Seizure and Altered Mental Status in Patient with MIS-C

Welcome to PICU Doc On Call, A Podcast Dedicated to Current and Aspiring Intensivists.I'm Pradip Kamat and I'm Rahul Damania. We are coming to you from Children's Healthcare of Atlanta - Emory University School of Medicine.Welcome to our Episode an 8-year-old admitted for PRESS syndrome with altered mental status secondary to seizures.Here's the case presented by Rahul:Our patient today is an eight-year-old who was admitted to the floor with a diagnosis of MIS-C. On his initial echo, his EF had mildly depressed systolic function, dilatation of coronaries, and worsening of inflammatory markers. As a result, the care team increased the dosing of the methylprednisolone administered to this patient. Since the initiation of methylprednisone, The patient's SBP had been steadily increasing with the latest systolic values approaching 140s-150s.On hospital day 3 patient had a generalized tonic-clonic seizure and became unresponsive for which a rapid response on the floor was called. The patient was emergently bagged and brought to the PICU for airway protection and intubationInitial vitals on PICU admission: He was afebrile, mildly tachycardic, and hypertensive to 160s even after sedation.In the PICU an initial head CT scan done after intubation and stabilization of the patient showed no bleeding or mass. cEEG monitoring was initiated, neurology consulted and an MRI was ordered for the following day. As his AMS was thought to be related to his BP, the team pursued BP control with Nicardipine.To summarize key elements from this case, this patient has:SeizureAltered mental statusHypertensionAcute respiratory failureAll of which brings up a concern for an acute CNS pathology.Absolutely, the differential is broad, however, right now I am thinking of an acute stroke categorized as hemorrhagic, ischemic, or venous thrombotic; a meningoencephalitis, CNS vasculitis, acute demyelinating encephalomyelitis, metabolic encephalopathy, tumor, or AMS related to hypertension.Pradip, let's transition into some history and physical exam components of this case?What are key history features in this child?MIS-C with cardiac dysfunction and coronary anomaliesIncrease in steroid dosageProgressive increase in BP as a result of this increaseRahul, are there some red-flag symptoms or physical exam components which you could highlight?The patient's physical exam was relatively normal. Of note, the fundoscopic exam did not reveal papilledema and no renal bruit was auscultated.His Pupils were equal, round, and reactive to light. The face was symmetric. Normal bulk and tone. The patient was sedated and did not withdraw extremities to noxious stimuli. Tendon reflexes were equal throughout. and no clonus is noted. Fundoscopic exam revealed no papilledema which may rule out increased ICP as a cause for our AMS.To continue with our case, Rahul ,what were the patient’s labs were consistent with:Down trending CRP, ESR, BNP, and troponinECHO is consistent with improved cardiac function as well as improvement of coronary dilatation.CT scan with no bleedMRI suggestive of changes in the posterior brain with distinct edema patternOK to summarize, we have:An eight-year-old, with acute severe hypertension, seizure altered mental status, and MRI changes suggestive of vasogenic edema in the posterior part of the brain -all this brings up the concern for posterior reversible encephalopathy syndrome (PRES) the topic of our discussion today.Rahul ,Let's start with a short multiple-choice question:A 19-year-old with h/o of renal transplant on tacrolimus and recent initiation of steroids for rejection presents with acute severe hypertension and a GTC seizure. The patient is afebrile with no rash. CT scan at OSH reveals no mass or hemorrhage. After stabilization and initiation of antihypertensive therapy, the next study of choice for diagnosis isA) Continuous EEGB) MRIC) Lumbar punctureD) Positron emission test (PET scan) of the brainRahul, the correct answer is B) MRI. Patients such as the one described in the above question are at high risk to develop PRES. MRI will show classic changes associated with PRES- Involvement of the parieto-occipital region of the brain. Vasogenic edema (typically affecting the brain white matter) is characterized by hyperintensity on FLAIR and T2-weighted MRI sequences. As seizure is a presentation of PRES as in our case above, cEEG monitoring especially if intubated is indicated but may not be helpful in diagnosis. An LP also will not help with the diagnosis of PRES and the patient in this question is afebrile. PET scan may have a role in unusual or atypical cases of PRES mainly to distinguish it from the tumor. There is decreased fluorodeoxyglucose (FDG) and Methionine(MET) uptake in most PRES cases compared to tumors such as gliomas or lymphomas.To summarize:The diagnosis of PRES relies on a combination of clinical presentation and neuroimaging. Acute or subacute presentation with encephalopathy, generalized tonic-clonic seizures (60-75% patients), headaches, visual field deficits, cortical blindness, hallucinations, or rarely focal findings such as aphasia or hemiparesis should raise suspicion for PRES. Headache+visual disturbances+generalized tonic-clonic seizures =PRES unless proven otherwise.Rahul, as you think about our case, what would be your differential?Infectious encephalitis (CSF is abnormal, CSF gram stain, CX or PCR)CNS vasculitis (CSF pleocytosis, cytotoxic edema in a non-PRES like pattern)Acute demyelinating encephalomyelitis (ADEM): H/o URI/bacterial infection, fever, usually asymmetric involvement of supratentorial regions on imagingmalignancy or tumor (glioma or lymphoma)-Typically subacute-chronic presentation, h/o malignancy, absence of quick resolution, abnormal CSF or blood workAnother important grouping I would consider is a toxidrome — some of these we mention in our prior podcast episodes so listeners please check them out!Rahul, can you comment on the pathogenesis of PRES**It is hypothesized that when the patient’s mean arterial BP exceeds the upper limits of cerebral autoregulation it leads to hyper-perfusion and the breakdown of the blood-brain barrier allowing interstitial extravasation of plasma and macromolecules and subsequently vasogenic edema. PRES can also develop in patients (15-20%) with normal BP or hypotension, which does not exceed the auto-regulatory capacity of the cerebral blood flow.In these patients, the endothelial dysfunction and breakdown of the blood-brain barrier could be from the cytokines and inflammatory mediators from systemic toxic effects of medications, etc. resulting in vasogenic edema. The posterior regions of the brain are more susceptible to vasogenic edema because little sympathetic innervation...