions:

The burden of neurologic complications of SCD is important in Africa and most likely underestimated. A better evaluation of this burden requires larger prospective studies using standard up-to-date screening methods. Accessibility to diagnostic tools such as neuroimaging, transcranial Doppler, EEG, and neuropsychological evaluation, as well as to preventive and therapeutic interventions and trained health care providers, should be improved in routine clinical practice.

Neurological complications of sickle cell disease in Africa: protocol for a systematic review

INTRODUCTION

Sickle cell disease (SCD) is highly prevalent in Africa. Considered as a public health problem, it is associated with high morbidity and mortality. Neurological complications of SCD can cause significant disability with important socioeconomic and psychological impact on the patients and their families, and can even lead to death if not properly managed. There are important knowledge gaps regarding the burden of neurological complications of SCD in African populations. We propose to conduct the first systematic review to summarise the epidemiological data available on neurological complications of SCD in Africa.

METHODS AND ANALYSIS

We will search PubMed, MEDLINE, EMBASE and the African Index Medicus from 1 January 1950 to 31 May 2016 for studies of neurological complications of SCD in Africa. After study selection, full-text paper acquisition, data extraction and synthesis, we will assess all studies for quality, risk of bias and heterogeneity. Appropriate methods of meta-analysis will be used to pool prevalence estimates from studies with similar features, globally and in major subgroups. This protocol complies with the 2015 Preferred Reporting Items for Systematic reviews and Meta-Analysis protocols (PRISMA-P) guidelines.

ETHICS AND DISSEMINATION

The proposed study will use published data. Therefore, there is no requirement for ethical approval. This review is expected to provide relevant data to help quantify the burden of neurological complications of SCD in African populations, inform policymakers and identify further research topics. The final report of the systematic review will be published in a peer-reviewed journal and presented at conferences.

REVIEW REGISTRATION NUMBER

CRD42016039574.