Keep it Lyte
At what serum concentration of [NA] can we start to see neurologic sequelae?
What is a ~120–125 mmol/L
This syndrome is typically heralded by recurrent thunderclap headaches, often triggered by exertion or Valsalva maneuvers.
What is reversible cerebral vasoconstriction syndrome (RCVS)?
This condition, common in ICU patients, is characterized by acute brain dysfunction and is worsened by benzodiazepines and deep sedation.
What is delirium (ICU-associated delirium)?
This laboratory abnormality, often markedly elevated after episodes of muscle breakdown, is a key clue to metabolic myopathies.
What is elevated creatine kinase (CK)?
This classic physical exam maneuver, in which a child uses their hands to “climb up” their thighs to stand, is a hallmark of Duchenne muscular dystrophy.
What is Gowers sign?
In this electrolyte disorder, neurologic manifestations are uncommon unless serum levels fall below ~2 mmol/L, and symptoms primarily involve progressive proximal muscle weakness.
What is hypokalemia?
This imaging finding—typically symmetric, posterior-predominant, and subcortical—is the hallmark of posterior reversible encephalopathy syndrome.
What is vasogenic edema?
This encephalopathy, seen in sepsis, is associated with impaired cerebral autoregulation in up to 60% of patients and may show diffuse slowing or triphasic waves on EEG.
What is sepsis-associated/metabolic encephalopathy?
In this glycogen storage disease, deficiency of myophosphorylase leads to early fatigue, cramps, and myoglobinuria with exertion.
What is McArdle disease (GSD type V)?
This laboratory test is the best initial screening study in boys with motor delay, calf hypertrophy, and proximal weakness.
What is a creatine kinase (CK) level?
This neurologic complication classically follows correction of severe hyponatremia and often presents days later with dysarthria, dysphagia, and quadriparesis.
What is central pontine myelinolysis (osmotic demyelination syndrome)?
In this syndrome, despite often severe intracranial arterial narrowing, initial brain parenchymal imaging is frequently normal.
What is RCVS?
This specific neuromuscular complication of critical illness shows a sensorimotor axonal pattern on nerve conduction studies with low amplitudes but relatively preserved conduction velocities.
What is critical illness polyneuropathy?
This symptom, characterized by dark urine following exercise, reflects muscle breakdown and is a common presenting feature of metabolic myopathies.
What is myoglobinuria?
This genetic principle predicts disease severity in dystrophinopathies, where out-of-frame mutations typically result in severe disease and in-frame mutations produce milder phenotypes.
What is the reading-frame rule?
This syndrome, often misattributed to uremia in renal failure patients, is characterized by seizures, visual disturbances, and posterior white matter changes on MRI due to hypertension.
What is posterior reversible encephalopathy syndrome (PRES)?
This shared pathophysiologic mechanism—combining abnormal cerebrovascular tone and endothelial dysfunction—is thought to underlie both PRES and RCVS.
What is cerebrovascular dysregulation?
This frequently underrecognized ICU complication affects up to 60–80% of mechanically ventilated patients and contributes to prolonged ventilation through impaired transdiaphragmatic pressure generation.
What is critical illness–associated diaphragm weakness?
In this metabolic pathway defect, patients may have normal strength at rest but develop symptoms during prolonged, low-intensity exercise such as fasting or endurance activity.
What are fatty acid oxidation disorders?
In this group of patients, cardiac involvement may precede skeletal muscle weakness and therefore requires routine surveillance even in minimally symptomatic individuals.
Who are patients with Becker muscular dystrophy and female carriers of dystrophin mutations?
This rare dialysis-related neurologic condition is thought to result from a reverse urea effect, where osmotic gradients persist because urea clears more slowly from the brain than from the blood.
What is dialysis disequilibrium syndrome?
This clinical-imaging dissociation describes the phenomenon in which thunderclap headaches resolve before angiographic vasoconstriction normalizes, often taking weeks to months.
What is the temporal dissociation between clinical recovery and angiographic resolution in RCVS?
This ICU-acquired condition is characterized by selective loss of thick (myosin) filaments, leading to profound weakness with relatively preserved sensory function.
What is critical illness myopathy?
This inheritance pattern, unique to many mitochondrial myopathies, results in transmission exclusively through affected mothers.
What is maternal (mitochondrial) inheritance?
This complication, a leading cause of mortality in dystrophinopathies, results from progressive myocardial fibrosis and often requires routine echocardiographic or cardiac MRI surveillance.
What is dilated cardiomyopathy?