HPI:A 58 y/o female with Hx diabetes, hyperlipidemia, and HTN brought into the ED by EMS after being found down at home.

• Per EMS, patient collapsed with ?shaking activity
• Noted to have recently been started on oxcarbazepine (Trileptal) for unknown reasons.

 Physical Exam

• BP 220/107 | Pulse 97 | Resp 16 | SpO2 98%
• Neuro: Alert. Moves all extremities. +language barrier

Differential Diagnosis:

• CVA / ICH 
• arrhythmia
• seizure
• Tox/metabolic

Initial Orders:

• Monitor, PIV access, continuous ECG monitoring Accu check
• Labs: CBC, BMP, hsTrop, ECG, CT head non-contrast

Further history from son:

• Pt found unconscious on the floor with her arms and legs tense and her tongue retracted into her mouth.

Workup results and clinical course:

• Presumptive diagnosis: seizure possibly from noncompliance with oxcarbazepine
• CT non-contrast head: acute subdural hematoma BMP: Na 118

Management:

• Nicardepene gtt for BP management
• IV Keppra load
• Hypertonic saline bolus
• Admitted to trauma ICU with neurosurgery and nephrology consulted
• Required intubation for depressed mental status and eventually discharged with trach.
• Required hypertonic saline infusion to achieve normonatremia.

Further history:

• Pt had been started on oxcarbazepine for mood disorder and had no history of seizures
• Oxcarbazepine was stopped in setting of outpatient labs demonstrating hyponatremia. 

Teaching Points:

• Hyponatremia should be on the ddx for seizure/encephalopathy
• Oxcarbazepine may cause hyponatremia in 1-10% of patients
• Do not anchor on epilepsy as cause of seizures!