A 6-year-old girl presents with status epilepticus. After initial seizure control with lorazepam and phenytoin, she remains unresponsive. EEG shows continuous spike-and-wave discharges despite clinical seizure cessation. Which investigation is most appropriate to guide further management and identify a potentially reversible cause?

## Management of Refractory Status Epilepticus ### Definition and Diagnostic Challenge **Key Point:** Refractory status epilepticus (RSE) is defined as seizures that persist despite adequate doses of two or more anticonvulsants. The clinical presentation may be misleading—seizures may appear to have stopped (non-convulsive status epilepticus, NCSE) while electrical activity continues on EEG. ### Role of Continuous EEG Monitoring **High-Yield:** Continuous EEG (cEEG) monitoring is the gold standard investigation in refractory/non-convulsive status epilepticus because it: - Detects ongoing electrical seizure activity when clinical signs are absent - Allows real-time assessment of response to medications - Guides escalation to third-line agents (propofol, midazolam infusions) - Identifies burst suppression or other patterns that indicate adequate sedation ### Investigation Strategy in Refractory SE ```mermaid flowchart TD A[Status Epilepticus]:::outcome --> B{Clinical seizures visible?}:::decision B -->|Yes| C[EEG to confirm]:::action B -->|No| D[Suspect NCSE]:::outcome C --> E[Seizures controlled?]:::decision E -->|Yes| F[Discontinue cEEG after 24h]:::action E -->|No| G[Refractory SE]:::urgent D --> H[Start cEEG immediately]:::action G --> I[cEEG + neuroimaging]:::action I --> J[Identify cause: infection, metabolic, structural]:::outcome J --> K[Escalate to ICU agents]:::action ``` ### Simultaneous Neuroimaging in RSE | Investigation | Indication | Yield | |---|---|---| | **Continuous EEG** | Confirm ongoing seizures, guide therapy escalation | Essential — 100% | | **Brain MRI** | Identify structural cause (tumor, malformation, stroke, encephalitis) | High in RSE (40–60%) | | **CT head** | Rule out acute hemorrhage, mass effect | Moderate — if MRI contraindicated | | **Lumbar puncture** | Diagnose CNS infection (encephalitis, meningitis) | High if fever/altered mental status | ### Clinical Pearl **Warning:** Do not assume seizures have stopped based on clinical observation alone. Patients in non-convulsive status epilepticus may appear merely confused or unresponsive. Continuous EEG is the only way to confirm seizure cessation and prevent further brain injury from ongoing electrical activity. ### Timing and Coordination 1. **Immediate:** Start cEEG at bedside while patient is in ICU 2. **Parallel:** Obtain brain MRI (or CT if unstable) to identify structural/metabolic etiologies 3. **Concurrent:** Lumbar puncture if meningitis/encephalitis suspected 4. **Guided by findings:** Escalate pharmacotherapy (propofol, midazolam, ketamine) based on cEEG response [cite:Harrison 21e Ch 369]