Pediatric moyamoya disease presenting as attention deficit hyperactivity disorder: Time to pay attention.

Sir,

Moyamoya disease is a rare progressive cerebrovascular condition resulting in bilateral stenosis of internal carotid artery and its branches.[1] On angiogram, the appearance of “puff of smoke” is due to the development of compensatory collateral circulation between internal and external carotid arteries. The prevalence in Eastern countries is much higher (1:20) than in the West.[1] The disease is associated with recurrent stroke, headache, and seizures.[234] In addition, cognitive decline, intellectual deficiency, and learning disabilities are also seen. Bilateral vasculopathy, early-onset, and long duration are associated with poor prognosis.[5] Attention deficits have been reported, attention deficit hyperactivity disorder (ADHD) has not been reported in literature.

Here, we discuss a case of moyamoya disease presenting with intellectual decline and ADHD.

Mr. K, a 14-year-old younger son of a school teacher, was brought with chief complaints of not being able to focus in studies, losing his belongings and spending the entire day with other children in the neighborhood giving them a bicycle ride and enjoying street food. He would refuse to attend the classes with his special educator who gave him home tuitions as he had dropped out of regular school owing to behavioral problems.

Mr. K started complaining of episodic headaches and recurrent seizures at 11 years of age, prompting neurological consultation. His electroencephalogram was suggestive of generalized seizure disorder and magnetic resonance imaging showed the presence of small hypointense gliotic areas in the left frontoparietal region with mass effect. His Digital subtraction angiogram showed bilateral “puff of smoke appearance” in supraclinoid regions [Figure 1]. He was diagnosed with moyamoya disease with bilateral supraclinoidal internal carotid artery narrowing. Bilateral encephaloduroarteriomyosynangiosis (EDAMS) procedure was carried out within the next 6 months. This surgical revascularization relieved him of headaches, and he was prescribed with phenytoin 200 mg and oxcarbazepine 150 mg for the management of seizures.

Figure 1

Digital subtraction angiogram image of the brain showing “puff of smoke” appearance in moyamoya disease (a) anteroposterior view, (b) lateral view. Arrows denote ‘puff of smoke’ appearance

On Malin's Intelligence Scale for Indian Children, his verbal IQ was 68 and Performance IQ was 67.[5] On Vineland Social Maturity Scale (VSMS) his Social Quotient (SQ) was 65. Inattention and hyperactivity were observed during the sessions. Assessment was done using Conners ADHD scale in which his score was 17. He was diagnosed with mild mental retardation and ADHD combined type as per DSM IV criteria. After his EDAMS procedure, on VSMS, his SQ was 61 and SA 8 years 6 months. His inattention and hyperactivity also increased so much so that the Conners ADHD scale score was 20.

He was on antiepileptics hence stimulants were not preferred; tablet atomoxetine 10 mg OD was started which he tolerated well.[6] The dose of atomoxetine was gradually titrated up to 40 mg/day keeping in view of the previous good response.

Available literature from Asian countries show a high preponderance of intellectual and attention deficits in moyamoya disease.[1] While data on adult neurocognitive evaluation are available, there are only a few reports on the pediatric population. Existing literature supports attentional deficits but the clinical presentation of ADHD has never been previously reported. Chronic ischemic hypoxic insults to the cerebrum are hypothesized to be causative for cognitive deterioration.[7] Domains of cognitive functioning such as intelligence, memory, and executive functioning are commonly affected. In pediatric patient's intelligence is most commonly affected.[8] These patients have poor working memory and have difficulty sustaining attention which is hypothesized due to hypoperfusion of the frontal lobe.[9]

Our case was distinct in terms of the presence of mental retardation and hyperactivity and inattention 5 years before the diagnosis of moyamoya disease. Definitive diagnosis could be reached at 11 years of age with digital subtraction angiography. The presence of low intellectual functioning and ADHD might be explained by the chronic cerebral hypoperfusion caused by bilateral internal carotid artery involvement. The neurosurgical procedure had relieved the patient of headaches, but attention deficits and behavior problems had remained even after the operation and needed specialized intervention. The deterioration in his SQ scores and ADHD scores even after neurosurgical procedure might have been due to the persisting cognitive dysfunction caused by the early age of onset, bilateral arterial involvement, and chronic cerebral hypoperfusion. He is currently on regular follow-up and managed with activity scheduling, behavior therapy, and special education at home.

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Conflicts of interest

There are no conflicts of interest.