0000000000174684
AUTHOR
Konrad J. Werhahn
showing 21 related works from this author
Decreased dopamine D2/D3-receptor binding in temporal lobe epilepsy: an [18F]fallypride PET study.
2006
Summary: Purpose: Although animal data are suggestive, evidence for an alteration of the extrastriatal dopaminergic system in human focal epilepsy is missing. Methods: To quantify D2/D3-receptor density, we studied seven patients with temporal lobe epilepsy (TLE) and nine agematched controls with positron emission tomography (PET) by using the high-affinity dopamine D2/D3-receptor ligand [ 18 F]Fallypride ([ 18 F]FP) suitable for imaging extrastriatal binding. TLE was defined by interictal and ictal video-EEG, magnetic resonance imaging (MRI), and [ 18 F]fluorodeoxyglucose ([ 18 F]FDG)-PET and was due to hippocampal sclerosis (HS), based on histology in all patients. Primary analysis was ba…
Weakness and focal sensory deficits in the postictal state.
2010
Postictal motor deficits may occur in patients following partial and generalized tonic-clonic seizures. Frequency is unclear, epidemiology being hampered by heterogeneous populations and variable methods of detection. Postictal paresis may affect any body part, may be bilateral, and may occur more frequently in seizures involving the sensorimotor cortex. Duration varies depending on the precise mode of testing from a few minutes to 36 hours. Sensory deficits following seizures have been rarely reported but may be missed if not specifically tested for. The lateralizing value of postical paresis is high (>90%), pointing to a seizure origin in the opposite frontal lobe. Postictal paresis often…
Magnetic stimulation in the definition of eloquent cortical areas
2003
Publisher Summary This chapter discusses the physiological principles of transcranial magnetic stimulation (TMS) and focus on detailing the techniques used in TMS mapping of the motor cortex relating it to the use of TMS in the presurgical assessment of patients with epilepsy. Since the main measure of TMS is the motor potential evoked in muscles, fine delineation of the functional topography of cortex is limited mainly to the primary sensorimotor cortex. In addition, TMS might be helpful to identify language dominance. The characterization of eloquent cortical areas is important in epilepsy surgery for the planning of the resection. TMS is not routinely employed for this purpose and TMS ma…
In vivo imaging of dopamine receptors in a model of temporal lobe epilepsy
2010
Alterations in dopamine neurotransmission in animal models of epilepsies have been frequently demonstrated using invasive neuroscience or ex vivo techniques. We aimed to test whether corresponding alterations could be detected by noninvasive in vivo brain imaging with positron emission tomography (PET) in the chronic phase of the rat pilocarpine model of temporal lobe epilepsy.Six pilocarpine-treated Wistar rats exhibiting spontaneous recurrent seizures and nine control rats were studied with PET using [(18)F]-fallypride, a high-affinity dopamine D(2/3) receptor ligand. Parametric images of [(18)F]-fallypride specific binding were calculated using a reference tissue method, and the two grou…
Antiepileptic drug use in nursing homes
2007
Contrary to former views, the incidence rate of epilepsy after the age of 65 years is higher than in childhood and adolescence, and epileptic seizures are one of the most common neurological problems in the elderly. Given that the incidence of epilepsy increases with advancing age and is not accompanied by an increase in mortality and given that elderly people now live longer, the prevalence of epilepsy is increasing with older age. Antiepileptic drugs (AEDs) are the primary treatment for epilepsy, although they are prescribed for other conditions too. Among nursing home residents the prevalence of seizures or epilepsy is between 5 and 8%, while AEDs are taken by approximately 5–10%. It is…
Antiamphiphysin-positive stiff-person syndrome associated with small cell lung cancer
2006
The paraneoplastic amphiphysin(+) stiff-person syndrome (SPS) has so far only been described in women with breast adenocarcinoma. Here, we describe the rare case of a female patient with antiamphiphysin(+) SPS due to small cell cancer of the lung.
Contralateral hand anesthesia transiently improves poststroke sensory deficits.
2005
Objective To test a possible strategy to alleviate somatosensory deficits after stroke. Methods Here, we applied ischemic nerve block to the intact hand of patients with chronic stroke, which in healthy subjects elicits improvements in sensibility of the other hand. Results We found that sensibility in the affected hand improved with intact hand anesthesia, but not with intact foot anesthesia or no anesthesia. Interpretation We conclude that reduction of sensory input from the intact hand leads to site-specific improvements in tactile discriminative skills in the affected hand after the period of anesthesia, a potentially relevant finding in designing neurorehabilitative interventions. Ann …
Dopaminergic modulation of low-Mg2+-induced epileptiform activity in the intact hippocampus of the newborn mouse in vitro
2012
To investigate whether epileptiform activity in the immature brain is modulated by dopamine, we examined the effects of dopaminergic agonists and antagonists in an intact in vitro preparation of the isolated corticohippocampal formation of immature (postnatal days 3 and 4) C57/Bl6 mice using field potential recordings from CA3. Epileptiform discharges were induced by a reduction of the extracellular Mg(2+) concentration to 0.2 mM. These experiments revealed that low concentrations of dopamine ( 3 μM dopamine enhanced epileptiform activity. The D1-agonist SKF38393 (10 μM) had a strong proconvulsive effect, and the D2-like agonist quinpirole (10 μM) mediated a weak anticonvulsive effect. The …
Antiepileptic drug use in nursing home residents: a cross-sectional, regional study.
2006
Summary The use of antiepileptic drugs (AED), their primary indication, comorbid conditions, and concomitant medications were collected from 565 nursing homes (NH) residents of six NH located around the city of Mainz, Germany representing 5.05% of all NH residents in the area. Data were collected from the electronic pharmacy files and by reviewing all available medical records. Average age was 82.2±2.4 years, 85.5% were women. Of 565 NH residents 28 (4.96%) received AED therapy, of which in 17 (63%) AED were prescribed for a seizure-related diagnosis. In 76.5% seizure types were unspecified and a distinction in focal and generalized epilepsy was made in only 23.5% of patients. Three patient…
Latency of interictal epileptiform discharges in long-term EEG recordings in epilepsy patients.
2015
AbstractPurposeTo assess the latency of interictal epileptiform discharges (IED) and seizures in long-term EEG recordings of patients with epilepsy.MethodIED latency was measured in 210 consecutive patients (mean (SD) age 38.6±13.9 years) with active epilepsy and the relationship to clinical variables was analyzed retrospectively. Median duration of EEG recording was 101.5h (95% confidence interval [CI] 92 to 117h).ResultsIEDs were absent in 45 (21.4%) and present in 165 (78.6%) patients who had a longer duration (p<0.001) and early onset (p<0.01) of epilepsy and more often had IEDs in prior standard EEGs (p<0.01), a structural etiology (OR 2.4, CI: 2.1–2.7), or temporal lobe epilepsy (OR 9…
Cognitive-behavioral screening in elderly patients with new-onset epilepsy before treatment
2014
Objectives Cognitive comorbidity at epilepsy onset reflects disease severity and provides a baseline estimate of reserve capacities with regard to the effects of epilepsy and its treatment. Given the high incidence of epilepsy at an older age, this study analyzed objective and subjective cognition as well as quality of life in elderly patients with new-onset focal epilepsy before initiation of anti-epileptic treatment. Materials and methods A total of 257 untreated patients (60–95 years of age) with new-onset epilepsy underwent objective assessment of executive function (EpiTrack) and performed subjective ratings of cognition (Portland Neurotoxicity Scale) and quality of life (QoL; QOLIE-31…
Influence of somatosensory input on motor function in patients with chronic stroke.
2004
In healthy volunteers, reduction of somatosensory input from one hand leads to rapid performance improvements in the other hand. Thus, it is possible that reduction of somatosensory input from the healthy hand can influence motor function in the paretic hand of chronic stroke patients with unilateral hand weakness. To test this hypothesis, we had 13 chronic stroke patients perform motor tasks with the paretic hand and arm during cutaneous anesthesia of the healthy hand and healthy foot in separate sessions. Performance of a finger tapping task, but not a wrist flexion task, improved significantly with anesthesia of the hand, but not the foot. This effect progressed with the duration of anes…
Impaired cerebrovascular autoregulation in patients with severe sepsis and sepsis-associated delirium
2012
Introduction Sepsis-associated delirium (SAD) increases morbidity in septic patients and, therefore, factors contributing to SAD should be further characterized. One possible mechanism might be the impairment of cerebrovascular autoregulation (AR) by sepsis, leading to cerebral hypo- or hyperperfusion in these haemodynamically unstable patients. Therefore, the present study investigates the relationship between the incidence of SAD and the status of AR during sepsis. Methods Cerebral blood flow velocity was measured using transcranial Doppler sonography and was correlated with the invasive arterial blood pressure curve to calculate the index of AR Mx (Mx>0.3 indicates impaired AR). Mx was m…
A randomized, double-blind comparison of antiepileptic drug treatment in the elderly with new-onset focal epilepsy.
2015
Objective: To compare the effectiveness of controlled-released carbamazepine (CR-CBZ) to levetiracetam (LEV) and to lamotrigine (LTG) in elderly patients with newlydiagnosedfocalepilepsy.Methods: Randomized, double-blind, parallel-group trial conducted between January2007andAugust2011,in47ambulatoryorhospitalsitesinGermany,Austria,orSwit-zerland. Eligible participants were aged ≥60, had new-onset epilepsy, had no acute ill-nessasthecauseoftheirseizures,andhadnocontraindicationtothedrugsinthetrial.Patients were randomized 1:1:1 to CR-CBZ, LTG, or LEV. Doses were up-titrated for6 weeks and could be maintained or adjusted depending on seizure relapse or tolera-bility over an additional period …
Early Diagnosis of Acanthamoeba Infection during Routine Cytological Examination of Cerebrospinal Fluid
2006
ABSTRACT Early identification of Acanthamoeba in cerebrospinal fluid is mandatory to prevent fatal granulomatous amebic encephalitis. In the case presented here amebic trophozoites were detected in a routine cerebrospinal fluid sample. The antibiotic treatment and the apparently low virulence of this isolate were responsible for the benign progression of the infection.
Does the Recruitment of Excitation and Inhibition in the Motor Cortex Differ?
2007
The level of excitability within the motor cortex can be described as a balance between excitation and inhibition, but it is unknown how well both processes correlate. To address this question, the authors measured motor cortical excitability and inhibition in healthy human subjects, comparing the recruitment of motor evoked potentials (MEPs) and the duration of the cortical silent period (CSP) after transcranial magnetic stimulation (TMS). Single-pulse "focal" TMS was applied at intensities varying between 90% and 200% of motor thresholds to the right motor cortex of 15 healthy volunteers. The peak-to peak size of MEP responses and the duration of the CSP were measured in small hand muscle…
Alteration of dopamine D2/D3 receptor binding in patients with juvenile myoclonic epilepsy
2010
Summary Purpose: To quantify extrastriatal and striatal D2/D3 receptor binding in patients with juvenile myoclonic epilepsy (JME) using the high-affinity dopamine D2/D3 receptor positron emission tomography (PET) ligand 18F-Fallypride ([18F]FP). Methods: Twelve patients with JME and 21 age-matched control subjects were studied. Dynamic images (180 min) were acquired after injection of [18F]FP. Patients had been seizure-free of all seizure types for at least 10 days before scanning. Parametric images of binding potential (BP) were created using the simplified reference tissue model. The images were stereotactically normalized using a ligand-specific template. We performed a voxel-based ana…
Epilepsy in the Elderly
2009
Epilepsy is the third most common disease affecting the brain in the elderly. Current demographic trends will lead to an increased prevalence of epilepsy in the general population.A selective literature search revealed 102 relevant publications as of September 2008, 50 of which were original articles.The level of evidence was found to be very low. No guidelines, systematic reviews or meta-analyses are available, and there have been only three randomized, double-blind trials of treatment for epilepsy in the elderly. The seizures often escape clinical attention, because premonitory symptoms (aura) and secondary generalization into tonic-clonic seizures are both rarer in older patients. On the…
Chapter 24 Bihemispheric plasticity after acute hand deafferentation
2003
Publisher Summary This chapter summarizes experiments showing that deprivation of somatosensory input could also elicit organizational changes in the hemisphere contralateral to the deafferented one. The existence of interactions among homotopic sites within cortical representations in both hemispheres provides a substrate for such an effect. It has been proposed that chronic deafferentation, in association with long-term practice as in blind, deaf, or individuals with amputation results in compensatory gains in the same and in other sensory modalities. However, the long-term changes described are mild and the question whether blind or deaf people develop enhanced capacities of their remain…
The safety and efficacy of add-on levetiracetam in elderly patients with focal epilepsy: A one-year observational study
2011
Abstract Purpose The long-term safety and efficacy of levetiracetam (LEV) was evaluated as add-on therapy in focal epilepsy patients ( n =491) aged at least 65 years who failed at least one monotherapy. Methods Patients ( n =491) with focal epilepsy treated with at least one antiepileptic drug in monotherapy with insufficient seizure control were included in this prospective open-label study. The recommended LEV dose range was 1000–3000mgperday. Follow-up visits were done approximately after 3, 6 and 12 months. Safety and efficacy was analysed based on all patients who received LEV (safety population, n =491) and all patients who were seen at all visits and completed the trial (per protocol…
Neuronavigation and epilepsy surgery
2010
Resective epilepsy surgery is an elective therapy indicated in focal epilepsy patients who are resistant to pharmacotherapy. Every effort should be undertaken to perform the procedures as safe and less traumatic as possible. Neuronavigation could represent a suitable tool to reduce surgical morbidity and increase surgical radicality. Here, we present a series of 41 patients who were operated on for medically intractable epilepsy using neuronavigation. Overall, complication rate was 17% with a favourable seizure outcome of 88% (Engel’s class I/II). Our data suggest that neuronavigation is a valuable surgical technique to accomplish a favourable outcome in epilepsy surgery.