Recurrent cerebral embolism in a young adult with Down?s syndrome

Abstract

Sirs: Patients with Down’s syndrome, the most common human chromosomal malformation, often suffer from a variety of concomitant disorders, such as congenital heart disease, leukemia, or malignancy [5]. Several cases of Down’s syndrome (DS) with stroke disorders and moyamoya-like vessels have been reported in the literature [2, 3, 10, 11]. We report here a case of recurrent embolic stroke in a young adult with DS. A 31-year-old right-handed female with DS developed a sudden onset of nuchal pain and vertigo. She could not stand because of weakness in her lower extremities. She was admitted to Osaka Medical College on September 6, 2003. A karyotype of trisomy 21 had been confirmed when the patient was 1 month old. Upon her admission now, the stigmata of DS were present: ocular hypertelorism; broad, flat facies; wide neck; low-set, posteriorly rotated ears; and short hands with clinodactylism. The rest of the physical examination, including her cardiovascular system, was unremarkable. She had entered into a confused state and her speech had become slow and slurred. A neurological examination showed hemiparesis with hyperreflexia and Babinski’s sign on the right side. Both eyes rested in an inward position, and there was paralysis of upward and downward gaze. Striking dysmetria was noted in the left upper and lower extremities. Her gait was very broad-based and she could not walk without support. Cranial MRI showed hypersignal intensity in the left cerebellar hemisphere on T2 and diffusionweighted images, and in the medial part of the left thalamus on diffusion-weighted images (Fig. 1a, b). MR angiography of the brain was normal. There were normal findings in several studies: complete blood count, sedimentation rate, prothrombin time, partial thromboplastin time, thrombin anti-thrombin III complex, fibrinogen, fasting plasma glucose, serum cholesterol, triglyceride, C-reactive protein, antinuclear antibody, rheumatoid factors, serology of syphilis, antiphospholipid antibodies, protein C, and urine homocystine levels. There were normal results in a cardiac evaluation that included electrocardiogram, echocardiogram, and 24-hour rhythm monitor. A spine roentgenogram revealed a dislocation of the C1 and C2 vertebrae (Fig. 2a). Color-coded Doppler ultrasonography showed anterograde and severely reduced flow in the left vertebral artery. She was treated with aspirin. On 13th day after admission, she suddenly developed memory disturbance. Neurologically, her hemiparesis and motor ataxia were not aggravated, and there was no evidence of other abnormalities. A follow-up MRI of the brain showed high signals in the pons as well as in the bilateral hippocampal and occipital regions on T2 and diffusion-weighted images (Fig. 1c, d). Three-dimensional helical CT (3D-CT) demonstrated hypoplasia of the left vertebral artery and local occlusion at the C2 level; this was the same portion where there was the atlantoaxial dislocation (Fig. 2b). After a relapse of the disease, she was treated with aspirin and ticlopidine hydrochloride. Her neurological signs, except for amnesia, then improved. The occurrence of stroke in DS has been rarely reported; and some of the cases that have been reported were secondary to cyanotic heart disease with paradoxical emboli or to meningitis [11]. Epidemiologic studies have found a higher incidence of moyamoya syndrome in patients with DS [6]. Patients with DS associated with cerebral amyloid angiopathy have been represented in few previous reports [4]. Our patient manifested a top-ofthe-basilar-artery syndrome without evidence of any congenital cardiac lesion, right-to-left shunts, or valvular endocarditis. These emboli usually present as cerebral infarcts in the carotid distribution. Moreover, there were no stenosed or occluded lesions of major arteries on cranial MR angiography. The findings of 3D-CT and Doppler ultrasonography suggested that posterior circulation stroke in our patient might result from kinking and occlusion of the vertebral artery at the level of an atlantoaxial dislocation. To our knowledge, there have been no previous reports of patients with DS associated with infarction caused by atlantoaxial dislocation. Stroke due to atlantoaxial dislocation has been observed in a few cases, most of which were caused by cervical spine trauma [8, 9] and rarely by ankylosing spondylitis [14] or cranio-cervical anomalies [1]. In a retrospective review of cineangiography of patients with DS, 40 % of LETTER TO THE EDITORS