Biomedical subjects

M A Mikati

Publications and source records attributed to M A Mikati.

At least 19 recordsLinked to original sources

PubMed2006

Two randomized vitamin D trials in ambulatory patients on anticonvulsants: impact on bone.

OBJECTIVE: To investigate the effects of two doses of vitamin D given over 1 year on bone density in ambulatory patients on long-term antiepileptic drug (AED) therapy. METHODS: We conducted two parallel, randomized, controlled trials in 72 adults (18 to 54 years old) and 78 children and adolescents (10 to 18 years) on long-term AED therapy. They received either low-dose vitamin D 400 IU/day or high-dose vitamin D 4,000 IU/day (adults) and 2,000 IU/day (children/adolescents). Bone mineral density (BMD) was measured using dual-energy x-ray absorptiometry. RESULTS: In adults, baseline BMD was lower than that of age- and gender-matched controls vs either a Western or an ethnically identical population. After 1 year, there were significant increases in BMD at all skeletal sites compared to baseline in the high-, but not in the low-dose treatment group. However, BMD at 1 year remained below normal. In children, baseline BMD was normal vs age- and gender-matched controls and showed significant and comparable increases in both treatment groups. CONCLUSIONS: In ambulatory adults on antiepileptic drugs, high-dose vitamin D therapy substantially increased bone mineral density at several skeletal sites. In children, both doses resulted in comparable increases in bone mass.

Adolescent↗

PubMed2006

Exacerbation of vocal tics after temporal lobectomy.

We describe a woman with intractable temporal lobe epilepsy secondary to dysgenesis of the left temporal lobe who had a marked and long-term exacerbation of her preexisting vocal tics after a temporal lobectomy that completely controlled her seizures. The patient was determined to have right-sided speech dominance by the Wada test. This is, to our knowledge, only the second reported case of exacerbation of tics after resection of the nondominant temporal lobe.

Adult↗

PubMed2002

Effect of antiepileptic drugs on bone density in ambulatory patients.

BACKGROUND: Long-term antiepileptic drug (AED) use causes multiple abnormalities in calcium and bone metabolism that have been most extensively described in institutionalized patients. The objective is to determine the effect of AED on vitamin D levels and bone density in ambulatory patients and to compare the effects of enzyme-inducing and -noninducing AED and of single vs multiple therapy on bone density. METHODS: A cross-sectional evaluation was conducted of 71 patients (42 adults and 29 children/adolescents) on anticonvulsant therapy for at least 6 months who presented to neurologists at a tertiary referral center. Bone mineral density (BMD) as well as serum 25 hydroxy-vitamin D (25-OHD) levels were measured. A detailed questionnaire assessing calcium intake as well as previous and current intake of antiepileptic medications was administered to all patients. RESULTS: Over 50% of adults and children/adolescents had low 25-OHD levels, but this finding did not correlate with BMD. Antiepileptic therapy decreased BMD in adults. Generalized seizures, duration of epilepsy, and polypharmacy were significant determinants of BMD, more so at skeletal sites enriched in cortical bone. Subjects on enzyme-inducing drugs such as phenytoin, phenobarbital, carbamazepine, and primidone tended to have lower BMD than those on noninducers such as valproic acid, lamotrigine, clonazepam, gabapentin, topamirate, and ethosuximide. CONCLUSION: Epilepsy and its therapy, including the newer drugs, are risk factors for low bone density, irrespective of vitamin D levels. Skeletal monitoring with the institution of appropriate therapy is indicated in patients on chronic antiepileptic therapy.

Adolescent↗

PubMed2001

Anticonvulsant action and long-term effects of gabapentin in the immature brain.

The anticonvulsant action and the long-term effects on learning, memory and behavior of the new generation antiepileptic drug gabapentin (GBP) were investigated in immature animals. Kainic acid (KA) was administered to rats on postnatal day (P) 35. Animals were treated with GBP or saline from P36 to P75 and spontaneous seizure frequency was monitored. After tapering the drug, the rats were tested in the water maze and open field test. Brains were then analyzed for histological lesions. Animals treated with GBP following KA-induced status epilepticus had a reduced incidence of spontaneous recurrent seizures, a better pathology score, and less aggressiveness compared to saline-treated controls. Effectiveness of GBP on seizure threshold was tested using flurothyl inhalation in 10 separate age groups of animals ranging from the newborn period to adulthood. Furthermore, GBP plasma concentration peaks were determined in all age groups. At all ages, GBP pre-treated animals demonstrated a higher seizure threshold. Plasma GBP concentrations did not significantly change with age. These data suggest that acute administration of a single therapeutic dose of GBP increases the seizure threshold at all ages studied, while chronic treatment following the status reduces spontaneous seizure frequency and cell damage and has no long-term adverse consequences on cognitive processes during development.

Acetates↗

PubMed2001

Classification of epilepsy syndromes and role of genetic factors.

In this report the types of epilepsy syndromes seen in children in a tertiary referral center in Beirut, Lebanon were studied and the importance of consanguinity and family history in the occurrence of these syndromes was investigated. Records of 230 pediatric patients evaluated during a 1-year period with the diagnosis of single seizure, febrile seizure, or epilepsy were reviewed. Each patient was classified according to the International League Against Epilepsy classification. The occurrence of consanguinity, of family history of febrile seizures or epilepsy, and of other variables was noted. Thirty-six percent of patients were diagnosed with localization-related epilepsy, 21.7% with generalized epilepsy, 11.7% with undetermined generalized or focal, and 24.3% with special syndromes. Twelve percent of patients were diagnosed with idiopathic, 15.1% with symptomatic, and 30.3% with cryptogenic epilepsies. Consanguinity was more common in patients with symptomatic and cryptogenic epilepsies than in patients with idiopathic epilepsies or with incidental seizures (P < 0.05). Family history of epilepsy was more common in patients with symptomatic, cryptogenic, and idiopathic epilepsies than in patients with incidental seizures (P < 0.05). Family history of febrile seizures but not consanguinity was more common in patients with febrile seizures (P < 0.05). We conclude that genetic factors are important not only in idiopathic epilepsies and febrile seizures but also in cryptogenic and symptomatic epilepsies.

Adolescent↗

PubMed2001

Isolated adipic aciduria.

Adipic acid can appear, in combination with other dicarboxylic acids, in the urine of patients in a number of underlying metabolic diseases. A child with seizures and mental retardation of unknown etiology who was found to have elevated isolated adipic aciduria on investigation for metabolic diseases is reported. A dietary artifact was suspected, and the adipic aciduria resolved after the child was kept on a specific restricted diet for 3 days. This is the third report of isolated adipic aciduria secondary to food. Findings confirm the previous reports of dietary origin of isolated adipic aciduria and should alert clinicians to such artifact before committing patients to unnecessary treatments.

Adipates↗

PubMed2001

Time sequence and types of memory deficits after experimental status epilepticus.

P35 rats subjected to kainate induced status epilepticus (SE) subsequently underwent four consecutive series of the Morris Water Maze. They demonstrated, compared with controls, an early (P46-49), and subsequent (P60-63) disturbance in acquisition, but not in long term retention, of spatial memory. They eventually achieved performance levels similar to those of controls (P74-77, P91-94). These data support the hypothesis that acquisition, but not long term retention, of spatial material is impaired in this model of temporal lobe epilepsy (TLE), probably due to the hippocampal injury that occurs after SE.

Animals↗

PubMed2000

Alternating hemiplegia of childhood: clinical manifestations and long-term outcome.

We present our analysis of 44 patients with alternating hemiplegia of childhood. The clinical course usually consisted of three phases. The first was dominated by abnormal eye movements and dystonic episodes, the second by hemiplegic spells and psychomotor regression, and the third by persistent developmental delay and fixed neurologic deficits. The age of onset was 0-54 months (mean = 7.9 +/- 13 months). The presenting signs included abnormal ocular movements in 65%, dystonia in 60%, and hemiplegia in 32%. Patients with an early onset of the disorder and an early appearance of hemiplegic spells faired the poorest developmentally. Developmental delay was present in 91%, ataxia in 68%, choreoathetosis in 50%, and seizures in 18%. Laboratory investigations suggested mitochondrial abnormalities and cerebrovascular dysfunction in several patients. Numerous therapies were largely ineffective. Flunarizine reduced the duration, severity, and frequency of the hemiplegic attacks in 78%. Patients who received flunarizine did not differ developmentally from those who did not. Our data suggest that flunarizine does not adversely affect and may favorably influence the outcome in patients with alternating hemiplegia of childhood. Additionally, the occurrence of autosomal-dominant cases of the syndrome, although rare, suggests that, in addition to mitochondrial dysfunction, genetic factors may be important.

Adolescent↗

PubMed2000

Successful use of intravenous immunoglobulin as initial monotherapy in Landau-Kleffner syndrome.

PURPOSE: There is a need for new and more effective therapies for Landau-Kleffner syndrome. In this article we present the first case in which a patient with Landau-Kleffner syndrome was given intravenous immunoglobulin (IVIG) as his first and only therapy and responded to it. METHODS: This previously healthy, left-handed boy presented at 31 months of age with a 3-month history of auditory agnosia, behavioral abnormalities, and progressive, eventually complete loss of speech. Electroencephalography (EEG) showed frequent and, in sleep, continuous right central and temporal spike slow wave discharges. Metabolic workup, magnetic resonance imaging, and auditory evoked potentials were normal. Cerebrospinal fluid IgG index was high (18%). The patient was treated with IVIG, as his initial and only therapy, receiving 500 mg/kg/day over four consecutive days. RESULTS: On the third day of IVIG, the patient started using single words, and on the fourth, two-word sentences. Two weeks later his speech and behavior returned to normal. At the end of 4 days of IVIG therapy, EEG was within normal limits. Two months later, however, he had a severe relapse clinically and by EEG. He promptly responded to another course of IVIG. A subsequent cerebrospinal fluid IgG index showed normalization (6%). Three months later he had essentially normal speech and behavior. CONCLUSIONS: Repeated, immediate, and remarkable clinical and EEG responses of this patient suggest that IVIG was helpful as first-line therapy in the treatment of Landau-Kleffner syndrome. It also supports the hypothesis that immunological mechanisms contributed to his symptoms.

Cerebral Cortex↗

PubMed1999

Consequences of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor blockade during status epilepticus in the developing brain.

To investigate if AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor activation contributes to acute manifestations and long term consequences of status epilepticus (SE), we administered the AMPA receptor antagonist NBQX to P35 rats undergoing kainic acid (KA)-induced SE. NBQX (30 mg/kg/dose) given intraperitoneally (i.p.) at 30, 60 and 90 min after i.p. KA injection (12 mg/kg) reduced severity of SE. When tested as adults, rats that had received KA and NBQX were similar to controls with no long term impairment in visuospatial memory (assessed by the water maze test), or histologic damage in the CA1 or CA3 hippocampal subfields. However, both P35 groups, those receiving KA alone and those receiving KA and NBQX, had similar rates of spontaneous recurrent seizures (SRS). In P15 rats, NBQX resulted in increased acute mortality from KA associated SE. These results indicate that the effects of NBQX on KA-induced SE are age dependent, and that non-NMDA receptor activation contributes to the acute manifestations and to the long term sequelae seen after KA-induced SE in the prepubescent rat brain.

Animals↗

PubMed1999

Unusual presentation of Kearns-Sayre syndrome in early childhood.

Congenital glaucoma and insulin-dependent diabetes mellitus were the predominant presenting signs in a patient with Kearns-Sayre syndrome. Thereafter, he developed short stature, pigmentary retinopathy, progressive external ophthalmoplegia, and ataxia. The diagnosis was confirmed by detecting a deletion of mitochondrial DNA in muscle, thus demonstrating that Kearns-Sayre syndrome can have the unusual presenting signs described above.

Adolescent↗

PubMed1998

Electroencephalographic discharges of temporal lobe seizures in children and young adults.

We investigated the discharge morphology and propagation patterns of electroencephalographic seizures of temporal lobe onset in 21 children and young adults who underwent invasive long-term EEG monitoring (LTM). Of those, 15 subsequently underwent anterior temporal lobectomy. The onset was focal in 63%. The most frequent discharge morphology was low amplitude beta (30%) or rhythmic/semirhythmic theta discharge (30%). Thirteen patients displayed several sequences of propagation with different spreading stages along a fixed path. Initial spreading to the ipsilateral frontal lobe was associated with a higher frequency of secondary generalization than initial spreading to the contralateral temporal lobe (P = 0.18). A comparison of 13 patients older than 18 years of age with 8 patients younger than 14 years showed a trend towards a lower rate of propagating from the temporal lobe (P = 0.13) in the younger age group. Discharge morphology was not correlated with age, focality, or outcome of surgery.

Adolescent↗

PubMed1998

Gabapentin in the treatment of refractory partial epilepsy in children with intellectual disability.

Twenty-six children with intellectual disability and six normal children, all suffering from refractory partial seizures, received open-label gabapentin (range = 10-50 mg kg(-1) day(-1); mean = 26.7 mg kg(-1) day(-1) as an add-on medication to their antiepileptic drug regimen. Mean seizure frequency during baseline was 9.5 seizures per week. Both groups had a significant reduction in seizure frequency. Response scores and response ratios did not differ between the intellectually disabled and normal groups (1.67+/-0.67 and 1.25+/-0.69, P = 0.697, and -0.400+/-0.089 and -0.283+/-0.159, P = 0.961, respectively). Behavioural side-effects were more likely to occur in patients with intellectual disability in comparison with the mentally normal group (P = 0.0107). In the present patient population, patients younger than 10 years of age, all of whom had intellectual disability, were more likely to have side-effects than those older than 10 years of age. Observed adverse effects, which were generally mild, occurred in patients with baseline intellectual disability, attention deficit disorder and behavioural problems. Behavioural adverse effects warranted discontinuation of the medication in only three patients. The severity of intellectual disability (mild versus moderate or severe) did not affect the extent of the response or the occurrence of side-effects. It is concluded that gabapentin is equally effective as an add-on medication against partial seizures in patients with or without intellectual disability. However, children with intellectual disability who also are less than 10 years of age with baseline attention deficit appear to be at a higher risk of behavioural side-effects.

Acetates↗

PubMed1997

Focal brain dysfunction in a 41-year old man with familial alternating hemiplegia.

The acute pathophysiologic changes during hemiplegic spells and the long-term outcome of alternating hemiplegia remain obscure. In a 41-year-old male with familial alternating hemiplegia we found an increase in right frontal cerebral blood flow 3 h into a 5-h left hemiplegic episode. A repeat high-resolution brain SPECT study performed 26 h after the resolution of the left hemiplegia revealed normalization of the frontal blood flow accompanied by hyperperfusion in the right parietal lobe. An interictal SPECT scan several weeks later showed no asymmetries. Head CT and MRI scans were negative. Neuropsychologic assessment and neurologic examination revealed evidence of a diffuse disorder which predominantly involved the right hemisphere. To our knowledge, there are no previous correlative studies of serial high-resolution brain SPECT with MRI, or of detailed neuropsychologic assessment, in adult patients with such an advanced course of alternating hemiplegia of childhood.

Adult↗

PubMed1997

Focal features in West syndrome indicating candidacy for surgery.

A subgroup of patients with West syndrome (WS) also have focal features, and some of these patients respond to surgical intervention. To determine the incidence of focal features in patients with WS and to establish the correlation of these features with outcome, all patients with WS treated in the Epilepsy Unit of the Children's Hospital (Boston, MA) during the years 1989 to 1992 were retrospectively evaluated. Focal features included partial seizures, hemiparesis, focal radiologic findings, asymmetric spasms, and lateralized hypsarrhythmia. The different focal features were later correlated with the natural history of the disease. Sixty-seven patients were included in the study. Sixty-six percent had asymmetric manifestations. Asymmetric spasms, hemihypsarrhythmia, and partial seizures combined with infantile spasms had significant association with asymmetric brain pathology. Focal features did not correlate with age of onset and outcome, but were associated with etiology. Eight of the nine patients who underwent epilepsy surgery had at least two focal features or more. Two of the operated children had focal features in the absence of magnetic resonance imaging abnormalities, thus indicating the necessity for positron emission tomography, the results of which justified surgery.

Brain↗

PubMed1997

Acute effects of MK801 on kainic acid-induced seizures in neonatal rats.

Kainic acid (KA) causes behavioral and electrographic status epilepticus (SE) in rats of all ages. In adult rats, the noncompetitive N-methyl-D-aspartate (NMDA) channel blocker MK801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine ) is anticonvulsant against KA-induced seizures: it reduces their severity and protects against neuronal damage, although it may worsen electrographic seizures. Here we examined the effects of MK801 on KA seizures in the immature brain. Neonatal rats (P11-P12) were pretreated with MK801 (0.01, 0.1, 0.5 or 1.0 mg/kg, i.p.) or saline twenty minutes prior to KA (2 mg/kg, i.p.). Clinical seizure behavior was monitored for > 6 hrs, and in some rats the EEG was monitored with an intrahippocampal or intracortical electrode. MK801 caused immobility alternating with hyperactivity, ataxia, scratching and sometimes alternate limb cycling, which correlated with the appearance of spikes on the EEG. Compared to KA alone or KA preceded by 0.01 mg/kg MK801, the higher doses of MK801 (0.1, 0.5 and 1.0 mg/kg) significantly lowered the latency to electrographic seizures (P < 0.001), ictal scratching (P < 0.0001), and status epilepticus (P < 0.0001). MK801 pretreatment did not lower significantly the death rate due to KA seizures. No histologic damage was seen after MK801, KA or both agents together. These results suggest that MK801 exacerbates KA-induced seizures in the neonatal brain, and may even cause ictal behavioral and electrographic manifestations by itself. The findings point to an age-dependency of NMDA antagonist action, and suggest caution in considering the use of NMDA antagonists in neonates.

Animals↗

PubMed1997

Lamotrigine in absence and primary generalized epilepsies.

Although lamotrigine has been approved in the United States as adjunctive therapy for partial seizures in patients older than 12 years, there is increasing evidence that it is just as effective, if not more effective, in the treatment of generalized seizures. A large number of open-label studies and some single-blind data, all using lamotrigine as add-on therapy in patients with previously refractory generalized seizures, are available. Controlled studies, some on newly diagnosed, previously untreated patients with generalized seizures are ongoing. Investigations have demonstrated that patients with the following generalized seizure types improve with lamotrigine add-on therapy: Typical and atypical absence, atonic, generalized tonic-clonic, myoclonic, and clonic seizures. Response rates, defined as the percentage of patients with better than 50% reduction in seizure frequency, have been, depending on seizure type, in the range of 30% to 56%, with 0 to 33% of the patients becoming seizure free. The best responses have been noted in typical and atypical absences, and atonic seizures. Children and adults appear to have comparable responses. In addition, add-on studies in patients with specific, previously refractory, epilepsy syndromes have demonstrated that the best improvement in seizure control occurs in patients with petit mal epilepsy, "other symptomatic" generalized epilepsies, and in Lennox-Gastaut syndrome, followed by patients with other myoclonic epilepsies, myoclonic absence and West syndrome. Many previously refractory patients are able to achieve lamotrigine monotherapy. However, patients with nonprogressive myoclonic epilepsy have little, if any, response. Early data from ambulatory encephalographic (EEG) recordings in patients with previously refractory absence seizures, and from controlled studies on patients with newly diagnosed typical absence seizures, appear to confirm the efficacy of lamotrigine in those patients. Controlled studies are ongoing in patients with absence seizures, in patients with generalized tonic-clonic seizures, and in patients with Lennox-Gastaut syndrome. Dosing in generalized seizures is similar to that for partial seizures. Because of the shorter half-life of lamotrigine in children, as compared to adults, higher (mg/kg) doses are often needed in young patients. We conclude that lamotrigine is a promising drug for absence and primary generalized seizures in both children and adults.

Adolescent↗

PubMed1997

Hypsarrhythmia: frequency of variant patterns and correlation with etiology and outcome.

To determine the frequency and significance of the EEG features of hypsarrhythmia, we analyzed the pre-ACTH records of 53 consecutive patients with infantile spasms for the severity of the following abnormalities: disorganization of background, slowing, high amplitude, spike activity, and for the presence or absence of each of the following patterns and variants: electrodecremental discharges, absence of normal sleep activity, relative normalization, hemihypsarrhythmia, burst suppression (BS), occipital hypsarrhythmia, interhemispheric asymmetry, and interhemispheric synchronization. We calculated a total score indicating the severity of the hypsarrhythmia for each record. The hypsarrhythmia variant patterns occurred frequently in up to 69% of the records. Patients with cerebral dysgenesis were more likely to have hemihypsarrhythmia or BS pattern persistent throughout the EEG. Patients with history of perinatal hypoxia-ischemia were more likely to have absence of normal sleep activity. The occurrence of each of the other variant patterns did not correlate with etiology. Favorable outcome did not correlate with the occurrence, or absence, of any of the variant patterns but was associated with faster background activity (< 75% delta), a lower total hypsarrhythmia score (< or = 10), and with absence of electrodecremental discharges on the pre-ACTH EEG. We conclude that variant patterns of hypsarrhythmia are frequent, generally do not correlate with prognosis, and thus are best included within the definition of hypsarrhythmia. The severity of the hypsarrhythmia, however, does have significant prognostic implications.

Adrenocorticotropic Hormone↗