Electroencephalogram findings in patients with posterior cortical atrophy.

AIM OF THE STUDY: The aim of this study is to evaluate standard scalp EEG findings in patients with posterior cortical atrophy (PCA), an atypical variant of Alzheimer's disease (AD). CLINICAL RATIONALE: PCA is a topographically selective variant of AD. Patients with typical AD have an increased likelihood of seizures, which may negatively impact overall functional performance and cognition. It is currently unknown what the typical EEG findings are for patients with PCA. MATERIALS AND METHODS: A retrospective chart review was performed on patients identified either with autopsy confirmed (n=13) or clinically (n=126) as PCA. RESULTS: 139 patients were included though only 23 (16.5%) had undergone EEG recording. The EEG was normal in 6 (26%), while an abnormal EEG was present in 17 (74%). Interictal epileptic discharges (IEDs) were found in 2 of the 23 patients (9%). CONCLUSIONS: This study of limited sample size suggests that there may be an increased predilection to find IEDs within PCA when compared to typical AD. Larger cohorts are required to determine frequency of abnormal EEGs in PCA, roles of AEDs in therapy, and in the selection of preferred AED. CLINICAL IMPLICATIONS: Patients with PCA would potentially benefit from an EEG for assessment of IEDs which may provide the clinician with a therapeutic opportunity.

CM-Pf deep brain stimulation in polyneuromodulation for epilepsy.

OBJECTIVE: Neuromodulation is a viable option for patients with drug-resistant epilepsies. We reviewed the management of patients with two deep brain neurostimulators. In addition, patients implanted with a device targeting the centromedian-parafascicular (CM-Pf) nuclear complex supplements this report to provide an illustrative case to implantation and programming a patient with three active devices. METHODS: A narrative review using PubMed and Embase identified patients with drug-resistant epilepsy implanted with more than one neurostimulator was performed. Combinations of vagus nerve stimulation (VNS), deep brain stimulation (DBS), and responsive neurostimulation (RNS) were identified. We provide a background of a newly reported case of an adult with a triple implant eventually responding to CM-Pf DBS as the third implant following suboptimal benefit from VNS and RNS. RESULTS: In review of the literature, dual-device therapy is increasing in reports of use with combinations of VNS, RNS, and DBS to treat patients with drug-resistant epilepsy. We review dual-device implants with thalamic DBS device combinations, functional neural networks, and programming patients with dual devices. CM-Pf is a new target for DBS and has shown a variable response in focal epilepsy. We report the unique case of 28-year-old male with drug-resistant focal epilepsy who experienced a 75% seizure reduction with CM-Pf DBS as his third device after suboptimal responses to VNS and RNS. After 9 months, he also experienced seizure freedom from recurrent focal to bilateral tonic-clonic seizures. No medical or surgical complications or safety issues were encountered. CONCLUSION: We demonstrate safety and feasibility in an adult combining active VNS, RNS, and CM-Pf DBS. Patients with dual-device therapy who experience a suboptimal response to initial device use at optimized settings should not be considered a neuromodulation "failure." Strategies to combine devices require a working knowledge of brain networks.

Edge-Enhancing Gradient-Echo MP2RAGE for Clinical Epilepsy Imaging at 7T.

The 3D edge-enhancing gradient-echo (EDGE) MR imaging sequence offers superior contrast-to-noise ratio in the detection of focal cortical dysplasia. EDGE could benefit from 7T MR imaging but also faces challenges such as image inhomogeneity and low acquisition efficiency. We propose an EDGE-MP2RAGE sequence that can provide both EDGE and T1-weighted contrast, simultaneously, improving data-acquisition efficiency. We demonstrate that with sequence optimization, EDGE images with sufficient uniformity and T1-weighted images with high gray-to-white matter contrast can be achieved.

Evidence that temporal lobe is a default area in absence epilepsy.

Correctly classifying seizures is essential for appropriate epilepsy management. Focal and generalized epilepsy rarely occur independently in the same patient. Cases of focal ictal evolution during seizures that are generalized in onset have been reported though these have included a small heterogeneous series of patients with generalized epilepsy and features on the EEG. We wish to report two patients with absence epilepsy that were noted on video-EEG monitoring to manifest a focal temporal electroclinical transformation from a typical absence seizure. Defining the electroclinical spectrum of absence seizures could add to our understanding of the selective cortical and subcortical networks that are involved in patients with "prototypic" generalized and focal seizures.

Disobedience and driving in patients with epilepsy.

OBJECTIVE: Motor vehicle accidents direct legislators to ensure pubic safety. We attempted to characterize and quantify driving risk in patients with seizures (PWS). METHODS: We delivered 12-question surveys to 287 consecutive PWS at an epilepsy clinic in Florida. Illegal and disobedient driving practices were analyzed. RESULTS: Eighty-three of 236 (35.2%) PWS were eligible to drive and 62.3% were ineligible with a seizure in <6 months (P<0.001, 95% CI: 0.57-0.70). Among the ineligible responders, 23.8% (35/147) of ineligible responders were illegally driving (14.83% of cohort); 11.86% (28/236) of PWS were disobedient refusing to obey the law, and 8.9% (21/236) of PWS were defiant and knew the law. Sadness (75/236, 31.8%) was the most common reaction to restriction, but disobedient PWS were angry (10/28, 35.7%). CONCLUSION: Overall, a small number of PWS are disobedient and illegally driving. A targeted approach to high-risk drivers with repeated verbal and supplemental driving information may help avoid unnecessary universal physician reporting for PWS.

Brain Abnormalities and Epilepsy in Patients with Parry-Romberg Syndrome.

BACKGROUND AND PURPOSE: Parry-Romberg syndrome is a rare disorder characterized by progressive hemifacial atrophy. Concomitant brain abnormalities have been reported, frequently resulting in epilepsy, but the frequency and spectrum of brain involvement are not well-established. This study aimed to characterize brain abnormalities in Parry-Romberg syndrome and their association with epilepsy. MATERIALS AND METHODS: This is a single-center, retrospective review of patients with a clinical diagnosis of Parry-Romberg syndrome and brain MR imaging. The degree of unilateral hemispheric atrophy, white matter disease, microhemorrhage, and leptomeningeal enhancement was graded as none, mild, moderate, or severe. Other abnormalities were qualitatively reported. Findings were considered potentially Parry-Romberg syndrome-related when occurring asymmetrically on the side affected by Parry-Romberg syndrome. RESULTS: Of 80 patients, 48 (60%) had brain abnormalities identified on MR imaging, with 26 (32%) having abnormalities localized to the side of the hemifacial atrophy. Sixteen (20%) had epilepsy. MR imaging brain abnormalities were more common in the epilepsy group (100% versus 48%, P < .001) and were more frequently present ipsilateral to the hemifacial atrophy in patients with epilepsy (81% versus 20%, P < .001). Asymmetric white matter disease was the predominant finding in patients with (88%) and without (23%) epilepsy. White matter disease and hemispheric atrophy had a higher frequency and severity in patients with epilepsy (P < .001). Microhemorrhage was also more frequent in the epilepsy group (P = .015). CONCLUSIONS: Ipsilateral MR imaging brain abnormalities are common in patients with Parry-Romberg syndrome, with a higher frequency and greater severity in those with epilepsy. The most common findings in both groups are white matter disease and hemispheric atrophy, both presenting with greater severity in patients with epilepsy.

Crying with left temporal lobe seizures and Wada testing.

Dacrystic seizures are characterized by crying and are rare in patients with epilepsy. The crying that occurs during complex partial seizures is expressed as an unconscious behavior unassociated with sadness or depressive quality. It has been reported to occur with focal seizures that are localized to the frontotemporal regions and is frequently lateralized to the nondominant hemisphere. We describe a woman with left temporal lobe epilepsy and recurrent complex partial seizures with crying behavior that was reproduced during left carotid methohexital anesthesia, suggesting functional inactivation by two different mechanisms. Following left amygdalohippocampectomy she became seizure free for >2years without perioperative mood destabilization. Localized functional networks that involve limbic structures may be involved in patients with dacrystic seizures with a favorable outcome following epilepsy surgery.

Clinical utility of EEG in diagnosing and monitoring epilepsy in adults.

Electroencephalography (EEG) remains an essential diagnostic tool for people with epilepsy (PWE). The International Federation of Clinical Neurophysiology produces new guidelines as an educational service for clinicians to address gaps in knowledge in clinical neurophysiology. The current guideline was prepared in response to gaps present in epilepsy-related neurophysiological assessment and is not intended to replace sound clinical judgement in the care of PWE. Furthermore, addressing specific pathophysiological conditions of the brain that produce epilepsy is of primary importance though is beyond the scope of this guideline. Instead, our goal is to summarize the scientific evidence for the utility of EEG when diagnosing and monitoring PWE.

Gabapentin treatment of seizures in acute intermittent porphyria.

Most antiepileptic drugs (AEDs) available have demonstrated porphyrogenicity in hepatic porphyrias. Gabapentin is a new AED not appreciably metabolized by the liver in humans. We report two patients with acute intermittent porphyria successfully treated with gabapentin without its inducing porphyric crisis.

Epileptic pseudodementia.

Dementia is a frequent cause of memory loss with aging. The incidence of complex partial seizures sharply rises after age 60. Complex partial seizures that occur with subtle clinical signs or loss of awareness, or occur during sleep may defy identification. We report five elderly patients fearing dementia in whom memory dysfunction was due to unrecognized complex partial seizures.

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.

Epileptic palatal myoclonus.

Palatal myoclonus (PM) is usually caused by lesions of the brainstem. We report a case of PM of focal cortical origin in a patient with epilepsia partialis continua. The PM sometimes occurred in isolation, and at other times was accompanied by unilateral face, neck, and arm twitching. This was documented by both EEG and SPECT.

Vagus nerve stimulation and drug reduction.

The authors prospectively assessed drug reduction and patient satisfaction in 21 patients using vagus nerve stimulation (VNS) for refractory epilepsy and compared results to a case-matched control group with a mean follow-up of 13.2 months. Significant antiepileptic drug (AED) reduction occurred in 9/21 (42.9%) of VNS patients averaging 0.43 AED/patient, with dose reduction in four patients (19.0%). For 12/21 (57.1%) patients not reducing AED, dose reduction occurred in 6/21 (28.6%). Drug and dose reduction of AED is possible in patients using VNS for refractory epilepsy without loss of seizure control and with improved patient satisfaction.

Induction of psychogenic nonepileptic seizures without placebo.

The diagnosis of psychogenic nonepileptic seizures (PNES) can only be made with EEG-video monitoring. The authors describe a provocative technique without placebo. Patients with a clinical suspicion for PNES underwent an activation procedure using suggestion, hyperventilation, and photic stimulation. Of 19 inductions performed, 16 (84%) were successful in inducing the habitual episode. The authors' technique had a sensitivity comparable to those using placebo (e.g., saline injection), but does not have disadvantages.

Ventricular asystole during vagus nerve stimulation for epilepsy in humans.

Electrical stimulation of the vagus nerve, a recently available option for patients with refractory epilepsy, has demonstrated safety and efficacy. We report four patients with refractory epilepsy who experienced ventricular asystole intraoperatively during initial testing for implantation of the vagus nerve stimulator. Acute intraoperative vagus nerve stimulation may create ventricular asystole in humans. Extracorporeal cervical vagus nerve stimulation testing with continuous EKG monitoring intraoperatively before generator implantation is warranted.

Technetium-99m-HMPAO SPECT in partial status epilepticus.

UNLABELLED: In this paper we correlate the findings on 99mTc-HMPAO brain SPECT with the results of clinical examinations and electroencephalography to determine the utility of SPECT in the evaluation of patients with suspected status epilepticus. METHODS: Thirteen patients with suspected status epilepticus underwent serial neurologic examinations, serial electroencephalograms, CT/MRI scanning and 99mTc-HMPAO SPECT. Seven patients were diagnosed with status epilepticus and six patients received other neurological diagnoses. RESULTS: All patients with status epilepticus at the time of the brain SPECT scan demonstrated focal hyperperfusion on SPECT in an area concordant with that suggested by EEG. One patient with status epilepticus demonstrated a persistent area of hyperperfusion on SPECT 24 hr after the cessation of status with no evidence of breakdown in the blood-brain barrier demonstrated by 99mTc-DTPA SPECT. No patient in this study without a diagnosis of status epilepticus had focal areas of hyperperfusion on SPECT. CONCLUSION: We suggest that a 99mTc-HMPAO SPECT scan demonstrating focal hyperperfusion in a patient being evaluated for partial status epilepticus is nonspecific. Even in the absence of a structural lesion causing local breakdown in the blood-brain barrier, it may indicate either ongoing status epilepticus or recently terminated status. However, a SPECT scan demonstrating no area of focal hyperperfusion argues against the diagnosis of partial status.

Long-term EEG monitoring: a clinical approach to electrophysiology.

Long-term electroencephalographic monitoring (LTM) is the capability of recording the EEG over long periods of time and not a specific duration. Prolonged EEG recording is used primarily for epilepsy monitoring, but LTM is also used in the intensive care unit, the operating room, and in the emergency department. The purpose of LTM is to expand the limited time sampling associated with shorter "routine" EEG recording. Audiovisual monitoring may also be used in conjunction with LTM to evaluate simultaneously a specific clinical behavior that may or may not be associated with EEG alteration. This is typically performed in a hospital setting for safety and ancillary testing purposes. LTM is used most frequently in the diagnosis and management of seizures and "spells," but has also gained wider application in the evaluation of sleep disorders, cerebrovascular disease, psychiatric conditions, and movement disorders. Computer-assisted LTM systems that process, analyze, compress, and store data digitally have become widely available in clinical practice both in the hospital as well as outside the hospital when the patient is ambulatory.

Outpatient seizure identification: results of 502 patients using computer-assisted ambulatory EEG.

Patients with epilepsy may not always be able to identify their seizures. Epilepsy management relies on patient reporting to validate whether seizures occur during treatment. The goal of this study was to assess the frequency of unreported seizures recorded during routine outpatient ambulatory EEG recording. The authors reviewed 552 records from 502 patients who underwent outpatient 16-channel computer-assisted ambulatory EEG monitoring (CAA-EEG). Seizure identification was evaluated by assessing push-button activation. Partial seizures were seen most commonly. A total of 47 of 552 records (8.5%) had partial seizures recorded on CAA-EEG, with 29 of 47 (61.7%) with electroclinical seizures identified by push-button activation. Seizures on EEG without push-button activation were analyzed separately and compared with a self-reported written diary to verify lack of recognition. A total of 18 of 47 records (38.3%) had some partial seizures that were unrecognized by the patient, and 11 of 47 records (23.4%) had seizures recognized only by the computer. The authors conclude that patients frequently have seizures outside of the hospital that go unrecognized. Underreporting of seizure frequency occurs in the outpatient setting and impacts optimal diagnosis and treatment for patients with epilepsy.

Interictal single-photon emission computed tomography in partial epilepsy. Accuracy in localization and prediction of outcome.

The role of interictal brain single-photon emission computed tomography (SPECT) was examined using (99mTc)- labeled hexamethylpropyleneamine oxime (HMPAO) in refractory partial epilepsy. The accuracy with which SPECT localized an epileptic focus and whether it predicted long-term postoperative seizure relief were assessed. Twenty patients were evaluated, 14 of whom ultimately had anterior temporal lobectomy with follow-up ranging from 41 to 56 months. A single-headed gamma camera was used. The interictal SPECT showed ipsilateral temporal hypoperfusion in 8 (47%) of 17 patients with temporal lobe epilepsy and showed either multilobar hypoperfusion or no perfusion defects in the rest. The sensitivity and specificity were similar in patients with a more complex clinical picture who required intracranial electrodes and those who did not. Presence or absence of temporal lobe hypoperfusion did not correlate with postoperative seizure relief. It is concluded that interictal SPECT with 99mTc-HMPAO with a single-headed gamma camera does not add useful information in preoperative localization or predicting postoperative seizure relief.