Magnetic resonance angiography in moyamoya disease

Moyamoya disease: a clinical spectrum, literature review and case series from a tertiary care hospital in Pakistan

Background

Moyamoya is a rare cerebrovascular disease of unknown etiology. The data on moyamoya disease from Pakistan is sparse. We report a case series of 13 patients who presented with moyamoya disease to a tertiary care hospital in Pakistan with a national referral base.

Methods

We conducted a retrospective review of thirteen patients who presented to The Aga Khan University and diagnosed with "Moyamoya Disease" during the period 1988 – 2006. These patients were identified from existing hospital database via ICD-9 codes. A predesigned questionnaire containing information about clinical presentation, management and neuroimaging was administered to all identified patients.

Results

There were seven males and six females. Mean age at presentation was 16.5 years and a female predominance was found in the pediatric age group (n = 10, 71.4%). Stroke (n = 11, 84.2%) was the most common presentation with motor deficit being the universal cortical symptom. Fever was a common symptom in the lower age groups (n = 4, 51.7%). Cerebral Angiography and Magnetic Resonance Angiography showed bilateral involvement of the vessels in eleven patients while unilateral in two. Subarachnoid and interventricular haemorrhage appeared in 2(15.4%) adults. Twelve (92.3%) patients were discharged as independent with minor deficits regardless of therapeutic modality. Only three (23.0%) patients underwent surgery whereas the remaining were managed conservatively.

Conclusion

Physicians when dealing with childhood strokes and characteristic deficits in adult population should consider Moyamoya disease.

Acute carotid arterial occlusion after burr hole surgery for chronic subdural haematoma in moyamoya disease

Ischaemic strokes and neurological deterioration have been described after revascularisation surgery in patients with moyamoya disease, but accelerated acute occlusion of the internal carotid artery after burr hole surgery has not been reported in this setting. A 66-year-old woman with known moyamoya disease who presented with right motor weakness underwent burr hole surgery for a bilateral chronic subdural haematoma. Postoperatively, the patient had a crescendo transient ischaemic attack and then deteriorated. Angiography showed complete occlusion of the left internal carotid artery. Burr hole surgery may cause postoperative acute occlusion of a preexisting stenotic artery in patients with moyamoya disease.

MR angiography of moyamoya disease before and after encephaloduroarteriosynangiosis

OBJECTIVE

Our purpose was to evaluate the usefulness of MR angiography in revealing moyamoya disease before and after encephaloduroarteriosynangiosis.

SUBJECTS AND METHODS

Twenty-six patients (51 hemispheres) with angiographically confirmed moyamoya disease who underwent encephaloduroarteriosynangiosis were included in the study. Findings on preoperative MR angiography were compared with those on conventional angiography. Postoperative neurologic status was categorized as poor, fair, good, or excellent. Postoperative MR angiography was examined for the appearance of the superficial temporal artery, changes in moyamoya vessels, and transdural collateral vessels into the middle cerebral artery territory.

RESULTS

Preoperative MR angiography revealed moyamoya disease in all patients (diagnostic accuracy, 100%). MR angiography correctly depicted the degree of internal carotid artery stenosis in 37 arteries (73%), moyamoya vessels in 33 hemispheres (65%), and the degree of stenosis in the middle, anterior, and posterior cerebral arteries in 125 (82%) of 153 arteries. After surgery, 39 hemispheres showed an excellent outcome, eight showed a good outcome, two a fair outcome, and two a poor outcome. On postoperative MR angiography, vascular supply to the middle cerebral artery territory via transdural collateral vessels increased in 28 hemispheres (55%) and decreased in four (8%). The size of the superficial temporal artery increased in 41 (80%) of 51 hemispheres. The extent of moyamoya vessels decreased in 27 hemispheres (53%) after surgery.

CONCLUSION

MR angiography can show the changes in the superficial temporal artery and development of transdural collateral vessels after encephaloduroarteriosynangiosis. Because MR angiography is noninvasive, it is valuable for evaluating postoperative changes.

Conventional cerebral angiography in children with ischemic stroke

A retrospective review of conventional cerebral angiograms of 46 children with ischemic stroke was undertaken. Comparison was made with findings on magnetic resonance imaging and magnetic resonance angiography where available. Thirty-six children (78%) underwent magnetic resonance angiography in addition to conventional cerebral angiography. Seven patients had normal cerebral angiograms. Magnetic resonance angiography was diagnostic in 25 of 28 patients with large vessel occlusion, stenosis, or moya-moya syndrome. Conventional angiography was abnormal in four of nine patients with a normal magnetic resonance angiography. All patients with normal conventional angiograms also had normal magnetic resonance angiograms. Conventional angiography, either diagnostic or yielding further information, altered management in five patients with arterial dissection, one patient with large vessel occlusion, one patient with large vessel stenosis, and four patients with arteritis. On the basis of this experience, a clinical algorithm for the use of conventional cerebral angiography in the investigation of ischemic stroke in children is proposed.

Evaluation of magnetic resonance angiography with selective maximum intensity projection in patients with childhood moyamoya disease

To determine whether magnetic resonance angiography with selective maximum intensity projection can facilitate the detection of cerebral moyamoya vessels in patients with childhood moyamoya disease, six patients with moyamoya disease (6 to 9 years old) and ten controls (4 to 16 years old) were evaluated by means of high resolution magnetic resonance angiography (matrix 512x384) with/without selective maximum intensity projection, and conventional angiography. In the patients with moyamoya disease, moderate or marked moyamoya vessels were detected but underestimated in 2/12 hemispheres on magnetic resonance angiography without selective maximum intensity projection. On magnetic resonance angiography with selective maximum intensity projection, moyamoya vessels were correctly assessed in 11/12 hemispheres (92%). In the controls, bilateral mild moyamoya vessels were detected in eight of 20 hemispheres (four of ten patients, under 7 years old), which were compatible with normal lenticulostriate arteries. Magnetic resonance angiography with selective maximum intensity projection is an accurate modality for assessing moyamoya vessels in moyamoya disease.

Clinical and neuroradiological findings of moyamoya disease in Italy

A total of 34 Italian patients (15 males and 19 females) suffering from Moyamoya disease (MMD) and selected by a questionnaire survey in 12 neuropediatric and neuroradiologic departments were studied in a multicentric study. The onset of the disease appeared either in childhood (27 patients, aged 0-16 years, mean 5.4 years) or in adulthood (seven patients, aged 25-55 years, mean 35 years). The early clinical symptoms consisted of transient ischemic attacks and/or stroke (20 cases), recurrent migraine-like headaches (seven cases), seizures (six cases) and hemorrhage (one case). A total of four familial cases were found. The final diagnosis was based in all cases on the conventional angiographic findings and more recently also on the magnetic resonance angiography (ten patients). The mean lag time between the first clinical manifestation and the angiographic diagnosis was about 2 years. A medical treatment (vasodilators, antiplatelet agents, calcium channel blockers) was followed by 21 patients, while five cases underwent a surgical revascularization. The follow-up ranges from 1 to 15 years (mean 6 years): A motor (16 cases) and/or mental impairment (14 cases) was detected especially in the childhood onset MMD; only one patient died. In nine cases the long-term outcome persisted without neurological deficit.

Variable presentation of cerebrovascular disease in monovular twins

We describe twin girls with bilateral cerebrovascular disease. In one child, a diagnosis of moyamoya disease was made after presentation in infancy with an acute hemiparesis; her asymptomatic sibling was found to have significant bilateral cerebrovascular disease after neuropsychological evaluation and assessment with transcranial Doppler ultrasound. Both subjects showed a discrepancy between verbal and performance IQ and deficits on a test of frontal-lobe function suggesting that these domains should be targeted in cognitive assessment. Family members of subjects with moyamoya are at risk of cerebrovascular disease. Clinical symptoms do not reliably predict disease and those at risk should be offered screening with non-invasive vascular imaging.