First Seizure in A Young Adult: Cracking the Viral Encephalitis Code – PLAB 2 Mock Scenario

examiner mla
Jun 15
2 min read

Summary:

This case involves a 21-year-old university student, presenting to the Emergency Department with a first-time seizure, preceded by a mild fever and flu-like symptoms. The scenario highlights the diagnostic evaluation and emergency management of suspected viral encephalitis, particularly HSV encephalitis.

Key Points:

Neurology – Seizure

First-time tonic-clonic seizure lasting 2 minutes.
No incontinence or tongue biting observed.
Post-ictal confusion with anterograde amnesia.
Importance of differentiating true seizure from pseudo-seizure (e.g., incontinence, tongue biting).

Infectious Disease – Encephalitis/Meningitis

Preceding symptoms: Headache, mild fever, flu-like illness, photophobia.
Differentials: Meningitis, encephalitis, epilepsy, substance-induced seizures.
Lack of neck stiffness suggests encephalitis over meningitis.
Risk of rapid progression to meningoencephalitis.

Lifestyle and History

No significant past medical, medication, or allergy history.
Occasional alcohol use; no smoking.
University student with possible unrecognized stressors.

Important Considerations:

Always assess seizure episodes in three phases: before, during, and after.
Consider encephalitis in febrile patients with seizures and photophobia.
HSV is the most common viral cause in this demographic.
Consider early antiviral treatment due to risk of neurological sequelae.

Diagnostic Approach:

Focused History: Seizure characteristics, febrile illness, CNS symptoms (photophobia, neck stiffness).
Focused Examination: General physical, vital signs, full neurological exam.
Investigations:
- Blood tests: FBC, CRP, electrolytes.
- Lumbar puncture (LP): CSF analysis (elevated protein, lymphocytes, normal glucose, HSV PCR).
- Imaging: CT/MRI brain if raised ICP or focal neurology suspected.
- Fundoscopy to assess raised ICP before LP.

Management:

Immediate:
- Admit for observation.
- Start empirical IV Acyclovir for HSV encephalitis.
- Administer IV fluids and antipyretics (e.g., Paracetamol).
- Start antiepileptics (e.g., Levetiracetam) for seizure control.
- Empirical antibiotics until bacterial meningitis is ruled out.
Further:
- Monitor for complications like increased intracranial pressure (ICP) and SIADH.
- Treat raised ICP with osmotic diuretics (e.g., Mannitol) if signs present.
- Monitor electrolytes and 24-hour urine output for SIADH.

Communication Skills:

Empathize with family’s distress, provide clear, calm explanations.
Use simple language to explain medical terminology (e.g., seizure, encephalitis).
Gain informed consent before examinations.
Use structured signposting during history taking.
Avoid overused or unnatural stock phrases.

Ethical Considerations:

Maintain patient dignity and confidentiality.
Ensure implied consent for physical examination.
Do not offer unnecessary referrals or overpromise outcomes.
Act within your competency and escalate if required.

Additional Resources:

GMC Good Medical Practice Guidelines
PLAB 2 Examiner Tips
NICE Guidelines: Encephalitis and acute seizure management