Thomas Bodner

Video‐EEG monitoring: Safety and adverse events in 507 consecutive patients

Purpose:  Video–electroencephalography (EEG) monitoring plays a central role in the presurgical evaluation of medically refractory epilepsies and the diagnosis of nonepileptic attack disorders (NEADs). The aim of this study was to analyze safety and adverse events (AEs) during video‐EEG monitoring.

Successful surgical treatment of insular epilepsy with nocturnal hypermotor seizures

Nocturnal hypermotor seizures (NHSs) suggest seizure onset in the frontal lobe. We present a patient with NHSs and insular seizure onset who underwent successful surgical treatment.

Dichotic listening performance and frontal lobe function

In the present paper we report on speech perception in left (n=16) and right (n=10) frontal lobe nonaphasic patients compared with healthy controls (n=26). The patients were inpatients of the University Clinic of Neurology, Innsbruck, Austria, who participated in a prospective neuropsychological study dealing with several aspects of lateralized functioning. The patients were tested with dichotic presentations of consonant-vowel syllables, which allows for specific probing of speech perception in the left and right hemisphere, respectively. The task was to report which syllable they heard best on each trial, emphasizing single answers on each trial. There were 36 dichotic trials with pairs of CV syllables made up of the six stop consonants /p/, /t/, /k/, /b/, /d/, /g/, all paired with the vowel /a/. There were always two different syllables presented on each trial, one in each ear. The results showed significant differences between the left and right lesioned patients in their performance on the dichotic listening test. While the right lesioned patients and the control subjects had a normal and expected right ear advantage, the left lesioned patients performed almost at random with regard to the right and left ear stimulus. The right lesioned patients and the control group showed a right ear advantage of the same magnitude, although the overall performance was somewhat impaired in the right lesioned group compared to the healthy control group. The left lesioned patients showed no ear advantage at all, and particularly their right ear scores were impaired compared to both the control group and the right lesioned patient group. The results are discussed in terms of the role played by the left frontal cortex in speech perception and language asymmetry.

Decision making under ambiguity and under risk in mesial temporal lobe epilepsy.

Decision making is essential in everyday life. Though the importance of the mesial temporal lobe in emotional processing and feedback learning is generally recognized, decision making in mesial temporal lobe epilepsy (mTLE) is almost unexplored so far. Twenty-eight consecutive epilepsy patients with drug resistant mTLE and fifty healthy controls performed decision tasks under initial ambiguity (participants have to learn by feedback to make advantageous decisions) and under risk (advantageous choices may be made by estimating risks and by rational strategies). A subgroup analysis compared the performance of patients affected by MRI-verified abnormalities of the hippocampus or amygdala. The effect of lesion side was also assessed. In decision under ambiguity, mTLE patients showed marked deficits and did not improve over the task. Patients with hippocampus abnormality and patients with amygdala abnormality showed comparable deficits. No difference was found between right and left TLE groups. In decision under risk, mTLE patients performed at the same level as controls. Results suggest that mTLE patients have difficulties in learning from feedback and in making decisions in uncertain, ambiguous situations. By contrast, they are able to make advantageous decisions when full information is given and risks, possible gains and losses are exactly defined.

Decision making in ambiguous and risky situations after unilateral temporal lobe epilepsy surgery.

Decision making is essential in everyday life. Though the importance of the mesial temporal structures in emotional processing and feedback learning is well established, decision making in patients after mesial temporal lobe surgery has rarely been studied. We studied 23 patients with mesial temporal lobe epilepsy after unilateral temporal lobe surgery and 26 healthy controls using two different gambling tasks, the Iowa Gambling Task (IGT) and the Probability-Associated Gambling (PAG) task. In the IGT, rules for gains and losses are implicit; in the PAG task, winning probabilities are well defined. Compared with healthy controls, patients performed poorly on the IGT (decisions under ambiguity). No group difference was found in the PAG task (decisions under risk). Results of the present investigation indicate that after mesial temporal lobe surgery, patients have difficulties in making decisions under ambiguity, whereas they decide advantageously when information about the decision situation is explicitly given.

Cerebral tau is elevated after aneurysmal subarachnoid haemorrhage and associated with brain metabolic distress and poor functional and cognitive long-term outcome

Background Recent evidence suggests axonal injury after aneurysmal subarachnoid haemorrhage (aSAH). The microtubule-associated protein, tau, has been shown to be elevated in the cerebrospinal fluid after aSAH, however, brain extracellular tau levels and their relation to long-term neurological and cognitive outcomes have not been investigated. Methods Serial cerebral microdialysis (CMD) samples were collected from 22 consecutive aSAH patients with multimodal neuromonitoring to determine CMD-total-tau by ELISA. CMD-total-tau was analysed considering other brain metabolic parameters, brain tissue oxygen tension (PbtO2), and functional and neuropsychological outcome at 12 months. All outcome models were analysed using generalised estimating equations with an autoregressive working correlation matrix to account for multiple measurements of brain extracellular proteins per subject. Results CMD-total-tau levels positively correlated with brain extracellular fluid levels of lactate (r=0.40, p<0.001), glutamate (r=0.45, p<0.001), pyruvate (r=0.26, p<0.001), and the lactate-pyruvate ratio (r=0.26, p<0.001), and were higher in episodes of hypoxic (PbtO2<20 mm Hg) brain extracellular lactate elevation (>4 mmol/L) (p<0.01). More importantly, high CMD-total-tau levels were associated with poor functional outcome (modified Rankin Scale ≥4) 12 months after aSAH even after adjusting for disease severity and age (p=0.001). A similar association was found with 3/5 neuropsychological tests indicative of impairments in cognition, psychomotor speed, visual conceptualisation and frontal executive functions at 1 year after aSAH (p<0.01). Conclusions These results suggest that CMD-total tau may be an important biomarker for predicting long-term outcome in patients with severe aSAH. The value of axonal injury needs further confirmation in a larger patient cohort, preferably combined with advanced imaging techniques.

Executive Functions in Chronic Mesial Temporal Lobe Epilepsy

There is no consensus as to whether mesial temporal lobe epilepsy (MTLE) leads to executive function deficits. In this study, we adopted an extensive neuropsychological test battery and assessed different executive functions in chronic, unilateral MTLE. Performance of MTLE patients was compared with that of healthy peers and with normative data. Several MTLE patients had scores below cut-off or below the 10th percentile of normative data. Scores of the whole patient group were overall in the average range of normative data. Relative to controls, MTLE patients performed poorly in tests of working memory, cognitive flexibility, categorical verbal fluency, set-shifting, categorization, and planning. These findings raise an important methodological issue as they suggest that executive function deficits in chronic MTLE may be individually variable and that their assessment should include different tests. Deficits in chronic MTLE are not limited to temporal lobe functions, such as memory, but may extend to extra temporal cognitive domains, such as executive functions.

Decision making under ambiguity in temporal lobe epilepsy: Does the location of the underlying structural abnormality matter?

Previous studies have reported decision-making deficits in patients affected by mesial temporal lobe epilepsy (TLE). The aim of the study described here was to assess the specificity of these deficits by comparing performance of patients with neocortical TLE, patients with mesial TLE, and healthy controls. The mesial TLE group performed lower than healthy controls and the neocortical TLE group in decision making under initial ambiguity. Although patients with neocortical TLE and controls showed a significant learning effect over the blocks of the Iowa gambling task, performance of patients with mesial TLE did not improve from the first to the last block of trials. Results suggest that TLE associated with neocortical brain abnormalities does not have deleterious effects on decision making as is found for epilepsy caused by mesial temporal lobe pathologies. The present findings highlight the specificity of the mesial temporal lobes in reward-based, adaptive learning and decision making.

Efficacy of Donepezil Treatment in Alzheimer Patients with and without Subcortical Vascular Lesions

In a pilot study designed as a case control study the efficacy of donepezil treatment was investigated in patients with Alzheimer’s disease (AD). Patients were stratified according to radiological criteria into patients without (AD group) and with subcortical vascular lesions (AD+SVD group). Changes in cognition were assessed as the primary outcome measurement after 6 and 18 months of treatment by the Mini-Mental Status Examination (MMSE) and the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) test battery. After 6 months, patients had improved from baseline by 0.7 points in MMSE score in the AD group and by 1.8 in the AD+SVD group. After 18 months of treatment, the AD+SVD group performed significantly worse in one CERAD subscore, whereas a deterioration in two subscores was observed in the AD group. A comparison between the 2 groups revealed that treatment did not lead to statistically significant differences between the AD and AD+SVD groups in any of CERAD parameters following 6 or 18 months of treatment. These data support previous observations that donepezil therapy is effective in AD patients with and without subcortical vascular lesions.

Supernumerary phantom limb as a rare symptom of epileptic seizures—case report and literature review

Supernumerary phantom limbs, that is, the awareness of an illusory extra limb is a fascinating neurologic symptom that has been described in a number of neurologic diseases including stroke, spinal injury, and epilepsy. Herein we report a case of a 70‐year‐old male patient with new‐onset focal seizures with left‐sided supernumerary phantom arm and leg as the only seizure manifestation. Ictal single‐photon emission computed tomography (SPECT) revealed a hyperperfusion in the right temporoparietal junction and allowed localization of the seizure‐onset zone. This report is accompanied by a discussion of phenomenology and terminology in the context of existing literature.