Cerebral perfusion, measured by Arterial Spin Labeling (ASL) perfusion MRI, in relation to outcome in children and young adults with ischaemic stroke

Causes and risk factors of stroke in children and young adults are different
from those in adults. Atherosclerosis of large arteries is extremely rare in
children and most children and young adults with arterial ischaemic stroke
(AIS) suffer from non-atherosclerotic arterial disease (arteriopathy).
Childhood arteriopathies may be progressive as in moyamoya disease, or
non-progressive as in dissection and inflammatory arteriopathies (transient
cerebral arteriopathy and post-varicella arteriopathy).
Arteriopathic stroke has a relatively high recurrence rate, depending on the
cause of stroke (6 - 42%, mainly within the first year). Neurological outcome
is poor in the majority of children.
Possible treatment options for patients with arterial ischaemic stroke include
corticosteroids, anticoagulants, and in moyamoya disease neovascularization
surgery.

Unfortunately, the prediction of stroke outcome and the course of the
arteriopathy is difficult in the acute stage of stroke. Knowledge of cerebral
perfusion deficits in different causes of young stroke could potentially help
identifying patients who are at risk of poor outcome or stroke recurrence.
Information on risk factors of poor outcome and stroke recurrence may
eventually guide treatment decisions.

The objective of the study is to assess whether in young patients with
arteriopathic stroke perfusion abnormalities in non-infarcted brain are
associated with the type and course of arteriopathy and stroke outcome in terms
of functional recovery and recurrence risk.
Furthermore, we would like to assess whether diffusion-weighted MRI (DWI)
changes in descending corticospinal tracts of the brain are associated with
motor outcome in children and young adults.

In the retrospective part of the study, 50 children and young adults (between 6
and 50 years of age) will be approached. All patients have been treated in the
UMCU for anterior circulation stroke caused by non-atherosclerotic
arteriopathy, between Januari 2000 and August 2007.
Patients will visit the UMC Utrecht once and will undergo conventional MRI, MR
angiography (MRA), and ASL perfusion MRI in the chronic stage of their disease.
If children will be restless during the MR investigation, they will be excluded
(< 7 years of age). General anesthesia will not be given to patients, solely
for the purpose of the study.
Functional stroke outcome wil be assessed as good or poor, using a two-item
questionnaire, a standardized outcome measure for children (PSOM), and the
modified Rankin Scale for young adults. The rate of recurrent stroke will be
determined.

In the prospective part of the study, 30 children and young adults (between 1
month and 50 years of age) will be included. In patients who present to the UMC
Utrecht with anterior circulation stroke, caused by non-atherosclerotic
arteriopathy, MRI and MRA will be performed as part of the diagnostic
investigations in the acute stage of stroke. For this research project ASL
perfusion will be added to the scan protocol (5 minutes extra) in children that
do not need to be sedated for MR investigation. Furthermore, diffusion-weighted
imaging (DWI) of the corticospinal tracts will be studied. In children, imaging
is performed 6 and 12 months after stroke, as part of the normal follow-up.
Again, ASL will be added to the scanprotocol in children > 6 years of age. In
adults MR imaging is not routinely done in the follow-up period. For this
research project MR imaging will be performed at 6 and 12 months after stroke.
Functional stroke outcome and stroke recurrence rates will be determined at a
follow-up duration of 1 year.

Retrospective part of the study: patients will visit the UMC Utrecht once.
Conventional MRI, MR angiography (MRA), and ASL perfusion MRI will be performed
and functional stroke outcome wil be assessed by filling in a questionnaire.
This will take about two hours in total. Children will not be sedated or
brought under anesthesia for the purpose of the study. Children who cannot
undergo MR scanning without general anesthesia will be excluded.

Prospective part of the study: functional stroke outcome and stroke recurrence
rates will be determined at a follow-up duration of 1 year (one hour twice).
MRI and MRA will be performed as part of the diagnostic investigations in the
acute stage of stroke. In most patients the cause of stroke is not evident
prior to the first imaging procedure. Therefore ASL perfusion will be added to
the scan protocol in the acute phase of stroke in all patients with suspected
anterior circulation stroke that do not need to be sedated for MR investigation.
In children with AIS, imaging is performed 6 and 12 months after stroke as part
of the normal follow-up. If children do not need to be sedated for follow-up MR
imaging, ASL perfusion will be performed (5 minutes extra). There are no extra
risks for participating in this study. In all patients DWI changes of the
corticospinal tracts will be studied.
For adult patients who don't need to undergo routine clinical follow-up
imaging, MRI (including DWI), MRA and ASL perfusion will be performed 6 and 12
months after stroke for this research project.