The current state of epilepsy guidelines: A systematic review

OBJECTIVE

The International League Against Epilepsy (ILAE) Epilepsy Guidelines Task Force, composed of 14 international members, was established in 2011 to identify, using systematic review methodology, international epilepsy clinical care guidelines, assess their quality, and determine gaps in areas of need of development.

METHODS

A systematic review of the literature (1985-2014) was performed in six electronic databases (e.g. Medline, Embase) using a broad search strategy without initial limits to language or study design. Six gray literature databases (e.g., American Academy of Neurology [AAN], ILAE) were also searched to minimize publication bias. Two independent reviewers screened abstracts, reviewed full text articles, and performed data abstraction. Descriptive statistics and a meta-analysis were generated.

RESULTS

The search identified 10,926 abstracts. Of the 410 articles selected for full text review, 63 met our eligibility criteria for a guideline. Of those included, 54 were in English and 9 were in other languages (French, Spanish, and Italian). Of all guidelines, 29% did not specify the target age groups, 27% were focused on adults, 22% included only children, and 6% specifically addressed issues related to women with epilepsy. Guidelines included in the review were most often aimed at guiding clinical practice for status epilepticus (n = 7), first seizure (n = 6), drug-resistant epilepsy (n = 5), and febrile seizures (n = 4), among others. Most of the guidelines were therapeutic (n = 35) or diagnostic (n = 16) in nature. The quality of the guidelines using a 1-7 point scale (7 = highest) varied and was moderate overall (mean = 4.99 ± 1.05 [SD]).

SIGNIFICANCE

We identified substantial gaps in topics (e.g., epilepsy in the elderly) and there was considerable heterogeneity in methodologic quality. The findings should offer a valuable resource for health professionals caring for people with epilepsy, since they will help guide the prioritization, development, and dissemination of future epilepsy-related guidelines.

Pretreatment EEG in childhood absence epilepsy: associations with attention and treatment outcome

OBJECTIVE

In children with newly diagnosed childhood absence epilepsy (CAE), determine pretreatment EEG features and their associations with baseline neuropsychological function and short-term treatment outcome.

METHODS

In a multicenter, randomized clinical trial, patients with CAE underwent a pretreatment, 1-hour video-EEG and neuropsychological testing with freedom-from-failure and seizure-freedom (SF) outcome assessed at the 16- to 20-week visit.

RESULTS

Detailed evaluation of the pretreatment EEG was possible for 99.8% of participants (445/446). Median time to first seizure was 6.0 minutes (range 0-59 minutes), median number of seizures was 5 (range 1-60), and median seizure duration was 10.8 seconds (range 3.3-77.6 seconds). Median duration of shortest seizure per EEG was 7.5 seconds (range 3.0-77.6 seconds). Seizure frequency was not associated with baseline measures of attention, executive function, or treatment outcome. Presence of a seizure lasting ≥20 seconds was noted in 29% of subjects (129/440); these children had higher median omissions T score on the Conners Continuous Performance Test (56.3 vs 51.6, p = 0.01). Patients with a shortest seizure of longer duration were more likely to demonstrate treatment success by both freedom-from-failure (p = 0.02) and SF (p = 0.005) criteria, even after controlling for age, treatment group, and number of seizures, with good predictive value (area under the curve 78% for SF).

CONCLUSIONS

CAE is reliably and quickly confirmed by EEG. Occurrence of a seizure ≥20 seconds, but not overall seizure frequency, was associated with differential baseline measures of attention. Patients whose shortest pretreatment EEG seizure was longer in duration were more likely to achieve SF, regardless of treatment.

Psychosis after resection of ganglioglioma or DNET: evidence for an association

PURPOSE

David Taylor and Murray Falconer suggested that some patients may develop a psychotic illness after resection of a ganglioglioma that led to intractable seizures. They implied that the mechanism of this association remained unclear. This concept is currently not universally accepted (M. Trimble, personal communication).

METHODS

We studied six children or young adults from four centers who developed psychosis after resection of a ganglioglioma or dysembryoplastic neuroepithelioma (DNET).

RESULTS

All patients were operated on because of intractable epilepsy. The lesions involved mainly the temporal lobe. Patients had good outcomes for seizure control. In none of the six was potentially psychogenic medication used nor were the psychotic symptoms postictal in nature. The psychosis was schizophreniform with paranoid features and prominent depressive symptoms. Although some behavioral abnormalities were described preoperatively, none had been psychotic before operation. This type of psychotic reaction was not encountered in the four centers in a comparable period after resection of other types of lesions. This complication is rare; it occurred in only one of 39 patients who had such a lesion resected.

CONCLUSIONS

Psychotic illness may rarely occur after resection of a ganglioglioma or DNET for treatment of intractable epilepsy. This does not seem to occur after removal of other types of lesions. Because the patients had good outcomes for seizures, the mechanism may be related to "forced normalization." The original observations of Taylor and Falconer are confirmed by this study; the reasons for the selective occurrence, however, remain speculative.

Complications of the ketogenic diet

PURPOSE

The ketogenic diet has been successfully used in treatment of pediatric epilepsy for >70 years. Few serious complications caused by the diet have been reported. We report complications that have been experienced by children receiving the ketogenic diet.

METHODS

In a 22-month period, we treated 52 children with the classic ketogenic diet and monitored them in a prospective manner.

RESULTS

Five children (10%) experienced serious adverse events (AE) after initiation of the diet. Four patients (80%) were treated with valproate (VPA) in addition to the diet, as compared with 25 (53%) of the other 47 children. Two patients developed severe hypoproteinemia within 4 weeks of initiation of the diet, and 1 of them also developed lipemia and hemolytic anemia. A third child developed Fanconi's renal tubular acidosis within 1 month of diet initiation. Two other children manifested marked increases in liver function tests, 1 during the initiation phase and the other 13 months later.

CONCLUSIONS

Clinicians who wish to use the ketogenic diet must be aware of the potential of serious AE and possible interactions of the diet with VPA.

The density of GABAB binding sites in the substantia nigra is greater in rat pups than in adults

Baclofen-displaced [3H]GABA (gamma-aminobutyric acid) binding to GABAB sites was assayed in brain regions obtained from adult and 14- to 17-day-old rats. The substantia nigra of rat pups exhibited a 3- to 5-fold higher density (Bmax) of GABAB binding sites than the nigra of adult rats. In contrast, the density of GABAB sites was lower in hippocampal and cerebellar tissue from pups, both approximately two-thirds the density in corresponding adult structures. This anatomically selective overproduction of GABAB receptors in immature substantia nigra is consistent with the increased anticonvulsant efficacy of the GABAB agonist baclofen observed in rat pups.