Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Not actin’ right: Lacunar infarct and pediatric stroke
Case presentation
A 17-year-old male presents with right-sided facial numbness and extremity weakness that has been intermittent for the past 1 month. Several hours ago, the patient noted he had difficulty ambulating when rising out of bed due to the weakness, causing him to fall. He was able to prevent injury by steadying himself on a chair. He went back to lie down and then called his mother, who noted that he had slurred speech. He was taken to an outside facility after being transported by emergency medical services. There, he was told he was “fine” and was discharged home. His mother then brought him for evaluation to your department after he felt weak and was having slurred speech again; he also was noted to have a right facial droop. He denies visual changes, ataxic episodes, altered consciousness, recent illness, and recent trauma. He has no significant medical or familial history.
Physical examination reveals a well-appearing patient in no distress. He has age-appropriate vital signs including his blood pressure. His physical examination is remarkable for right facial droop, tongue deviation to the right, and right upper extremity weakness. He has no other neurologic deficits.
Imaging considerations
Pediatric patients presenting with symptoms concerning for a stroke or who have previously had a stroke and there is concern for recurrence should undergo imaging as soon as possible. There are several options available to the clinician.
Computed tomography (CT)/CT angiography (CTA)/CT venography (CTV)
This imaging modality is rapid and available but does involve exposure to ionizing radiation. Unenhanced CT is useful in detecting hemorrhage and changes of ischemic stroke within 6 hours after the onset of the ischemic process, although prior to this, the study may be unremarkable. , The sensitivity and specificity of CT for pediatric stroke have not been validated in studies, but expert opinion for its use has been based on extrapolation and application from existing adult data. Non—contrast CT is the initial imaging modality in patients with a history and examination concerning for hemorrhagic and, in some cases, ischemic stroke.
CTA and perfusion studies may also be performed in children with suspected ischemic events and are often utilized in patients in whom magnetic resonance imaging (MRI) might be contraindicated, such as those with cochlear implants or other medical devices that are not MRI compatible. CTV is very useful in detecting cavernous sinus thrombosus. ,
MRI/MRI-angiogram (MRA)–venogram (MRV)
MRI is an excellent modality for imaging patients with concerns for an ischemic event. A typical standard stroke protocol includes fluid attenuated inversion recovery (FLAIR), diffusion-weighted imaging, and susceptibility-weighted imaging (SWI) and T1 sequences. Certain sequences of MRI are highly sensitive in the detection of parenchymal hemorrhage, subarachnoid hemorrhage (FLAIR and SWI sequences particularly), and, using perfusion techniques, cerebral blood flow, cerebral blood volume, and transit times. , , MRA and MRV can be used to evaluate cerebral blood vessel patency and evaluate vascular anatomy, and vascular imaging should be obtained when the cause of stroke is suspected to be ischemic or hemorrhagic. MRI is more sensitive than CT for acute ischemia and is better at evaluating the posterior fossa and can be useful in diagnosing stroke mimics.
The International Pediatric Stroke Study Neuroimaging Consortium recommends MRI as a first-line imaging study. , Due to the time required to perform the study, sedation, especially in younger patients, may be required. There are fast-acquisition protocols that some institutions have implemented, but this is still a 20-minute study, and sedation, even when these protocols are utilized, may still be required.
Ultrasound (US)
This modality is useful in neonates or infants with open fontanelles, allowing for imaging of the cerebral parenchyma, although visualization of the posterior fossa may be limited. Ischemic injury of the parenchyma may be seen as areas of increased echogenicity with mass effect. However, US has been shown to be less sensitive compared to CT and MRI in detecting ischemic lesions. , While this limits the usefulness of cranial US in detecting ischemia, the availability, lack of ionizing radiation, and portability of this modality make it useful in neonates to evaluate parenchymal hemorrhage, intraventricular hemorrhage, and gross anatomic evaluation of the cerebrum in neonates.
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here