William O. Tatum

How many patients with psychogenic nonepileptic seizures also have epilepsy

The proportion of patients with psychogenic nonepileptic seizures (PNES) who also have epilepsy has been reported to vary from 10% to over 50%. The authors reviewed all 32 patients diagnosed with PNES in our EEG–video monitoring unit over a period of 1 year, and only 3 (9.4%) had interictal epileptiform discharges to support a coexisting diagnosis of epilepsy. Thus, the authors believe that only a small proportion of patients with PNES have coexisting epilepsy.

Outcome of Prolonged Video‐EEG Monitoring at a Typical Referral Epilepsy Center

Summary:  Purpose: When seizures do not respond to medications, video‐EEG monitoring is the best available diagnostic tool and is the principal activity of epilepsy centers. The purpose of this study was to analyze the eventual disposition of patients who undergo video‐EEG monitoring at a typical referral epilepsy center.

Overintepretation of EEGs and misdiagnosis of epilepsy.

&NA; The overinterpretation of EEGs is a known problem that has not been reported specifically. The authors report a series of EEGs on patients who were diagnosed eventually with psychogenic nonepileptic seizures and who had an EEG read as epileptiform. Of the 15 actual records available for review, the overread patterns were wicket spikes (n = 1), hypnagogic hypersynchrony (n = 1), and hyperventilationinduced slowing (n = 1). In the other 12 records, the overread patterns were simple fluctuations of sharply contoured background rhythms or fragmented &agr; activity. Rather than well‐described normal variants, the overinterpreted patterns tend to be normal fluctuations of background activity.

Postmarketing experience with topiramate and cognition

Summary: Ideal antiepileptic drugs (AEDs) are designed to stop seizures with limited central nervous system (CNS) side effects. However, CNS‐related treatment‐emergent adverse events (TEAEs) often occur in patients receiving AEDs. Topiramate (TPM) is an AED proven to be safe and effective as adjunctive treatment for epilepsy patients with partial seizures. Double‐blind, placebo‐controlled, multicenter trials demonstrated potential effects on cognition. The P.A.D.S. (post‐marketing antiepileptic drug survey) group, a cooperative group of 14 epilepsy centers that collaborate on obtaining data about new AEDs and devices, prospectively collected standardized data forms before and during treatment with TPM for epilepsy, and analyzed the postmarketing experience of CNS TEAEs with TPM. Our results from 701 treated patients show that cognitive complaints were the most common reason to discontinue TPM. The presence of complaints did have predictive value if the patient would discontinue TPM, although was not specific as to when discontinuation would occur. The spectrum of complaints in our open‐label prospective multicenter postmarketing study was similar to those observed in controlled clinical trials. We were unable to demonstrate a specific population, dose titration, or concomitant AED that was at risk to discontinue treatment.  We conclude that most patients treated with TPM will continue therapy beyond 6 months. Cognitive complaints and not efficacy reflect the primary reason for discontinuing therapy. Psychomotor slowing was the most common complaint, yet most patients elect to continue treatment, with “better” or “much better” ratings of both seizure and global improvement during treatment.

Epilepsy surgery, delays and referral patterns—are all your epilepsy patients controlled?

RATIONALE Epilepsy surgery is a standard of care in the treatment of medically intractable epilepsy, but is underutilised. We describe the results of epilepsy surgery and the referral patterns at a referral epilepsy programme. METHODS We reviewed the outcome of epilepsy surgery performed at the University of South Florida and Tampa General Hospital epilepsy programme for the years 2000 and 2001. The typical presurgical evaluation included clinical evaluation, EEG-video monitoring, MRI with dedicated epilepsy protocol, PET, SPECT, neuropsychological testing and Wada testing. We used the Engel outcome classification, and focused on the referral information to determine how and when in the course of their illness patients arrive at a referral epilepsy centre. RESULTS In the 2-year period (2000-2001), a total of 36 epilepsy surgeries were performed. Twenty-nine temporal lobectomies, six extratemporal resections and one corpus callosotomy. Ages varied from 17 to 65 years. Overall results were: 30 (83%) seizure-free [class I], 5 (17%) rare seizures or almost seizure-free [class II] and 1 no improvement. Of the 29 temporal lobectomies, 27 (93%) are completely seizure-free [class I] and 2 (7%) are >90% improved [class II]. Duration of seizures before being seen at the epilepsy centre averaged 18 years (range 2-58 years). Twenty-two (61%) were sent by their neurologists, while 14 (39%) came self-referred without having discussed surgery with their neurologists. Five (14%) were specifically advised by their neurologist to not consider surgery. Two had participated in clinical trials of antiepileptic drugs (AEDs) before being seen at the epilepsy centre. CONCLUSIONS Epilepsy surgery has high efficacy and very low morbidity. Yet, there continues to be a long delay in the referral of patients to the epilepsy centre, suggesting that surgery for epilepsy is underutilised.

Short-term outpatient EEG video with induction in the diagnosis of psychogenic seizures

To analyze the yield of short-term outpatient EEG video monitoring, the authors reviewed data on all patients who underwent this procedure at their center. All patients were suspected of having psychogenic nonepileptic seizures (PNES) on clinical grounds. The total number of cases of short-term outpatient EEG video monitoring was 74. In 49 (66%) cases, the suspected diagnosis of PNES could be confirmed, thereby obviating the need for prolonged inpatient EEG video monitoring.

When drugs don’t work An algorithmic approach to medically intractable epilepsy

Article abstract—Nonpharmacologic options for the treatment of epilepsy include epilepsy surgery, vagus nerve stimulation, and the ketogenic diet. The advantages and limitations of these treatment modalities have been extensively reviewed, but there is no general consensus on when each option should be considered. The authors propose an algorithm based on the type of epilepsy. Generally, nonpharmacologic options should be considered early—i.e., after the first few drug failures. Because of their good outcome with resective surgery, mesial temporal and lesional neocortical epilepsies should be considered for resection. Conversely, nonlesional neocortical epilepsies are probably best approached with vagus nerve stimulation first. For symptomatic or cryptogenic generalized epilepsies, which are commonly intractable, vagus nerve stimulation and the ketogenic diet appear to be reasonable options to consider before palliative surgery such as corpus callosotomy. Idiopathic (i.e., genetic) generalized epilepsies are only rarely refractory to medications and can be outgrown. In rare cases, vagus nerve stimulation may occasionally play a role in their treatment.

Open-label pilot study of levetiracetam (Keppra) for the treatment of levodopa-induced dyskinesias in Parkinson's disease

We evaluated the tolerability and preliminary efficacy of levetiracetam (LEV; Keppra) in reducing levodopa‐induced dyskinesias in Parkinsons disease (PD) in an open‐label pilot study. Nine PD patients who were experiencing peak‐dose dyskinesias for at least 25% of the awake day and were at least moderately disabling were treated with LEV in doses up to 3,000 mg for up to 60 days. The primary outcome measure was the percent of the awake day that patients spent on without dyskinesia or with nontroublesome dyskinesia (good on time). The mean dose of LEV at endpoint was 625 ± 277 mg/day. LEV significantly improved percent of the awake day on without dyskinesia or with nontroublesome dyskinesia at endpoint compared to baseline (43% ± 12% vs. 61% ± 17%; P = 0.02). Percent on time with troublesome dyskinesia decreased from 23% ± 10% at baseline to 11% ± 6% at endpoint, although not significantly. There was no significant increase in off time from baseline to endpoint. There was a 56% dropout rate, mostly due to somnolence. In PD patients who experienced peak‐dose dyskinesia for at least 25% of the awake day, LEV significantly improved on time without dyskinesia or with nontroublesome dyskinesia.

A past psychiatric history may be a risk factor for topiramate-related psychiatric and cognitive adverse events.

OBJECTIVES Topiramate (TPM) is a new antiepileptic drug (AED) that has been found to be associated with a high prevalence of cognitive adverse events (CAEs). The prevalence of psychiatric adverse events (PAEs) has yet to be established. The purpose of this study was to determine the prevalence of PAEs related to TPM when used in polytherapy regimens in a large cohort of adult patients with epilepsy, to identify any association between the occurrences of CAEs and PAEs and to identify predictors of PAEs and CAEs. METHODS Investigators from 16 epilepsy centers (PADS group) prospectively obtained postmarketing safety and efficacy data on 596 patients aged 16 years and older. All data were recorded on standardized data retrieval forms, completed at the initial visit, while follow-up data were obtained every 6 months or at the time of discontinuation. RESULTS PAEs were identified in 75 (12.6%) patients: 30 (5%) experienced symptoms of depression and 34 (5.7%) of aggressive behavior and irritability, while 9 patients experienced symptoms of psychosis (1.5%). CAEs were reported by 247 (41.5%) patients. There was a significant association between the occurrences of CAEs and PAEs. A past psychiatric history was a predictor of CAEs, while older age and past psychiatric history were predictors of PAEs. CONCLUSIONS The use of TPM in polytherapy regimens can cause PAEs and CAEs and their occurrence is significantly correlated. Patients with a past psychiatric history may be at a higher risk for experiencing PAEs and CAEs.

Clinical utility of sleep-deprived versus computer-assisted ambulatory 16-channel EEG in epilepsy patients: a multi-center study

PURPOSE The objective of this prospective study was to compare the usefulness of a sleep-deprived electroencephalogram (EEG) versus a computer-assisted 16-channel ambulatory EEG in patients with historical information consistent with epilepsy but with a normal or non-diagnostic initial routine EEG. METHODS A total of 46 patients had both a 30-60 min sleep-deprived EEG and a computer-assisted ambulatory 24 h EEG. Each EEG was assigned a number and reviewed independently by two board-certified electroencephalographers for the presence of interictal epileptiform discharges and seizures. RESULTS Both the sleep-deprived EEG and ambulatory EEG improved detection of epileptiform discharges by a similar amount (24% versus 33%); however, the ambulatory EEG detected seizures in 7/46 (15%) patients, and in three patients the seizures were solely detected by the computer. CONCLUSIONS we conclude that the computer-assisted ambulatory EEG offers greater benefit than a sleep-deprived recording because in addition to detecting interictal epileptiform discharges, it may also capture seizures. The discovery of unsuspected seizures can significantly impact clinical management.