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.

CSF neuron-specific enolase after methohexital activation during electrocorticography.

We report changes in CSF and serum neuron-specific enolase (NSE) before and after methohexital infusion during electrocorticography in three patients undergoing epilepsy surgery. NSE is a critical enzyme for energy metabolism that accounts for 1.5% of all soluble brain protein and is an accepted marker of neuronal injury. CSF NSE rose three- to fourfold from baseline within 60 minutes after methohexital activation. Serum NSE was unchanged. This report supports evidence that CSF NSE rises acutely after induction of epileptiform activity and suggests that CSF NSE is a marker of seizure activity.

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.

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.

Status epilepticus increases CSF levels of neuron-specific enolase and alters the blood-brain barrier.

Neuron-specific enolase (NSE) is a sensitive marker of brain damage in stroke, global ischemia, and coma. Serum NSE is also correlated with the duration and outcome of status epilepticus (SE). CSF-NSE levels have not been previously reported in SE. We report the CSF concentrations of NSE in 11 patients with cryptogenic/remote symptomatic SE. CSF obtained within 24 hours of SE showed increased concentrations of NSE in 9 of 11 patients. The mean CSF-NSE for the group was elevated compared with the levels for normal control subjects (30.8 +/- 18.33 versus 10.76 +/- 3.08 ng/mL; p = 0.002). Further, CSF-NSE levels were elevated compared with simultaneous serum levels in the same group of patients (p = 0.01). In addition, the CSF/serum albumin ratio (QAlb), a measure of the integrity of the blood-brain barrier, was increased in SE patients compared with control individuals (33.4 versus 4.79 x 10(-3); p = 0.0001). An increase of QAlb correlated with CSF-NSE (rs = 0.66, p = 0.04) and serum NSE levels (rs = 0.83, p = 0.004). CSF-NSE is a promising in vivo marker for brain injury after SE.

Compulsive polydipsia following meningioma resection: an epileptic phenomenon? Case report.

The authors report the case of an individual who developed compulsive polydipsia following resection of a left sphenoidal ridge meningioma. The episodic, stereotyped nature of his symptoms, response to treatment, and electroencephalographic and magnetic resonance imaging findings are all highly consistent with temporal lobe-onset epilepsy. The pathophysiology of this underrecognized phenomenon is discussed.

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.

Use of antiepileptic drugs in nontraumatic neurosurgical procedures. Is there any best route and time of administration?

We assessed in 15 consecutive patients the best route and time of administration for phenytoin (PHT) prophylaxis in neurosurgical procedures. We also correlated PHT levels in serum and cerebrospinal fluid after oral and parenteral loading doses. The mean PHT level was 13.9 micrograms/ml in serum and 2.03 micrograms/ml in cerebrospinal fluid (CSF), with a significant correlation between levels in both compartments (r = 0.73, p < 0.01). Mean PHT levels among the different groups were not statistically significant. We conclude that therapeutic levels of PHT in CSF can be achieved independently of the route of administration, as long as accepted loading doses are used.

Limited efficacy of experimental anti-epileptic drugs in refractory temporal lobe epilepsy: implications for patient management and study recruitment.

Patients with refractory temporal lobe epilepsy (TLE) are commonly recruited for investigational anti-epileptic drug (XAED) studies. However, the long-term outcome of TLE after exposure to XAEDs is poorly documented. In this pilot study, we report the USC Epilepsy Center's experience of 19 patients with TLE enrolled in three XAED trials. The data reinforce that TLE is a drug-resistant epilepsy, and referral of good surgical candidates for surgery rather than XAED trials is more likely to result in remission.

Treatment of refractory partial status epilepticus with multiple subpial transection: case report.

Status epilepticus (SE) represents a medical emergency that annually affects 60,000--150,000 individuals in the United States. Selective neuronal loss in vulnerable areas has been pathologically demonstrated following convulsive SE primarily affecting the limbic system, thalamus and cerebellum. Morbidity in those cases that follow refractory SE (RSE) is poorly documented. There have been anecdotal reports of surgical treatment for this condition, especially secondary to brain lesions. We report a 6-year-old patient who was in RSE for 60 days, without a brain lesion documented by MRI. The patient underwent multiple subpial transection (MST) of the sensorimotor cortex, which by ictal EEG and ictal SPECT proved to be the epileptogenic zone. We conclude that MST should be considered as an alternative treatment for refractory partial SE.

Time distribution of epileptic seizures during video-EEG monitoring. Implications for health insurance systems in developing countries.

An attempt was made to identify guidelines to help establish epilepsy monitoring units in developing countries. We assessed the time distribution of seizures during video-EEG monitoring and we also estimated the minimum time required for such a procedure and the impact of these variables upon the health insurance system. Mean time for recording five stereotyped clinical events was 72 hours, with a significant number of events recorded between midnight and 0600 hours (P < 0.05). This pilot study may help to establish local policies that will warrant an adequate work-up for our patients.

An open-label evaluation of the tolerability and safety of Stalevo (carbidopa, levodopa and entacapone) in Parkinson's disease patients experiencing wearing-off.

OBJECTIVES: To evaluate the tolerability, safety and efficacy of Stalevo (carbidopa, levodopa and entacapone) in Parkinson's disease (PD). BACKGROUND: Levodopa provides the most effective symptom control for the treatment of Parkinson's disease (PD). However, its long-term use is limited by the development of motor complications such as wearing-off. Catechol-O-methyltransferase (COMT) inhibitors such as entacapone extend the plasma half-life of levodopa and reduce 'off' time. Stalevo is a new levodopa product that combines carbidopa, levodopa and entacapone in one tablet. Clinical studies have not been reported with this compound. DESIGN METHODS: An open-label, multi-center US trial evaluated 169 consecutive PD patients experiencing end-of-dose wearing-off, with (n = 39) and without (n = 130) mild dyskinesia. Patients were switched from immediate-release carbidopa/levodopa to Stalevo and were treated for four weeks. Assessments included tolerability measures, adverse events profile, the disease-specific quality of life instrument PDQ-39, UPDRS parts II, III, and question 39 and investigator and patient global clinical assessments. RESULTS: 14 subjects (8%) discontinued treatment with Stalevo, of which 12 (7%) were due to adverse events. 11/130 (8.5%) subjects developed new onset dyskinesia and 17/39 (43.6%) of patients with existing dyskinesia reported a worsening in their dyskinesia. However, this was managed by a change in dose in 21.4% of patients and in another 10.7% dyskinesias resolved without any need for dose adjustment. Other side effects were infrequent and mild, the most common being nausea (12.4%) dizziness (6.5%) and somnolence (6.5%). Stalevo treatment resulted in significant improvements in PDQ-39 and UPDRS (II + III) scores (p < 0.001). Assessment of 'off' time demonstrated a reduction in off time in 32% of patients, compared with an increase in 7% of patients. Improvements were noted by both investigator (68.1%) and patient (68.6%) assessments. CONCLUSIONS: Switching PD patients experiencing wearing-off from carbidopa/levodopa therapy to Stalevo was safe, well tolerated and resulted in clinical improvement.

Assessment of colour vision in epileptic patients exposed to single-drug therapy.

Diplopia, blurred vision and colour disturbances are well-known side effects associated with anti-epileptic drugs (AEDs). Farnsworth-Munsell 100-hue colour test (F-100) is an accepted and sensitive tool to detect changes in colour perception. To determine the impact of AEDs upon colour vision, we evaluated 37 consecutive patients with complex partial seizures exposed to monotherapy with phenytoin (PHT, carbamazepine (CBZ) or valproic acid (VPA). All had normal IQ and no congenital disturbances in colour vision or ocular diseases. Twenty normal controls were used for statistical analysis. Thirteen patients were exposed to PHT, 12 to CBZ and 12 to VPA. Visual colour perception was impaired in 30/37 (82%) of the study group. The most significant abnormality was detected in the blue-yellow axis in 10/13 patients exposed to PHT (p < 0.02) and in 8/12 treated with CBZ (p < 0.009). In 8/12 patients taking VPA, no significant abnormality was observed (p < 0.06). None of the studied patients complained of colour vision disturbances. Our findings strongly support the negative effect of AEDs upon colour vision discrimination, most likely due to changes at the retinal processing level. F-100 proved to be very useful to assess early toxicity due to AEDs.

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.

Transient epileptic amnesia in dementia: a treatable unrecognized cause of episodic amnestic wandering.

The authors present two patients with dementia who displayed recurrent transient episodes of amnestic wandering and disorientation characterized by getting lost in familiar environments. At other times these patients did not wander or become disoriented. The inability to recall any information during these episodes, and the marked difference of the episodic amnesia exacerbations from the progressive amnesia characteristic of Alzheimer disease seen in these patients led to their evaluation. These clinical episodes and the bilateral interictal epileptiform electroencephalographic changes found in both patients led to the diagnosis of transient epileptic amnesia, a syndrome that can be diagnostically elusive. These transient amnestic wandering events subsided after treatment with antiepileptic drugs in both patients. The authors suggest that transient wandering of this type may be caused by ictal events or postictal confusional states. This report emphasizes the importance of recognizing transient epileptic amnesia as an easily treatable cause of episodic behavioral abnormalities responsive to antiepileptic therapy, especially in those patients who have a markedly inconsistent pattern of wandering, disorientation in familiar settings, and amnesia exacerbation manifested by no recall of the emotional stress of getting lost or of any information during these episodes. Recognition of this type of behavioral disruption and its proper treatment can lead to improved quality of life for these patients, maintain these patients in their homes and out of chronic care institutions longer, and facilitate the community's and caretaker's interactive roles with the patient.

Carbamazepine-induced antinuclear antibodies and systemic lupus erythematosus-like syndrome.

A 20-year-old woman developed a systemic lupus erythematosus (SLE)-like syndrome and a positive antinuclear antibody (ANA) soon after initiation of carbamazepine (CBZ) therapy. Symptoms and serology became normal after CBZ was discontinued. CBZ-induced SLE is an important but underecognized phenomenon.

Lidocaine in refractory status epilepticus: confirmation of efficacy with continuous EEG monitoring.

Lidocaine was efficacious in 2 patients with refractory status epilepticus (RSE) unresponsive to several antiepileptic drugs (AEDs), including high-dose barbiturates. We confirmed the efficacy of lidocaine with, for the first time in adults, continuous EEG monitoring. Lidocaine, when properly used, may be a treatment option in RSE.

Cerebral neurocytoma: an unusual cause of refractory epilepsy. Case report and review of the literature.

We report a patient with medically refractory complex partial seizures (CPS) caused by a cerebral neurocytoma located near the amygdala. Neurocytoma represents an important addition to the differential diagnosis and, in particular, must be differentiated from oligodendroglioma and dysembryoplastic neuroepithelial tumor. Accurate pathological differential has therapeutic and prognostic implications.

High-dose tamoxifen in treatment of brain tumors: interaction with antiepileptic drugs.

The incidence of seizures related to primary brain tumors is 20-80%. High-dose tamoxifen was recently reported as a novel treatment for patients with malignant gliomas who have failed standard therapies. Tamoxifen inhibits protein kinase C (PKC) in vitro and thus may regulate glioma cell growth by modulating intracellular signal transduction. We report a patient with a recurrent supratentorial pilocytic astrocytoma who had an untoward interaction between high-dose tamoxifen therapy and phenytoin (PHT), drugs that share a common enzyme for metabolism, therefore emphasizing the need to monitor concomitant antiepileptic drug (AED) levels when high-dose tamoxifen therapy is instituted.