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Biomedical subjects

Frank G Gilliam

Publications and source records attributed to Frank G Gilliam.

13 recordsLinked to original sources
PubMed2006

Changing frontal contributions to memory before and after medial temporal lobectomy.

Frontal recruitment was characterized using functional magnetic resonance imaging (fMRI) during memory encoding in temporal lobe epilepsy (TLE) patients before and after unilateral medial temporal lobectomy. Twenty-four TLE patients and 12 healthy controls underwent a preoperative fMRI session consisting of verbal and nonverbal incidental memory-encoding tasks that typically lead to robust, lateralized frontal activity in controls. A similar postoperative fMRI session was performed in a subset of patients. Preoperatively, the verbal task resulted in significant additional recruitment of right frontal cortex in left TLE patients, compared with controls. Right TLE patients instead showed typically lateralized frontal activation. Bilateral frontal recruitment has been observed in older adults and in young adults in situations of difficult task demands. Typical right-lateralized patterns of frontal recruitment were found in both patient groups during the nonverbal task, indicating that the bilateral frontal recruitment pattern was engaged dynamically depending on the task. After surgery, left TLE patients regained more lateralized frontal activity. These results demonstrated differences in frontal recruitment in left and right TLE patients. Such differences emerged in specific task settings and were influenced by surgery, suggesting a dynamic mechanism of frontal recruitment that can be obtained in TLE patients, possibly as a response to presurgical dysfunction.

Adaptation, Physiological↗
PubMed2006

Adverse psychiatric effects of antiepileptic drugs.

Psychiatric symptoms provide potential insights into the pathophysiology of psychiatric conditions in epilepsy patients. Evaluating the psychiatric effects of newer AEDs is complicated by several important factors including (a) the relatively high rate of mood and anxiety disorders in persons with pharmacoresistant epilepsy, and (b) the variety of methods used to assess the occurrence and severity of psychiatric symptoms. Clinical trials to assess adverse psychiatric effects of AEDs need a control group to adjust for the spontaneous occurrence of symptoms, as well as to demonstrate potential positive psychotropic effects. The follow-up should be long enough to differentiate between drug-related effects and the natural course of the comorbid disorder. Psychiatric problems should be defined using appropriate instruments as well as self-report.

Anticonvulsants↗
PubMed2006

Rapid detection of major depression in epilepsy: a multicentre study.

BACKGROUND: Depression is a common comorbid disorder in epilepsy but is not routinely assessed in neurology clinics. We aimed to create a rapid yet accurate screening instrument for major depression in people with epilepsy. METHODS: We developed a set of 46 items to identify symptoms of depression that do not overlap with common comorbid cognitive deficits or adverse effects of antiepileptic drugs. This preliminary instrument and several reliable and valid instruments for diagnosis of depression on the basis of criteria from the Diagnostic and Statistical Manual IV, depression symptom severity, health status, and toxic effects of medication were applied to 205 adult outpatients with epilepsy. We used discriminant function analysis to identify the most efficient set of items for classification of major depression, which we termed the neurological disorders depression inventory for epilepsy (NDDI-E). Baseline data for 229 demographically similar patients enrolled in two other clinical studies were used for verification of the original observations. FINDINGS: The discriminant function model for the NDDI-E included six items. Internal consistency reliability of the NDDI-E was 0.85 and test-retest reliability was 0.78. An NDDI-E score of more than 15 had a specificity of 90%, sensitivity of 81%, and positive predictive value of 0.62 for a diagnosis of major depression. Logistic regression showed that the model of association of major depression and the NDDI-E was not affected by adverse effects of antiepileptic medication, whereas models for depression and generic screening instruments were. The severity of depression symptoms and toxic effects of drugs independently correlated with subjective health status, explaining 72% of variance. Results from a separate verification sample also showed optimum sensitivity, specificity, and predictive power at a cut score of more than 15. INTERPRETATION: Major depression in people with epilepsy can be identified by a brief set of symptoms that can be differentiated from common adverse effects of antiepileptic drugs. The NDDI-E could enable rapid detection and improve management of depression in epilepsy in accordance with internationally recognised guidelines.

Adult↗
PubMed2006

Musicogenic seizures can arise from multiple temporal lobe foci: intracranial EEG analyses of three patients.

PURPOSE: To determine the ictal-onset zone of musicogenic seizures by using intracranial EEG monitoring. METHODS: Musicogenic seizures in three patients with medically intractable musicogenic epilepsy were first localized by using noninvasive methods including, in one patient, ictal magnetoencephalography (MEG) and magnetic resonance spectroscopy (MRS). The ictal-onset zones in these patients were then further localized using by intracranial EEG monitoring, and the outcomes of the two patients who underwent epilepsy surgery were determined. RESULTS: Patient 1's musicogenic seizures localized to the right lateral temporal lobe, patient 2's originated in the right mesial temporal lobe, and patient 3's arose independently from both mesial temporal lobes. Patients 1 and 2 underwent resective epilepsy surgery and are seizure free (Engel class I). CONCLUSIONS: Musicogenic epilepsy is a heterogeneous syndrome with seizures that can arise from multiple temporal lobe foci. Patients with medically intractable musicogenic epilepsy and with unilateral ictal onset zones may be considered candidates for resective epilepsy surgery.

Adult↗
PubMed2005

Diagnosis and treatment of mood disorders in persons with epilepsy.

PURPOSE OF REVIEW: Epilepsy is a common, disabling neurological disorder associated with increased rates of comorbid psychiatric disorders as compared with the general population. RECENT FINDINGS: Mood disorders, especially major depression, appear to be more prevalent in persons with epilepsy than in those with the other chronic disorders and the general population. Depression may have more influence on quality of life than do cognitive and seizure factors. Although psychological, social, and vocational disabilities contribute to mood dysfunction in epilepsy, functional neuroimaging studies have consistently shown correlation of presence of cerebral abnormalities with increased severity of symptoms of depression. Most persons with epilepsy are not routinely screened for depression, and depression is subsequently treated in only a minority of patients. Although serotonin receptor density is greatest in brain regions commonly associated with epilepsy, such as the mesial temporal and prefrontal areas, no controlled trials have investigated the efficacy of serotonin reuptake inhibitors in persons with epilepsy. Optimal methods to identify and treat depression in epilepsy require substantial further research. SUMMARY: Depression is a common comorbid condition with significant negative effects on health status in persons with epilepsy, but additional understanding of the disorder is needed to improve diagnosis and treatment.

Antidepressive Agents↗
PubMed2005

Correlation of severity of FDG-PET hypometabolism and interictal regional delta slowing in temporal lobe epilepsy.

PURPOSE: We investigated the association of severity of hypometabolism detected by positron emission tomography (PET) with [(18)F]fluorodeoxyglucose (FDG) and persistence of interictal EEG focal slowing in patients with refractory temporal lobe epilepsy. METHODS: Eighty temporal lobes of 40 consecutive patients with intractable temporal lobe epilepsy (mean age, 43.5 years) were studied. All patients underwent video-EEG monitoring, magnetic resonance imaging (MRI), and FDG-PET. Patients with either normal MRI or with unilateral mesial temporal sclerosis, but no other structural abnormality, were included. Interictal EEG delta slowing was graded as none, infrequent (one episode or less/hour), intermediate (more than one episode/hour), or continuous. PET hypometabolism was graded as none, mild, moderate, or severe. RESULTS: The severity of temporal lobe hypometabolism with PET was significantly correlated with the amount of delta activity in the interictal EEG, independent of MRI findings (Spearman r = 0.46; p < 0.0005). CONCLUSIONS: This observation suggests related underlying pathophysiologic mechanisms for metabolic and electrical dysfunction in temporal lobe epilepsy.

Adult↗
PubMed2005

Epilepsy and common comorbidities: improving the outpatient epilepsy encounter.

Epilepsy is a chronic disorder that has been associated with other specific health problems. Evidence from recent clinical and basic investigations indicates that aspects of cerebral dysfunction associated with a lowered seizure threshold may also predispose toward other disorders such as depression, cognitive impairment, sleep disorders, and migraine. Similarly, certain types of brain injury may also increase the risk of adverse antiepileptic drug (AED) effects. For example, a history of febrile seizures is associated with a three fold increase in the occurrence of negative psychiatric effects of two newer AEDs. Poor fitness and obesity are also reported at higher rates in epilepsy. Some comorbid conditions in epilepsy, such a depression and anxiety, may have a greater influence on subjective health status than does seizure rate. Management strategies employed in the outpatient clinic to maximize overall health outcomes should include screening and treatment for the commonly coexistent conditions in persons with epilepsy.

Comorbidity↗
PubMed2004

Depression in epilepsy: ignoring clinical expression of neuronal network dysfunction?

Epilepsy is a chronic disorder that adversely affects social, vocational, and psychological functioning. Despite the variety and complexity of the negative clinical associations with epilepsy, depression is remarkable in prevalence and related adverse effects on health status. An estimated 30-50% of persons with refractory epilepsy have major depression, and depression has a stronger correlation than seizure rate with quality of life. Suicide is one of the leading causes of death in epilepsy. Available data indicate that depression may result from underlying brain dysfunction rather than social and vocational disability. Most patients with depression are not screened systematically for the diagnosis, and are subsequently not treated. Although the density of serotonin receptors is greatest in limbic brain regions commonly involved in human epilepsy, such as the mesial temporal and prefrontal areas, no prior randomized controlled trials have evaluated the efficacy of serotonin reuptake inhibitors for depression in epilepsy.

Adult↗
PubMed2003

Limitations of monotherapy trials in epilepsy.

Monotherapy is considered optimal management for most patients with epilepsy, but designing monotherapy trials in epilepsy has proved to be a complex endeavor. Consideration of the validity of evidence for efficacy, potential risks to patients, clinical applicability of results, and effects of dosing and titration rates on efficacy and tolerability creates unique challenges. This article reviews pertinent aspects of trials of conversion to monotherapy in refractory patients and equivalence trials in newly diagnosed patients to better understand their limitations. Despite the inherent difficulties in designing monotherapy trials in epilepsy, previous monotherapy studies have provided important information for clinical management with new treatments.

Anticonvulsants↗
PubMed2003

Rates and risk factors for suicide, suicidal ideation, and suicide attempts in chronic epilepsy.

Studies of causes of death among people with epilepsy suggest that the lifetime prevalence rate of suicide is elevated. Although not all of the studies have reported an increased risk for suicide, the collective data yield an average rate of approximately 12% among people with epilepsy, compared with 1.1-1.2% in the general population. The increased risk for suicide appears to affect children and adolescents as well as adults. Rates of suicide attempts have also been reported to be elevated among people with epilepsy. A suicide attempt is a significant risk factor for completed suicide. Certain psychiatric disorders, including primary mood disorders, also increase the risk for suicide. Among people with epilepsy, psychiatric comorbidity is common, and rates of mood disorders, particularly major depression, have consistently been reported to be elevated. Other potential risk factors are family issues, physical health, personality, life stress, previous suicidal behavior, and access to firearms. Assessing severity of risk helps to determine the appropriate level of intervention. The suicidality module of the Mini-International Neuropsychiatric Interview is a practical tool to help quantify current suicide risk.

Chronic Disease↗
PubMed2003

Mechanisms of depression in epilepsy from a clinical perspective.

The epilepsies are a complex group of disorders commonly associated with brain dysfunction, social isolation, and vocational difficulty. Each of these factors may contribute to increased prevalence of depressive disorders in epilepsy, but the specific mechanisms are not completely understood. The brain regions commonly involved in various types of epilepsies, such as the hippocampus and amygdala in temporal lobe epilepsy and subcortical nuclei in idiopathic generalized epilepsies, are important components of current models of depression. Increased understanding of mechanisms of depression in epilepsy is not only crucial for improving care of many persons with seizures, but may also yield useful information about principal mechanisms underlying both depression and epileptogenesis.

Brain↗
PubMed2002

Time course of lamotrigine de-induction: impact of step-wise withdrawal of carbamazepine or phenytoin.

OBJECTIVE: The objective of the present analysis is to examine lamotrigine (LTG) pharmacokinetics both during polytherapy with enzyme inducing antiepileptic drugs and to evaluate the time course of de-induction following the step-wise withdrawal of enzyme inducers. BACKGROUND: LTG pharmacokinetics can be significantly influenced by concomitant AEDs, and the addition of enzyme inducers can markedly increase LTG clearance, thereby reducing serum concentrations. A clinically relevant question is how will LTG clearance and resulting plasma concentrations be altered during concomitant enzyme inducer withdrawal/conversion process. DESIGN/METHOD: As part of a previously published, active-control, LTG monotherapy trial, dose and plasma concentration data for LTG, carbamazepine (CBZ) or phenytoin (PHT) were obtained. Following the attainment of a LTG target dose of 500 mg/day, CZB or PHT were withdrawn in weekly 20% decrements. Following inducer withdrawal, LTG was then continued as monotherapy for an additional 12 weeks. Plasma concentrations and daily doses of LTG, CBZ, or PHT were obtained at regularly scheduled study visits during inducer withdrawal and during LTG monotherapy. Pharmacokinetic analysis of the plasma concentration data was done to determine the time-course and effect of inducer plasma concentration on LTG oral clearance (Cl(o)), where LTG Cl(o) was estimated as the dose/concentration ratio. RESULTS: Of the 156 patients enrolled in this trial, 76 were assigned to LTG arm, 43 completed the withdrawal to monotherapy phase with 28 successfully completing the study. In a subset analysis of completers, LTG Cl(o) determined prior to withdrawal of the inducers was significantly greater in patients (n=28) on LTG+PHT (160% increase) than in those (n=48) receiving LTG+CBZ (62% increase): 1.77+/-0.77 vs. 1.06+/-0.41 ml/min/kg, respectively, p=0.017. The significant reduction in LTG Cl(o) occurred only when CBZ plasma concentrations reached approximately 2 microg/ml or PHT plasma concentrations reached zero. CONCLUSIONS: Mean LTG plasma concentrations will approximately double following the withdrawal PHT; however increases of only 60% may occur following the withdrawal of CBZ. Importantly, these data suggest that LTG concentrations would not be expected to increase until the concomitant inducer is almost completely removed.

Adolescent↗