Use of the ketogenic diet in an adult with myoclonic status epilepticus

Abstract

Status epilepticus (SE) is difficult to treat, with significant morbidity and mortality1. The failure of multiple antiepileptic drugs (AEDs) prompts clinicians to consider alternative therapeutic treatment options. The ketogenic diet (KD) is a high fat, low carbohydrate (CHO) and adequate protein diet which is well documented to reduce seizures in children with refractory epilepsy2. There is emerging evidence to support the use of the KD in adults1. The KD is believed to work by triggering biochemical changes in the brain’s signalling system3. Metabolic changes likely related to the KD’s anticonvulsant properties include ketosis, reduced glucose, elevated fatty acid levels, and enhanced bioenergetic reserves3. This case study reports improvement in seizure control, in the absence of sedation, after initiation of the KD in an adult with refractory myoclonic SE following a hypoxic-ischaemic brain injury. Two weeks following injury, a previously fit and healthy middle-aged male, developed myoclonic status epilepticus which was clear clinically and on EEG. The patient was sedated with midazolam and propofol, ventilated and fed via a naso-gastric tube, which was substituted with a percutaneous endoscopic gastrostomy (PEG). The highest level of sedation resulted in 960kcals/day provided via propofol infusion. Seizure suppression was achieved initially using propofol, midazolam and thiopentone, and later a number of less sedating AEDs including, at different times, lorazepam, clonazepam, levetiracetam, phenytoin, topiramate, phenobarbitone and valproic acid. High-dose midazolam, propofol and thiopentone controlled clinical and electrographic myoclonic seizure activity and induced burst suppression on EEG. However, when the dose of these sedating AEDs was reduced, frequent clinical and EEG seizures occurred and were often stimulus provoked. The KD commenced on day 36 via the PEG with a feeding mixture of Ketocal 4:1, Protifar, Liquigen, Calogen and Maxijul which provided 93g CHO/day. There were no episodes of hypoglycaemia or acidosis, but the production of ketones was inadequate, and therefore the feeding regime was altered to further reduce the CHO content (final regime provided 4.5g/day) and increase the MCT content (Ketocal, Protifar and Liquigen were used for the final feeding regime). Once adequate ketosis was achieved, indicated by blood ketone levels between 1.3-3.2mmol/L, it became possible to tail and stop midazolam, propofol and thiopentone, and achieve adequate, though not complete, myoclonic seizure control without significant sedation using piracetam, levetiracetam, clonazepam and phenobarbitone in doses to achieve normal trough serum levels, following which awareness was regained. A trial to reintroduce CHO, once seizure management was sustained, was implemented on day 113. Maxijul was introduced gradually in increments of 20g every three days but was stopped at day 5, after the addition of a total of 45g CHO, as seizure activity increased to the extent that propofol was reintroduced. Reintroduction of the KD resulted in reduced seizure activity, and made it possible again to stop the propofol, and continue with non-sedating AEDs. Further CHO challenges were not trialled due to the apparent success of the KD. This case illustrates that should AED management fail to adequately control myoclonic SE, the KD should be considered with the goal of reducing seizure frequency and the use of sedating AEDs. 1. Cervebka M, Hartman A, Geocadin R & Kossoff E (2011) Neurocritical Care Society 15:519-524 2. Neal EG, Chaffe H, Schwartz RH, Lawson MS, Edwards N, Fitzsimmons G, Whitney A, Cross JH. (2008) Lancet Neurol 7:500506. 3. Masino S, Rho J (2012) Jaspers Basic Mechanisms of the Epilepsies 4:2-28