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Warren T Blume

Publications and source records attributed to Warren T Blume.

At least 19 recordsLinked to original sources
PubMed2006

Drug effects on EEG.

Although excess beta activity and a mild theta increase may be the most common EEG alterations associated with medication, more remarkable changes may also appear. Although changes such as diffuse delta, triphasic waves, bisynchronous spikes or polyspikes, burst suppression or electrocerebral inactivity may indicate a dismal prognosis under many circumstances; these patterns may fully resolve to a normal EEG if drug administration is the unique or principal cause.

Anticonvulsants↗
PubMed2006

The progression of epilepsy.

Prognosis for seizure control and cognitive development varies considerably among syndromes. Several factors may interact to influence outcome of an epilepsy including a causative etiology, ictal and interictal discharges, seizure-related trauma or systemic perturbations, and antiepileptic drug (AED) effects. Clinical evidence convincingly supporting Gowers' hypothesis that seizures beget seizures is lacking. Short-term seizure suppression by early treatment does not appear to influence long-term prognosis. Malignant epilepsy syndromes usually begin in infancy or childhood, have a high seizure frequency, resist the initial AED, and are often associated with progressive cognitive dysfunction. Prompt management of some severe epilepsy syndromes may lessen cognitive decline. However, aggressive AEDs therapy must be balanced against the potential for cognitive side effects, particularly if multiple AEDs are used. Several experimental paradigms closely parallel human TLE as both have an initial precipitating injury (IPI), a latent period, then recurrent spontaneous seizures. In humans, an IPI is any medical event with neurological implications. Although transition from a latent period to a seizure disorder certainly constitutes "progression" of the disorder, convincing clinical evidence of subsequent worsening has not emerged. Substantial clinical and experimental evidence indicates some cognitive regression and focal atrophy with time for TLE and other intractable syndromes. However, seizure frequency and severity, established early in the disorder, appear stable in most patients, and even regress in benign syndromes. Factors mitigating or extinguishing epilepsies need to be further sought.

Adolescent↗
PubMed2005

Occipital epilepsy: lateral versus mesial.

This study compares ictal semiology, neurological examination and scalp EEG between lateral and mesial occipital epilepsy to assess the contribution non-invasive data make in determining the epileptogenic region within an occipital lobe. We assessed seizure origin in 41 occipital patients as lateral (11 patients), mesial (20) and both surfaces (10) as indicated by subdurally recorded seizures (nine), a lesion whose removal reduced seizure quantity by > or =90% (six), or who met both criteria (26). No aspect of semiology distinguished lateral from mesially originating occipital seizures. A pre-operative visual field deficit appeared in eight (42%) out of 19 testable patients with mesial originating seizures, three (30%) out of 10 patients with both surfaces epileptogenic, but none of the 10 testable patients whose seizures arose only from the lateral surface (P = 0.0373, lateral versus mesial and both surfaces). Although occipital seizures appeared on the majority of the first five scalp EEG recordings in four (36%) out of 11 patients with laterally originating occipital seizures compared with none of 20 patients in whom seizures originated mesially (P = 0.0105), no other scalp EEG feature distinguished seizures from these surfaces. We conclude that subdural electroencephalography is likely to be necessary to delineate the epileptogenic region within an occipital lobe. Nonetheless, focally originating scalp-recorded seizures accurately lateralized the epileptogenic zone in 20 (49%) of our 41 patients compared with only one (2%) which originated contralaterally (P = 0.0001). This relationship held when considering only the first five scalp EEGs: the seizures of 10 patients (24%) appeared ipsilaterally and none contralaterally (P = 0.001). Moreover, interictal occipital (01,2) and posterior temporal (T5, T6) spikes appeared consistently and significantly (P < 0.001) more commonly ipsilateral to epileptogenesis than contralateral using multiple methods of analysis.

Adolescent↗
PubMed2004

Lennox-Gastaut syndrome: potential mechanisms of cognitive regression.

Lennox-Gastaut (L-G) syndrome is an intractable generalized epilepsy of childhood onset, associated with spike waves at a slow rate and paroxysmal fast activity. These epileptiform discharge patterns are thought to reflect excessive neocortical excitability and arise from neuronal and synaptic features peculiar to the immature central nervous system. The epileptic processes associated with L-G syndrome may lead to enduring patterns of abnormal activity and connectivity. These abnormal patterns compete with normal developmental mechanisms and may result in subsequent impairment and/or regression of cognition. Recurring or prolonged seizures themselves may also damage the brain. We hypothesize that the presence of slow spike waves diverts the brain from normal developmental processes toward seizure-preventing mechanisms. Adding to this burden, antiepileptic medications, sleep disruption, and social isolation all retard cognitive development and the learning process at a crucial time of brain maturation.

Brain↗
PubMed2004

Properties of after-discharges from cortical electrical stimulation in focal epilepsies.

OBJECTIVE: This study sought to determine whether certain aspects of after-discharges (ADs) obtained during cortical functional mapping provide better correlations between stimulus site and that of spontaneous seizures. Secondly, we wished to determine the percentage of stimulations evoking ADs and, of these, the percentage which clearly involves more than one electrode position, potentially inaccurately localizing cortical function. Thirdly, we wished to quantify the incidences of the several AD morphologies described by Jasper [in: Epilepsy and the functional anatomy of the human brain, 1954, p. 183; p. 692] and to assess whether certain morphologies had a greater tendency to evolve in frequency or morphology. METHODS: In these 29 patients requiring invasive recordings to determine principal epileptogenic areas, only subdural strips were placed in 19 patients, only grids in 2 patients, and both in 8 patients. A median of 21 electrodes per patient was stimulated of a median of 63 electrodes placed, with the following parameters: biphasic, monopolar, 50 Hz, 0.3 ms pulse duration, 1.5-18 mA. Coverage involved the frontal and parietal lobes (9 patients), frontal parietal temporal lobes (8), frontal temporal (3), temporal (2), occipital (2) and occipital temporal (2) with other combinations in 3 additional patients. Classification of AD morphologies was determined by a pilot study using IFSECN definitions [Electroenceph clin Neurophysiol 1974;37:538] and descriptions by Jasper [in: Epilepsy and the functional anatomy of the human brain, 1954, p. 183] and Gloor [in: Advances in neurology, vol. 8, 1975; p. 59]. RESULTS: Four hundred and two ADs (12%) were elicited by 3358 trains of electrical stimuli of which 260 (65%) clearly involved more than only the stimulated electrode position. Thus, 260 (8%) of 3358 stimulations evoked an AD that could mislocalize cortical function. The proportion of stimulating electrodes eliciting ADs ranged among patients from 4 to 83% (median 33%). Polyspike bursts and sequential spikes were the most common AD morphologies. Ten percent of ADs evolved in morphology, frequency or both. Evolution occurred more commonly (44%) with rhythmic waves than with other AD morphologies (7%). Neither evolving ADs, ADs producing clinical seizures, or ADs exceeding 10 s correlated topologically with spontaneous seizure origins. CONCLUSIONS: Although occurring in a minority of cortical electrical stimuli, ADs may involve more than the stimulus site and therefore may inaccurately localize cortical function. Our material failed to disclose any consistent relationship between the site of stimulus eliciting ADs and that of spontaneously appearing seizures, even when certain aspects of such ADs were analysed. SIGNIFICANCE: These data illustrate the need for scrutiny of the post-stimulus electrocorticogram for ADs and particularly those involving extra stimulus sites. Whether varying the stimulus parameters prospectively will disclose a better seizure localizing value for ADs remains to be determined.

Adolescent↗
PubMed2004

Spared somatomotor and cognitive functions in a patient with a large porencephalic cyst revealed by fMRI.

To date functional magnetic resonance imaging (fMRI) has not been extensively used in presurgical evaluation of patients with intractable epilepsy. Patient S.P. presented with left frontal originating seizures, secondary to a large porencephalic cyst that encompassed much of his occipital and temporal cortex and a substantial portion of ipsilateral parietal cortex. Nevertheless, S.P. did not demonstrate any gross impairments of praxis or speech. Scalp electroencephalogram (EEG) telemetry revealed reduced background activity in the left hemisphere, an absence of identifiable normal sleep states, and confirmed the left frontal origin of his seizures with a prolonged postictal state, suggesting that the remaining cortex in S.P.'s left hemisphere did not function normally despite his apparently normal appearance. Dichotic listening results also suggested that S.P. had an atypical language representation suggestive of either bilateral or right hemisphere speech representation. Surgical intervention to remove the remaining left hemisphere cortex was a serious consideration for treatment of S.P.'s seizures. We used fMRI to evaluate whether or not the remaining cortex in S.P.'s left hemisphere supported any cognitive or motor functions. Even though the volume of cerebral cortex was severely reduced and displaced in the left hemisphere, fMRI revealed significant activation in this remaining tissue in response to motor, somatosensory, and word generation tasks. In other words, we were able to demonstrate using fMRI that the remaining tissue in S.P.'s left hemisphere continued to support some motor and cognitive functions. The possible implications of these findings in terms of functional reorganisation are discussed briefly.

Brain Diseases↗
PubMed2004

Contralateral motor automatisms in neocortical temporal lobe epilepsy.

BACKGROUND: The lateralizing value of the motor automatisms is generally doubted in most patients with temporal lobe epilepsy. However, subgroup analysis of the seizures of temporal lobe origin suggests a role for motor automatisms in discriminating seizures of neocortical versus mesial temporal lobe origin. METHODS: Video-EEG of a patient with well-defined neocortical temporal lobe epilepsy was reviewed to assess the localizing value of motor automatisms. RESULTS: We report a patient with left upper extremity motor automatisms and clonic movements of the proximal left lower extremity with altered awareness as the sole manifestations of right temporal neocortical seizures. CONCLUSION: Early onset unilateral motor automatisms without dystonic posturing can localize the seizure origin to the contralateral temporal lobe neocortex.

Automatism↗
PubMed2004

Indices of resective surgery effectiveness for intractable nonlesional focal epilepsy.

Among 70 patients with intractable focal epilepsy and no specific lesion, as determined by both MRI (magnetic resonance imaging) and histopathology, outcome after resective surgery was polarized: 26 (37%) became seizure free (SF), and 27 (39%) were not helped. Eighteen (42%) of 43 standard temporal resections rendered patients SF, somewhat more than eight (30%) of 27 other procedures. To seek reliable prognostic factors, the subsequent correlative data compared features of the 26 SF patients with those of the 27 not helped. Although ictal semiology guided the site of surgical resection, it and other aspects of seizure and neurologic history failed to predict surgical outcome. However, two aspects of preoperative scalp EEGs correlated with SF outcomes: (a) among 25 patients in whom >50% of clinical seizures arose from the later resected lobe and no other origins, 18 (72%) became SF compared with seven (28%) of 25 with other ictal profiles; (b) 13 (93%) of 14 temporal lobe patients whose interictal and ictal EEGs lacked features indicative of multifocal epileptogenesis became SF compared with five (33%) of 15 with such components. The considered need for subdural (SD) EEG reduced SF outcome from 18 (90%) of 20 patients without SD to eight (24%) of 33 with SD; this likely reflected an insufficient congruity of ictal semiology and interictal and ictal scalp EEG for localizing epileptogenesis. Within this SD group, >50% of clinical seizure origins from a later resected lobe increased SF outcome somewhat: from two (14%) of 14 without this attribute to six (40%) of 15 with it; 100% of such origins increased SF outcome from two (12%) of 16 to six (46%) of 13.

Adolescent↗
PubMed2003

Transient lesion in the splenium of the corpus callosum in an epileptic patient.

Pathogenesis of a rarely occurring transient, isolated focal lesion of the splenium of the corpus callosum in epilepsy patients is uncertain: frequent seizures or antiepileptic drug reduction causing ischemia or demyelination is possible. The several MRI sequences, including diffusion-weighted imaging, in this first case of occipital epilepsy suggest ischemia from rapid carbamazepine reduction, frequent seizures, or a combination of both.

Adult↗
PubMed2003

Diagnosis and management of epilepsy.

This article concisely describes the more common epilepsy conditions and will enable physicians to efficiently evaluate and manage these disorders. Salient aspects of the history and examination, together with electroencephalography, will usually determine the epilepsy syndrome (category), forming the basis for any further investigation and possible antiepileptic therapy. Imaging may be required in some circumstances.

Disease Management↗
PubMed2002

A longitudinal study of the effects of seizure symptoms on the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) clinical interpretation.

This study investigated whether the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) items reflecting seizure symptoms spuriously inflate MMPI-2 scores in persons with epilepsy. In a repeated measures prospective design, patients with epilepsy completed the MMPI-2 prior to epilepsy surgery and again two years later when they were either seizure-free or not seizure-free. Compared to baseline scores, only seizure-free patients showed a decline in endorsement of seizure items, and only on one scale, Hypochondriasis (Hs). Clinical profiles were not meaningfully different when readministered when seizures were no longer present. Moreover, profiles generated by individuals with and without seizures were not significantly different. We conclude the MMPI-2 is a valid test in an epilepsy population, as seizure content did not alter its clinical interpretation. In using the MMPI-2 in patients with epilepsy, a modest correction on the Hs and Schizophrenia (Sc) scales is warranted in selected cases. In MMPI-2 research, assessing both statistical and clinical significance is recommended.

Adult↗
PubMed2002

Divalproex extended-release versus the original divalproex tablet: results of a randomized, crossover study of well-controlled epileptic patients with primary generalized seizures.

PURPOSE: To compare the safety and efficacy of two formulations of divalproex, extended-release divalproex versus the original divalproex tablet, in adolescent and adult patients with epilepsy. METHODS: Eligible patients were between the ages of 12 and 65 years with primary generalized epilepsy, which was controlled over the month prior to study enrollment with divalproex or valproic acid 1000 mg to 2000 mg/day. The patients were well-controlled; 39 of 43 (91%) had no seizures in the previous year. Patients were randomized to receive 84 days of either divalproex two times a day (b.i.d.)/three times a day (t.i.d.) or extended-release divalproex qd and then (crossed over to) 84 days of the comparator formulation. During the two treatment periods, patients received the same daily dose equivalent of divalproex as was taken during the month prior to study entry. The clinical status of patients was evaluated at a screening visit and at four subsequent visits conducted every 42 days. RESULTS: There was no statistically significant difference between the formulation groups for seizure control rate (95% [41/43] for divalproex and 93% [40/43] for extended-release divalproex). Likewise, the formulation groups were similar based on the incidence of treatment-related adverse events. The most frequently reported (< or =11.4% for either formulation) treatment-related adverse events were asthenia, tremor, nausea, and dizziness. CONCLUSIONS: Extended-release divalproex was similar to divalproex for the treatment of well-controlled, primary generalized epilepsy in terms of overall safety and efficacy parameters.

Adolescent↗
PubMed2002

Invited review: clinical and basic neurophysiology of generalised epilepsies.

Electroencephalography (EEG) clarifies several aspects of generalised epileptic seizures and epilepsies. For the clinician, it assists in the diagnosis of the epileptic condition and helps assign the disorder to an appropriate syndrome. This assignation and the quantity of epileptic discharges estimate severity and prognosis. When combined with relevant basic science investigations, EEG studies may disclose significant pathophysiological mechanisms. Therefore, this paper first describes EEG characteristics of the several disorders included under the broad category of "generalised". The review then relates these phenomena to germane experimental data intending that this binocular survey will provide a more meaningful perspective of these disorders.

Animals↗
PubMed2002

Sedative doses of remifentanil have minimal effect on ECoG spike activity during awake epilepsy surgery.

The use of remifentanil for sedation during awake epilepsy surgery has been described in a case report. However, little information is available regarding the effect of remifentanil on the quality of intraoperative electrocorticography (ECoG). This study was designed to investigate the effect of sedative doses of remifentanil on ECoG interictal spike activity among patients undergoing awake anterior temporal lobectomy for refractory epilepsy. Ten adult patients were studied prospectively. After baseline EcoG recordings were obtained, remifentanil was administered as a continuous infusion at 0.1 microg/kg/min and the ECoG recorded continuously for 15 minutes. Recordings obtained before and during the administration of remifentanil were compared with respect to spike frequency and location. A trend toward a small decrease in spike frequency was observed as patients became increasingly somnolescent and background ECoG activity slowed. The difference was not statistically significant. Blood pressure and heart rate were not adversely affected by the administration of remifentanil. Respiratory rates decreased in all patients (mean decrease, 8 breaths/min) and one patient transiently developed a respiratory rate of 4 breaths per minute that elicited a decrease in the rate of remifentanil administration. Remifentanil administered at sedation doses does not adversely affect intraoperatively recorded interictal spike activity. Further investigation of the use of this drug during awake epilepsy surgery is warranted.

Adult↗