CEN — Emergency Nursing
CEN Neurologic Emergencies Review
Neurologic emergencies in the ED are about time and recognition: the stroke with a closing treatment window, the seizure that won't stop, the headache that's a bleed, the altered patient whose cause you must systematically uncover. The CEN tests rapid stroke pathways, status epilepticus management, the structured approach to altered mentation, and the can't-miss diagnoses (subarachnoid hemorrhage, meningitis, increased ICP).
This guide reviews high-yield emergency neurology with CEN-style questions and rationales. Educational review only — stroke protocols, treatment windows, and medications follow your department's policies and current guidelines; verify before applying.
Stroke and seizures
Stroke: the ED job is fast recognition (a validated stroke scale — facial droop, arm drift, speech, plus gaze/neglect), last-known-well time custody (it, not symptom-discovery time, starts the treatment clock — a wake-up stroke's clock starts at bedtime), an immediate glucose check (hypoglycemia mimics stroke), NPO/aspiration precautions until swallow-screened, expedited imaging, and blood-pressure management that diverges by type (ischemic strokes often tolerate higher pressures before thrombolysis with strict ceilings after; hemorrhagic strokes need tighter control). Thrombolysis and thrombectomy windows make minutes matter — the stroke pathway is a choreography the CEN expects you to know.
Status epilepticus is a true emergency: prolonged or repeated seizures without recovery injure neurons and cause systemic harm (hyperthermia, rhabdomyolysis, acidosis, airway compromise). Management is time-driven — protect the airway and oxygenate, position safely (nothing in the mouth), benzodiazepines first-line, then a second-line antiepileptic per protocol, check glucose and sodium and a pregnancy test (eclampsia), and escalate for refractory cases. For first-time seizures and the postictal patient, the workup hunts causes (metabolic, structural, infectious, toxic, withdrawal) while protecting the airway.
Altered mentation and the can't-miss diagnoses
The altered-mentation approach is systematic so nothing reversible is missed — a common framework is AEIOU-TIPS: Alcohol, Epilepsy/Electrolytes/Encephalopathy, Insulin (glucose — check it on everyone), Opiates/Overdose, Uremia, Trauma/Temperature, Infection, Psychiatric, Stroke/Shock/Space-occupying lesion. The first moves are universal: airway/breathing/circulation, glucose, oxygen, and consideration of naloxone/thiamine where indicated, then a structured workup. Don't anchor on 'intoxication' or 'psych' — those are diagnoses of exclusion in the ED.
Can't-miss diagnoses: subarachnoid hemorrhage (sudden 'worst headache of my life,' possibly with neck stiffness — high-risk even if improving); bacterial meningitis (fever, headache, neck stiffness, altered mentation, possibly petechial/purpuric rash — time-critical antibiotics, and don't let the LP delay them; droplet precautions); increased ICP/herniation (declining consciousness, a blown pupil, Cushing's triad — head elevation/midline, airway, and emergent management); and spinal emergencies (cord compression). The neuro throughline for the ED: pin the timeline, check the sugar, support the airway, recognize the dangerous headache, and never let a 'reassuring' transient improvement downgrade a high-risk presentation.
Practice questions with answers & rationales
Q1. A patient woke with right-sided weakness and slurred speech; she was normal when she went to bed at 10 p.m. What time starts the treatment clock?
Answer: 10 p.m. — the last-known-well time, not when she discovered the symptoms on waking. Treatment eligibility for thrombolysis/thrombectomy is calculated from the last moment she was verifiably normal, so a wake-up stroke's clock starts at bedtime. Establishing and documenting an accurate last-known-well time (with witnesses) is among the highest-value things the ED nurse does, because it determines access to time-critical therapy.
Q2. Why is a glucose check among the very first steps in any stroke or altered-mentation presentation?
Answer: Because hypoglycemia is a common, immediately reversible mimic of stroke and altered mentation — correcting it can resolve the deficit entirely, while missing it both delays the right treatment and risks harm. It's fast, cheap, and changes the differential, which is why 'check the glucose' is a near-universal early step and a frequent correct CEN answer in neuro scenarios.
Q3. A patient has been seizing for several minutes without regaining consciousness. What are the priorities?
Answer: Status epilepticus: protect the airway and oxygenate, position safely (don't force anything into the mouth), give first-line benzodiazepines promptly, follow with a second-line antiepileptic per protocol, check glucose and sodium (reversible causes), consider eclampsia in pregnancy, and escalate to anesthetic agents if refractory. Time is the enemy — ongoing seizures injure the brain and cause systemic complications, so rapid, stepwise treatment is the tested approach.
Q4. How does blood-pressure management differ between ischemic and hemorrhagic stroke in the ED?
Answer: Ischemic stroke often tolerates (or even benefits from) higher blood pressure before thrombolysis to perfuse the penumbra, with strict ceilings after thrombolytics and bleeding vigilance. Hemorrhagic stroke generally requires tighter blood-pressure control to limit hematoma expansion, plus anticoagulation reversal. Applying the wrong approach — aggressively lowering an ischemic stroke's pressure or permitting permissive hypertension in a bleed — can worsen outcomes, which is exactly what the exam probes.
Q5. A patient presents with sudden 'worst headache of my life,' now somewhat improved, with mild neck stiffness. What's the concern and the triage implication?
Answer: Subarachnoid hemorrhage — a thunderclap, sudden-onset headache (a sentinel bleed) is high-risk even if currently improving, because catastrophic rebleeding can follow. This warrants high acuity and expedited evaluation (imaging, and possibly LP if imaging is non-diagnostic), and the transient improvement does not lower the risk. The lesson: certain headaches are dangerous by description, and reassurance from improvement is a trap.
Q6. Why shouldn't antibiotics wait for the lumbar puncture in suspected bacterial meningitis?
Answer: Bacterial meningitis is rapidly lethal, and delays in antibiotics worsen outcomes — so empiric antibiotics (and steroids per protocol) should be given promptly, without waiting for the LP if it would significantly delay treatment (cultures may still guide later therapy). Add droplet precautions and supportive care. The time-critical principle — treat first, confirm second — and infection-control precautions are the tested points.
Q7. A head-injured patient shows a declining level of consciousness, a fixed dilated pupil, and bradycardia with hypertension. What is happening and what are the priorities?
Answer: Herniation from increased ICP with a Cushing response — an emergency. Priorities: secure the airway and oxygenate (hypoxia worsens brain injury), elevate the head of bed and keep it midline to optimize venous drainage, ensure ventilation at a normal rate (brief hyperventilation only per protocol for active herniation), provide osmotherapy per protocol, and mobilize emergent neurosurgical care. Recognizing the triad and acting on the secondary-injury-prevention basics is the tested priority.
Common mistakes to avoid
- Using symptom-discovery time instead of last-known-well to start the stroke clock.
- Skipping the glucose check in stroke and altered-mentation presentations.
- Delaying status epilepticus treatment or failing to escalate through the medication steps.
- Applying the wrong blood-pressure strategy for the stroke type (ischemic vs hemorrhagic).
- Downgrading a thunderclap headache because it 'improved,' or missing the SAH/meningitis patterns.
- Letting the LP delay antibiotics in suspected bacterial meningitis.