[Paraneoplastic syndrome presenting as epilepsia partialis continua].

Area of Science:

• Neurology
• Oncology

Background:

• Epilepsia partialis continua (EPC) is a rare focal epilepsy characterized by continuous focal seizures.
• The differential diagnosis for prolonged focal seizures can be challenging, especially in the absence of a clear underlying cause.

Observation:

• A 59-year-old male smoker presented with new-onset EPC, initially suspected as hemiballismus or brachial myoclonus.
• Initial investigations, including paraclinical examinations, did not reveal a neoplastic cause.
• A cerebral MRI after 5 months identified a left cavum neoplasm, and a subsequent head and neck MRI confirmed a left rhinopharyngeal neoplasm with metastatic disease.

Findings:

• The rhinopharyngeal neoplasm was the underlying cause of the patient's EPC.
• Cerebral metastases secondary to bronchopulmonary cancer with mediastinal invasion were identified.
• Crucially, the EPC preceded the diagnosis of the primary neoplastic process by one year.

Implications:

• This case highlights the importance of considering occult malignancies in patients presenting with new-onset focal epilepsy, even with initial negative workups.
• The diagnostic delay underscores the need for thorough and potentially repeated investigations in complex neurological presentations.
• Understanding the temporal relationship between neurological symptoms and cancer development is critical for accurate diagnosis and management.