Proposal: different types of alteration and loss of consciousness in epilepsy.

There are at least five types of alterations of consciousness that occur during epileptic seizures: auras with illusions or hallucinations, dyscognitive seizures, epileptic delirium, dialeptic seizures, and epileptic coma. Each of these types of alterations of consciousness has a specific semiology and a distinct pathophysiologic mechanism. In this proposal we emphasize the need to clearly define each of these alterations/loss of consciousness and to apply this terminology in semiologic descriptions and classifications of epileptic seizures. The proposal is a consensus opinion of experienced epileptologists, and it is hoped that it will lead to systematic studies that will allow a scientific characterization of the different types of alterations/loss of consciousness described in this article.

Noninvasive correlates of subdural grid electrographic outcome.

PURPOSE: To investigate reasons for patients not proceeding to resective epilepsy surgery after subdural grid evaluation (SDE). To correlate noninvasive investigation results with invasive EEG observations in a set of patients with nonlesional brain MRIs. METHODS: Retrospective study of adult epilepsy patients undergoing SDE during an 8-year period at Cleveland Clinic. Construction of semiquantitative "scores" and Bayesian predictors summarizing the localizing value and concordance between noninvasive parameters in a subset with nonlesional MRIs. RESULTS: One hundred forty patients underwent SDE, 25 of whom were subsequently denied resective surgery. In 10 of 25, this was caused by a nonlocalizing subdural ictal EEG onset. Eight of 10 such patients were nonlesional on MRI. Among all nonlesional patients (n = 34 of 140), n1 = 10 of 34 patients had nonlocalizing and n2 = 24 of 34 had localizing, subdural ictal onsets. As groups, n1 and n2 were statistically disjoint relative to their noninvasive scores. Bayesian measures predictive of focal invasive ictal EEG were highest for complete concordance of noninvasive parameters, decreasing with lesser degrees of concordance. A localizing scalp interictal EEG was a particularly good Bayesian prognosticator. CONCLUSIONS: A small but significant proportion of SDE patients are denied subsequent therapeutic resective surgery. This is due to several reasons, including a nonlocalizing intracranial ictal EEG. The majority of such patients have nonlesional MRIs. The noninvasive data may be summarized by a semiquantitative score, as well as Bayesian likelihood ratios, which correlate with subsequent invasive outcome. This approach may find use in the selection and counseling of potential surgical candidates offered SDE.

Phenobarbital withdrawal seizures may occur over several weeks before remitting: human data and hypothetical mechanism.

This case is the first report of a patient who had phenobarbital (PB) withdrawal seizures after having been seizure-free for 3 years following temporal lobe surgery. The patient had been taking PB for 14 years when a gradual taper of PB was started. When PB was at 60 mg/d, a titration of lamotrigine (LTG) was started. However, typical complex seizures occurred when the patient was on PB 60 mg/d, along with LTG 25mg/d. PB was increased back to 90 mg/d and levetiracetam (LEV) was titrated. Seizures appeared when the patient was on PB 30 mg/d and LEV 750 mg BID and continued for 3 weeks after PB was stopped and the patient was on LEV 1,000 mg BID. For the following 6 months, her aura frequency remained elevated in comparison to her baseline aura of two auras per month for the previous year before the start of the PB taper. She was followed for 24 months after her last PB withdrawal seizure. During the last 8 months, her aura frequency returned to her baseline. As suggested by animal studies, the PB withdrawal seizures and increase in aura frequency in this patient may be explained by changes in her levels of GABA(A) receptor subunits.

Complications during the Wada test.

OBJECTIVE: The intracarotid amobarbital procedure (IAP) is routinely used in the preoperative workup of patients with epilepsy. We previously reported dissections and seizures as complications of this procedure and now have reviewed our cohort for additional complications associated with the IAP. METHODS: Charts of 677 consecutive patients were reviewed for complications during the IAP. RESULTS: Complications were observed in 74 patients (10.9%) and included encephalopathy (7.2%), seizures (1.2%), strokes (0.6%), transient ischemic attacks (0.6%), localized hemorrhage at the catheter insertion site (0.6%), carotid artery dissections (0.4%), allergic reaction to contrast (0.3%), bleeding from the catheter insertion site (0.1%), and infection (0.1%). Older patients were more prone to strokes and dissections, whereas younger patients more frequently experienced seizures. Use of amobarbital was associated with encephalopathy, whereas methohexital was related to seizures. CONCLUSION: The IAP bears the risk of minor and major complications in up to 11% of patients. Risks, benefits, and possible alternative options have to be considered when a patient is to undergo the IAP.

Repeated intracarotid amobarbital tests.

RATIONALE: Our goal was to determine the frequency of repeated intracarotid amobarbital test (IAT) at our center and to estimate the retest reliability of the IAT for both language and memory lateralization. METHODS: A total of 1,249 consecutive IATs on 1,190 patients were retrospectively reviewed for repeat tests. RESULTS: In 4% of patients the IAT was repeated in order to deliver satisfactory information on either language or memory lateralization. Reasons for repetition included obtundation and inability to test for memory lateralization, inability to test for language lateralization, no hemiparesis during first test, no aphasia during first test, atypical vessel filling, and bleeding complications from the catheter insertion site. Language lateralization was reproduced in all but one patient. Repeated memory test results were less consistent across tests, and memory lateralization was unreliable in 63% of the patients. DISCUSSION: In spite of test limitations by a varying dose of amobarbital, crossover of amobarbital from one side to the other, testing of both hemispheres on the same day, practice effects, unblinded observers, fluctuating cooperation of the patients, and a biased sample of patients language lateralization was reproduced in all but one patient. In contrast, repeated memory test results were frequently contradictory. Memory results on IAT therefore seem much less robust than the results of language testing. Gain of reliable information versus the risks of complications and failed tests has to be considered when a patient is subjected to an IAT.

Seizures during intracarotid methohexital and amobarbital testing.

BACKGROUND: Methohexital and amobarbital have been used as agents for Wada testing in the presurgical evaluation of patients with epilepsy. Previous experience with methohexital as an anesthetic indicates that methohexital may decrease seizure threshold and may trigger seizures. METHODS: A retrospective chart review of 760 intracarotid amobarbital and methohexital tests was performed to determine the frequency of seizures associated with preoperative intracarotid barbiturate testing for language and memory lateralization. RESULTS: Sixteen patients (2.1%) who had seizures were found. In 3 patients, seizures occurred prior to barbiturate injection, and in 13, following barbiturate injection. After injection of amobarbital, 4 of 538 patients (0.7%) had a seizure. Nine of 222 patients had a seizure after methohexital injection (4.1%) (P=0.001). CONCLUSION: Patients with a previous history of epilepsy may be at higher risk for seizures after methohexital injection as compared with amobarbital injection.

Evaluating the contributions of state-of-the-art assessment techniques to predicting memory outcome after unilateral anterior temporal lobectomy.

PURPOSE: Although anterior temporal lobectomy (ATL) is an effective treatment for many patients with medically refractory temporal lobe epilepsy (TLE), one risk associated with this procedure is postsurgical decline in memory. A substantial number of past studies examined factors that predict memory decline after surgery, but few have investigated multiple predictors simultaneously or considered measures that are currently in use. METHODS: This study compared the relative contributions made by presurgical neuropsychological test scores, MRI-based hippocampal volumetric analysis, and Wada test results to predicting memory outcome after ATL in a group of 87 patients. RESULTS: Logistic regression analyses indicated that noninvasive procedures (neuropsychological testing and MRI) made significant contributions to improving the prediction of memory outcome in this sample. The results from the Wada procedure did not significantly improve prediction once these other factors were considered. The only exception was in predicting memory for visual information after a delay, in which Wada results improved prediction accuracy from 78% to 81%. CONCLUSIONS: Current neuropsychological tests and MRI volumetric measures predict changes in verbal and visual memory after ATL. The relatively small change in correct classification rates when Wada memory scores are considered calls into question the benefits of using Wada test results to predict memory outcome when the results of noninvasive procedures are available.

Intracranial lipomas and epilepsy.

INTRODUCTION: Intracranial lipomas are rare, mostly congenital lesions. Sporadic case reports suggest an association with focal epilepsy. METHODS: All admissions to our epilepsy monitoring unit who had had brain MRI were reviewed for intracranial lipomas during 6 consecutive years. RESULTS: Five patients with intracranial lipomas were identified (0.14%). Lipomas were located in the midline (3 cases), in the tectal region, and over the parietal cortex. Another intracranial pathology was identified in two patients causing the epilepsy in these cases (head trauma and hemimegaencephaly). In two other cases the Video EEG monitoring findings were not congruent with the location of the lipoma, but no other explanation for their epilepsy was found. In one patient a large midline lipoma extending into the right lateral ventricle was thought to be the cause of the patient's right hemispheric seizures. No other clinical symptoms or complications of the lipomas were noted. DISCUSSION: Intracranial lipomas are rare, incidental, often asymptomatic findings and usually located near the midline. In only one of our five patients was the lipoma interpreted as the definite cause of the epilepsy.

Coexistence of focal and idiopathic generalized epilepsy in the same patient population.

PURPOSE: To review the clinical, electrographic, radiological, and pathological findings of patients with coexistent idiopathic generalized and partial epilepsy syndromes. METHODS: We performed a medical record review and a phone interview with all patients hospitalized to the Cleveland Clinic epilepsy monitoring unit (EMU) between 1992 and 2002 who fulfilled clinical and EEG criteria of coexistent partial and generalized epilepsy syndromes. RESULTS: Seven patients were identified. Two (29%) were men with a mean age of 26 years. Four had a history of febrile seizures. Family history was positive in five. Mean duration of the generalized epilepsy syndrome was 11 years, and of the focal epilepsy 18 years. An equal number of patients developed focal versus generalized epilepsy first. Interictal EEG activity was predominantly generalized. Four had video-EEG documentation of both types of seizures. In the rest, only focal seizures were recorded but interictal activity strongly suggested a coexistent generalized epilepsy. MRI showed hippocampal atrophy in all, and hippocampal dysplasia in three. Five patients had PET imaging, all with hypometabolism in areas corresponding to the ictal onset on EEG. Four patients underwent epilepsy surgery with good surgical outcome and pathological confirmation of hippocampal sclerosis in all. CONCLUSION: We found a 0.2% incidence of coexistent focal and primary generalized epilepsy. Febrile seizures and a positive family history were common. Good seizure control was achieved after temporal lobectomy, even when interictal generalized activity predominated.

Optimizing outcomes in pregnant women with epilepsy.

Women with epilepsy are more likely to have maternal and fetal complications during pregnancy. Risks can be minimized with preconception planning, careful obstetric care, and close postpartum follow-up.

Now we lay them down to sleep: ethical issues with the use of pharmacologic coma for adult status epilepticus.

The use of pharmacologic coma (PC) to treat status epilepticus (SE) is not always successful, and there are no guidelines for the duration of PC in an attempt to achieve seizure control. Using clinical cases, we explore three concepts: (1) SE as a terminal condition; (2) PC resulting in permanent unconsciousness; and (3) use of PC for extended periods. Regarding a patient's Advance Directive/Living Will, these three concepts can pose ethical complexities for the medical team due to the notions of unconsciousness, cognitive appreciation, and life support being relevant to both PC therapy as well as these documents. We argue that when PC therapy is not reversing the patient's clinical course and only offering to sustain organic life, it is ethically appropriate to discontinue such therapy and provide the patient comfort care. If PC therapy is only expected to sustain organic life, it is ethically appropriate not to offer it.

The effect of total hip arthroplasty surgical approach on gait.

This study examined the effect of the surgical approach used in total hip arthroplasty (THA) on gait mechanics six months following surgery. Quantitative gait analysis was performed on 29 subjects: 10 anterolateral (A-L) and 10 posterolateral (P-L) THA patients and nine able-bodied, velocity-matched subjects. Discriminant function analysis was used to determine the distinction of the groups with respect to sagittal plane hip range of motion, index of symmetry, trunk inclination, pelvic drop, hip abduction, and foot progression angles. The A-L group had the largest trunk inclination (3.0+/-2.4 degrees) and the smallest hip range of motion (34.0+/-7.4 degrees). Both THA groups demonstrated greater asymmetry as expressed by the smaller symmetry index (0.97+/-0.04 for A-L and 0.98+/-0.05 for the P-L) than the able-bodied group (0.99+/-0.01). The classification procedure correctly classified 89% of the control group cases, 90% of the A-L cases, and 50% of the P-L cases. These results support the conclusion that six months following surgery, the gait of the majority (85%) of THA patients has not returned to normal. The A-L patients displayed distinct gait patterns, while a small percentage (30%) of the P-L patients demonstrated normal gait. While these differences are statistically significant, the clinical significance is unknown and linked to the duration that they persist.

Tolerability and pharmacokinetics of oral loading with lamotrigine in epilepsy monitoring units.

PURPOSE: To investigate the tolerability and pharmacokinetics of oral loading with lamotrigine (LTG) among epilepsy patients after temporary drug discontinuation in an epilepsy monitoring unit. METHODS: We conducted a pilot study among epilepsy patients (18 years or older) receiving maintenance doses of LTG. LTG was discontinued on admission and restarted at the end of epilepsy monitoring. LTG was given as a single oral dose calculated based on the population expected volume of distribution (Vd, 1.0 L/kg) and target blood level on admission. Baseline and serial blood levels of LTG were determined hourly for 10 to 12 h after the loading dose. OUTCOME MEASURES: (a) frequency of patients with side effects; (b) time to maximum concentration (Tmax), maximum concentration (Cmax), actual volume of distribution, and half-life. RESULTS: Twenty-four patients received a single oral load of LTG (mean, 6.5 +/- 2.7 mg/kg). Overall, LTG loading was well tolerated with no serious adverse events or skin rash observed. Two patients had transient and mild nausea 1 to 2 h after the oral load. The mean estimated pharmacokinetic parameters are as follows: Tmax, 3.1 +/- 2.1 h; Cmax, 8.2 +/- 6.5 mg/L; Vd, 1.1 +/- 1.0 L/kg; clearance, 0.08 +/- 0.08 mg/L/h; half-life, 22 +/- 30 h. All patients reached their target blood levels. CONCLUSIONS: Epilepsy patients temporarily discontinued from LTG can be restarted with a single oral loading dose. This was well tolerated, and therapeutic levels can be achieved within 1 to 3 h.

Carotid artery dissection after the intracarotid amobarbital test.

A retrospective chart review of 435 consecutive intracarotid amobarbital tests (IAT) was performed to determine the frequency of carotid artery dissection (CAD) associated with IAT. Three patients with a CAD were found (0.7%). Mean age of patients with dissection (51.3 years) was higher than the average age of 432 patients without dissection (31.7 years) (p < 0.05). All patients had clinical symptoms including face or neck pain. Patients undergoing the IAT are at risk of CAD. Age may be a risk factor.

Gabapentin increases slow-wave sleep in normal adults.

PURPOSE: The older antiepileptic drugs (AEDs) have a variety of effects on sleep, including marked reduction in rapid-eye-movement (REM) sleep, slow-wave sleep (SWS), and sleep latency, and an increase in light sleep. The effects of the newer AEDs on sleep are unknown. Our purpose was to study the effect of gabapentin (GBP) on sleep. METHODS: Ten healthy adults and nine controls were the subjects of this study. All underwent baseline and follow-up polysomnography (PSG) and completed sleep questionnaires. After baseline, the treated group received GBP titrated to 1,800 mg daily. Polygraphic variables and Epworth Sleepiness Scale (ESS) scores, a subjective measure of sleep propensity, were compared by using the Wilcoxon signed rank test. RESULTS: Nine of the treated subjects achieved the target dose; one was studied with 1,500 mg daily because of dizziness experienced at the higher dose. GBP-treated subjects had an increase in SWS compared with baseline. No difference in the ESS or other polygraphic variables was observed. However, a minor reduction in arousals, awakenings, and stage shifts was observed in treated subjects. CONCLUSIONS: GBP appears to be less disruptive to sleep than are some of the older AEDs. These findings may underlie the drug's therapeutic effect in the treatment of disorders associated with sleep disruption.