WSO - April 2024 - 452

1216037
WSO
International Journal of StrokeBirkeland et al.
Research
Long-term stroke risk in Moyamoya
disease
Peter Birkeland1 , Victoria Hansen2, Vinosha Tharmabalan1,
Jens Lauritsen3,4, Troels Nielsen5, Thomas Truelsen6,
Sverre Rosenbaum7 and Paul von Weitzel-Mudersbach8
Abstract
Background: Moyamoya disease (MMD) is considered a progressive disease with an ongoing risk of recurrent stroke.
However, there is a lack of long-term observational data to quantify the extent of the stroke risk.
Methods: This study aimed to provide insight into the long-term stroke risk in MMD and explore possible risk factors
for stroke. Records from all patients diagnosed with MMD in 13 clinical departments from 6 different Danish hospitals
between 1994 and 2017 were retrospectively reviewed until 2021.
Results: The cohort comprised 50 patients (33 females and 17 males). Patients were followed up for a median of
9.4 years, with more than 10 years of follow-up for 24 patients. Ten patients had 11 new stroke events-6 ischemic
strokes and 5 brain hemorrhages. Events occurred at a median of 7 years and up to 25 years after diagnosis. The overall
Kaplan-Meier 5-year stroke risk was 10%. Patients with bypass performed had significantly fewer events than conservatively
treated patients (HR 0.25, 95% confidence interval (CI) 0.07-0.91, p < 0.05). All but one event occurred in females,
a difference that reached statistical significance.
Conclusions: The study provides data on the extent of the risk of recurrent stroke in MMD. Bypass surgery patients
had fewer stroke events than those treated conservatively. There was a trend toward a higher stroke risk in females.
Data access statement: The data supporting this study's findings are available from the corresponding author upon
reasonable request.
Keywords
Moyamoya disease, long-term, stroke risk
Received: 19 August 2023; accepted: 17 October 2023
Introduction
Moyamoya disease (MMD) is a rare idiopathic steno occlusive
cerebrovascular disease affecting the distal intracranial
internal carotid artery or its proximal branches with a network
of basal collaterals.1 The disease was formerly almost
exclusively associated with East Asia but is now known to
occur worldwide. The highest incidence is in Japan, that is,
0.94 per 100,000 person-years.2,3 Characteristically, the
disease either presents in childhood or young middle age.3
It is almost twice as common in females as in males; a few
studies have suggested a more aggressive disease course in
females.4,5
Clinical events include ischemic stroke caused by narrowed
vessels and hemorrhage from rupture of fragile collaterals.
MMD is considered a progressive disease with a
continued significant risk of recurrent stroke. However,
International Journal of Stroke, 19(4)
International Journal of Stroke
2024, Vol. 19(4) 452 -459
© 2023 World Stroke Organization
Article reuse guidelines:
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DOI: 10.1177/17474930231216037
journals.sagepub.com/home/wso
https://doi.org/10.1177/17474930231216037
1Department of Neurosurgery, Copenhagen University Hospital,
København Ø, Denmark
2Department of Neurology, Aalborg University Hospital, Aalborg, Denmark
3Department of Orthopaedic Surgery, Odense University Hospital,
Odense, Denmark
4Department of Clinical Research, University of Southern Denmark,
Denmark
5Department of Neurosurgery, Odense University Hospital, Odense C,
Denmark
6Department of Neurology, Copenhagen University Hospital,
København Ø, Denmark
7Department of Neurology, Bispebjerg Hospital, København, Denmark
8Department of Neurology, The Danish Stroke Center, Aarhus
University Hospital, Aarhus N, Denmark
Corresponding author:
Peter Birkeland, Department of Neurosurgery, Copenhagen University
Hospital, Blegdamsvej 9, DK-2100 København, Denmark.
Email: Peter@Birkeland.dk
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