Neurology & Psychiatric Emergencies

Acute Ischemic Stroke Management Algorithm

Time is brain. Step 3 focuses on eligibility criteria, blood pressure thresholds, and mechanical intervention windows:

flowchart TD
    Onset["Acute Focal Neurological Deficit (Last Known Normal documented)"] --> CT["Stat Non-Contrast Head CT within 20 Minutes"]

    CT --> Hemorrhage{"Intracranial Hemorrhage?"}
    Hemorrhage -- Yes --> NeuroSurg["ICH Protocol: Reverse Anticoagulation + Lower SBP < 140 mmHg + Emergent Neurosurgery"]
    Hemorrhage -- No --> Ischemia["Ischemic Stroke Confirmed"]

    Ischemia --> TimeWindow{"Time from Last Known Normal?"}

    TimeWindow -- "< 4.5 Hours" --> CheckBP{"BP < 185/110 mmHg and No Contraindications?"}
    CheckBP -- Yes --> tPA["Administer IV Thrombolysis (Alteplase / Tenecteplase)\nMaintain BP < 180/105 mmHg for 24 hours"]
    CheckBP -- "No (BP too high)" --> Labetalol["IV Labetalol / Nicardipine to SBP < 185 mmHg -> Give Thrombolytic"]

    TimeWindow -- "< 24 Hours with LVO" --> CTA["CTA Head/Neck: Large Vessel Occlusion (ICA or MCA M1)?"]
    tPA --> CTA
    CTA -- LVO Present --> EVT["Endovascular Mechanical Thrombectomy (EVT) within 24 Hours"]
    CTA -- No LVO --> Medical["Permissive Hypertension (Up to 220/120 mmHg if no tPA) + Antiplatelet Therapy"]

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Status Epilepticus Step-Wise Treatment Protocol

Continuous seizure activity ≥ 5 minutes, or ≥ 2 discrete seizures without complete return to consciousness between episodes:

Phase	Time Elapsed	First-Line Interventions	USMLE Step 3 Notes
Phase 1: Emergent Control	0 – 5 minutes	Assess ABCs, high-flow O₂, check fingerstick glucose. If hypoglycemic: Give IV Thiamine 100 mg BEFORE 50% Dextrose.	Never give glucose before thiamine in malnourished/alcoholic patients (prevents acute Wernicke encephalopathy).
Phase 2: First-Line Benzodiazepine	5 – 20 minutes	IV Lorazepam 4 mg (repeat once in 5–10 min). If no IV access: IM Midazolam 10 mg or Rectal Diazepam 10–20 mg.	Benzodiazepines are the only proven first-line agents to terminate active firing.
Phase 3: Second-Line Antiepileptic	20 – 40 minutes	IV Levetiracetam (Keppra) 60 mg/kg (max 4500 mg), OR IV Fosphenytoin 20 mg PE/kg, OR IV Sodium Valproate 40 mg/kg.	Administer even if seizures stop after benzodiazepine to prevent recurrence.
Phase 4: Refractory Status Epilepticus	> 40 minutes	Intubate patient. Continuous IV infusion of Propofol, Midazolam, or Ketamine. Transfer to ICU with Continuous Video EEG Monitoring.	Continuous EEG is mandatory to confirm electrographic cessation.

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Neuroleptic Malignant Syndrome vs Serotonin Syndrome

Key Differential Contrast

Neuroleptic Malignant Syndrome (NMS) vs Serotonin Syndrome

Clinical Feature	Neuroleptic Malignant Syndrome (NMS)	Serotonin Syndrome	Discriminating Clue
Triggering Pharmacologic Agent	Dopamine D2 antagonists (Haloperidol, Fluphenazine, Metoclopramide) or abrupt withdrawal of Dopamine agonists (Levodopa)	Serotonergic agents (SSRIs, SNRIs, MAOIs, TCAs, Tramadol, Meperidine, Linezolid, MDMA, St. John's Wort)	Check medication list for dopamine vs serotonin agent
Onset of Symptoms	Insidious onset developing over 1 to 3 days to weeks	Rapid onset developing within 6 to 24 hours of drug exposure or dose escalation	Serotonin syndrome is hyperacute; NMS is subacute
Neuromuscular Tone & Reflexes	'Lead-pipe' generalized rigidity, hyporeflexia, bradykinesia	Hyperreflexia, spontaneous / inducible clonus, ocular clonus, tremor	Clonus and hyperreflexia point to Serotonin Syndrome; Lead-pipe rigidity points to NMS
Pupils & Gastrointestinal Signs	Normal pupils, normal bowel sounds	Mydriasis (dilated pupils), hyperactive bowel sounds, diarrhea	Mydriasis and hyperactive bowels favor Serotonin Syndrome
Targeted Pharmacotherapy	Stop offending antipsychotic; give Dantrolene (ryanodine receptor blocker) or Bromocriptine (dopamine agonist)	Stop serotonergic drug; give Cyproheptadine (5-HT2A antagonist) + IV Benzodiazepines	Dantrolene for NMS; Cyproheptadine for Serotonin Syndrome