Acute porphyria presenting as epilepsia partialis continua

Abstract

Purpose: The porphyrias are a defect in the biosynthesis of heme which can be associated with different neurological symptoms during acute attacks such as peripheral neuropathy, mental disturbance and seizures. So far, there have only been a few case reports of status epilepticus, none of which were of epilepsia partialis continua (EPC). We present here two cases of hereditary coproporphyria (HCP) manifesting EPC as part of the clinical presentation.

Method: The patients' medical charts, EEG and imaging studies were carefully reviewed.

Results: Case 1 is a 49-year-old male who first presented a tonic-clonic seizure. Case 2 is a 30-year-old male who came to the emergency room for a convulsive status epilepticus. Both evolved to EPC over the next days. EPC persisted despite several antiepileptic drug trials. Diagnosis of HCP was confirmed by a high level of urine, fecal and serum porphyrins in both cases and by genetic testing in one. Over the last 3 years, the first patient has continued to present non-disabling EPC and has had four tonic-clonic seizures associated with alcohol consumption. The second patient died from brain edema one month and half after admission.

Conclusion: Acute porphyrias should be included in the differential diagnosis of new onset status epilepticus, including EPC. Their recognition is important as it modifies significantly patient management, since many anticonvulsants are porphyrogenic.

Keywords: Acute porphyria; Epilepsia partialis continua; Status epilepticus.

Fig. 1

FLAIR sequence showing hyperintensity over both mesial temporal structures (a), with mild incomplete regression after 2 years (b).

Fig. 2

a EEG with left frontotemporal periodic lateralized epileptiform discharges. b Left frontotemporal periodic discharges evolving into rhythmic slow activity discharge most prominent over the left frontotemporal region (HFF = 35 Hz; LFF = 1 Hz).

Fig. 3

FLAIR image showing right hemispheric gyriform hyperintense signal changes.

Fig. 4

EEG showing diffuse slowing activity, right frontal subtle/blunted periodic lateralized epileptiform discharges and left-sided muscle artifacts due to left facial jerks.