Moyamoya Disease (MMD) is a rare disease defined by a bilateral stenosis or occlusion of
the terminal internal carotid artery (ICA) and proximal arteries of the circle of willis.
The stenosis is usually accompanied by fine collateral vessels appearing as "a puff of
smoke" on conventional DSA giving the disease its name (Japanese). The disease is known
to progress over time in 20-40% of adult patients, also to initially not affected
vessels. To prevent from ischemic or hemorrhagic strokes, most patients need
microsurgical revascularization with extracranial-intracranial (EC-IC) bypasses for the
affected cerebrovascular territories. The indication for a possible revascularization
should always be decided based on functional imaging identifying cerebrovascular
territories with an insufficient reserve capacity. The "gold-standard" for measuring the
cerebrovascular reserve is H2 15O PET/CT with Acetazolamide challenge (ACZ), whereat also
SPECT and different MRI techniques are used but with less sensitivity. Main drawback of
H2 15O PET/CT is its very limited availability, high costs, the need to inject ACZ and
radiation exposure. Further, the costs of H2 15O PET/CT for Moyamoya patients are not
covered by the German health insurance system as no valid high-quality studies are
available to prove a possible benefit of this examination.
Throughout the last years the investigators have focused our research on different MRI
techniques in Moyamoya patients aiming to find reliable examinations for the evaluation
of the cerebral blood flow and to detect and monitor disease progression:
The investigators' newly developed semi-automated algorithms for the evaluation of
CO2-triggered BOLD MRI (breathhold fMRI) sequences to identify a reduced vasoreactivity
showed a promisingly high correlation to the results of the cerebrovascular reserve
measurements as seen in PET/CT. Further, the investigators were able to show that disease
progression can be predicted by a temporary contrast enhancement of the vessel wall seen
over approximately 24 months as high-resolution vessel-wall imaging was performed
consequently in all patients.
Therefore, the main goals of this study are to improve patient care in Moyamoya patients
with the following three key elements:
Defining the value of CO2 triggered BOLD MRI in the evaluation of cerebral
hemodynamics pre- and postoperatively compared to H2 15O PET/CT aiming to possibly
prove or reduce the need for PET/CT examinations.
Understanding radiographic and pathophysiologic processes causing disease
progression as seen by vessel-wall imaging to enable timely revascularization or
possibly non-surgical treatment of this disease in the future.
Possible new insights in disease-pathophysiology and progression as seen in vessel
wall imaging by correlating imaging results with biosampling (peripheral blood
Defining a standardized recommendation for pre- and postoperative hemodynamic and
MR-morphologic evaluation of Moyamoya patients based on the results of this study.
As secondary objectives the following elements will be analyzed:
Neuropsychological impairment in correlation to the hemodynamic and MR-morphologic
status of the brain.
Feasibility of resting-state fMRI to evaluate cerebral vasoreactivity.
To achieve these goals, the investigators are planning to prospectively include 50
Moyamoya patients in this study with a standardized imaging, neuropsychological testing
and biosampling protocol with a two-year follow-up. Under the assumption of a homogenous
inclusion of patients, recruitment should be finished after two years with one year of
follow-up after the inclusion of the last patient. This cohort will provide reliable
information on standardized diagnostic patterns and possibly a broader understanding of
pathophysiology causing disease development and progression.
