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Biomedical subjects

D G Vossler

Publications and source records attributed to D G Vossler.

12 recordsLinked to original sources
PubMed2004

Ictal stuttering: a sign suggestive of psychogenic nonepileptic seizures.

OBJECTIVE: To determine if ictal stuttering (IS) is more common among patients with psychogenic nonepileptic seizures (PNES) than patients with epileptic seizures (ES). METHODS: The authors prospectively reviewed the medical records, EEG-video recordings, and Minnesota Multiphasic Personality Inventory-2 (MMPI-2) scores of consecutive adults of normal intelligence diagnosed with either PNES or ES. RESULTS: A total of 230 (117 PNES and 113 ES) patients were studied. PNES patients were older (p = 0.029), more likely to be female (p < 0.001), and had a shorter duration of seizure disorder (p < 0.001) than ES cases. Ten (8.5%) PNES subjects and no ES cases demonstrated IS. The proportion of patients with IS in these two groups was significantly different (p = 0.004). PNES patients with IS were of similar age as but had an even shorter (p = 0.010) duration of seizure disorder (mean = 3.0 years) than those without IS. Scores on the hypochondriasis, depression (D), and hysteria scales of the MMPI-2 were significantly higher among PNES subjects than in ES patients (p < or = 0.002). However, seven PNES patients with IS had a lower mean score on the D scale than did 98 PNES cases without stuttering (p = 0.005). This produced a more sharply defined "conversion V" appearance on the MMPI-2 graph in the stutterers. CONCLUSIONS: Ictal stuttering was present in 8.5% of 117 consecutive patients with psychogenic nonepileptic seizures, but was not observed in a consecutive series of 113 adults with epileptic seizures. Patients with psychogenic nonepileptic seizures with ictal stuttering had a shorter duration of seizure disorder and a more prominent conversion profile on the Minnesota Multiphasic Personality Inventory than either patients with psychogenic nonepileptic seizures without stuttering or subjects with epileptic seizures.

Adult↗
PubMed2000

Femoral artery ischemia during spinal scoliosis surgery detected by posterior tibial nerve somatosensory-evoked potential monitoring.

STUDY DESIGN: A case report of unilateral leg ischemia caused by femoral artery compression detected using posterior tibial nerve somatosensory-evoked potentials during spinal scoliosis instrumentation surgery. OBJECTIVES: To report a rare cause of intraoperative unilateral loss of all posterior tibial nerve somatosensory-evoked potential waveforms. SUMMARY OF BACKGROUND DATA: Failure to obtain adequate popliteal fossa, spinal, subcortical, and cortical potentials during posterior tibial nerve somatosensory-evoked potential spinal cord monitoring usually results from technical factors or chronic conditions affecting the peripheral nerve. METHODS: A 16-year-old boy with thoracic scoliosis had normal posterior tibial nerve somatosensory-evoked potentials both before surgery and in the operating room immediately after anesthesia induction and prone positioning on a four-post spinal frame. RESULTS: One hour after the start of surgery, a minimal amplitude reduction of the right popliteal fossa potentials appeared. Fifteen minutes later, the amplitudes of the popliteal fossa, subcortical, and cortical potentials evoked by right posterior tibial nerve stimulation became substantially reduced. Subsequently, all waveforms were lost. Malfunction of the right posterior tibial nerve stimulator was initially suspected, but when proper function was verified, a search for other causes of this loss led to discovery of leg ischemia. The patient was repositioned on the spinal frame, and all posterior tibial nerve somatosensory-evoked potentials waveforms began to reappear 7 minutes later. There was no postoperative clinically detectable complication. CONCLUSIONS: Although technical malfunction should always be suspected when all intraoperative somatosensory-evoked potential waveforms are initially seen and subsequently lost, one should also consider the possibility that intraoperative ischemia due to limb positioning could be the etiology.

Adolescent↗
PubMed1999

Treatment of seizures in subcortical laminar heterotopia with corpus callosotomy and lamotrigine.

Focal and generalized cortical dysgeneses are sometimes seen on the magnetic resonance images (MRI) of patients with epilepsy. Subcortical laminar heterotopia are bilateral collections of gray matter in the centrum semiovale that resemble a band or "double cortex" on MRI. We studied one male and two female patients with subcortical laminar heterotopia who had moderate to severe developmental delay, early-onset epilepsy, and medically refractory seizures. Atonic, atypical absence, tonic, myoclonic, complex partial, and generalized tonic-clonic seizures were recorded. Interictal and ictal electroencephalographic patterns were generalized and, less commonly, multifocal. Two years after corpus callosotomy, one patient was free of generalized tonic-clonic and atonic seizures, but the other patient who had undergone callosotomy had no significant reduction in seizure frequency. With lamotrigine treatment, the patient who had not had surgery had complete cessation of monthly episodes of status epilepticus and a dramatic reduction of generalized tonic-clonic seizures, and the other patient who received lamotrigine had a 50% reduction of her atonic seizures. In patients with subcortical laminar heterotopia, atonic and generalized tonic-clonic seizures can be substantially reduced or eliminated by corpus callosotomy or treatment with lamotrigine.

Adult↗
PubMed1998

Temporal ictal electroencephalographic frequency correlates with hippocampal atrophy and sclerosis.

We studied 328 complex partial seizures (CPS) in 63 consecutive patients with temporal lobe epilepsy who underwent scalp electroencephalography/video monitoring, magnetic resonance imaging (MRI), and surgery. The initial ictal discharge (IID), defined as the first sustained electrical seizure pattern localized to the surgical site, was determined. If the IID was rhythmic waves, the median frequency was measured. To determine if IID frequency correlates with hippocampal atrophy (HA) or sclerosis (HS), hippocampal volume ratios (HVRs) were measured (n = 52) or assessed visually (n = 11) on MRI, and mesial temporal histopathology specimens (n = 22) were graded for HS. Sixteen patients (25%) had no or mild HA (HVR = 0.78-1.02), and 47 patients (75%) had moderate-to-marked unilateral (HVR = 0.33-0.76), or bilateral, HA. Theta frequency IIDs were significantly more commonly associated with moderate-to-marked HA than were delta IIDs. Theta frequency IIDs occurred in 19% of patients with mild or no HA, and 79% of patients with moderate-to-marked HA; delta IIDs occurred in 63% of patients with little to no HA, and 13% of those with moderate-to-marked HA. In addition, the median IID frequency inversely correlated with HVR and directly correlated with HS severity. In conclusion, faster frequency rhythmic IIDs during temporal lobe CPS correlate with greater degrees of ipsilateral HA on MRI, and higher grades of HS.

Adolescent↗
PubMed1997

Recent advancements in epilepsy.

This article reviews selected medical and surgical advances that the authors view as important to improving the treatment of patients with epilepsy. This includes a review of six new antiepileptic drugs (fosphenytoin, felbamate, gabapentin, lamotrigine, toprimimate, and vigabatrin), recent studies of the surgical technique of Multiple Subpial Transections, and a summary of a prospective longitudinal study on anterior temporal lobectomy.

Acetates↗
PubMed1996

Cataplexy and monoamine oxidase deficiency in Norrie disease.

Norrie disease (ND) is an X-linked recessive disorder causing ocular atrophy, mental retardation, deafness, and dysmorphic features. Virtually absent monoamine oxidase (MAO) type-A and -B activity has been found in some boys with chromosome deletions. We report the coexistence of cataplexy and abnormal REM sleep organization with ND. Three related boys, referred for treatment of medically refractory atonic spells and apneas, underwent extended EEG-video-polysomnographic monitoring. They demonstrated attacks of cataplexy and inappropriate periods of REM sleep during which they were unarousable. One boy also had generalized tonic-clonic seizures. Previous testing revealed that all three have complete ND gene deletions. In all subjects, platelet MAO-B activity was absent, serum serotonin levels were markedly increased, and plasma catecholamine levels were normal. Data from the canine narcolepsy syndrome model implicate abnormal catecholaminergic and cholinergic activities in the pathogenesis of cataplexy. Our findings suggest that abnormal MAO activity or an imbalance between serotonin and other neurotransmitter levels may be involved in the pathogenesis of human cataplexy.

Adult↗
PubMed1995

Multiple subpial transections for partial seizures in sensorimotor cortex.

We report six patients with complex partial seizures arising from the primary sensorimotor cortex who underwent invasive long-term ictal electroencephalogram/video monitoring and brain mapping and then multiple subpial transections. Although four patients demonstrated no abnormalities on magnetic resonance imaging, each patient showed moderate to marked gliosis in cortex biopsied from the site of ictal onset. Extensive preoperative and postoperative neuropsychological tests demonstrated no functional deficits resulting from surgery. Only one patient failed to derive significant postoperative seizure improvement, and he subsequently underwent additional subpial sectioning without further significant improvement. We propose a modification for this surgical technique and hypothesize that these patients may represent a syndrome of central cortical epilepsy.

Adolescent↗
PubMed1983

Metastatic choroidal melanoma. Hepatic binding protein reactivity toward a liver-metastasizing clone.

A clone of B16 malignant melanoma cells with a preference for metastasis to the liver was isolated and characterized. The parent tumor cells (F1) were injected in the tail vein of C57BL/6 mice, and the resultant liver colonizing cells were isolated and then subcultured for two to three weeks. The cells were then reinjected into the next series of mice. After five such passages, a clone (L4) of melanoma cells was obtained that metastasized almost exclusively to the liver. A hepatic binding protein (HBP) was isolated from rabbit liver that agglutinated neuraminidase-treated F1 and L4 malignant melanoma cells. Different agglutination titers found between the parent and liver-metastasizing clone demonstrated differences in cell-surface properties between the parent tumor and the liver-metastasizing clone. These results demonstrate that malignant melanoma cells can be selected for preferential liver metastasis and can be recognized and agglutinated by specific HBPs. Metastasis from human uveal malignant melanoma may occur by similar mechanisms.

Animals↗
PubMedDate not supplied

Epilepsy in schizencephaly: abnormal cortical organization studied by somatosensory evoked potentials.

Median nerve short-latency somatosensory evoked potentials (MN-SSEP) are recorded from the scalp to assess parietal lobe function and from the cortex to identify primary sensory and motor areas before epilepsy surgery. Nevertheless, the origins of many of the MN-SSEP waveforms and the reliability of this technique for localizing the central sulcus are not definitively known. We studied a child with a unilateral, closed, right parietal schizencephalic cleft and frequent simple partial seizures before the child underwent cortical resection. The sensory examination, neuroimaging, and electrical brain stimulation findings indicated a normal thalamus and an abnormal parietal lobe. Scalp-recorded MN-SSEPs showed intact widespread N18 potentials bilaterally, but absent right, although normal left parietal N20 and P27 waveforms. Cortically recorded MN-SSEPs could not localize the central sulcus owing to an absence of the expected negative potential over the right postcentral gyrus and the presence of waves with abnormal latencies over the precentral cortex. These findings suggest that: (a) the N18 potential probably originates at or below the level of the thalamus, (b) the N20 and P27 peaks are most likely generated by parietal cortex or white matter, and (c) cortically recorded MN-SSEPs can fail to localize the central sulcus before epilepsy surgery when congenital anomalies exist in the parietal lobe.

Adolescent↗