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Brain & Development 1996; 18:81-3

Short communication

Occlusion of unilateral carotid artery in Down syndrome
Roberto Gaggero a,*, Paolo Tortori Donati b, Roberto Curia a, Maurizio De Negri a
a Division of Child Neuropsychiatry, lstituto G. Gaslini, Largo G. Gaslini 5, 16148 Genoa, Italy
b Department ofNeuroradiology, lstituto G. Gaslini, Genoa, Italy

Received 28 March 1995; accepted 20 September 1995

The association between moyamoya phenomena and Down syndrome (DS) is reported in the literature. This paper
reports a case of DS, which at age 9 presented right hemiparesis, secondary to the occlusion of the left internal
carotid artery; cerebral angiography (CAG) showed a collateral circulation that mimicks the moyamoya phenomenon. Clinical recovery was almost complete; a second CAG after 15 months showed a persistent occlusion of the
left internal carotid artery and an opacification of the left middle cerebral artery from abnormal vessels; but the
collateral circulation is not enhanced. This case proves that in DS cerebrovascular occlusions may present
moyamoya-like phenomena. These differ however from the true moyamoya disease in a number of aspects: the
arterial occlusion is unilateral, the evolution is favorable and revascularization does not occur through the peculiar
abnormal vessels of the moyamoya syndrome.

Keywords: Down syndrome; Moyamoya disease; Moyamoya syndrome; Stroke

1. I N T R O D U C T I O N
In infancy cerebrovascular diseases are rare: their incidence is
2.52 per 100000 subjects in the pediatric age [1]. The etiology is
hemorrhagic in more than half of the cases [1]. The conditions
secondary to arterial occlusion are mainly associated with well
known diseases (cardiopathy, hemopathy), but in about half no
significant causes are found [2]. One particular group includes
cases of vascular dysplasia, such as moyamoya disease and
fibromuscular dysplasia. The moyamoya syndrome consists of a
progressive stenosis of the main cerebral vessels with development of an abnormal vascular network in the basal ganglia, with
multiple anastomoses between internal and external carotid arteries [3,4]; the incidence of this syndrome is more prevalent in
patients with Down syndrome (DS) [5].
We present a DS case of cerebral ischemia caused by stenosis
of the internal carotid artery. The longitudinal angiographic study

* Corresponding author. Fax: (39) (10) 381303.
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showed a vascular condition similar to moyamoya syndrome, but
with some different peculiar aspects.

2. C A S E R E P O R T
The patient, born on 18 April 1983, presented a typical
clinical picture of DS, with moderate mental retardation and no
sign of cardiopathy. At 9 years and 6 months of age, the patient
presented a sudden right hemiparesis associated with slight aphasia. The first cerebral CT scan performed after 12 h revealed two
hypodense areas in the left occipito-temporal and left parietal
regions (Fig. 1). Hemiparesis progressively improved in a few
days; clinical and laboratory exams ruled out the presence of
cardiopathy, vasculitis, coagulation disorders and protein C abnormalities.
Another CT scan performed after 7 days showed the same
hypodense temporo-parieto-occipital zone, with signs of reperfusion. A low dose anti-coagulation therapy was started and it is
still continuing. Without any certain etiological data two cerebral
angiographies (CAGs) were performed after 20 days and 15

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R. Gaggero et al. / Brain & Deuelopment 1996; 18:81-3

Fig. 1. Cranial CT. Hypodense area in the left occipito-temporal region.
Fig. 3. First CAG. A thin vascular network spreads from the carotid
siphon within the encephalic base.

months, respectively; the selective angiography was performed
through the femoral artery under general anesthesia.

3. R E S U L T S

OF THE ANGIOGRAPHIC

STUDY

The first CAG (Fig. 2) showed a stenosis of the entire left
internal carotid artery, more marked in the portion distal to the
branching of the ophthalmic artery. From the carotid siphon (Fig.
3) a thin moyamoya-like network, extending to the base of the
brain, was revealed. The second CAG, performed after 15 months

Fig. 2. First CAG. Stenosis of the left internal carotid artery, 2 cm above
the carotid bifurcation up to the siphon.

(Fig. 4), revealed an increased size of the left carotid artery, with
a severe stenosis or an occlusion 1 cm above the origin of the
ophthalmic artery.
Some branches of the left middle cerebral artery were partially opacified; the abnormal moyamoya-like vessels around the
internal carotid artery were not enhanced compared to the previous angiography.

Fig. 4. Second CAG. Increased size of the left carotid artery with a
persistent occlusion 1 cm above the origin of the ophthalmic artery. Some
branches of the left middle cerebral artery are partially opacified. The
vascular network around the internal carotid artery is not enhanced.

R. Gaggero et al. / Brain & Development 1996; 18:81-3

4. D I S C U S S I O N

AND CONCLUSION

The incidence of both cerebral arterial occlusion and moyamoya syndrome [5] is higher in patients with DS than in the
general population.
Recently some Japanese authors [6,7] have underlined the
necessity of distinguishing moyamoya disease from moyamoya
syndrome, the latter being secondary to diverse underlying conditions, such as neurofibromatosis, tumors, meningitis, etc. Moyamoya disease is characterized by a progressive and bilateral
occlusion of the circle of Willis with a particular network of
revascularization at the skull base and of anastomoses, definable
as a 'rete mirabile'; the moyamoya syndrome on the contrary
may be unilateral [6].
The relationship between this phenomenon and DS may be
explained according to two different perspectives: (1) DS constitutes a risk factor for cerebrovascular diseases [8]; (2) there is a
genetic association between DS and the moyamoya gene [9]. The
case presented here shows the possibility that an apparently
unexplained internal carotid occlusion may occur in patients with
DS, with vascular phenomena similar to those observed in moyamoya disease. However, there are several important differences:
the arterial occlusion is unilateral; the evolution is characterized
by an almost complete recovery; the revascularization mechanisms do not occur through the typical vessels of the moyamoya
phenomenon. Therefore, it is possible to hypothesize that in DS
syndrome a vascular congenital disorder can cause cerebral occlusive phenomena, with consequent revascularization mechanisms different from moyamoya disease. The true moyamoya
disease, described by Japanese authors [3,7,9], has to be clearly
differentiated. This distinction is also supported by differences
between the vascular wall anomalies noticed in moyamoya dis-

83

ease and those observed in DS, as described in neuropathologicai
studies [6,10].

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