[Hypokalemia in Lennox-Gastaut syndrome]. / Ipopotassiemia in sindrome di Lennox-Gastaut.

The Lennox-Gastaut Syndrome (LGS) is a childhood epileptic encephalopathy. Incidence: 1/1.000.000/year, prevalence: 15/100.000. LGS covers 5-10% of epileptic patients and 1-2% of childhood epilepsies. Also referred to as cryptogenic or symptomatic generalized epilepsy. LGS is characterized by: multiple seizures (atypical absences, axial tonic seizures and sudden atonic or myoclonic falls), diffuse slow cryptic EEG waves when awake (<3 Hz), fast rhythmic peaks (10 Hz) during sleep, mental retardation and personality disorders. The LGS is not responding to treatment. Some new drugs have proven to be effective in controlling the disease (Felbamate, Lamotrigine, Topiramate, Levetiracetam). The mortality rate is about 5%; only rarely death is due to epilepsy, which is usually caused by stroke or epileptic episodes. Here we describe the case of a 45-year-old female patient with LGS, severe hypokalemia, mental retardation and focal seizures. Normal renal function: creatinine 0.9 mg/dl, urea 26 mg/dl, creatinine clearance 96 ml/min, serum potassium levels to the minimum: 3.5 mEq/L. This level of potassium, however, had been achieved with the assumption of 8 oral tablets/day of potassium chloride. Osmotic diuresis, use of diuretics, Bartter, Gitelman (normal urinary calcium and magnesium) and pseudo-Bartter syndromes were all excluded whereas aldosteronism was found. Our findings lead to hypokalemia related to assumption of topiramate and hyperaldosteronism. Reduction in drug intake was not effective due to the increased seizures, so the drug was maintained, along with potassium supplementation. In conclusion, the patient has been diagnosed with hypokalemia and iatrogenic hyperaldosteronism, rare in our outpatient practice.

Perceived efficacy of cannabidiol-enriched cannabis extracts for treatment of pediatric epilepsy: A potential role for infantile spasms and Lennox-Gastaut syndrome.

There is a great need for safe and effective therapies for treatment of infantile spasms (IS) and Lennox-Gastaut syndrome (LGS). Based on anecdotal reports and limited experience in an open-label trial, cannabidiol (CBD) has received tremendous attention as a potential treatment for pediatric epilepsy, especially Dravet syndrome. However, there is scant evidence of specific utility for treatment of IS and LGS. We sought to document the experiences of children with IS and/or LGS who have been treated with CBD-enriched cannabis preparations. We conducted a brief online survey of parents who administered CBD-enriched cannabis preparations for the treatment of their children's epilepsy. We specifically recruited parents of children with IS and LGS and focused on perceived efficacy, dosage, and tolerability. Survey respondents included 117 parents of children with epilepsy (including 53 with IS or LGS) who had administered CBD products to their children. Perceived efficacy and tolerability were similar across etiologic subgroups. Eighty-five percent of all parents reported a reduction in seizure frequency, and 14% reported complete seizure freedom. Epilepsy was characterized as highly refractory with median latency from epilepsy onset to CBD initiation of five years, during which the patient's seizures failed to improve after a median of eight antiseizure medication trials. The median duration and the median dosage of CBD exposure were 6.8 months and 4.3mg/kg/day, respectively. Reported side effects were far less common during CBD exposure, with the exception of increased appetite (30%). A high proportion of respondents reported improvement in sleep (53%), alertness (71%), and mood (63%) during CBD therapy. Although this study suggests a potential role for CBD in the treatment of refractory childhood epilepsy including IS and LGS, it does not represent compelling evidence of efficacy or safety. From a methodological standpoint, this study is extraordinarily vulnerable to participation bias and limited by lack of blinded outcome ascertainment. Appropriately controlled clinical trials are essential to establish efficacy and safety.