A 32-year-old woman on combined oral contraceptive pills (35 µg ethinyl estradiol + norethisterone) for 2 years presents with sudden-onset severe unilateral headache with photophobia and neck stiffness. She denies any recent trauma or fever. Blood pressure is 140/90 mmHg. On neurological examination, she has positive Kernig's and Brudzinski's signs. What is the most appropriate immediate next step in management?

Explanation

## Clinical Context This patient presents with **classic meningitis signs** (severe headache, photophobia, neck stiffness, positive Kernig's and Brudzinski's signs) in the setting of **OCP use**. The elevated blood pressure and acute neurological findings suggest a **serious CNS event** rather than simple migraine. ## Critical Assessment **Key Point:** The combination of **meningeal signs + OCP use** raises concern for: 1. **Meningitis** (infectious or aseptic). 2. **Cerebral venous sinus thrombosis (CVST)** — a rare but serious thrombotic complication of combined OCPs. 3. **Subarachnoid hemorrhage** — though less likely given the clinical presentation. **Warning:** This is a **medical emergency**. The presence of meningeal signs mandates immediate investigation to rule out life-threatening CNS pathology. ## Management Algorithm ```mermaid flowchart TD A[Severe headache + meningeal signs + OCP use]:::outcome --> B{Acute CNS emergency?}:::decision B -->|Yes| C[Discontinue OCP immediately]:::action C --> D[Urgent neuroimaging<br/>and/or lumbar puncture]:::action D --> E{Diagnosis confirmed?}:::decision E -->|Meningitis/CVST| F[Treat underlying condition<br/>Switch to non-hormonal contraception]:::action E -->|Migraine/other| G[Reassess OCP safety<br/>Consider alternative]:::action ``` ## Why Discontinue OCP Immediately? 1. **CVST risk:** Combined OCPs increase the risk of thrombotic events, including CVST, especially in the presence of other risk factors (age, smoking, thrombophilia). 2. **Ongoing risk:** Continuing the OCP while a serious CNS event is being ruled out is dangerous and may worsen the condition. 3. **Standard of care:** In any acute neurological emergency, hormonal contraceptives should be discontinued pending investigation. **High-Yield:** OCPs containing **30–35 µg ethinyl estradiol** carry a **3–4 fold increased risk of VTE** compared to non-users. The risk is further elevated in the presence of: - Migraine with aura (increased stroke risk). - Smoking (especially age > 35). - Thrombophilia. - Immobility or recent surgery. ## Investigations Needed 1. **Urgent CT head** (non-contrast) — rule out hemorrhage, mass, or signs of CVST. 2. **Lumbar puncture** — if CT is normal or shows CVST, LP can confirm meningitis (CSF analysis: cell count, glucose, protein, culture, PCR). 3. **MR venography** — if CVST is suspected. **Clinical Pearl:** Aseptic meningitis can occur as a complication of OCP use or as an independent infection. The key is to **rule out serious pathology** before reassessing the role of the OCP. ## Follow-up Contraception Once the acute condition is treated: - If **meningitis or CVST is confirmed:** Switch to a **non-hormonal method** (copper IUD, barrier methods, sterilization) or **progestin-only pill** (lower thrombotic risk). - If **migraine is confirmed:** OCPs are **contraindicated if migraine has aura** (increased stroke risk); switch to non-hormonal methods. - If **no serious pathology is found:** Reassess OCP safety based on risk factors; consider lower-dose formulations or alternative methods. [cite:Park 26e Ch 10; Harrison 21e Ch 391]