Arterial ischaemic stroke in a pediatric patient with COVID-19

A 6-year-old boy was admitted to the emergency department with right hemiparesis, one month after being diagnosed with COVID 19 by RT-PCR.

The MRI revealed an area of acute ischaemic stroke presented with restricted diffusion affecting the left lenticular nucleus and extending to the anterior portion of the internal capsule. “Ivy sign” was present in the ipsilateral convexity, which represents prominent leptomeningeal collaterals. The MR angiography showed occlusion of the left middle cerebral artery involving distal M1 and M2 segments. Arterial wall inflammation was also present at the intracranial segments of the left internal carotid artery depicted as an increased signal on FLAIR sequence of the vessel wall and narrowing of its lumen. On MRI perfusion there was a decreased blood flow and volume in the left basal ganglia and ipsilateral parietal parenchyma. There was a mild mass effect with distortion of the left lateral ventricle. Mechanical thrombectomy allowed for clot retrieval and restored blood flow to the left middle cerebral artery.

In the follow-up MRI, the left lenticular nucleus infarct evolved from an early acute to a chronic stroke. MRI perfusion showed normal flow and volume and no ischaemic lesion was found in parietal parenchyma.

Pediatric stroke is quite rare and the ischaemic subtype accounts approximately for 50% of cases (whereas in adults accounts for 80-85%). Diagnosis Diagnostic delay leads to significant morbidity and mortality. Ischaemic stroke often presents as a focal neurologic deficit (hemiplegia). The most frequent cause is cardiac disease, whereas vascular/cerebral vasculitis is less frequent [1].

An arteriopathy is defined as the presence of an arterial wall abnormality. Pediatric cerebral arteriopathies can be divided into large-medium size arteriopathies and small vessel arteriopathies. Both can be subdivided into inflammatory (which is a synonym of vasculitis) and non-inflammatory. Moyamoya disease is an example of a non-inflammatory large-medium size arteriopathy and post-varicella angiopathy belongs to the inflammatory (post-infectious) large-medium size arteriopathy category [2, 3].

COVID-19 can cause neurological involvement by overproduction of cytokines, coagulopathies, thrombus formation, and direct viral invasion of neurons and cerebrovascular endothelial cells [4]. These can result in ischaemic strokes, encephalitis, seizures, and demyelinating disorders [5]. Pediatric ischaemic strokes due to COVID-19 are very rare but there are some cases reported in the literature [6].

Less than 1% of pediatric patients hospitalized with COVID-19 had ischaemic strokes (a similar proportion is reported in adults), and most of these patients had other risk factors for stroke indicating that COVID-19 can be a contributing factor in pediatric patients with a predisposition. Stroke locations of pediatric patients with COVID-19 include thalamocapsular, basal ganglia, midbrain, and anterior/middle/posterior cerebral arteries territories [6].

Code stroke protocol is very important for early diagnosis and treatment in arterial ischaemic occlusions. MRI protocol should include T2WI, FLAIR, and diffusion sequences along with non-contrast perfusion MRI and Angio-MRI sequences to diagnose treatable cerebral arterial occlusions with an endovascular approach, identify signs of arteriopathy (irregularity and hypersignal of wall vessel in FLAIR) and exclude stroke mimics.