When Should a Brain MRI Be Performed in Children with New-Onset Seizures? Results of a Large Prospective Trial.

BACKGROUND AND PURPOSE: There is a paucity of data regarding the incidence of structural brain lesions in children with new-onset unprovoked seizures. Our aim was to determine the frequencies and types of epileptogenic lesions detected on a dedicated epilepsy protocol MR imaging according to age group, the presence of developmental delay, and the number and types of seizures. MATERIALS AND METHODS: Consecutive children between 6 months and 18 years of age with new-onset unprovoked seizures were included. The frequencies and types of epileptogenic lesions were determined and then stratified according to sex, age groups, the presence of developmental delay, and the number and types of seizures at presentation. Multivariate analysis was used to identify variables significantly associated with the presence of epileptogenic lesions. RESULTS: One thousand children were included. An epileptogenic lesion was identified in 26%, with malformations of cortical development being the most common lesion (32%), followed by hypoxic-ischemic injury (20%) and vascular etiologies (16%). Univariate analysis showed a significant increase in the frequency of epileptogenic lesions with decreasing age, the presence of developmental delay, and the number and types of seizures at presentation. The presence of developmental delay and seizure type at presentation remained significant in a multivariate analysis. CONCLUSIONS: We documented a relatively high rate of epileptogenic lesions in children with new-onset seizures, with the presence of developmental delay and specific seizure types being associated with a higher likelihood of detecting an epileptogenic lesion on neuroimaging. This study fulfills the requirements of the study design recommended by the Practice Committee of the American Academy of Neurology, and we hope that our results will assist the relevant societies and committees in formulating neuroimaging guidelines for children with new-onset seizures.

Asymptomatic brain magnetic resonance imaging abnormalities in splenectomized adults with thalassemia intermedia.

BACKGROUND: A high incidence of thrombotic events in thalassemia intermedia (TI) patients led to the identification of a hypercoagulable state. Brain involvement has not been widely studied in TI, although limited reports confirm a low incidence of overt stroke and high incidence of silent brain infarcts. PATIENTS/METHODS: This was a prospective study conducted on 30 adult, splenectomized TI patients. Patients were screened for absence of neurological signs or symptoms, and stroke-related risk factors. Patient charts were reviewed for demographics, duration since splenectomy, and any history of transfusion therapy. Blood samples were obtained for complete blood counts and serum ferritin. Direct determination of liver iron concentration (LIC) was performed by R2 magnetic resonance imaging (MRI). Brain MRI was performed on all patients, looking for ischemic lesions and/or atrophy. RESULTS: The mean age of patients was 32.1 +/- 11 years (range, 18-54 years), with a male to female ratio of 13:17. Eighteen patients (60%) had evidence of one or more white matter lesions (WMLs) on brain MRI, all involving the subcortical white matter. Fourteen patients had evidence of multiple WMLs, with a mean of 5 +/- 10 lesions (range, 2 to > 40 lesions). The vast majority of patients (94%) had small (< 0.5 cm) to medium (0.5-1.5 cm) WMLs, with only one patient showing evidence of a large (> 1.5 cm) WML. Eleven patients (37%) had mild cerebral atrophy. On multivariate analysis only age and transfusion history were independently and significantly associated with the occurrence of zero, single or multiple WMLs. CONCLUSION: WMLs and brain atrophy are a common finding in adult, splenectomized, TI patients. Increasing age and transfusion naivety are associated with a higher incidence and multiplicity of lesions.

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%; Fisher's test P < 0.05). The driving response was asymmetric in 7/36 patients (37%) with unilateral spike foci versus none in the control group (Fisher's 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.

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

PURPOSE: To evaluate the safety and efficacy of high dose gabapentin (GBP) monotherapy (3,000-4,800 mg/day) in patients with medically refractory partial epilepsy. METHODS: GBP monotherapy at daily doses up to 4,800 mg was attempted in patients participating in the open-label phase of a double-blind, dose-controlled, GBP monotherapy trial. For those who achieved monotherapy, the types and severity of adverse events were assessed and the average seizure frequency per 28 days while maintained on the highest daily GBP dose was compared to the seizure frequency during the baseline phase of the double blind trial. Correlation analysis between GBP serum level, total daily dose, and percentage of seizure change from baseline was performed. RESULTS: A total of 45 patients participated in the open-label phase of the trial and 23 (51%) were converted successfully to GBP monotherapy. In those patients, the average daily gabapentin dose was 3,900 mg and the mean length of follow-up was 252 days. Compared to baseline, there was a mean reduction of 54%, 43%, and 14% for simple partial, complex partial and secondarily generalized seizures respectively, while maintained on high-dose GBP monotherapy. A significant linear correlation between daily GBP dosage (2,400-4,800 mg) and resultant mean serum levels was found (r = 0.51; p < 0.01). There was no significant correlation between seizure frequency and total daily GBP dose or with serum levels. High-dose GBP monotherapy was well tolerated; only one patient exited the trial because of adverse events. The most common adverse event was tiredness/sleepiness and was not dose-related. CONCLUSIONS: GBP monotherapy is well tolerated in daily doses of up to 4,800 mg and is effective in a subgroup of patients with medically refractory partial epilepsy.