A 3.5-year-old girl who could no longer talk, chew or swallow after a prolonged seizure has been diagnosed with Moyamoya disease, a rare and progressive cerebrovascular disorder, according to a case report published in the Egyptian Pediatric Association Gazette. The child arrived at hospital 25 days after a generalized tonic-clonic seizure that lasted nearly an hour and left her with dysphagia and global aphasia. She had already suffered two similar seizures during the preceding year and eight months, the first of which was triggered by fever. Only after magnetic resonance imaging and magnetic resonance angiography were performed did clinicians identify the severe arterial narrowing and abnormal collateral vessels that define the disease, graded as Suzuki stage II–III.
Moyamoya disease is characterized by progressive stenosis or occlusion of the terminal portions of the internal carotid arteries and their proximal branches, particularly the anterior and middle cerebral arteries. As blood flow through these vessels diminishes, a network of fragile collateral vessels forms at the base of the brain to compensate. On angiographic imaging these tiny vessels cluster in a pattern that resembles a puff of smoke, the visual feature that gave the disease its Japanese name, meaning something hazy or smoky. The exact etiology remains unclear, but genetic predisposition, developmental vascular abnormalities and environmental factors have all been implicated.
The condition shows a bimodal age distribution, with one peak in childhood between roughly 5 and 14 years and another in adulthood between 45 and 54 years. Children typically present with ischemic manifestations such as transient ischemic attacks, cerebral infarction, seizures and progressive neurological deficits, whereas adults more often present with intracranial hemorrhage. Early diagnosis matters because progressive cerebral hypoperfusion can lead to repeated ischemic events and permanent neurological disability, and early-onset disease may progress rapidly during critical periods of brain development.
In this case, the girl was born preterm by normal vaginal delivery, had reached her developmental milestones without delay, and was the third child of consanguineous parents with no family history of epilepsy. On admission she was conscious and oriented but uncooperative, drooling saliva, with an oxygen saturation of 98 percent on room air, a regular heart rate of 94 beats per minute and a blood pressure of 80/50 mmHg. Examination of her lower limbs revealed reduced bulk, increased tone, muscle power of 3 out of 5 on the right side, exaggerated deep tendon reflexes and an extensor plantar response on the same side. Blood tests showed mild anemia with a hemoglobin of 10.8 g/dL, normal ferritin, serum iron and TIBC levels, mildly elevated SGPT and slightly increased serum chloride; dengue NS1 was negative and urinalysis was normal.
Crucially, the family brought a one-year-old CT scan and epilepsy-protocol brain MRI performed after the first seizure in 2024. The CT had revealed focal atrophy of the left frontotemporal region with widening of the sulci and the left Sylvian fissure. The earlier MRI showed atrophy of the left midbrain suggestive of Wallerian degeneration, along with gliosis in the left frontal lobe and the right paraventricular subcortical frontal lobe, findings highly suggestive of a prior ischemic infarct. In retrospect, these images documented long-standing cerebrovascular injury that had gone unrecognized as Moyamoya disease for more than a year.
During the current admission, MRI revealed a large wedge-shaped area of cerebrospinal fluid intensity measuring 2 to 3 centimeters, with parenchymal volume loss and marginal gliosis in both frontal lobes, and dilatation of the ipsilateral cerebrospinal fluid spaces. The 3D time-of-flight MRA with maximum intensity projection demonstrated severe stenosis of the terminal internal carotid arteries and hazy basal collateral circulation, the classic puff of smoke phenomenon. Both anterior and middle cerebral arteries were moderately attenuated, both posterior cerebral arteries were attenuated, and there was a paucity of distal cortical vessels with flame-shaped basal collaterals. FLAIR imaging showed hyperintense cortical signals known as the ivy sign, alongside gliotic changes in the frontal lobes. An electroencephalogram recorded diffuse encephalopathy during sleep but no epileptiform discharges.
The differential diagnosis initially included recurrent stroke syndrome secondary to Moyamoya disease as well as metabolic disorders such as mitochondrial encephalomyopathy, including MELAS syndrome, genetic cerebrovascular conditions including leukodystrophies, and vasculitides such as primary central nervous system angiitis of childhood. The authors identify two features that made this diagnosis unusually difficult: the first episode occurred at approximately 2.5 years of age, whereas the mean peak age for pediatric Moyamoya disease is around 4 years, and the presence of dysphagia suggested involvement of deeper brain structures, which is uncommon at such an early age. The presence of characteristic angiographic findings on MRA ultimately established the diagnosis, although digital subtraction angiography remains the gold standard for confirmation and detailed vascular evaluation.
The child was managed with nutritional support, aspirin, sodium valproate, levetiracetam and trihexyphenidyl hydrochloride, and was referred for digital subtraction angiography and neurosurgical evaluation. This reflects the standard two-track approach to the disease. Medical therapy is generally supportive: antiplatelet agents such as aspirin reduce the risk of thrombosis, while anticonvulsants control seizures. However, medical therapy alone does not halt disease progression, which is driven by progressive intimal thickening and vascular remodeling of the affected arteries. Surgical revascularization procedures, including direct or indirect bypass techniques such as encephaloduroarteriosynangiosis, are considered the most effective treatment for improving cerebral blood flow and reducing the risk of recurrent strokes in pediatric patients.
The report also highlights the role of advanced perfusion imaging. Arterial spin labeling MRI has emerged as a valuable noninvasive tool for assessing cerebral blood flow and hemodynamic impairment in pediatric Moyamoya disease, but it was not performed in this case because of limited availability at the treating institution. Conventional MRI and MRA nonetheless provided sufficient evidence of chronic ischemic injury and characteristic vascular abnormalities to establish the diagnosis and guide further management. The Suzuki staging system, which ranges from stage I, initial narrowing of the carotid arteries, to stage VI, complete occlusion with disappearance of collateral circulation, places this patient’s angiographic findings at stage II to III.
The authors draw a practical lesson from the fever that preceded the child’s first seizure: a febrile seizure should not exclude Moyamoya disease from the differential diagnosis, because such presentations can mimic simple febrile seizures and delay recognition of the underlying cerebrovascular pathology. They argue that Moyamoya disease should be considered in young children presenting with recurrent seizures and focal neurological deficits, particularly when neuroimaging demonstrates prior ischemic injury such as cortical atrophy, gliosis or old infarcts. Early neurovascular imaging with MRI and MRA, followed by prompt referral for specialized neurosurgical care, is presented as essential to prevent further neurological deterioration and to optimize long-term outcomes in a disease whose earliest signs are easily mistaken for more common childhood neurological events.
Subject of Research: Early-onset Moyamoya disease in a young child presenting with recurrent seizures and dysphagia
Article Title: Early-onset Moyamoya disease presenting with recurrent seizures and dysphagia in a 3.5-year-old child: a case report
Article References: Haque, F., & Islam, R. (2026). Early-onset Moyamoya disease presenting with recurrent seizures and dysphagia in a 3.5-year-old child: a case report. Egyptian Pediatric Association Gazette, 74(1), Article 125. https://doi.org/10.1186/s43054-026-00627-z
Image Credits: AI Generated
DOI: 10.1186/s43054-026-00627-z
Keywords: Moyamoya disease, pediatric neurology, stroke, seizures, dysphagia, MRI, magnetic resonance angiography, Suzuki staging, cerebral hypoperfusion, revascularization, case report, cerebrovascular disorder
News Source: Ophelia Keating. (October 28, 2026). Rare Early-Onset Moyamoya Disease Diagnosed in a 3.5-Year-Old Girl After Recurrent Seizures. Scienmag.
