|Ahead of print publication
Moyamoya angiopathy masquerading as febrile seizures
Ritwik Ghosh1, Souvik Dubey2, Subhankar Chatterjee3, Biman Kanti Ray2
1 Department of General Medicine, Burdwan Medical College and Hospital, Burdwan, West Bengal, India
2 Department of Neuromedicine, Bangur Institute of Neurosciences, Institute of Post Graduate Medical Education and Research and SSKM Hospital, Kolkata, West Bengal, India
3 Department of General Medicine, Rajendra Institute of Medical Sciences, Ranchi, Jharkhand, India
|Date of Submission||17-Jan-2020|
|Date of Decision||17-Mar-2020|
|Date of Acceptance||24-Jun-2020|
Flat-A304, Block A, Siddhibinayak Apt Litchi Bagan, Ranchi - 834 009, Jharkhand
Source of Support: None, Conflict of Interest: None
While fever is a well-described precipitating factor of moyamoya-specific symptoms, moyamoya angiopathy (MMA) mimicking recurrent febrile seizures has never been reported before. Here, we report a case of MMA in a 4-year-old child who was misdiagnosed as simple febrile seizures on multiple occasions. This case underscores the importance of identifying early clinicoradiological clues of MMA for earlier diagnosis and better prognosis.
Keywords: Febrile seizure, moyamoya angiopathy, moyamoya disease, seizure
| Introduction|| |
Moyamoya angiopathy (MMA) is a progressive occlusive intracranial vasculopathy with characteristic angiographic findings of stenosis or occlusion at the terminal portion of the internal carotid artery (ICA) and proximal anterior cerebral artery (ACA) and/or middle cerebral artery (MCA) together with the abnormal vascular network (classically appears like “puff of smoke”) at the base of the brain. MMA is divided into moyamoya syndrome (MMS) or quasi-moyamoya or akin-moyamoya (those with a well-recognized associated condition and angiographic evidence of uni/bilateral stenosis) and moyamoya disease (MMD, those without any associated disorder and bilateral stenosis)., Although originally described among the Japanese population, MMA is now being increasingly reported worldwide. Indian studies have indicated that MMA from this part of the world shares distinct qualities and is marked by greater latency period between symptom onset and angiographic diagnosis., While fever is a well-described precipitating factor of MMA-specific symptoms, MMA masquerading as recurrent febrile seizures has never been reported before.
| Case Report|| |
A 4-year-old male child with uneventful birth and normal developmental milestones till the age of 18 months, presented with a history of abrupt fall from a chair with a brief period of loss of consciousness along with sudden-onset speech disturbance 7 days back.
History from the parents revealed that 18 months back, he had a single episode of loss of consciousness lasting about 5 min associated with high-grade fever secondary to the throat infection. He was then hospitalized and diagnosed as a simple febrile seizure (SFS) (semiology: generalized tonic-clonic seizure). The initial computed tomography (CT) scan of the brain and electroencephalography (EEG) revealed no abnormality, and he had no residual neurodeficit. Six months from this first attack, he again had a similar attack of a generalized tonic-clonic seizure with loss of consciousness associated with a febrile episode. This time, the caregiver observed this as left focal seizure with secondary generalization. He was again discharged from the hospital with a diagnosis of SFS. Both EEG and CT scan of the brain failed to demonstrate any abnormality this time too. Approximately 1 year after the second attack, he suddenly fell on the ground from the bed followed by simple focal seizure with secondary generalization. On regaining consciousness, he was having postictal confusion and left hemiparesis. A CT brain showed a small hypodense area at the right paraventricular and right paracaudate region along with age-disproportionate enlargement of the Sylvian fissures bilaterally [Figure 1]. He was discharged from the hospital with aspirin (37.5 mg/day), levetiracetam (400 mg/day), valproate (400 mg/day), and regular physiotherapy. His hemiparesis recovered almost fully in 1 year, but cognitive abilities took a downhill course. One month before the presentation, he had a breakthrough seizure due to an inadvertent stoppage of medications along with some visual deficits not clearly defined in his left eye field. His mother also had a history of SFS.
|Figure 1: Computed tomography of the brain showing a small hypodense area suggestive of infarct at the right paraventricular and right paracaudate region along with age disproportionate enlargement of the Sylvian fissures bilaterally|
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On examination, the patient had markedly decreased word output without any grammatical sense, but comprehension for spoken language was intact (Broca's aphasia). The rest of the neurological examination was normal except mild residual left-sided spastic hemiparesis (power 5-/5, exaggerated deep tendon reflexes, and extensor plantar response). Other systemic examination was normal.
Magnetic resonance imaging brain showed acute infarct in the left frontal region in exclusively cortical distribution; old infarct; and gliotic changes in right para-caudate, paraventricular, and right parietooccipital cortex with prominent “ivy sign.” Magnetic resonance angiography showed a distinct narrowing in bilateral ICA in its terminal part, proximal MCA, ACA, and P1 segment of posterior cerebral arteries (PCA) with multiple collaterals [Figure 2]. Thus, he was diagnosed as a case of MMA. Relevant investigations were sent to rule out syndromic MMD and all came out negative.
|Figure 2: Magnetic resonance imaging of the brain (left panel) showing acute infarct in the left frontal region in exclusively cortical distribution, old infarct, and gliotic changes in right paracaudate, paraventricular, and right parietooccipital cortex with prominent “ivy sign.” Magnetic resonance angiography of the cerebral vessels (right panel) showed a distinct narrowing in the bilateral ICA in its terminal part, proximal middle cerebral artery, anterior cerebral artery, and P1 segment of the posterior cerebral arteries with multiple collaterals|
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| Discussion|| |
MMA follows a bimodal age distribution of disease, with initial peak occurs in children around 5 years of age. Childhood MMA generally presents with subtle findings of transient ischemic attacks, stroke, seizures, movement disorders, etc.
As per the semiology of seizure given by the caregiver, our patient fulfilled all the criteria of SFS during the initial two attacks and hence was discharged after stabilization without doing further diagnostic workups. The third attack did have stigma on brain imaging but was given lesser importance because MMA is a frequently overlooked condition for its low incidence rate. Moreover, most of the cases of MMA are diagnosed with a significant latency period between the appearance of the index symptom and final angiographic diagnosis., Hyperventilation, stress, fever, and dehydration may also precipitate ischemic symptoms., In this case too, the warning sign was unfortunately missed which first unmasked the underlying MMA. Febrile episode with seizure without any definite neurodeficit, normal EEG, and cerebral CT may lure a general practitioner or primary health-care provider or even pediatrician to diagnose it as a case of SFS. This further warrants the importance of proper history taking and the importance of the semiology of seizure. However, this does not stay true always as in this case, the febrile episodes precipitated the ischemic symptoms of MMA on multiple occasions.
Precise knowledge about infarct topography is often helpful in diagnosing hemodynamic strokes such as MMAs. In childhood MMA, infarct topography usually reveals an atypical territorial, gyral, and border zone or watershed patterns. In our case, the infarcts in the left frontal (causing Broca's aphasia), right peri and para-ventricular (causing hemiparesis), and right parietooccipital (causing visual field loss) areas followed atypical, watershed, and gyral pattern. This, when found, should be taken as a clue for earlier diagnosis and favorable prognosis. In our case the latency in the diagnosis is so prolonged that the patient has developed “ivy sign,” PCA involvement, posterior circulation stroke, cortical atrophy, and cognitive dysfunctions. All of these are individually known factor signifying poor prognosis. Cognitive decline, intellectual impairment, and poor scholastic performance ensue due to chronic significant cerebral hypoperfusion, even before imaging shows atrophic changes in strategic locations in MMA.
| Conclusion|| |
To conclude, recent epidemiological data have confirmed that the incidence of MMA is on the rise in East Asian countries. In children, ischemic symptoms are most common. Fever is a definite precipitating factor for MMA and seizure may also be a presenting feature. Hene, a febrile seizure may be more than just a fever with seizure even in seemingly appropriate clinical settings and should be investigated thoroughly. Even on a historical basis, where the semiology of seizure description may not be accurate by the caregiver, more so in the rural background where health awareness is one of the most important shortcomings.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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