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Biomedical subjects

P S Gott

Publications and source records attributed to P S Gott.

At least 19 recordsLinked to original sources
PubMed1999

Serum neuron-specific enolase in the major subtypes of status epilepticus.

OBJECTIVES: To determine the relative magnitudes of neuron-specific enolase (NSE) levels after complex partial status epilepticus (SE), absence SE, generalized convulsive SE, and subclinical generalized convulsive SE (frequently referred to as acute symptomatic myoclonic status epilepticus). BACKGROUND: NSE is a marker of acute brain injury and blood-brain barrier dysfunction, which is elevated in SE. METHODS: Serum NSE levels were drawn in 31 patients 1, 2, 3, and 7 days after SE. Patients were classified as acute symptomatic or remote symptomatic, and the duration and outcome of SE were determined and correlated with the peak NSE level. RESULTS: NSE was elevated significantly in all four subtypes of SE, but NSE levels were highest in complex partial and subclinical SE. The mean peak NSE level for the complex partial SE group was 23.88 ng/mL (n = 12), 21.5 ng/mL for absence SE (n = 1), 14.10 ng/mL for the generalized convulsive SE group (n = 12), and 37.83 ng/mL for the subclinical SE group (n = 6), all of which was significantly higher than normal control subjects (5.02 ng/mL). Outcome was significantly different between the three groups (p = 0.0007), and was significantly worse for subclinical SE (p = 0.0005, subclinical versus generalized convulsive SE). CONCLUSION: Serum NSE levels were highest in complex partial and subclinical generalized convulsive SE. The extremely high levels of NSE in subclinical SE reflect the severity of the acute neurologic insults and poor outcome common to subclinical SE. High NSE levels in complex partial SE reflects the long duration of SE in this subgroup, and potential for brain injury.

Electroencephalography↗
PubMed1997

Significance of multimodality evoked potential abnormalities in sarcoidosis.

To assess central nervous system (CNS) involvement with normal CNS examination, multimodality evoked potentials were obtained in 25 patients with confirmed multisystem sarcoidosis. Twelve patients had abnormal evoked potentials: brainstem auditory evoked potentials (BAEP) were abnormal in 5, median nerve somatosensory evoked potentials (SEP) were abnormal in 4, and visual evoked potentials (VEP) were abnormal in 6 patients. Contrast-enhanced magnetic resonance imaging (MRI) of the brain in two patients with abnormal evoked potentials revealed no supportive structural lesions. Multimodality evoked potentials can detect subclinical neurosarcoidosis and are an important adjunct to neuroradiology in the diagnosis of neurosarcoidosis.

Adult↗
PubMed1996

Neuron-specific enolase, a marker of acute neuronal injury, is increased in complex partial status epilepticus.

PURPOSE: To determine whether complex partial status epilepticus (CPSE) causes brain injury in humans. Serum neuron-specific enolase (s-NSE) is an accepted marker of acute brain injury, and increases in s-NSE have been correlated with the duration and outcome of generalized convulsive status epilepticus. s-NSE levels in CPSE are unknown. Increase in s-NSE in CPSE would provide new information about the degree of brain injury in CPSE and would help confirm that CPSE is a medical emergency. METHODS: This was a pilot prospective study of serial levels of s-NSE and outcome in CPSE. Eight patients with confirmed CPSE and no acute neurologic deficit were identified prospectively. Results were compared with those of normal and epileptic control groups, and outcome was assessed at hospital discharge or at 7 days with the Glasgow Oucome Scale (GOS). RESULTS: The mean peak s-NSE was 21.81 ng/ml, which for the 8 patients with CPSE was four times higher than that of normal controls (mean s-NSE = 5.36 SD = 1.66, p = 0.0003) and epileptic controls (mean s-NSE = 4.61 SD = 1.74, p. = 0.001). CONCLUSION: The increase in s-NSE provides new evidence that CPSE causes brain injury in humans.

Biomarkers↗
PubMed1996

Spouses of demented patients with low cobalamin levels: a new risk group for cobalamin deficiency.

Low serum cobalamin levels are common in conditions such as dementia and often represent mild deficiency. We surveyed serum cobalamin levels prospectively in spouses and blood relatives of demented patients to determine if any familial predisposition exists for the low levels. Cobalamin status in most of the relatives found to have low levels was assessed further by means of blood counts, metabolic tests, neurologic evaluation, absorption studies and response to cobalamin therapy. Serum cobalamin levels in 36 spouses correlated with those of the 36 demented patients related to them (r = 0.46, p = 0.004). A significant association was not seen in 34 blood relatives of 34 demented patients (r = 0.27). Most importantly, 67% of the spouses of demented patients with low serum cobalamin had low values themselves, compared with only 3% of the spouses of patients with normal levels (p = 0.001). Detailed study of 4 of the 5 spouses (and 3 blood relatives) with low cobalamin levels showed no anemia in any case. Nevertheless, 4 of the subjects had metabolic evidence of deficiency and one had electrophysiological abnormalities; all these defects improved with cobalamin therapy. These observations identify a hitherto unsuspected group of people at high risk for cobalamin deficiency and suggest that spouses of demented patients with low cobalamin levels should also have their cobalamin levels measured. The increased frequency of low serum cobalamin levels in spouses of demented patients with low levels represents in most cases a true, mild cobalamin deficiency that responds to treatment.

Adult↗
PubMed1995

The frequently low cobalamin levels in dementia usually signify treatable metabolic, neurologic and electrophysiologic abnormalities.

Cobalamin levels are frequently low in patients with dementia, but it is unclear if they represent definable deficiency and what the mechanisms are. Therefore, patients being evaluated for dementia who had low cobalamin levels but no obvious evidence of deficiency were studied hematologically, neurologically and with metabolic tests and were re-evaluated after cobalamin treatment. Abnormalities suggestive of or diagnostic for deficiency were documented in most of the 16 demented and nondemented patients. Metabolic results: 50% of patients tested had abnormal deoxyuridine suppression and 44% had increased serum methylmalonic acid and/or homocysteine levels; these test results correlated with each other. Neurologic results: 73% of patients had clinical abnormalities, primarily mild neuropathies, not attributable to other causes, 75% had electroencephalographic abnormalities, 77% had abnormal visual evoked potentials and 33% had abnormal somatosensory potentials. Metabolic and neurologic dysfunction were present together or absent together in all but 2 cases. Cobalamin therapy improved 50-100% of the various types of abnormalities, although it did not improve cognitive function in the 13 demented patients. Food-cobalamin malabsorption was found in 60% of the patients. Despite the absence of megaloblastic anemia and rarity of traditional malabsorption of free cobalamin, low cobalamin levels in demented patients frequently represent mild cobalamin deficiency and are often associated with food-cobalamin malabsorption. Perhaps most importantly, this is accompanied not only by metabolic changes but by evidence of mild neurologic dysfunction. Their frequent reversibility by cobalamin confirms that these defects indeed arise from cobalamin deficiency. Although the long-standing dementia does not improve, treating such patients with cobalamin has other concrete benefits.

Aged↗
PubMed1995

Serum neuron-specific enolase in human status epilepticus.

Neuron-specific enolase (NSE) is a sensitive marker of brain injury after stroke, global ischemia, and coma. We report changes in serum NSE (s-NSE) in 19 patients who sustained status epilepticus. s-NSE peaked within 24 to 48 hours after status epilepticus. The mean peak s-NSE level for the entire group was elevated compared with the levels for normal controls (24.87 ng/ml versus 5.36 ng/ml, p = 0.0001) and for epileptic controls (24.87 ng/ml versus 4.61 ng/ml, p = 0.0001). The mean peak s-NSE level for the 11 subjects without an acute neurologic insult (15.44 ng/ml) was also significantly increased compared with levels for normal and epileptic controls. Further, s-NSE was significantly correlated with outcome and duration. We conclude that s-NSE is a promising in vivo marker of brain injury in status epilepticus and warrants further study in larger populations.

Humans↗
PubMed1994

Outcomes of pregnancy associated with antiepileptic drugs.

OBJECTIVE: To determine whether exposure to antiepileptic drugs during pregnancy is associated with poor fetal outcomes (anomalies and death) and to assess the relative risks with phenobarbital, phenytoin sodium, and carbamazepine. DESIGN: The design was a prospective case-control cohort study of pregnant women with epilepsy and their offspring. Outcomes were compared with those of a control group of 355 healthy women and their offspring. SETTING: The obstetrics service at Los Angeles County/University of Southern California Medical Center, Los Angeles, a large, inner-city, teaching hospital. PATIENTS: Two hundred eleven subjects who were pregnant during the years 1987 through 1990, 174 of whom were delivered of infants, were available for analysis. A control group of 355 healthy women and their offspring from the same hospital were randomly selected from a computerized database. INTERVENTION: None. MAIN OUTCOME MEASURE: Anomalies and fetal death were the primary outcome measures. RESULTS: Offspring of women with epilepsy who were exposed to antiepileptic drugs had a higher rate of fetal death and anomalies than did the control population (P = .001). Abnormal outcomes were associated with the three major antiepileptic drugs (carbamazepine, phenytoin, and phenobarbital). In terms of abnormal outcome (death and anomalies), phenobarbital was associated with the highest relative risk, phenytoin with intermediate relative risk, and carbamazepine with the lowest relative risk (P = .019). Numbers were insufficient for assessment of risk associated with valproic acid. CONCLUSION: All three major antiepileptic drugs (phenobarbital, phenytoin, and carbamazepine) are associated with an increased risk of fetal death and anomalies. We found phenobarbital to be most associated with poor pregnancy outcome.

Abnormalities, Drug-Induced↗
PubMed1993

Predictive value of P300 event-related potentials compared with EEG and somatosensory evoked potentials in non-traumatic coma.

Developments in ethical decision making are increasing demand for more accurate predictions of outcome in coma. New neurophysiologic tests are needed to improve the ability to predict awakening as well as poor outcome. We have recently reported that the P300 event-related potential (P300) correlates with awakening and depth of nontraumatic coma. In this companion study, the predictive value of the P300 was compared with median nerve somatosensory evoked potentials (SEP) and EEG in 20 patients in non-traumatic coma. We also evaluated the predictive value of a simplified grading scale for both the EEG and SEP (the USC SEP scale and USC EEG scale). The presence of a P300 was significantly associated with higher Glasgow coma scores (GCS) and awakening. Severe abnormalities of the somatosensory evoked potentials significantly correlated with the absence of awakening and a low GCS. Moderate abnormalities of the SEP were significantly associated with awakening and higher GCS scores. The EEG was significantly associated with GCS score and severe abnormalities of the EEG were predictive of the absence of awakening and very low GCS scores. The data indicates that the P300 and SEP are more effective than the EEG in predicting awakening, and that the SEP and EEG are more effective than the P300 in predicting poor outcome. We conclude that, in addition to EEG and SEP, the P300 should be considered in the prognostic evaluation of patients in nontraumatic coma. Further, simplified scales for the EEG and SEP are predictive of depth of coma and outcome.

Adult↗
PubMed1991

P300 auditory event-related potentials in nontraumatic coma. Association with Glasgow Coma Score and awakening.

Auditory event-related potentials (ERPs) were performed in 20 patients with nontraumatic coma to determine the presence of a P300 ERP in coma and its association with the Glasgow Coma Score and awakening (Glasgow Outcome Score, > or = 3). A standard "oddball" paradigm was used: frequent tone, 1 kHz; rare tone, 2 kHz and 4 Hz; probability, 20%. The Glasgow Coma Score was determined concurrently with the P300 ERP. Thirty percent (6/20) of the comatose patients had a P300 ERP. The mean Glasgow Coma Score was significantly higher for those with a P300 ERP. Eighty-three percent (5/6) of those with a P300 ERP awoke. Presence of a P300 ERP was associated significantly with awakening, but absence of a P300 ERP did not preclude it.

Adult↗
PubMed1991

Unruptured intracranial aneurysms: seizures and antiepileptic drug treatment following surgery.

Twenty-one patients operated on for unruptured intracranial aneurysms were studied retrospectively in order to identify the incidence of postoperative seizures, factors predictive of seizures, and the response to discontinuation of antiepileptic drugs. The overall risk of postoperative seizures in initially seizure-free patients was 15.7%. Although seizures were not uncommon, antiepileptic drugs were successfully tapered in most of the patients before 12 months.

Anticonvulsants↗
PubMed1990

Assessment of median nerve somatosensory evoked potentials in cerebral ischemia.

Seventy patients with cerebral ischemia (21 with transient ischemic attack and 49 with stroke) were studied with short-latency median nerve somatosensory evoked potentials to characterize the evoked potentials in all ischemic patients and to investigate their efficacy for prognosis in stroke. Within 72 hours of symptom onset, all 70 patients received a scaled neurologic function score, with a maximum of 50 points. Somatosensory evoked potential abnormalities were found in 10% (2/19), 42% (15/36), and 93% (14/15) of all patients with initial neurologic examinations who had normal (50 points), mild-moderate (30-49 points), and severe deficits (less than or equal to 29 points), respectively. Thirty-seven of the 49 stroke patients were available for a follow-up neurologic assessment. Eight-nine percent (8/9) of the stroke patients with poor outcome had somatosensory evoked potential abnormalities; 82% (9/11) of the stroke patients with severe neurologic deficits at onset had poor outcome. Results demonstrate that somatosensory evoked potential abnormalities are common in patients with cerebral ischemia but that somatosensory evoked potential findings are not significantly better than a detailed neurologic examination in predicting outcome from stroke.

Adult↗
PubMed1988

Noradrenergic cerebral stimulation of sensorineural impaired subjects: yohimbine effects on speech intelligibility and the auditory brain response.

Norepinephrine has been shown to improve signal-to-noise ratios of sensory systems, including that of the auditory system. Yohimbine has been observed to cause a selective increase of cerebral norepinephrine. It was administered in one dose to sensorineurally impaired subjects with the object of improving their speech hearing in noise. Speech intelligibility was measured by the adaptive procedure. Mild, significant improvement was noted in one of the hearing components, "attenuation," and an adverse effect was shown on "distortion," owing to noise. Auditory brainstem response was improved significantly. The objective of temporarily improving intelligibility in noise was not attained.

Aged↗
PubMed1985

Interhemispheric transmission: assessment with vibratory somatosensory evoked potentials.

Interhemispheric transmission time (ITT) was derived from vibratory somatosensory evoked potentials (VSEP) arising in homologous cortical sensory--association areas of normals. Two different vibratory sources, an audiometer bone oscillator or an Optacon, were used to stimulate each index finger independently. ITT was calculated by subtracting the latency of the first major peak over the contralateral cortex (CL) from the latency of the corresponding peak over the ipsilateral area (IL-CL = ITT). Readily identified aberrant values were observed and rejected from the series of measurements leaving clear normal ranges. In addition to providing normal ITT data, clinical correlations were illustrated in two different disorders. Results suggested that important information relating to diagnosis and therapy of brain pathologies affecting interhemispheric transmission can now be made available in both experimental and clinical situations.

Adolescent↗
PubMed1985

Migraine: a diagnostic test for etiology of food sensitivity by a nutritionally supported fast and confirmed by long-term report.

A diagnostic procedure during a nutritionally supported fast week followed by conventional food sensitivity management achieved major improvement for 80% of a migraine panel. This procedure gave a reliable (0.8 correlation coefficient) prognosis on the substantial value of this approach for selection of the treatment of migraine. The study gave two lines of evidence which indicate that migraine has an etiology of food sensitivity.

Adult↗
PubMed1984

Voluntary control of two lateralized conscious states: validation by electrical and behavioral studies.

A subject is described who can voluntarily select and hold either of two qualitatively different states of consciousness. Evidence is presented which confirmed differential left or right hemisphere dominance in each state. Asymmetries of EEG alpha and task performance scores indicated a state-dependent shift in functional lateralization. Evoked response studies showed directional changes in rate of interhemispheric transmission correlated with state-related hemisphere dominance. These findings demonstrated that capability for voluntary endogenous control of cerebral dominance under natural conditions.

Adult↗
PubMed1983

Abnormal visual evoked potentials in myotonic dystrophy.

Pattern-shift visual evoked potentials (VEPs) were recorded in 17 patients with myotonic dystrophy. Abnormalities of latency or amplitude were found in 10 patients (59%) with no obvious retinal or other significant ocular abnormality. All patients had a visual acuity of 20/30 or better. Since most patients had bilateral VEP abnormalities, localization of the disturbance was not certain.

Adult↗
PubMed1982

Transcallosal, interfornicial approaches for lesions affecting the third ventricle: surgical considerations and consequences.

A group of 11 patients with a variety of lesions affecting the 3rd ventricle have been treated using a direct transcallosal interfornicial approach to the region. In 3 patients, no attendant hydrocephalus was present. In an effort to minimize potential cortical injury related to the approach, we studied the venous anatomy in the region of the coronal suture. Based on this study, appropriate flap placement and interhemispheric entry points were defined. Although no lasting, clinically apparent morbidity was observed in any of the 11 cases, we performed more sophisticated studies of the interhemispheric transfer of somesthetic and perceptual motor tasks, as well as psychometric testing related to parameters of intelligence and memory, 3 to 8 months postoperatively in 6 cases. The results and clinical material indicate that this surgical technique is a safe, feasible alternative in the management of a wide spectrum of pathological lesions within this region. A transcallosal, interfornicial approach offers excellent visualization of the entire 3rd ventricle without the dependence on hydrocephalus or an extensive extra-axial mass to enhance the exposure. With proper planning and technique, it may be accomplished with a minimum of physiological consequence.

Brain Diseases↗