Wassim Nasreddine

Valproate-induced thrombocytopenia : A prospective monotherapy study

Purpose: The frequency of valproate (VPA)‐induced thrombocytopenia varied widely in previous studies, due to methodological differences. Our objective was to evaluate the relationship between trough VPA plasma levels and platelet counts and assess risk factors for the development of thrombocytopenia.

Conversion to high dose gabapentin monotherapy in patients with medically refractory partial epilepsy.

Summary: Purpose: To evaluate the safety and efficacy of high dose gabapentin (GBP) monotherapy (3,0004,800 mg/ day) in patients with medically refractory partial epilepsy.

Oxcarbazepine in neuropathic pain

Neuropathic pain is a frequent condition that can result from a variety of underlying conditions and is frequently chronic and difficult to treat. A number of drugs are used to treat neuropathic pain, including anticonvulsants and antidepressants. Oxcarbazepine, a recently introduced antiepileptic drug, was found to possess antineuralgic properties in animal models of neuropathic pain. Several double-blind, placebo-controlled trials have evaluated oxcarbazepine in painful diabetic neuropathy and trigeminal neuralgia. There is good evidence that oxcarbazepine is effective in relieving the pain associated with trigeminal neuralgia. Its efficacy in treating painful diabetic neuropathy is less clear; however, it seems to be useful when tolerated at doses of 1800 mg/day.

Predictive value of early EEG after epilepsy surgery.

To determine whether EEG performed within few months after epilepsy surgery is predictive of seizure outcome, 58 consecutive patients undergoing surgery for presumptive temporal lobe epilepsy (TLE) who had clinical follow-up of at least 2 years and EEG data available both pre- and postoperatively were analyzed. Patients were classified by preoperative brain magnetic resonance imaging into lesional, cryptogenic, and hippocampal sclerosis groups. Seizure outcome was classified according to Engels outcome scale. Comparison was made between the presence of interictal epileptiform discharges (IEDs) in the postoperative EEG and seizure outcome. Patients who experienced seizures within 2 months after surgery were considered to have early recurrence. The mean follow-up period was 3 years. Sixty percent of patients achieved a class I seizure outcome. Almost all (95%) postoperative EEGs were obtained within 4 months after surgery. IEDs were present in 26% of postoperative EEGs, but were significantly less frequent in EEGs recorded after the first two postoperative months (P = 0.011). The presence of IEDs on postoperative EEGs was not predictive of seizure outcome either in the whole cohort or in any of the subgroups, regardless of whether it was performed within or after the first two postoperative months. It was also not predictive of outcome in the 44 patients (76%) who did not suffer early recurrence. The authors conclude that EEG performed a few months after epilepsy surgery is not useful as a predictor of long-term seizure outcome.

Responses to photic stimulation in patients with occipital spikes

OBJECTIVE To determine the effect of intermittent photic stimulation (IPS) and frequency of asymmetric driving responses in patients with occipital spikes. METHODS The amplitude of the driving response at 4 flash frequencies was measured from a referential montage in 60 patients with occipital spikes and in 60 normal EEG records from age-matched patients. Responses were classified as asymmetric if the amplitude at one occipital area was less than 50% of the amplitude at the other. RESULTS A measurable photic response occurred significantly less frequently in patients with occipital spikes (48%) compared to the control group (70%; Fishers test P < 0.05). The driving response was asymmetric in 7/36 patients (37%) with unilateral spike foci versus none in the control group (Fishers test, P < 0.001). The amplitude was suppressed ipsilateral to the focus in 5 patients, all of whom had an ipsilateral structural lesion or focal slowing. In two cases the amplitude was higher ipsilateral to the focus, neither having slowing or a structural lesion. CONCLUSIONS Patients with occipital spikes have an increased frequency of asymmetric driving response. An attenuated response ipsilateral to the focus seems to be related to an underlying lesion while the presence of an epileptiform focus in some cases with no slowing on EEG and normal imaging studies may lead to an accentuation of this response.

Effects of divalproex sodium on hemoglobin level.

A small number of molecular and clinical studies found an association between increases in fetal hemoglobin concentration and valproate (VPA) use. However, the effect of VPA on total hemoglobin (Hb) level has not been studied. We herein review a randomized, double-blind, parallel group, multicenter, concentration-response design trial that compared the safety and efficacy of target trough plasma VPA concentrations in patients with complex partial seizures treated with divalproex sodium as monotherapy. Trough VPA concentrations and concomitant Hb levels that were drawn at baseline and intermittently throughout a 24-week period were analyzed. A total of 549 trough plasma VPA levels and concomitant total Hb levels were analyzed. Correlation between all study variables (gender, age, trough plasma VPA level, duration of exposure, baseline Hb level) and change in total Hb level showed that only baseline Hb level was a significant factor (inverse relationship). Hb increase was evident in 47.0% of values. A clinically relevant increase in Hb (>0.5 g/dL) occurred in 23.9% of values. VPA is associated with a change in total Hb level that correlates inversely with baseline Hb levels.

Astasia-abasia and psychogenic tremor post-temporal lobectomy.

Temporal lobectomy can be complicated by somatoform disorders, psychiatric illnesses and non-epileptic psychogenic seizures. We report a woman who developed astasia-abasia and psychogenic tremor following temporal lobectomy for refractory epilepsy. To our knowledge, this type of conversion reaction following temporal lobectomy has not been previously reported.

Covert brain ischaemia in splenectomised adults with thalassemia intermedia: An emerging entity

Covert brain ischaemia in splenectomised adults with thalassemia intermedia: An emerging entity -

Efficacy and tolerability of treatment with lacosamide: Postmarketing experience from the Middle East region

PURPOSE Lacosamide (LCM) was recently introduced in the Middle East. The aim of this study was to evaluate the safety, tolerability, and efficacy of LCM in patients with focal onset seizures and determine if our results are comparable with those derived from Western countries. METHODS This is a retrospective analysis from two medical centers on consecutive patients diagnosed as having focal onset seizures and treated with add-on LCM. The primary efficacy variables were the 50% responder and seizure-free rates, and the secondary outcome variables included the percentages of patients who achieved seizure remission during the last 6-month follow-up period and the percentages of discontinuation due to lack of efficacy or tolerability. RESULTS One hundred four patients with a mean age of 30.9 years and experiencing a mean of 9.4 seizures per month during baseline were included. The 50% responder rates were 69% and 70% at 6- and 24-month follow-ups, respectively. Patients concomitantly treated with a sodium channel blocker were less likely to achieve seizure remission during the last 6-month follow-up period while the early introduction of LCM resulted in a significantly higher likelihood of achieving such a remission. Eighty-eight percent of patients were still maintained on LCM at the last follow-up, and the most common adverse events consisted of dizziness and somnolence, double vision, and nausea/vomiting. CONCLUSIONS Our data show similar efficacy and tolerability to those reported from Western countries. Our results also substantiate the early introduction of LCM and support the dose reduction of baseline AED especially that of sodium channel blockers to minimize adverse events.