As the population of patients treated with deep brain stimulation (DBS) grows and the patients age, more will require routine or emergent electrophysiologic tests. DBS artifact may render these uninterpretable, whereas stopping DBS may release symptoms that confound evaluation. The authors find that monopolar, but not bipolar, stimulation produces significant artifact during EKG, EEG, and polysomnography.

Aged↗

PubMed2006

Interictal and postictal circadian and ultradian luteinizing hormone secretion in men with temporal lobe epilepsy.

PURPOSE: Hypothalamic regulation of the reproductive axis in temporal lobe epilepsy (TLE), represented by the ultradian pulsatile secretion of luteinizing hormone (LH), has been shown to be altered interictally and postictally. Our objective is to determine if epilepsy or seizures disrupt normal circadian fluctuations of LH as well as circadian organization of ultradian bursts of LH. METHODS: We characterized LH secretion in 10 men with TLE during two 24-h blocks: an interictal epoch and a postictal epoch initiated by a seizure. Serum LH was measured every 10 min and characterized by circadian and ultradian patterns with cosinor and deconvolution analysis. RESULTS: Mean peak serum concentrations of LH occurred at approximately 0400 in controls, were significantly delayed approximately 5 h interictally, and were randomly distributed postictally. Burst amplitudes differed significantly by phase among controls, with the largest amplitudes between 0101 and 0700 and the smallest between 1301 and 1900. No phase differences were present in interictal or postictal epochs. Burst frequency weakly but significantly was slowest between 0101 and 0700 in controls, but did not differ significantly by phase in either interictal or postictal epochs. Postictal LH burst frequencies, but not amplitudes, were significantly decreased immediately postictally. CONCLUSION: The pulsatile secretion of LH in TLE is abnormal both in the circadian as well as the ultradian domain. Interictal effects consist mainly in loss of circadian fluctuations in LH burst amplitude, whereas postictal effects consist of altered burst timing. Altered daily patterns of neuroendocrine signals may underlie other disorders of homeostasis in TLE.

Activity Cycles↗

PubMed2006

Conduction aphasia as a function of the dominant posterior perisylvian cortex. Report of two cases.

Assessment of eloquent functions during brain mapping usually relies on testing reading, speech, and comprehension to uncover transient deficits during electrical stimulation. These tests stem from findings predicted by the Geschwind-Wernicke hypothesis of receptive and expressive cortices connected by white matter tracts. Later work, however, has emphasized cortical mechanisms of language function. The authors report two cases that demonstrate that conduction aphasia is cortically mediated and can be inadequately assessed if not specifically evaluated during brain mapping. To determine the distribution of language on the dominant cortex, electrical cortical stimulation was performed in two cases by using implanted subdural electrodes during brain mapping before epilepsy surgery. A transient isolated deficit in repetition of language was reported during stimulation of the posterior portion of the dominant superior temporal gyrus in one patient and during stimulation of the supramarginal gyrus in the other patient. These cases demonstrate a localization of language repetition to the posterior perisylvian cortex. Brain mapping of this region should include assessment of verbal repetition to avoid potential deficits resembling conduction aphasia.

Adult↗

PubMed2005

Clinical findings of the phakomatoses: tuberous sclerosis.

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Adolescent↗

PubMed2004

Standardized mental status testing for nonconvulsive status epilepticus.

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Anticonvulsants↗

PubMed2003

Depression in intractable partial epilepsy varies by laterality of focus and surgery.

PURPOSE: Depression sometimes occurs after surgical treatment for medically intractable partial epilepsy. The risk of pre- and postsurgical depression may vary by laterality of seizure focus. We reviewed the pre- and postsurgical psychological assessments and clinical courses of patients to identify those at highest risk for postsurgical mood disorders. METHODS: Depression status was assessed in a consecutive series of epilepsy patients before and 1 year after epilepsy surgery with the use of Scale 2 of the MMPI-2 and a clinical depression index (CDI) scoring the occurrence of depressive symptoms, psychiatric referral, or attempted/completed suicide. Outcome at 1 year was modeled by regression techniques as functions of preoperative mood measurements, side of epilepsy surgery, and preoperative verbal intelligence. RESULTS: The CDI and Scale 2 MMPI-2 correlated significantly (r = 0.341; p < or = 0.01). Left (n = 54 subjects) and right (n = 53) surgery groups did not differ by sex, seizure outcome, age, education, age at first seizure, duration of epilepsy, or intellect. Higher presurgical depressive morbidity (p = 0.0037) and right-sided surgery (p = 0.0003) predicted higher postoperative CDI. Higher preoperative Scale 2 scores, indicating worse depressive traits, predicted worse postoperative Scale 2 scores (p < 0.0001). Although side of surgery did not predict Scale 2 scores, Scale 2 scores of patients with preoperative right-sided foci tended to have worse postsurgical Scale 2 scores (p = 0.08). Findings for the temporal lobectomy subgroup (n = 90) were similar to those of the overall sample. CONCLUSIONS: Patients undergoing right hemispheric epilepsy surgery, especially those with high presurgical depression-related morbidity, may be particularly susceptible to clinical depression. Our findings support other studies that show an interhemispheric modulation of depressive traits and symptoms.

Adolescent↗

PubMed2003

The safety and utility of recombinant human bone morphogenetic protein-2 for cranial procedures in a nonhuman primate model.

OBJECT: The goal of this study was to evaluate the safety and efficacy of recombinant human bone morphogenetic protein 2 (rhBMP-2) in cranial applications. METHODS: Critical-sized calvarial defects were created bilaterally in four rhesus monkeys, and bilateral rectangular bone flaps were created in six others. Control and rhBMP-2-treated sides were randomly chosen for each animal, and an absorbable collagen sponge was used to deliver the growth factor. Over a 6-month period postoperatively, the animals were serially evaluated for bone healing and adverse BMP-related consequences by using the following methods: computerized tomography (CT) scanning, magnetic resonance (MR) imaging, electroencephalography, histological investigations, and cerebrospinal fluid (CSF) analysis. The critical-sized defects for the rhBMP-2-treated and control sides attained 71 +/- 12% and 28 +/- 11% closure, respectively (four animals; p = 0.04). The CT scans demonstrated that the bone flaps treated with rhBMP-2 had complete osteointegration in five of six animals, whereas scans of the untreated bone flaps demonstrated uniformly poor osteointegration with the intact skull. Histological analysis confirmed well-formed bridges of bone on the rhBMP-2-treated sides. No epileptogenic activity was detected in any of the animals, and MR imaging revealed no evidence of adverse effects on the brain parenchyma. Meningitic irritation was not found on postoperative CSF sample analysis. CONCLUSIONS: Treatment of bone flaps and critical-sized cranial defects with rhBMP-2 leads to improved bone formation and osteointegration in nonhuman primates. Initial evaluation of rhBMP-2 appears to indicate a good safety profile for use in cranial procedures in primates.

Animals↗

PubMed2002

Interictal and postictal alterations of pulsatile secretions of luteinizing hormone in temporal lobe epilepsy in men.

Mesial temporal lobe epilepsy has been associated with abnormalities of reproductive physiology, but the mechanisms of hormonal dysregulation are not clear. Chronic effects of the epileptic state and the acute impact of seizures could alter hypothalamic function, which is represented by the downstream pulsatile secretion of luteinizing hormone. This study evaluates the interictal and postictal secretion of luteinizing hormone in mesial temporal lobe epilepsy. We characterized luteinizing hormone secretion in patients with mesial temporal lobe epilepsy during two 24-hour epochs: an interictal baseline and a postictal interval initiated by an electrographically confirmed spontaneous seizure. Males, rather than females, were studied so that menstrual cycles could not account for differences between epochs. Blood luteinizing hormone and prolactin (as a positive control) were measured every 10 minutes. Deconvolution analysis defined luteinizing hormone secretion in terms of interpulse interval, amplitude, and mass. Approximate entropy quantitated relative degradation in the orderliness of serial luteinizing hormone release. Interictal baseline epochs were compared to those of healthy controls with unpaired Student's t tests and between interictal and postictal epochs within epileptic patients with paired t tests. Ten epileptic men completed both interictal and postictal epochs. Interictally, seizure patients had lower mean concentrations, slower pulse rates, and higher peak amplitudes than healthy male controls. Within epileptic patients, mean interpulse interval, pulse amplitude, and pulse mass were not affected by the occurrence of seizures, whereas the orderliness of pulse mass decreased postictally. Acute seizures induced timing irregularity in luteinizing hormone secretion, whereas chronic epilepsy was associated with changes in luteinizing hormone pulse frequency, amplitude, and mass. Altered timing and regularity of neuroendocrine pulse patterns may underlie other disorders of homeostasis in mesial temporal lobe epilepsy.

Adult↗

PubMed2002

Quality of life outcome is associated with cessation rather than reduction of psychogenic nonepileptic seizures.

The outcome of psychogenic nonepileptic seizures (NES) is usually judged by recurrence of spells, but functional outcome or quality of life (QOL) is less well described. We tested the hypothesis that a decrease in NES recurrence yields corresponding improvement in QOL. Patients with NES were diagnosed with continuous video-EEG. We determined spell rate and QOL through a telephone interview at least six months after diagnosis. Thirty subjects consented to a follow-up interview (mean 17.4+/-1.5 months between diagnosis and interview). The rate of NES per week decreased significantly, and 10/30 (33%) had complete resolution. QOL, measured by the QOLIE-10 scale, did not improve proportionately with reduction in NES. However, subjects who reported a cessation of NES noted a significantly better total QOLIE-10 score (20.7+/-2.2) than those with continuing NES (27.4+/-1.6, P=0.02 by unpaired t test). Cessation rather than reduction of NES is associated with better QOL outcome.

Journal Article↗

PubMedDate not supplied

Stroboscopic artifact in digital video-EEG.

Combined digital video-EEG (DV-EEG) systems eliminate many familiar technical artifacts of older analog recorders; however, new and unanticipated technical issues are becoming evident. In this report, a case is described that identifies one of these technical limitations that could represent a pitfall to accurate data interpretation. An EEG was recorded on an 18-year-old man with history of photically sensitive generalized tonic-clonic seizures, revealing photoparoxysmal responses that appeared to outlast photic stimulation. However, in an attempted video-EEG correlation, the digital video recording showed variable appearance or absence of photic bursts that did not correlate with EEG photic tick marks, initially suggesting desynchronization between video and EEG signals. However, the absence of flashes seen on the video record resulted from stroboscopic artifact caused by mismatch between strobe frequency, video sampling rate, and video display characteristics. Stroboscopic aliasing is a DV-EEG specific artifact that can complicate accurate interpretation of photoparoxysmal responses.

Adolescent↗