ORIGINAL

Niger J Paed 2013; 40 (2): 158 –164

Oniyangi O

Ahmed P

Otuneye OT

Okon J

Strokes in children with sickle cell

disease at the National Hospital

Abuja Nigeria

Aikhionbare HA

Olatunji OO

Akano AO

DOI:http://dx.doi.org/10.4314/njp.v40i2,10

Accepted: 13th October 2012

Abstract Background: Strokes

occur in sickle cell disease (SCD),

and are associated with significant

morbidity and mortality.

Objectives: To determine the

prevalence of strokes amongst chil-

dren with SCD, and document the

major clinical features, complica-

tions, effect of treatment with

chronic transfusion therapy (CTT)

and outcome.

Methods: A descriptive retrospec-

tive study of SCD children with

strokes seen at the National Hospi-

tal Abuja, Nigeria over a 2.5 year

period from January 2009 – June

Imaging) done in 16 (61.5%) children

showed cerebral atrophy in 10,

acute cerebral infarcts in 9, chronic

cerebral infarcts in 6, acute intra

cranial haemorrhage in 1 and nor-

mal imagings in 4 children.

Twelve (12) children (46.2%) chil-

dren had recurrences of stroke rang-

ing in number from 1 to 4, which

occurred 6 months to 3 years after

the initial stroke. There were no

statistical significant differences

between the children with recur-

rences of stroke compared to those

without regarding the age, sex,

weight or PCVs p > 0.05.

Oniyangi O

(

)

Ahmed P, Otuneye OT, Okon J

Aikhionbare HA, Olatunji OO

Akano AO

Department of Paediatrics

National Hospital PMB 425 Garki,

Abuja Nigeria.

Email: seyioniyangi@yahoo.co.uk

2

012. Data was collected by scruti-

Fifteen (15) children (57.7%) were

enrolled in CTT. Two (2) out of 7

children (28.6%) that had regular

CTT had stroke recurrence; com-

pared to 5 out of 11 children

(45.4%) with no CTT (p > 0.05).

Four (4) out of 6 (66.7%) children

with irregular CTT and 1 of 2 chil-

dren who stopped CTT had stroke

recurrence.

nizing case files obtained from the

hospital medical records unit. In-

formation obtained included demo-

graphic data, clinical features,

packed cell volume (PCV), brain

imaging, long term neurologic

deficits, effect of CTT, stroke re-

currence and outcome.

Results: There were 31 children

with strokes among 596 children

with SCD documented in the regis-

ter, giving a prevalence of 5.2%.

Twenty six (26) case notes were

retrieved. There were 12 males

and 14 females, M: F ratio of 0.9:1;

mean age was 6.4 years (SD 3.4)

range: 1 year 7 months – 14 years;

mean PCV at the time of strokes

was 21.1% (SD 3.9) range 14 –

Outcome: 17 children were alive, 7

were lost to follow up, 1 died and 1

was referred to another center.

Conclusion: Strokes were an impor-

tant cause of morbidity in Nigerian

children with SCD, with major long

term neurologic deficits. CTT ap-

peared beneficial in preventing

stroke recurrences. Primary preven-

tion strategy by Trans Cranial Dop-

pler ultrasound studies of the cere-

bral arteries, with the aim of

promptly initiating appropriate preven-

tive therapy for stroke is strongly advo-

cated.

2

9%. All (100%) had Haemoglobin

SS on electrophoresis. Presenta-

tions were convulsions 18, inability

to use limbs 11, weakness of limbs

1

0; long term neurological deficits

were hemiplegia 11, cognition loss 11.

Three (3) children had no deficits.

Brain imaging (Computed Tomogra-

phy Scan and Magnetic Resonance

Key words: Sickle cell disease,

Stroke, Children, Chronic

Transfusion Therapy

1

59

Introduction

A stroke was defined as an acute neurologic syndrome

secondary to occlusion of a cerebral artery or haemor-

rhage with resultant ischaemia and neurologic signs and

Strokes (cerebrovascular accidents CVA) are potentially

devastating consequences of sickle cell disease (SCD),

which have be₁en associated with significant morbidity

and mortality.

1

symptoms lasting greater than 24 hours. These were

infarctive and/or haemorrhagic strokes based on avail-

able clinical and neuro imaging studies of Computed

Tomographic (CT) scan and/or Magnetic Resonance

Imaging (MRI) of the brain.

The reported risk of a first stroke in SCD is up₁t_-o₅ 0.85

per 100 patient years in the first 20 years of life,

with

Recurrence rates of

have been reported from devel-

1

– 9

a prev₆alence of₁_,u₃p_,₅_–to₇_,₉11.5%.

14% - 61.5%

Children with SCD attending the clinic received a stan-

dard of care according to the unit policy. This comprised

SCD genetic counseling of the caregivers and child (as

was appropriate for age); counseling for immunizations

and nutrition, information on how to prevent and iden-

tify crises and early management of same; as well as

regular growth monitoring, clinical evaluations, PCV

assessments, folic acid supplementation and malaria

chemo prophylaxis; and additional Pneumococcal and

Haemophilus B Influenza immunizations. In addition,

they received an information booklet on SCD. There

were facilities available for prompt management of ill-

nesses and complications, emergency admissions, blood

transfusions, and exchange blood transfusions. The chil-

dren could be seen at any time at the Emergency Paedi-

atric Unit.

oped and developing countries including Nigeria respec-

tively.₁_–T₇h_,₉e_-y₁₀commonly occur in children up to 14 years

of age

in all forms of SCD, with the highest inci-

1 -3, 5 - 7 1 – 6, 8 – 10

dences in sickle cell anaemia.

Deaths

and debilitating neurological sequels to the growing

child such as cognition loss, motor and sensory deficits,

learning difficulties, psychological and emotional prob-

lems as well as sei₁z_, u₆r_–e₇_,₉d_,i₁s₁o_–r₁d₃ers have been recorded

after the first stroke.

The aim of this study was to determine the prevalence of

strokes amongst our patients with SCD, describe its

clinical features, haematocrit levels on admission, radio-

logical brain imaging, neurological deficits, recurrences,

effect of management with chronic blood transfusions

therapy (CTT), and the outcome of these children. It is

hoped that this information will increase the awareness

to strokes in SCD, and the use of Trans Cranial Doppler

Children with strokes were seen for follow up in the

clinic, and after parental counseling offered chronic

transfusion therapy (CTT) - blood transfusions on a

monthly basis (every 4 weeks). The aim of CTT was to₆

keep the PCV > 30% and the haemoglobin S < 30%,

which is a secondary preventive measure for strokes in

SCD. We were however unable to routinely assess the

Hb S% in them. Packed red blood cell transfusions

(

TCD) ultrasound studies of the cerebral vessels as a

6 –

p₇_,r₁i₄mary prevention screening tool for strokes in SCD.

This is important particularly in low resource coun-

tries of the world such as ours w₁₁here TCD studies are

not yet a routine standard of care.

(

haemoglobin genotype AA) were given as required and

Materials and methods

the volumes determined by the formula [(Desired Hb -

Actual Hb) x Weight (kg) x 3], according to the unit

policy. Post transfusion PCVs were determined after 48

– 72 hours. The children had their serum iron studies

assessed and iron chelating therapy prescribed as re-

quired. Hydroxyurea starting at 15mg/kg and increasing

to 30mg/kg was given to all the children with strokes

after parental counseling. This drug was closely moni-

tored for side effects by 2 monthly complete blood

counts, liver and kidney function tests. Other supportive

therapy as required for rehabilitation such as physiother-

apy, speech therapy, hearing aids, anti convulsant ther-

apy were provided in association with the appropriate

specialist departments.

This is a descriptive retrospective study of children with

SCD seen at the paediatric unit of the National Hospital

Abuja, a referral center located in the capital city of Ni-

geria over a 2.5 year period from January 2009 – June

2

012. The hospital provides tertiary level health care and

receives patients from both its immediate environs and

surrounding cities. The paediatric unit of the hospital

has facilities for emergency paediatric care, inpatient

admissions, newborn care and outpatient specialist clin-

ics; which includes a weekly sickle cell clinic.

All children attending the sickle cell clinic had their

haemoglobin genotype determined by cellulose acetate

haemoglobin electrophoresis methods carried out by the

Haematology unit of the hospital.

The results were presented as simple frequencies and

percentages and shown in tables. Descriptive statistics

were expressed as means +/- 2 standard deviations. Sta-

tistical evaluations were done by Microsoft Excel 2007

and Statistical Package for Social Sciences SPSS ver-

sion 16. Associations between variables were done by

the chi square test as appropriate. A p value of less than

0.05 was considered as been statistically significant.

Medical notes of children with SCD who had strokes

were retrieved from the medical records department and

the following information obtained: demographic data,

clinical features, packed cell volume (PCV), and radio-

logical brain imaging as at the time of the stroke. Infor-

mation on long term neurologic deficits (if any), man-

agement with chronic blood transfusion therapy (CTT),

recurrence of strokes and their outcome was also

obtained.

1

60

Results

There were 17 (65.4%) radiological brain imaging stud-

ies done in 16 children; 8 Computed Tomography (CT)

Scans, and nine Magnetic Resonance Imagings (MRI)

(Table 3). Ten (38.5%) children had no brain imaging

study done. The imaging studies were done in the acute

phase - first 72 hours and up to a week after the stroke

event. These brain imagings showed cerebral atrophy

(Fig 1) in 10 children, acute cerebral infarcts (Fig 2) in

nine children, chronic cerebral infarcts in six children

and intra cranial haemorrhage in one child (Fig 3). The

child with the intracranial haemorrhage had the CT scan

done 48 hours after the stroke. There were four normal

brain imagings. One child had two CT scans of the

brain; the initial scan was normal, while the scan ob-

tained after the second stroke three years later was ab-

normal, showing multiple old and new infarcts.

There were 31 children with strokes among the 596 chil-

dren with SCD seen in the paediatric unit, giving a

prevalence of 5.2%. Twenty six (26) case notes were

retrieved and the data is presented. There were 12 males

and 14 females, M: F ratio of 0.9:1; mean age was 6.4

years (SD 3.4), age range 1 year 7 months – 14 years.

The mean duration of follow up was 2.8 years (SD 1.4),

range 0.4 – 6 years. The packed cell volumes (PCV) at

the time of the strokes ranged from 14 – 29%, with a

mean of 21.1% (SD 3.9). The mean expected weight for

age according to the modified Wellcome classification

was 96.3% with a range of 76.6 – 122%. There were 22

(

84.6%) children with normal weight (80 – 120% ex-

pected weight for age), and 2 (7.7%) children each with

under nutrition (60 - < 80% expected weight for age)

and over nutrition (> 120% expected weight for age)

respectively. All (100%) the children had Haemoglobin

SS (sicke cell anemia) on Haemoglobin electrophoresis.

Clinical presentations were: convulsions in 18, inability

to use limbs in 11, and weakness of parts of the body in

Table 3: Radiological imaging (CT scan and MRI brain) in 16

children with SCD and stroke

CT/MRI brain findings n = 17*

Frequency (%)

Cerebral atrophy

10 (58.8%)

9 (52.9%)

6 (35.3%)

4 (23.5%)

1 (5.9%)

1

0, coma in 7 and headaches in 5 children respectively

Acute cerebral infarcts

Chronic cerebral infarcts

Acute ischaemic changes

Acute cerebral bleed

Porencephalic cyst

Normal

(

Table 1). Long term neurological deficits observed dur-

ing follow up were: hemiplegia and cognition loss 11

children each, aphasia in 8 children, facial nerve palsy in

1 (5.9%)

4 (23.5%)

7

children, and swallowing incoordination in 5 children.

Three (3) children had no long term neurological deficits

Table 2).

*One child had 2 CT scans of the brain

(

Fig 1

Table 1: Presenting clinical features found in 26 children with

SCD and stroke

7

years, male MRI brain: T2

FLAIR MRI brain

Transverse plane)

Wedge shaped area of

Presentations n = 26

Frequency (%)

(

•

hypo intensity in the right

frontal lobe and prominence

of the adjacent cerebral

sulci - cerebral infarction

Convulsions

Inability to use limbs

Weakness of limbs

Coma

Headaches

Fever

Inability to talk

Slurred speech

Inability to see

Others

18 (69.2%)

11 (42.3%)

10 (38.5%)

7 (26.9%)

5 (19.2%)

4 (15.4%)

3 (11.5%)

2 (7.7%)

•

Prominence of the

right Sylvian fissure and

inter hemispheric fissure,

dilatation of the frontal horn

of the right lateral ventricle

2 (7.7%)

–

porencephalic cyst

Others 1 (3.8%) each of unsteady gait and dizziness

Fig 2

Table 2: Long term neurological deficits in 26 children with

SCD and stroke

7

years, male MRI brain: T2

FLAIR MRI brain

Transverse plane)

T2 weighted MRI of the

Long term Neurological deficits n = 26

Frequency (%)

(

•

brain in transverse plane

showing cerebral atrophy of

the right cerebral hemisphere

Cognition loss

Hemiplegia

Aphasia

11 (42.3%)

8 (30.8%)

7 (26.9%)

5 (19.2%)

3 (11.5

2 (7.7%)

3 (11.5%)

Hemipareisis

Facial nerve palsy

Swallowing incordination

Seizure disorder

Slurred speech

Urinary/Faecal incontinence

Quadriplegia

ADHD

None

Others

Others 1 (3.8%) each of behavioural disorder, learning disability and

deafness. ADHD - Attention Deficit Hyperactivity Disorder

1

61

Fig 3

0 years, female MRI brain: T2

FLAIR MRI brain (Transverse

plane)

weight, or PCV (Table 4).

Fifteen (57.7%) children were enrolled in a monthly

chronic blood transfusion therapy (CTT, hyper transfu-

sion) programme, a standard of care for children with

1

6

SCD who have had strokes , while 11 children (42.3%)

•

Hypo intense areas consis-

were not (Table 4). These transfusions had been given

for a period of four months to three years, eight months

at the time of writing. Of the seven children with regular

blood transfusions, five (71.4%) had no recurrence of

stroke while two (28.6%) did. Four (66.7%) of six chil-

dren on irregular CTT as well as five of the 11 (45.4%)

children not on blood transfusions had recurrences of

strokes. These differences were not statistically signifi-

cant p > 0.05 (Table 4). Two children – an 11 year old

girl and a 10 year old boy stopped the transfusions after

tent with intra ventricular

bleed/hemorrhage in both bod-

ies of the lateral ventricles

worse on the left side;

•

Dilatation of the left lat-

eral ventricle with resultant

atrophy of the adjacent cerebral

cortex

Twelve children (46.2%) children had recurrences of

stroke ranging in number from one to four, which oc-

curred from six months to three years after the initial

stroke. There were no statistical significant differences

between the children with recurrences of stroke com-

pared to those without recurrence regarding the age, sex,

8

months and one year, five months respectively. The

girl had a recurrence of stroke after three years, while

the boy did not have a recurrence of stroke in 4 years of

follow up.

Table 4: Demographic features, PCV values, effect of chronic transfusion therapy, and outcomes on recurrence of stroke in 26

children with SCD

Recurrence of stroke

Yes

Recurrence of stroke

No

Ch₂i square

X

Degree of freedom df

2

P value

0.78

Age (years)

1

5

1

- < 5

- < 10

0 - < 15

5

4

3

4

6

4

0.503

%

weight for age

8

6

8

0 – 120%

0 – 80%

0 - 120%

9

1

2

13

1

0

2.59

4.57

2

4

0.27

0.34

PCV (%)

15%

<

1

2

8

1

0

1

2

5

3

1

2

Unknown PCV

Sex

5 - < 20%

0 - < 25%

5 - < 30%

a

Male

Female

5

7

0.18

1.89

1

2

0.67

0.38

CTT

Regular CTT

Irregular CTT

Stopped CTT

Outcome

2

4

1

5

2

1

Lost to follow up

Alive

Dead

3

8

1

0

4

9

0

1

nd

2.06

3

0.56

Referred to other hospital

2

The children with the unknown PCV at the time of stroke had been transfused prior to arrival at the hospital

children commenced blood transfusion therapy after the 2 stroke

a

CTT – Chronic transfusion therapy: - Regular: Monthly blood transfusions as required; Stopped: No blood transfusions for more

than 4 consecutive months; Irregular: Irregular blood transfusions but not for up to 4 consecutive months in between transfusions

Regarding outcome at the time of writing, 17 (65.4%) of

the children were alive, 7 (26.9%) were lost to follow

up, 1 had died, while 1 was referred to another centre

child who is wheel chair bound attends a regular school.

An 8 year old girl died during a recurrent stroke episode

at the hospital, while the referral was due to relocation

of the family.

(

Table 4). The 17 children who are alive are been fol-

lowed up in our clinic and are receiving, in addition to

standard care for SCD offered at our center, rehabilita-

tion by physiotherapy, speech therapy, hearing aids, and

other medications such as anti-convulsants as required.

Two children attend special schools for the mentally

handicapped and for children with special needs

Discussion

The 5.2% prevalence of strokes amongst our patients

with SCD is higher than 4.01% reported from th₁e Coop-

erative Study of Sickle Cell Disease (CSSD), though

respectively. Another child was taken out of regular

th

school due to persistently poor performance, and a 4

1

62

,6-7, 19 – 22

with infarctive strokes

1

lower than previous rep₂orts of 7.8% from the Jamaican

cohort study of SCD, and 11.5% reported from the

Dallas cohort study of SCD. It is however similar to

CSSD and other studies,

occurring more commonly than haemorrhagic strokes.

We were unable to do magnetic resonance angiography

or other arteriogram as was done in these studies just

alluded to, which would have yielded further informa-

tion. Cerebral haemorrhage₁_,s₆_-a₇re uncommon in children

and only one of the chil-

5

recent pr₈evious reports₉ of up to 5.4% from Nigeria by

Ahmed and Fatunde though much higher than <1%

1

15

and Akinyanju 3

previously reported by Izuorah

decades earlier. All the children had sickle cell anaemia

and the age range was similar to previous reports w₁_-i₅th

majority of the children being below 10 years of age.

Low steady state haemoglobin concentration and acute

decreases in the steady state haematocrit h₁_,a₂_,v₆_,e₇_,b₁₄een iden-

with SCD during a stroke

dren who had brain imaging in this study had this fea-

1

ture, similar to the CSSD. It is also noteworthy that four

children in this study had normal brain imagings despite

the clinical features of strokes. It is likely that in these

children so referred to, the investigations were done

quite early in the course of the stroke before the radio-

logical changes could be recorded by the brain imaging

techniques available at the hospital. It has been docu-

mented that CT scans may not show abnormalities

within the first 24 hours of a stroke, whereas diffusion-

weighted and T2 weighted MRI may show ischaemic

changes and haemor₆r_-h₇a_,₂g₀ e_-₂s₂ within the immediate 1 - 3

tified as risk factors for strokes in SCD.

About

a quarter of the children of this study had PCV of less

than 25% at the time of the stroke. The significance of

this finding as a possible risk factor for stroke in this

study could not be ascertained. We were not privy to

the steady state haematocrit levels of the children and

could therefore not determine if this represented acute

decreases in steady state haematocrit or not. This was a

limitation of the study.

hours of the event.

We also had children with

brain imagings done during the acute stroke event that

showed evidence of chronic cerebral infarcts, thus

strengthening the suggestion of previous silent infarcts

(brain infarction on ima₁_,g₆i_-n₇g_,₂₁s_-t₂u₂dies in the absence of

The clinical features at time of stroke such as convul-

sions, weakness of parts of the body, inability to use the

limbs, headaches and coma have been previously re-

ported as are the varying long term neurological deficits

of hemiple₂g_,₃i_,a₆,_–₉a_,p₁₁h_-₁a₃s_,i₁a₆ and facial nerve palsy recorded in

neurologic symptoms).

This underscores the

importance of Trans Cranial Doppler (TCD) studies of

the cerebral vessels as a screening tool to identify chil-

dren with SCD at high risk of stroke and₆c_–o₇m_,₁m₄ ence

This

this study.

While these manifestations are in

6-7, 11, 13, 16

consonance with most previous studies,

a

striking feature in the present study is the cognition loss

in over 50% of the patients. Severe deficits like quadri-

plegia, deafness and swallowing in-coordination were

also among those observed. These have enormous sig-

nificance, emphasizing the loss of the ability of these

children to attain their true potentials and live a normal

quality of life. The need for particular investigations

such as radiological brain imagings, and various forms

of rehabilitation including physiotherapy, special

schools, special care givers, medications, speech therapy

and hearing aids increases the cost of care of these chil-

dren and constitute a burden to the family and society.

Of note are the three children with clinical and radio-

logical features of strokes, and no long term neurologi-

cal deficit. Such oc₁c_,u₆r_–r₇e_,n₁₃ces have been previously re-

therapy for primary prevention of strokes.

therapy comprises regular blood transfusions intended to

reduce the Hb S concentration to < 30% when there are

abnormally high blood flow velocities of the cerebral

arteries on TCD studies. This recommendation is based

on the results of the St₄roke Prevention Trial in Sickle

1

Cell Anaemia (STOP) study that showed a clear bene-

fit for prophyla₆c_,₇tic transfusions in preventing stroke in

these children.

Strokes in children with SCD have been reported to re-

cur in up to 14% of cases in developed countries, while

in deve₁l_, o₃_,p₅_,i₆n_,₇g_,₉ countries the recurrence of 61% is much

higher.

We had a recurrence rate of 42%, which

was higher than has been previously reported for devel-

oped countries, but similar to₁_,s₃_,tu₅_–d₇i_,e₉s from Nigeria and

The difference in

ported in literature.

Associations of the location

and volume of anatomical sites of CNS infarcts with

specific areas of neurocognitive dysfunction have been

described by Kirkham, Schatz and others, in defining the

other developing countries.

recurrence rates between the developed and developing

countries could be attributed to better health care in the

developed countries of the world and the use of the hy-

per transfusion programmes, wh₁i₁ch is not done routinely

6

–

t₇y_,₁p₇e_-₁a₈nd magnitude of neurological sequelae in stroke.

Thus, when the site of the cerebral infarcts occurs

in non motor areas of the brain, there may be minimal or

no motor deficits, although subtle₇_,n₁e₇u_,₁r₈o cognitive dys-

functions may appear in the future.

in most developing countries.

It has also been sug-

gested that there might be some genetic o₆_-r₇_,₂e₄nviron-

mental factors responsible for this difference.

It was not possible to have radiological imagings for all

the children in the study. This was due to the cost of the

investigations which could not be afforded by some of

the care givers. This highlights the need for health insur-

ance in low resource countries with wide spread poverty

or appropriate increase in government funding to cater

for the health needs of her people. The findings from

radiological imaging done at the time of stroke among

our patients were similar to those reported from the

Chronic Transfusion Therapy CTT (hyper transfusion

programs) to keep the PCV > 30% and the Hb S concen-

tration < 30% are the standard of care to prevent secon-

dary recurrence of strokes in SCD, reducing₆_-₇the risk

from approximately 67% to less than 10% .

Some

caregivers in the present study refused this form of treat-

ment despite counseling . We had difficulties maintain-

ing the blood transfusions over the period of this report,

as well as managing the ensuing complications that

1

63

6

,7

arose, such as non availability of blood as required,

transfusion related costs and iron overload. Majority

CTT in the secondary prevention of strokes in SCD.

Despite the fact that the small sample size in this study

makes any definitive statement about usefulness of CTT

(hyper transfusion programme) difficult, it does seem to

have been beneficial in preventing recurrence of strokes

in these SCD patients.

(

71.4%) of the children receiving CTT in this study did

not have recurrence of strokes; in comparison to about

5% of the children who never received these transfu-

sions that had stroke recurrences. These findings are

4

6

7

similar to what was reported by Adams and Kirkland.

The recurrence of strokes despite regular blood transfu-

sions in SCD as found in this study have been previ-

6

, 7, and 24

It was suggested that although

ously reported.

Conclusion

chronic transfusions can reduce the risk of having a re-

6

currence of stroke, it cannot completely eliminate it.

We found that strokes occur with a prevalence of 5.2%

and constitute an important cause of morbidity in SCD

patients in Abuja, Nigeria, with convulsions being the

commonest presenting feature and hemiplegia and cog-

nition loss the most commonly encountered long term

neurological deficits. It was also noted that chronic

transfusion therapy (hyper transfusion programme) did

seem beneficial in preventing stroke recurrences in these

patients. It is advocated that primary prevention of

strokes₁b₄y Transcranial Doppler studies of the cerebral

arteries as a screening tool be done on regular basis in

children with SCD so as to initiate preventive measures

as deemed appropriate.

Moyamoya disease, the formation of a mass of small

friable blood vessels in response to severe stenosis or

occlusion of major intracranial vessels, frequently seen

in SCD, has been identified as a risk factor for stroke

6

, 7, 24 - 25

These

recurrence despite regular transfusion.

blood vessels, which have a propensity to rupture, may

be responsible for the occurrence of frequent strokes.

Indeed, recurrent infarctions have been reported to be

more likely to occur in children with moyamoya syn-

7

drome. Furthermore, we had one child who stopped

CTT, as well as the 6 children who never had CTT who

had no recurrence of strokes in the follow up period.

These children, who were not on CTT, had been receiv-

ing the drug hydroxyurea. S₆_,₇im_,₂₆ilar experiences have

Conflict of interest : None

Funding : None

been documented elsewhere

and indeed hydroxy-

urea has been suggested as an alternative treatment to

Reference

7. Kirkham FJ, deBaun MR: Stroke

in children with sickle cell disease.

Curr Treat Options Neurol.

2004 ; 6(5):357–375.

Akar N, Uysal LZ et al: Treatment

Challenges in Pediatric Stroke

Patients. Stroke Res Treat. 2010

Dec 28;2011: Article ID 534362,

doi:10.4061/2011/534362

14. Adams RJ, McKie VC, Hsu L,

Files B, Vichinsky E et al: Pre-

vention of a first stroke by transfu-

sions in children with sickle cell

anemia and abnormal results on

transcranial Doppler ultrasonogra-

phy. N Engl J Med. 1998 ; 339

(1):5-11

15. Akinyanju OO: A profile of sickle

cell disease in Nigeria. Ann N Y

Acad Sci. 1989; 565:126-36

6. Quinn CT, Rogers ZR, Buchanan

GR: Sickle Cell Anaemia and aca-

demic achievements in Africa:

1

.

Ohene-Frempong K, Steven J,

Weiner SJ, Sleeper LA, Scott TM

et al: Cerebrovascular Accidents in

Sickle Cell Disease: Rates and

Risk Factors. Blood. 1998; 91(1):

8. Ahmed PA, Otuneye OT. Stroke at

National Hospit_ra_dl Abuja. Pre-

sented at the 33 Annual and Gen-

eral Scientific Meeting of the Pae-

diatric Association of Nigeria.

January 2002

9. Fatunde OJ, Adamson FG, Ogun-

seyinde O, Sodeinde O, Familusi

JB et al: Stroke in Nigerian chil-

dren with sickle cell disease. Afr J

Med Med Sci. 2005 ; 34(2):157-60

10. Gill FM, Sleeper LA, Weiner SJ,

Brown AK, Bellevue R et al:

Clinical events in the first decade

in a cohort of infants with sickle

cell disease. Cooperative Study of

Sickle Cell Disease. Blood. 1995;

86(2):776-83

11. Izuora GI, Kaine WN, Emodi I:

Neurological disorders in Nigerian

children with homozygous sickle

cell anaemia. East Afr Med J. 1989

66(10):653-7

12. Kehinde MO, Temiye EO, Danesi

MA: Neurological complications

of sickle cell anemia in Nigerian

Africans—a case-control study: J

Natl Med Assoc. 2008 ; 100

2

88-294.

2

3

4

.

Powars D, Wilson B, Imbus C,

Pegelow C, Allen J et al: The natu-

ral history of stroke in sickle cell

disease. Am J Med. 1978 ; 65

(3):461-71.

Balkaran B, Char G, Morris JS,

Thomas PW, Serjeant BE et al:

Stroke in a cohort of patients with

homozygous sickle cell disease. Br

J Haematol. 2005 ; 128(6):751-66

Neonato MG, Guilloud-Bataille M,

Beauvais P, Bégué P, Belloy M et

al: Acute clinical events in 299

homozygous sickle cell patients

living in France. French Study

Group on Sickle Cell Disease. Eur

J Haematol. 2000 ; 65(3):155-64.

Quinn CT, Rogers ZR, Buchanan

GR: Survival of children with

1

SCA patients in the general popu-

lation in Nigeria or Africa Blood.

2

004 ; 103(11): 4023–4027

1

7. Schatz J, Craft S, Koby M, Siegal

MJ, Resar L et al: Neuropsy-

chologic Deficits in Children with

Sickle Cell Disease and Cerebral

Infarction: Role of Lesion Site and

Volume. Child Neuropsychology.

5

.

sickle cell disease. Blood. 2004 ;

1

03(11): 4023–4027.

1

999; 5 (2): 92-103

6

.

Adams R, Ohene-Frempong K,

Wang W: Sickle Cell and the

Brain. doi: 10.1182/asheducation-

2

001.1.31 ASH Education Book

January 1, 2001 vol. 2001 no. 1 31-

6.

(4):394-9

4

1

3. Yılmaz A, Teber S, Bektas O,

1

64

1

8. Craft S, Schatz J, Glauser TA, Lee

B, DeBaun MR: Neuropsychologic

effects of stroke in children with

sickle cell anemia. J Pediatr.

22. Moser FG, Miller ST, Bello JA et

al: The spectrum of brain MR

abnormalities in sickle-cell dis-

ease: A report from the coopera-

tive study of sickle cell disease.

Am J Neuroradiol. 1996 ; 17

(5):965–972

23. Hoppe C: Defining stroke risk in

children with sickle cell anaemia.

J Pediatr. 1992; 120 (3):360-366

24. Buchanan GR, Bowman WP,

Smith SJ: Recurrent cerebral

ischemia during hyper transfusion

therapy in sickle cell anemia. J

Pediatr. 1983 ; 103(6):921-3

25. Seeler RA, Royal JE, Powe L et al:

Moyamoya in children with sickle

cell anemia and cerebrovascular

occlusion. J Pediatr. 1978 ; 93

(5):808-10

26. Ware RE, Zimmerman SA,

Schultz WH: Hydroxyurea as an

alternative to blood transfusions

for the prevention of recurrent

stroke in children with sickle cell

disease. Blood. 1999 1; 94

(9):3022–3026

1

993 ; 123(5):712-7

1

9. Ogunseyinde AO, Obajimi MO,

Fatunde OJ: Computed tomo-

graphic pattern of stroke in chil-

dren with sickle cell anaemia in

Ibadan. Afr J Med Med Sci. 2005;

3

4(2):115-8

2

0. Zimmerman RA: Diffusion

weighted imaging. Crit Rev Neu-

rosurg. 1997; 7:221–227

1. Pavlakis SG, Bello J, Prohovnik I

et al: Brain infarction in sickle cell

anemia: magnetic resonance corre-

lates. Ann Neurol. 1988 ; 23

(2):125–130.