Ali M. Bozorg

Laser ablation therapy: An alternative treatment for medically resistant mesial temporal lobe epilepsy after age 50

Selective anterior mesial temporal lobe (AMTL) resection is considered a safe and effective treatment for medically refractory mesial temporal lobe epilepsy (MTLE). However, as with any open surgical procedure, older patients (aged 50+) face greater risks. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has shown recent potential as an alternative treatment for MTLE. As a less invasive procedure, MRgLITT could be particularly beneficial to older patients. To our knowledge, no study has evaluated the safety and efficacy of MRgLITT in this population. Seven consecutive patients (aged 50+) undergoing MRgLITT for MTLE were followed prospectively to assess surgical time, complications, postoperative pain control, length of stay (LOS), operating room (OR) charges, total hospitalization charges, and seizure outcome. Five of these patients were assessed at the 1-year follow-up for seizure outcome. These data were compared with data taken from 7 consecutive patients (aged 50+) undergoing AMTL resection. Both groups were of comparable age (mean: 60.7 (MRgLITT) vs. 53 (AMTL)). One AMTL resection patient had a complication of aseptic meningitis. One MRgLITT patient experienced an early postoperative seizure, and two MRgLITT patients had a partial visual field deficit. Seizure-freedom rates were comparable (80% (MRgLITT) and 100% (AMTL) (p>0.05)) beyond 1year postsurgery (mean follow-up: 1.0years (MRgLITT) vs. 1.8years (AMTL)). Mean LOS was shorter in the MRgLITT group (1.3days vs. 2.6days (p<0.05)). Neuropsychological outcomes were comparable. Short-term follow-up suggests that MRgLITT is safe and provides outcomes comparable to AMTL resection in this population. It also decreases pain medication requirement and reduces LOS. Further studies are necessary to assess the long-term efficacy of the procedure.

Efficacy of temporal lobe surgery for epilepsy in patients with negative MRI for mesial temporal lobe sclerosis

Epilepsy surgery is a successful treatment for refractory temporal lobe epilepsy (TLE). Reports suggest fewer seizure-free outcomes for patients with TLE and who have a negative brain MRI (nMRI) for mesial temporal sclerosis. Data were collected prospectively from patients with nMRI who underwent temporal lobe surgery for TLE characterized by unilateral ictal temporal lobe seizure onset based on a scalp video electroencephalogram or invasive subdural electrode recordings. A total of 86 patients were followed for at least 24 months after surgery. Outcome was evaluated using the Engel classification. Seizure control was obtained by 55% (47/86) of patients (Class [CL]-I), 27% (23/86) showed significant improvement (CL-II) and 19% (16/86) were deemed surgical failures. Shorter duration of epilepsy, later onset of seizures, and ictal theta rhythm (5-7 Hz) were the most significant predictors of postoperative seizure control. Although hypometabolism on positron emission tomography scan and significant memory disparity (>2.5/8) were not significant prognosticators independently, cumulatively they were predictors for favorable outcome.

Medical marijuana in neurology

Constituents of the Cannabis plant, cannabinoids, may be of therapeutic value in neurologic diseases. The most abundant cannabinoids are Δ9-tetrahydrocannabinol, which possesses psychoactive properties, and cannabidiol, which has no intrinsic psychoactive effects, but exhibits neuroprotective properties in preclinical studies. A small number of high-quality clinical trials support the safety and efficacy of cannabinoids for treatment of spasticity of multiple sclerosis, pain refractory to opioids, glaucoma, nausea and vomiting. Lower level clinical evidence indicates that cannabinoids may be useful for dystonia, tics, tremors, epilepsy, migraine and weight loss. Data are also limited in regards to adverse events and safety. Common nonspecific adverse events are similar to those of other CNS ‘depressants’ and include weakness, mood changes and dizziness. Cannabinoids can have cardiovascular adverse events and, when smoked chronically, may affect pulmonary function. Fatalities are rare even with recreational use. There is a concern about psychological dependence, but physical dependence is less well documented. Cannabis preparations may presently offer an option for compassionate use in severe neurologic diseases, but at this point, only when standard-of-care therapy is ineffective. As more high-quality clinical data are gathered, the therapeutic application of cannabinoids will likely expand.

Essential oils as a cause of breakthrough seizure after temporal lobectomy

Breakthrough seizures are often encountered in patients with well-controlled epilepsy for no obvious reason. We report a case of a breakthrough seizure after temporal lobectomy secondary to topical administration of essential oils. We recommend inquiring about the use of essential oils in patients with well-controlled epilepsy who experience breakthrough seizures.

The yield of routine outpatient electroencephalograms in the veteran population.

The objective of this study is to determine the yield of routine outpatient electroencephalogram (EEG) in the diagnosis of epilepsy in the veteran population. All consecutive outpatient EEGs at the James A. Haley Veterans Affairs Hospital in Tampa, FL from October 31, 2005, to October 30, 2007, were retrospectively reviewed. During the 2 years of the study, 636 routine outpatient EEGs were performed at James A. Haley Veterans Affairs Hospital. The age range for the patients was 21 to 97 years with a mean age of 55 years. Eighty-five EEGs (13.4%) were classified as abnormal. Nineteen EEGs (3%) in the past 2 years contained epileptiform abnormalities. Sixty-eight EEGs (10.7%) had other abnormalities such as slowing, asymmetry, excessive beta activity, or a combination of abnormalities. Thirty-six EEGs (5.7%) clearly demonstrated psychogenic nonepileptic attacks as documented by normal EEG and video recording of the patients habitual event. Single routine outpatient EEG has been reported to have a sensitivity of 29% to 55% in detecting interictal epileptiform discharges in patients with a suspected diagnosis of epilepsy. In our study, only about 3% of the patients had clear abnormalities suggestive of epilepsy. Interestingly, by using routine EEGs, we were able to definitively diagnose more patients with psychogenic nonepileptic attacks than epileptic seizures.

Clinical utility of the Wechsler Memory Scale—Fourth Edition (WMS-IV) in predicting laterality of temporal lobe epilepsy among surgical candidates

This study evaluated the accuracy of the Wechsler Memory Scale--Fourth Edition (WMS-IV) in identifying functional cognitive deficits associated with seizure laterality in localization-related temporal lobe epilepsy (TLE) relative to a previously established measure, the Rey Auditory Verbal Learning Test (RAVLT). Emerging WMS-IV studies have highlighted psychometric improvements that may enhance its ability to identify lateralized memory deficits. Data from 57 patients with video-EEG-confirmed unilateral TLE who were administered the WMS-IV and RAVLT as part of a comprehensive presurgical neuropsychological evaluation for temporal resection were retrospectively reviewed. We examined the predictive accuracy of the WMS-IV not only in terms of verbal versus visual composite scores but also using individual subtests. A series of hierarchal logistic regression models were developed, including the RAVLT, WMS-IV delayed subtests (Logical Memory, Verbal Paired Associates, Designs, Visual Reproduction), and a WMS-IV verbal-visual memory difference score. Analyses showed that the RAVLT significantly predicted laterality with overall classification rates of 69.6% to 70.2%, whereas neither the individual WMS-IV subtests nor the verbal-visual memory difference score accounted for additional significant variance. Similar to previous versions of the WMS, findings cast doubt as to whether the WMS-IV offers significant incremental validity in discriminating seizure laterality in TLE beyond what can be obtained from the RAVLT.

Long-term radiosurgery effects in the treatment of temporal lobe epilepsy.

Epilepsy surgery is an effective treatment for medically resistant temporal lobe epilepsy (TLE). To minimize complication rates and potentially improve neuropsychology outcomes, stereotactic radiosurgery (SRS) has been explored as an alternative. Two pilot trials have demonstrated the effectiveness of SRS for the treatment of medically resistant TLE, with seizure-free outcomes for approximately 65% of patients at last follow-up. Despite encouraging results, no conclusive long-term outcomes are available for SRS. This article discusses a single patient who presented with recurrent seizures, worsening headaches, and persistent abnormal MRI findings 7 years and 8 months after SRS. This 29-year-old woman with a history of medically refractory complex partial seizures since childhood was referred for evaluation. Medical management had failed in this patient. The workup was compatible with left mesial temporal lobe onset, with MRI findings suggestive of mesial temporal sclerosis. In 2003, at the age of 23 years, she underwent Gamma Knife surgery (GKS) targeting the left temporal mesial area with a dose of 24 Gy at the 50% marginal isodose line. After GKS, the patients seizures decreased in frequency over several months, but auras were persistent. Nine months after treatment, she developed worsening headaches. A follow-up MRI study demonstrated a thick, irregular, enhancing lesion in the medial part of the temporal lobe. She was placed on corticosteroids, with resolution of her headaches. Her seizures and headaches recurred in March 2010. An MRI study showed a 2.2-cm, ill-defined, enhancing cystic lesion in the left mesial temporal lobe with T2 and FLAIR hyperintensity, which was presumably radiation induced. At that time, the patient opted for left temporal lobe resection to control her seizures. Histological examination showed moderately severe, remote, longstanding sclerosis at the level of the hippocampus. A vascular lesion was identified, and it was most consistent with radiation-induced capillary hemangioma. The entorhinal region was severely damaged, with hemorrhage, necrosis, neuronal loss, astrogliosis, and hemosiderin deposition. There was evidence of radiation vasculopathy. Radiation-induced lesions after SRS for the treatment of epilepsy are not well documented. Although GKS is a promising technique for the treatment of medically resistant TLE, the ideal candidate is not yet well defined. The selection of the appropriate technical parameters to obtain a desirable functional effect without histological damage to the surrounding neural tissue remains a challenge. This case illustrates the need for long-term follow-up when radiosurgery is used for epilepsy.

Sensitivity of Green’s Word Memory Test Genuine Memory Impairment Profile to Temporal Pathology: A Study in Patients With Temporal Lobe Epilepsy

Performance validity tests (PVTs) such as Green’s Word Memory Test (WMT) are designed to have face validity as memory tests while individuals with neurologically based memory deficits can score adequately provided there is sufficient task engagement. Some patients with severe memory loss have performed poorly on the WMT, raising questions about false positive errors. This study compared performances of 43 patients with left, right, or bilateral temporal lobe epilepsy on the WMT to a test known to be sensitive to temporal lobe pathology, the Rey Auditory Verbal Learning Test (RAVLT). The right TLE group outperformed the left on the WMT free recall (FR) scores and RAVLT short-delay and long-delay trials (Trials 6 and 7) (p < .05); no other between-group differences occurred (p ≥ .10). Ten participants (20.4%) performed below the cut-off score on at least one WMT effort subtest, but eight (80%) exhibited the genuine memory impairment profile (GMIP). Logistic regression found no WMT subtest contributed to predicting side of seizure with RAVLT scores in the model. Data suggest WMT primary effort subtests are generally insensitive to known temporal lobe pathology, and using the GMIP is valuable to identify individuals with severe memory loss who score below criterion on WMT primary effort subtests.

An update on epilepsy

The understanding of seizures and epilepsy as a disease has accelerated to reflect advances in the understanding of the interplay of seizures and epilepsy on neurophysiology, neuroplasticity, sleep, neuropsychology, behavior and social functioning of the individual, which interact with and can be affected by an individual’s quality of life, educational development and occupational success. Updates in the treatment of status epilepticus, epilepsy in children and adults (particularly women), and psychogenic nonepileptic seizures/attacks have been announced. There is increasing emphasis on untangling the interactive forces of new antiepileptic medications from epilepsy/seizures on the neurophysiological, neuropsychologic and psychiatric/behavioral functioning of individuals with epilepsy. The role of GABA in the pathophysiology of seizures and status epilepticus has led to novel therapy proposals. Neurostimulation technologies and neurosurgical procedures have improved the clinical outcomes of patients with epilepsy, and have led to important advances in understanding the neuropathophysiology of epilepsy/seizures and brain plasticity. For example, neurostimulation allows long-term in vivo electroneurophysiological recordings of specific brain regions that has not been previously possible in humans. The 64th Annual Meeting of the American Epilepsy Society and the 3rd Biennial North American Regional Epilepsy Congress provided state-of-the-art updates to scientific and clinical practice issues in the treatment of epilepsy.

Predictors of surgical outcome in medically-resistant temporal lobe epilepsy with bilateral features on pre-operative evaluation

OBJECTIVE This study identifies potential prognostic factors for favorable anterior mesial temporal lobe (AMTL) resection outcomes in patients with medically refractory temporal lobe epilepsy (TLE) with bilateral features on pre-operative examination. METHODS Thirty-one patients demonstrated bilateral features defined as: bilateral independent temporal or bitemporal ictal onsets on surface or intracranial EEG, or bitemporal interictal epileptiform abnormalities on surface EEG with bilateral radiographic mesial temporal sclerosis. Surgical outcomes were classified according to reduction in seizure frequency: I (100% reduction), II (≥75% reduction), III (50-74% reduction), IV (<50% reduction). RESULTS Of 31 patients, 14 (45%) improved to class I and 9 (29%) had a class II outcome at an average of 4 years after surgery. Eight (26%) patients did not exhibit good surgical outcome (class III, class IV). We found that neuropsychological and Wada memory scores were significantly correlated (p<0.05) with surgical outcome, and logistic regression found neuropsychological evaluation significantly predicted better surgical outcome (p<0.05). CONCLUSIONS When bilateral features are present on pre-operative evaluation, neuropsychological and Wada test results can provide unique data to better identify those patients more likely to achieve substantial seizure reduction.