🧠 Parkinson Hyperpyrexia Syndrome (PHS) is a rare, life-threatening emergency seen in Parkinson’s disease. It often follows the abrupt withdrawal or reduction of dopaminergic drugs (💊 levodopa) or occurs during intercurrent illness, surgery, or trauma. ⚡ Pathophysiology: sudden dopamine deficiency → severe motor decompensation + autonomic failure, similar to neuroleptic malignant syndrome (NMS).

🔥 Key Clinical Features

🌡️ Hyperpyrexia: Fever >38°C, rapid onset.
⚡ Severe Rigidity: Worse than baseline Parkinsonism.
💓 Autonomic Dysfunction: Sweating, tachycardia, unstable BP, dehydration.
🧩 Neuro Features: Confusion, delirium, dysphagia, stupor → coma in severe cases.
🩸 Rhabdomyolysis & AKI: Risk of renal failure from myoglobinuria.

⚠️ Common Triggers

❌ Sudden withdrawal of levodopa or dopamine agonists.
🤒 Intercurrent infection (pneumonia, UTI).
🩺 Post-surgery or trauma.
Dehydration, metabolic stress, or hospitalisation without correct drug administration.

🧪 Investigations

📈 ↑ Creatine kinase (muscle breakdown).
🧪 Abnormal renal & liver function, high WCC.
💧 Electrolyte imbalance: hypernatraemia, AKI.
Rule out sepsis with cultures & CXR.

🔍 Differential Diagnosis

NMS: Antipsychotic drug exposure.
Sepsis: Infection as cause of fever/confusion.
Malignant Hyperthermia: Triggered by anaesthesia.
Heat Stroke: Environmental exposure.

🚨 Complications

Acute kidney injury (rhabdomyolysis).
Aspiration pneumonia, respiratory failure.
Sepsis, DIC, thromboembolism.
⚰️ Death if untreated.

💊 Management

Restart Dopaminergic Therapy: Resume levodopa/agonist at full dose. - NG tube if not swallowing. - Rotigotine patch (2–4 mg/24h) or SC Apomorphine (1–2 mg/hr) if needed.
Fluids & Electrolytes: IV fluids to prevent AKI.
Temperature Control: Cooling blankets, antipyretics.
ICU Care: Ventilation or haemodialysis in severe cases.
Muscle Relaxants: Dantrolene (10 mg/kg/day) if rigidity severe.
Palliation: Consider in advanced/end-stage PD after a trial of active therapy.

💡 Exam Tip: - PHS vs NMS: PHS = Parkinson’s patient + sudden levodopa withdrawal. NMS = antipsychotic use. - Always check the patient’s medication history in acute confusion/fever with rigidity. - ⚠️ Hospitals sometimes miss Parkinson’s drug timings → can precipitate PHS!

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Parkinson Hyperpyrexia Syndrome