High-resolution vessel wall-magnetic resonance imaging (VW-MRI) has been used to detect regional vessel wall pathology, significantly contributing to the diagnosis of primary angiitis of the central nervous system (PACNS) from other arteriopathies. In this study, we aimed to describe three cases of PACNS initially presenting as acute ischemic stroke, diagnosed and followed up with VW-MRI.
The medical records of three patients diagnosed with PACNS were retrospectively reviewed. We also reviewed the clinical application of VW-MRI in published articles for the pediatric cases since 2016.
The initial presenting symptoms were headache, diplopia, confused mentality, hemiplegia, dysarthria, and dizziness. All patients had acute infarction on brain MRI, with suspicion of vasculopathy on magnetic resonance angiography. VW-MRI revealed narrowing of vessels with concentric wall thickening and diffuse enhancement in the anterior cerebral artery (n=1), middle cerebral artery (n=1), posterior cerebral artery (n=2), lenticulostriate artery (n=1), anterior inferior cerebellar artery (n=1), and vertebral artery (n=1), suggestive of vascular wall pathology. After excluding the possible etiologies of vasculitis, the clinical diagnosis of PACNS was established. Three patients received high-dose steroid and cyclophosphamide therapy. Two patients were treated with long-term azathioprine based upon the findings of persistent vessel enhancement on VW-MRI. All patients were regularly followed up with VW-MRI for more than 1 year. We summarized the clinical and radiological features of the published pediatric cases using VW-MRI to date.
High-resolution VW-MRI plays an important role in diagnosing childhood PACNS, as results correlate with disease activity.
Primary angiitis of the central nervous system (PACNS) is characterized by inflammation and destruction of vessels, leading to ischemic changes in the vascular territory [
In recent research, gadolinium enhancement of the vessel wall on high-resolution intracranial vessel wall-magnetic resonance imaging (VW-MRI) has been used to classify the etiologies of ischemic stroke in adults [
The aim of this study is to show the value of VW-MRI in the differential diagnosis and management of PACNS in children. We describe three cases of clinically diagnosed PACNS that initially presented with acute ischemic stroke, in which the clinical diagnosis of PACNS was reached with the aid of VW-MRI.
This study included three patients who were clinically diagnosed with PACNS at Samsung Medical Center between December 2018 and May 2020. Data on age at diagnosis, sex, family history, clinical characteristics, neurological examinations, laboratory findings, image findings, medical therapy, and treatment response were collected retrospectively based on patients’ medical records. This study was approved by the Institutional Review Board of the Samsung Seoul Hospital (IRB No. 2020-05-049). Written informed consent by the patients was waived due to a retrospective nature of our study.
Intracranial vessel wall imaging was performed using high-resolution, 3-T MRI equipment (Achieva, Philips Medical System, Best, The Netherlands). The vessel wall imaging protocol included three-dimensional pre- and post-contrast fast T1-weighted images (T1WI) and proton density (PD) images with multiplanar reconstruction. T1WI was performed using a three-dimensional turbo spin echo (TSE) sequence with the following parameters: repetition time (TR)/echo time (TE)=650 ms/18 ms; TSE factor 32; field of view=180×180×35 mm; matrix size=512×512; voxel size=0.700×0.700×0.703 mm2; and spectral presaturation with inversion recovery fat suppression. The parameters used for the PD images were TR/TE=2,000 ms/16 ms, TSE factor 8, field of view=240×180×143 mm, voxel size 0.486×0.486 mm, reconstruction matrix size=880, number of signal averages=2, and slice thickness=6.6 mm. Vessel walls were visualized using the black-blood technique with pre-regional 80-mm-thick saturation pulses to saturate the incoming arterial flow.
We also reviewed the clinical application of VW-MRI in published articles describing pediatric cases since 2016.
The radiologic findings and clinical course of the three cases are shown in
An 8-year-old boy experienced headaches and diplopia, with transient motor weakness 3 weeks prior. He had normal development and no medical history. He visited a local hospital, where brain MRI showed multifocal acute infarction in the left occipital lobe and bilateral cerebellum. His symptoms worsened within 1 day. Repeated brain MRI revealed an increase in the extent of the infarct, and brain MRA findings were suspicious for left posterior cerebral artery (PCA) occlusion. The initial impression was mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) because he had mildly elevated lactic acid levels (3.14 mmol/L) at the local hospital. He was started on clopidogrel and the mitochondrial cocktail: a combination of coenzyme Q1, L-carnitine, lipoic acid and multivitamins (retinol, tocopherol, ascorbic acid, thiamine, riboflavin, nicotinamide, pyridoxine, cyanocobalamin, dexpanthenol, biotin, and cholecalciferol). He also received steroid pulse therapy (methylprednisolone; 15 mg/kg/day) because the possibility of vasculitis was not completely ruled out. MELAS genetic testing was negative.
The patient was referred to our hospital for further evaluation and management on the 3rd day of steroid pulse therapy. On admission, he complained of headache, dizziness, and diplopia. In addition, he was diagnosed with right homonymous hemianopsia and cerebellar dysfunction based on a neurological examination. The white blood cell count, hemoglobin, and platelet count were 19,750/μL, 13.7 g/dL, and 321,000/μL, respectively. His lactic acid level was normal. Inflammatory markers, including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and the results of coagulopathy testing with autoimmune antibodies were unremarkable. Echocardiography, including a cardiac shunt test, was negative and showed no structural abnormalities. Thoracoabdominal CTA, abdominal ultrasonography, and lower extremity Doppler ultrasonography revealed no findings of thromboembolism. We could exclude paraneoplastic thromboembolism because whole-body positron emission tomography showed no evidence of malignancy. After methylprednisolone pulse therapy for 3 days followed by methylprednisolone at 1 mg/kg/day, the patient’s condition deteriorated, with symptoms including partial seizures, headache, right facial palsy, and decreased mentality shortly afterward. Oxcarbazepine and diphenylhydantoin were administered as antiseizure medications. Brain MRI and MRA demonstrated progression of the infarction with aggravated occlusion of the left PCA (
Under the clinical diagnosis of PACNS after excluding other causes of vasculitis, we maintained and slowly tapered the steroid dosage to oral prednisolone at 1 mg/kg/day and observed neurologic improvement in the patient. However, he had an additional newly developed infarction with acute headache and vomiting on day 30 and was treated with cyclophosphamide (750 mg/m2 body surface area [BSA]) monthly for 4 months as induction therapy, followed by azathioprine (25 mg daily) maintenance therapy. After initiation of cyclophosphamide, he had no recurrent headache, and vessel wall enhancement became less evident at the 2-month follow-up VW-MRI. After 2 years, there was no vessel wall enhancement (
An 11-year-old girl presented with a sudden onset of confused mentality, right hemiplegia, and dysarthria. She had no history of fever or systemic illness. Brain MRI indicated acute ischemic infarction in the left basal ganglia, but CTA showed normal findings, without any steno-occlusive lesions in the bilateral cerebral arteries. The laboratory test results, including the evaluation of infection, autoimmune diseases, metabolic diseases, and coagulopathy, were normal. Echocardiography was normal, with a negative saline shunt test. During heparinization, brain MRI revealed an interval increase in the extent of the acute infarction involving the left basal ganglia, insula, frontotemporoparietal lobe, and nearby white matter with diffuse brain swelling (
VW-MRI revealed multifocal irregular enhancement with narrowing of the left distal ICA, left middle cerebral artery, left lenticulostriate artery, and left proximal ACA (
A 6-year-old boy presented with recurrent dizziness, vomiting, and ataxia for more than 1 month. He had no history of trauma. The neurological examination findings were normal upon admission. His brain MRI demonstrated multistage infarction, mainly involving the left thalamus and cerebellum, and the right anterior inferior cerebellar artery (AICA) was poorly visualized on MRA (
The clinical and radiological features of the pediatric cases using VW-MRI published to date are summarized in
This study describes the usefulness of VW-MRI in the clinical diagnosis and treatment of PACNS in three children. All patients presented with acute ischemic stroke, suggesting vasculopathy. VW-MRI revealed evidence of vessel wall inflammation. This allowed a rapid etiologic evaluation and shortened the number of complicated steps. Although all three patients partially recovered with steroid pulse therapy, they eventually received cyclophosphamide for recurrent attacks or progression. We conducted follow-up with serial VW-MRI to monitor the treatment response, which was helpful in determining the timing and duration of immunosuppressive therapy.
Childhood PACNS is an inflammatory brain disease, which is defined by newly acquired focal and/or diffuse neurologic deficits and/or psychiatric symptoms in a child 18 years of age or younger, together with angiographic and/or histologic evidence of vasculitis in the absence of an underlying systemic condition known to cause or mimic these findings, as stated in the Calabrese criteria [
MRI and cerebral angiography are important for establishing a diagnosis of PACNS. MRI, including T2/fluid-attenuated inversion recovery sequences and diffusion-weighted images, reveals ischemic parenchymal lesions according to vessel territories [
Recently, high-resolution VW-MRI has been used for intracranial arterial wall imaging, mostly in adults [
High-resolution VW-MRI is useful in the diagnosis of PACNS, the main pathology of which is inflammation of the arterial wall, by demonstrating vessel wall thickening and contrast enhancement [
We reviewed the literature on pediatric cases using VW-MRI to date, as summarized in
We report three cases of childhood PACNS diagnosed based on the findings of vessel wall inflammation using high-resolution VW-MRI after excluding other possible causes of cerebral angiitis. The first patient in our series showed recurrent acute infarction without a definite diagnosis, despite a thorough work-up. VW-MRI revealed narrowing of vessels with concentric wall thickening and diffuse enhancement. These findings played a critical role in the diagnosis of PACNS and in predicting the progression of inflammation. In the second and third cases, VW-MRI gave a direct clue for reaching the diagnosis of PACNS without TFCA. The finding of vessel wall enhancement on VW-MRI furnished important evidence of vasculitis, differentiating the possible etiologies of vasculopathy. The early diagnosis of PACNS prompted the introduction of immunosuppressive treatment. The treatment plan for the third patient was uncertain because of chronic symptoms and nonspecific laboratory findings when he was transferred to our hospital. VW-MRI supported the diagnosis of PACNS with the initiation of immunosuppressants, and the patient fully recovered without any neurologic deficits. Because VW-MRI showed vessel wall enhancement, which indicates active inflammation, we also followed up patients with serial VW-MRI to monitor the disease course and to determine the duration of treatment. Better neurologic outcomes seem to be attributed to an earlier diagnosis with VW-MRI. Although our study was a retrospective study with a small sample size at a single center, which limits the generalizability of the results, the practical use of VW-MRI in the diagnosis and management of childhood PACNS is meaningful. A systematic approach towards establishing the exact sensitivity and specificity of VW-MRI in diagnosing childhood PACNS remains a topic for further research.
In summary, high-resolution VW-MRI is a promising and useful modality for the early diagnosis and follow-up of childhood PACNS, as it directly visualizes vessel wall inflammation. We recommend VW-MRI for patients suspected of PACNS when the differential diagnosis of arteriopathies is difficult with cerebral angiography, or when the angiography procedure is restricted. VW-MRI could play an important role in identifying the pathophysiology of childhood arteriopathies and could aid in an early diagnosis.
Supplementary materials related to this article can be found online at
Clinical course of pediatric patients with primary angiitis of the central nervous system (PACNS). Case 1: An 8-year-old male patient experienced headache, dizziness, leg weakness, and diplopia at initial presentation. He experienced partial seizures and aphasia in 4 days. Brain magnetic resonance imaging (MRI) revealed multifocal acute infarction in the left occipital area. High-resolution intracranial vessel wall-magnetic resonance imaging (VW-MRI) revealed PACNS; therefore, he was treated with high-dose steroid therapy and cyclophosphamide monthly as induction therapy, followed by azathioprine as maintenance therapy. Case 2: An 11-year-old female patient presented with a sudden onset of confused mentality, right hemiplegia, and dysarthria. Brain MRI indicated an acute infarction in the left basal ganglia. VW-MRI revealed vessel wall enhancement in the left distal internal carotid artery and middle cerebral artery. Cyclophosphamide was administered due to progressive infarction even after high-dose steroid therapy. Her symptoms improved, but the last VW-MRI showed a relapse of vessel wall enhancement, and azathioprine was initiated. Case 3: A 6-year-old male patient presented with dizziness, vomiting, and ataxia. Brain MRI demonstrated multistage infarction, mainly involving the left thalamus and cerebellum. VW-MRI revealed vessel wall enhancement in the right anterior inferior cerebellar artery. Although the patient received high-dose steroid therapy, he experienced motor weakness with a newly developed infarction. In addition to the second high-dose steroid therapy, cyclophosphamide was initiated. mPD, methylprednisolone; OXC, oxcarbazepine; DPH, diphenylhydantoin; IV, intravenous; PD, prednisolone; CPM, cyclophosphamide; BSA, body surface area; AZA, azathioprine; LEV, levetiracetam.
Jeehun Lee is an editorial board member of the journal, but he was not involved in the peer reviewer selection, evaluation, or decision process of this article. No other potential conflicts of interest relevant to this article were reported.
Conceptualization: JL and JL. Data curation: JS and DL. Formal analysis: JS and JYS. Methodology: JYS and JHK. Project administration: JL and JL. Visualization: JS and DL. Writing-original draft: JS and JYS. Writing-review & editing: JL and JL.
Comparison of brain images in patients with primary angiitis of the central nervous system. Case 1: Brain magnetic resonance imaging (MRI) (Aa) shows a multifocal infarction in the left occipital lobe and thalamus on fluid-attenuated inversion recovery (FLAIR). Magnetic resonance angiography (Ba) reveals left posterior cerebral artery (PCA) occlusion (arrow). High-resolution vessel wall-magnetic resonance imaging (VW-MRI) was performed, and post-contrast T1-weighted images (T1WI) obtained before treatment (Ca) show wall enhancement of the left PCA, which disappeared in follow-up post-contrast T1WI (Da) obtained after treatment. Case 2: T2-weighted image (Ab) demonstrates acute infarction in the left basal ganglia, insula, and frontotemporoparietal lobe. Magnetic resonance angiography (Bb) shows a decreased caliber of the left middle cerebral artery (MCA) (arrow) and anterior cerebral artery (ACA) (arrowhead). Post-contrast T1WI of VW-MRI (Cb) shows enhancement of the left proximal ACA (arrow). Follow-up post-contrast T1WI of VW-MRI (Db) shows disappearance of the vascular wall enhancement. Case 3: Initial brain MRI (Ac) shows an infarction in the right cerebellum on FLAIR. The right anterior inferior cerebellar artery is not seen on magnetic resonance angiography (Bc, arrow). There is focal enhancement at the basilar tip in post-contrast T1WI of VW-MRI (Cc). Follow-up post-contrast T1WI (Dc) shows disappearance of the enhancement.
Clinical and radiologic features of published pediatric cases using VW-MRI
Study | No. of patients | Age | Presenting symptoms (n) | MRA findings (n) | Vessel wall enhancement on VW-MRI (n) | Clinical diagnosis (n) | CASCADE classification (n) | Treatment (n) |
---|---|---|---|---|---|---|---|---|
Ohno et al. (2016) [ |
2 | 7 mo–5 yr | Fever (2) | Stenosis or occlusion (2) | Positive (2) | PACNS (2) | NA | Steroid (2) |
Malaise (2) | Negative (0) | Immunosuppressants (1) | ||||||
Headache (1) | ||||||||
Hemiparesis (2) | ||||||||
Dysarthria (1) | ||||||||
Stence et al. (2017) [ |
16 | 6 mo–19 yr | NA | Normal (1) | Positive (13) | PACNS (4) | Unilateral FCA (10) | Steroid (4) |
Stenosis or occlusion (14) | Negative (3) | Antiphospholipid Antibody syndrome (1) | Bilateral cerebral arteriopathy (2) | Immunosuppressants (2) | ||||
Vessel wall irregularity (5) | Idiopathic cause (2) | Cardioembolic (1) | ||||||
Pseudoaneurysm (1) | Moyamoya (1) | Aortic/cervical arteriopathy (2) | ||||||
Dissection (1) | Other/idiopathic (1) | |||||||
VZV vasculitis, vasculopathy (2) | ||||||||
Invasive mucormycosis (1) | ||||||||
Cardioembolic (1) | ||||||||
Radiation-induced vasculopathy (1) | ||||||||
Takayasu’s arteritis (1) | ||||||||
ADA2 deficiency (1) | ||||||||
Dlamini et al. (2018) [ |
26 | 3–11 yr | Focal motor deficit (21) | Normal (8) | Positive (9) | TCA (3) | NA | NA |
Seizures (5) | Stenosis or occlusion (15) | Concentric (7) | PACNS (1) | |||||
Headache (4) | Aneurysm (1) | Eccentric (2) | Vasospasm (1) | |||||
Ataxia (2) | Dissection (1) | Cardioembolic (2) | ||||||
Fever (2) | Pseudoaneurysm (1) | Idiopathic (1) | ||||||
Dissecting aneurysm (1) | ||||||||
Negative (17) | TCA (5) | |||||||
Vasculitis (1) | ||||||||
Moyamoya (2) | ||||||||
Presumed arterial dissection (3) | ||||||||
Cardioembolic (1) | ||||||||
Idiopathic (3) | ||||||||
Perinatal stroke (1) | ||||||||
Microangiopathic hemolytic syndrome (1) | ||||||||
Perez et al. (2020) [ |
9 | 5–14 yr | NA | NA | Positive (6) | NA | FCA inflammatory subtype (9) | Antiviral for VZV (2) |
Negative (3) | Steroids and aspirin (1) | |||||||
Anticoagulation and immunosuppression (1) | ||||||||
Anticoagulation alone (5) |
VW-MRI, vessel-wall magnetic resonance imaging; MRA, magnetic resonance angiography; CASCADE, childhood acute ischemic stroke standardized classification and diagnostic evaluation; PACNS, primary angiitis of the central nervous system; NA, not available; VZV, varicella zoster virus; ADA2, adenosine deaminase 2; FCA, focal cerebral arteriopathy; TCA, transient cerebral arteriopathy.