Repeated Successful Crisis Intervention of Mitochondrial (POLG1) Epileptic Encephalopathy with High-Dose I.V. Magnesium Therapy

Background: The most common nuclear-coded mitochondrial diseases are due to mutations in the polymerase gamma (POLG) gene. POLG1-associated epilepsy (often characterized by an occipital zone of origin of seizures) is characterized by intermittent critical exacerbations, which often result in a non-convulsive status epilepticus and are mostly refractory to treatment. At the functional level, it is unclear whether the exacerbation is primarily due to epileptic neuronal overactivity or primarily to a disturbed energy metabolism.

Methods: We report on the clinical course (over 3 years) of a now 20-year-old female patient with a compound heterozygous mutation in the POLG1 gene. The patient initially suffered multiple stroke-like episodes. Clinically, intermittent neurological crises with increasing visual disturbance (homonymous hemianopia), accompanied by progressive dizziness and pronounced ataxia, culminating in a full picture of epileptic encephalopathy with non-convulsive status epilepticus. Different anticonvulsive and metabolically frustrating therapeutic attempts are described. However, the use of high-dose intravenous magnesium therapy was able to break through such crises successfully and quickly. As shown in the chronological overview graphic and verifiable with EEG documentation derived before and afterwards, the Mg-IV intervention therapy was able to repeatedly demonstrate its effectiveness in the patient.

Conclusion: Epileptic seizures often occur as a consequence of mitochondrial disease, such as the POLG1 mutation. Crisis of epileptic encephalopathies with therapy-refractory status epilepticus-often life-limiting is feared. We have repeatedly been able to prove that such a neurometabolic crisis was successfully resolved by means of high-dose IV mg infusion in our patient. This knowledge may also be transferable to other patients with mitochondrial related epilepsies, and thus useful as an effective emergency medication.

Publication History

Article published online:
28 October 2021