Adjunctive lacosamide treatment for adult focal-onset epilepsy: focus on comorbid intellectual/developmental disorders and differing responses.

BACKGROUND: Data regarding lacosamide treatment as an adjunctive therapy in patients representative of a focal-onset epilepsy population including those with and without intellectual/developmental disorders (IDDs) are limited. PURPOSE: To evaluate the retention rates of lacosamide in focal-onset epilepsy patients with and without IDD. PATIENTS AND METHODS: We retrospectively reviewed all consecutive electronic and paper medical records of patients diagnosed with focal-onset epilepsy who were treated with lacosamide in two tertiary epilepsy centers. RESULTS: One hundred and thirty-six patients who met the inclusion criteria were studied. Number of patients with IDD was 46 (33.8%). Median lacosamide dose was 300 mg/day. A total of 39 patients (28.7%) experienced side effects, and 22 of them (16.2%) discontinued lacosamide. The 1-, 2-, and 3-year retention rates of lacosamide in patients with IDD were 68%, 62%, and 53%, respectively. Kaplan-Meier survival analysis showed that the retention rates were significantly lower in patients with IDD when compared to patients without IDD (P=0.04). Cox regression analysis showed that concomitant use of sodium channel blocker antiepileptic drugs (AEDs) was the only independent predictor of retention rate of lacosamide treatment (P=0.03). In the subgroup of patients with IDD, the analysis was performed again and the number of background AEDs was the only predictor for the retention rate of lacosamide (P=0.04). CONCLUSION: When compared to patients without IDD, retention rates of lacosamide adjunctive therapy were lower in patients with IDD. However, these rates were higher than the rates suggested with previously registered AEDs including lamotrigine, levetiracetam, and topiramate. Therefore, irrespective of having comorbid IDD, we might suggest that lacosamide is a well-retained drug with a high efficacy profile in patients with focal-onset epilepsy.

Efficacy, tolerability, and retention rates of zonisamide in older adult patients with focal-onset epilepsy: Experiences from two tertiary epilepsy centers.

OBJECTIVE: The objective of this study was to evaluate the efficacy, tolerability, and retention rates for zonisamide (ZNS) in older adult patients with focal-onset epilepsy. PATIENTS AND METHODS: Chart reviews of patients aged 60years and older with focal-onset epilepsy treated with ZNS in two tertiary epilepsy centers were analyzed retrospectively. RESULTS: Eighty-five patients (41 males, 44 females) aged over 60years (range: 60-81) with focal-onset epilepsy treated with ZNS were identified; 55.3% of the patients (n=47) were on monotherapy. The median and average doses of ZNS doses were 200mg/day (range: 100-400) and 212.9±84.2mg/day, respectively. With ZNS treatment, 67.1% of the patients (n=57) were seizure-free for a median of 28months (range: 10-56) whereas 20% (n=17) of the patients had seizures that were unresponsive to ZNS treatment. Best seizure control was achieved in patients with poststroke epilepsy; seizure freedom was 80% in this subgroup. Overall retention rate was found to be 83.5%. There was no significant relation between receiving poly- or monotherapy and discontinuation of ZNS (p=0.18). Thirty-two of the patients (37.6%) lost weight. Median weight loss was 8kg (range: 2-16). There was no significant correlation between weight loss and the administered doses of ZNS (r=0.34; p=0.12). CONCLUSION: Despite limitations due to the retrospective design of the study, the results show that ZNS is a well-retained drug with high efficacy in older adult patients with epilepsy.

Clinical utility of serum lactate levels for differential diagnosis of generalized tonic-clonic seizures from psychogenic nonepileptic seizures and syncope.

BACKGROUND: The differential diagnosis of generalized tonic-clonic seizures (GTCS), psychogenic nonepileptic seizures (PNES), and syncope constitutes a major challenge. Misdiagnosis rates up to 20 to 30% are reported in the literature. PURPOSE: To assess the clinical utility of serum lactate levels for differentiation of GTCS, PNES, and syncope based on gender differences. METHODS: Data from 270 patients were evaluated retrospectively. Only patients ≥18 years old with the final diagnosis of GTCS, PNES, or syncope in their chart were recruited. Serum lactate levels were measured in the first 2h of the index event. RESULTS: Serum lactate levels in patients with GTCS (n=157) were significantly higher than in the patients with PNES (n=25) (p<0.001) and syncope (n=88) (p<0.001). When compared with the females, serum lactate levels in patients with GTCS were significantly higher in the male subgroup (p=0.004). In male patients the ROC analysis yielded a serum lactate value of 2.43mmol/l with a sensitivity of 0.85 and a specificity of 0.88 as the optimal cut-off value to distinguish GTCS from other events. The ROC analysis for the AUC yielded a high estimate of 0.94 (95% confidence interval: 0.91-0.98). When a cut-off value of 2.43mmol/l was chosen for the females, which was an optimal value for male patients, the specificity was 0.85, however, the sensitivity was 0.64. CONCLUSION: We propose that serum lactate level when measured in the first 2h after the index event has a high clinical utility in the differential diagnosis of GTCS, PNES, and syncope. With concomitant clinical signs and physical examination findings besides neuroimaging and EEG, elevated levels of lactate should be taken into account when evaluating a patient with impaired consciousness. On the other hand, the suggested cut-off value 2.43mmol/l might not have a discriminative effect between GTCS, PNES, and syncope in female patients. This finding should be verified in a prospectively designed study with a larger patient population.