3-year-Old with Cough and Leg Weakness

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, A Three-Year-Old with recent cough and leg weakness.Here's the case presented by Rahul.A 3-year-old previously healthy female presented to the hospital with a 2-week history of productive cough and congestion and the new 1-day onset of bilateral weakness. Today, the mother noticed weakness and inability to stand/walk following after shower as well as her voice becoming hoarse. She also noticed her lying more limp sitting on her lap, unable to sit up fully without her mother supporting her. She had no trouble holding up her head. The mother endorses increased fussiness but is able to be consoled. Decreased p/o intake, last meal was yesterday. About 1-2 weeks prior to this patient also had non-bloody diarrhea that resolved spontaneously after a few days.UOP normal with 2-3 wet diapers. No difficulty breathing. No history of head trauma or trauma to lower extremities, no erythema/swelling to joints. No pain associated with leg movement. No previous difficulty with walking - developing normally otherwise. No fever, recent travel, H/O sick contact at home (sibling with URI). No allergies, immunization UTD. CMP largely unremarkable. CBC with leukocytosis to 19.72 with L shift and platelets of 647. CRP 0.3, ESR 12.Afebrile, RR 24/min, HR 130, BP 140/86.On PE: Patient was coughing, had a hoarse voice heart and lung exam was normal. Normal abdominal exam. No rashNeurological exam: PERRL, (A+O) X3, 3-4/5 strength at ankles and knees and 5/5 in arms, +UE DTR's but none at patella or ankles. Has a wide-based ataxic gait and needs to hold on to the wall/furniture to ambulate.Rahul, to summarize key elements from this case, this patient has:A cough with a hoarse voiceNo feverInability to stand/walk (i.e. lower extremity weakness) with no DTRs in patellae or ankleNormal mental statusDiarrhea (non-bloody) preceding neurological weaknessAll of these bring up a concern for Guillain-Barré syndrome-An immune-mediated disease possibly triggered by a recent infection and targeting the peripheral nervous system.Let's transition into some history and physical exam components of this case?What are key history features in this 3-year-old childAcute (B) leg weaknessCough with hoarseDiarrheal illnessNo fever, no /o rash or traumaPradip, Are there some red-flag symptoms or physical exam components which you could highlight?Bilateral lower leg weakness with absent patellar and AJ DTRsNormal mental statusNo rash, traumaRahul continues with our case, the patient's initial labs and imaging were consistent with:The CMP, CBC with differential, and blood gas were unremarkableESR = 12, CRP 0.29, pro-cal 0.09(all normal)Normal CPKNormal Urine analysisA lumbar puncture revealed colorless CSF with 4 white cells, 0 reds, Glucose 73 (serum Glucose 90) and protein 94, Gram stain and culture-negativeMRI of the brain and lumbar spine with and without contrast was completely normalChest radiograph with no infiltrate or atelectasisNerve conduction studies were not performedAny patient with acute ascending lower extremity flaccid paralysis with CSF showing acellular protein predominance should be considered to have Guillain-Barré syndrome unless proven otherwise. MRI brain spine is necessary to rule out any other etiologies such as brain tumor or spinal pathologies. Features strongly supporting the diagnosis of Guillain-Barré syndrome include a progression of onset over several days to less than 4 weeks, symmetrical involvement, painful onset, mild/absent sensory symptoms, cranial nerve involvement, autonomic dysfunction, absence of fever, and recovery 2 to 4 weeks after the onset of peak or plateauing of symptoms.Rahul Let's start with a short multiple-choice question:A five-year-old girl with acute ascending bilateral lower limb weakness, normal MRI, CSF with acellular protein predominance would require immediate airway management in case the girl hasA) A chest radiograph with large atelectasisB) A Maximum inspiratory force of -40cm H20C) A vital capacity of > 25cc/kgD) A strong coughRahul, the correct answer is A. Chest radiograph with large atelectasis, which suggests upper airway compromise and weakness of pharyngeal and laryngeal muscles leading to difficulty in the clearing of secretions and airway maintenance and resulting in aspiration. A maximum inspiratory force of less negative than -30cm H20 is a risk for respiratory arrest (i.e. more sub-atmospheric the better), a maximum inspiratory force of -40 is actually good (> 60% predicted). The answer C is wrong because its a vital capacity of < 20mL/kg that puts a patient at risk for respiratory failure. D) A strong cough is not an indication for intubation or suggestive of impending respiratory failure but hoarseness or a weak cough is. Remember trends are more important than a single value. In infants: inability to lift their head when supine, bulbar symptoms, tachypnea, increasing O2 requirement, and use of accessory muscles of respiration implies impending respiratory failure. Remember hypercarbia is a late finding of impending respiratory arrest. PFT measurement in GB syndrome is remembered as the 20/30/40 rule: A vital capacity < 20ml/kg, a maximum inspiratory pressure less negative than -30cm H2O, or maximum expiratory pressure of ≤ 40cm H2O. Serial measurements are required.Rahul, what is the pathogenesis of Guillain-Barré Syndrome?The exact pathogenesis is unknown. An immune trigger such as infection, vaccine, etc affects peripheral nerve components due to molecular mimicry. A gastrointestinal or upper respiratory tract illness within 4 weeks of presentation triggers the onset of Guillain-Barré Syndrome. Possible viral agents include cytomegalovirus (detected in 26%), Epstein-Barr virus, influenza, and human immunodeficiency virus, and bacterial triggers include *Mycoplasma*, *Haemophilus*, and, most commonly, *Campylobacter jejuni*, which accounts for 20% to 30% of US and European cases. Although rare, vaccination (influenza), surgery, trauma, transplant, lymphoma, and systemic lupus erythematosus have also been associated with GBS. Recently GBS after exposure to Zika virus has been described with most patients having a complete recovery.As you think about our case, what would be your differential for Guillain-Barré syndrome and neuromuscular weakness in general?Encephalopathy....