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Felix Rosenow

Publications and source records attributed to Felix Rosenow.

At least 19 recordsLinked to original sources
PubMed2006

Cyclical excitability of the motor cortex in patients with catamenial epilepsy: a transcranial magnetic stimulation study.

PURPOSE: The pathophysiology of catamenial epilepsy is still unclear. Therefore, we investigated the cortical excitability of women with catamenial epilepsy during different phases of the menstrual cycle. METHODS: Using transcranial magnetic stimulation, six patients suffering from catamenial epilepsy were investigated during ovulatory cycles. On days 8, -14, -7 and 2 of the cycle (day 1 being the first day of menstrual bleeding), resting motor threshold (RMT), cortical silent period (CSP), intracortical inhibition (ICI) and intracortical facilitation (ICF) were investigated. The non-parametric Friedman-test for multiple comparisons and Wilcoxon signed rank test were used for statistical analysis. RESULTS: Five patients suffered from focal epilepsy (three right hemispheric, one bitemporal, one unknown origin) and one patient had idiopathic generalized epilepsy. All patients experienced perimenstrual seizure clustering and two also showed an increased seizure frequency during the luteal phase. In the right hemispheres there was a significant change of CSP duration in the course of the menstrual cycle (chi(2)=8.3, P=0.041), due to a shorter CSP during the luteal phase (Z=-2.0, P=0.043) and menstruation (Z=-2.2, P=0.028) as compared to the follicular phase. There was no significant variation of CSP in the left hemispheres. RMT, ICI and ICF showed no significant changes in the course of the menstrual cycle. CONCLUSIONS: The CSP changes suggest a decreased inhibition involving GABA-ergic neurotransmission during the luteal phase and menstruation. These TMS alterations correlated with the clinical course of the epilepsies and were found in the hemispheres containing the majority of the epileptogenic zones.

Adult↗
PubMed2006

Language dominance in mesial temporal lobe epilepsy: a functional transcranial Doppler sonography study of brain plasticity.

Functional transcranial Doppler sonography was used to study hemispheric language dominance (HLD) in 24 right-handed patients with left temporal lobe epilepsy (TLE) and a structural lesion in the left temporal lobe and in 69 healthy controls. Twenty-five percent of the patients and 4% of controls showed atypical (right or bilateral) HLD. Degree of HLD was not correlated with age, Full Scale IQ, Verbal IQ, spike frequency, seizure frequency, age at seizure onset, or duration of TLE. Atypical HLD appears to be lesion-induced, independent of epilepsy characteristics.

Adolescent↗
PubMed2006

Modulation of electrically induced pain by paired pulse transcranial magnetic stimulation of the medial frontal cortex.

OBJECTIVE: Aim of this study was to investigate whether paired pulse transcranial magnetic stimulation (ppTMS) applied over the medial frontal cortex (MFC) affects acute Adelta fiber-mediated electrically induced pain. In addition, we investigated whether this effect depends on the time course of the stimulation, on the noxious stimulus intensity or on the ppTMS intensity. METHODS: For painful stimulation, the electrical stimulus for the nociceptive flexion reflex (NFR) was used. PpTMS (ISI: 50 ms) was applied over the medial frontal cortex at different intervals ranging from 0 to 1,000 ms following the previous elicited NFR in 10 healthy volunteers. Three sequences at 3 different NFR stimulus intensities (at NFR threshold, 1.3 x and 1.6 x NFR threshold) with a ppTMS stimulus intensity at 1.2 x resting motor threshold (RMT) and one sequence with elevated ppTMS at 1.6 x RMT stimulus intensity were performed. Pain intensity and pain unpleasantness were assessed by visual analogue scales. RESULTS: Pain ratings differed in dependence of the interstimulus interval between NFR and ppTMS. Post-hoc t-tests revealed an increased verbal pain report within interstimulus intervals from 25 to 75 ms at NFR threshold as well as for 25 ms at 1.3 x NFR threshold when ppTMS was applied at 1.2 x RMT and from 0 to 75 ms at 1.6 x NFR threshold when ppTMS was applied at 1.6 x RMT. CONCLUSIONS: The present data suggest that ppTMS over MFC-applied in a certain time window-can enhance pain perception of acute Adelta fiber-mediated electrically induced pain. We hypothesize that the increase of pain is due to interference between ppTMS and the incoming nociceptive input. Further pain processing might be modulated by direct effects on MFC or indirect effects on anterior cingulate cortex (ACC) or spinal nociception. SIGNIFICANCE: Brain areas involved in cognitive and emotional adaptation to pain can be used, in place of primary motor areas, as cortical targets in TMS trials of experimental or ongoing pain.

Adult↗
PubMed2006

Modulation of human motor cortex excitability by single doses of amantadine.

Amantadine-sulfate has been used for several decades to treat acute influenza A, Parkinson's disease (PD), and acute or chronic drug-induced dyskinesia. Several mechanisms of actions detected in vivo/in vitro including N-methyl-D-aspartate (NMDA)-receptor antagonism, blockage of potassium channels, dopamine receptor agonism, enhancement of noradrenergic release, and anticholinergic effects have been described. We used transcranial magnetic stimulation (TMS) to evaluate the effect of single doses of amantadine on human motor cortex excitability in normal subjects. Using a double-blind, placebo-controlled, crossover study design, motor thresholds, recruitment curves, cortical stimulation-induced silent period (CSP), short intracortical inhibition (ICI), intracortical facilitation (ICF), and late inhibition (L-ICI) in 14 healthy subjects were investigated after oral doses of 50 and 100 mg amantadine with single and paired pulse TMS paradigms. Spinal cord excitability was investigated by distal latencies and M-amplitudes of the abductor digiti minimi muscle. After intake of amantadine, a significant dose-dependent decrease of ICF was noticed as well as a significant increase of L-ICI as compared to placebo. The effect on ICF and L-ICI significantly correlated with amantadine serum levels. ICI was slightly increased after amantadine intake, but the effect failed to be significant. Furthermore, amantadine had no significant effects on motor thresholds, MEP recruitment curves, CSP, or peripheral excitability. In conclusion, a low dose of amantadine is sufficient in modulating human motor cortex excitability. The decrease of ICF and increase of L-ICI may reflect glutamatergic modulation or a polysynaptic interaction of glutamatergic and GABA-ergic circuits. Although amantadine has several mechanisms of action, the NMDA-receptor antagonism seems to be the most relevant effect on cortical excitability. As L-ICI can be influenced by this type of drug, it may be an interesting parameter for studies of motor learning and use-dependent plasticity.

Adult↗
PubMed2006

Status epilepticus after stroke is associated with increased long-term case fatality.

PURPOSE: The aim of this study was to determine the long-term case fatality of patients with a first episode of status epilepticus (SE group) of cerebrovascular etiology, as compared with that in acute stroke patients without SE (AS group). METHODS: Patients with SE who had been prospectively admitted to an epidemiologic study were retrospectively compared with a cohort of patients from the local stroke registry. The main outcome end point was overall survival. Survival curves were generated according to the Kaplan-Meier method and compared by using the log-rank test. An extended Cox model was used to examine the impact of patient group on the risk of death. Covariates considered potential confounders included age at diagnosis, sex, type of stroke, affected hemisphere, and localization of lesions. RESULTS: Of 166 patients who entered the study, 93 patients were in the SE group, and 73 patients were in the AS group; 53 SE patients and 35 AS patients died during the study. Patient group (SE vs. AS) showed no significant impact on survival (p=0.0832) in univariate analysis. In contrast, the results from a multivariable analysis suggest that after 6 months, patients with SE were at about twice the risk of death as were patients with AS [hazard ratio of 2.12 with 95% confidence interval, 1.04-4.32, p=0.0392]. CONCLUSIONS: The occurrence of SE in patients with cerebrovascular disease indicates a high risk of death within 3 years. In contrast, the case fatality risk attributable to recurrent status or seizures is lower.

Aged↗
PubMed2006

Direct and indirect costs of refractory epilepsy in a tertiary epilepsy center in Germany.

PURPOSE: There are only few studies on the costs of epilepsy in Germany. Therefore, we performed a pilot study to estimate the direct and indirect costs of refractory epilepsy in a German epilepsy center. METHODS: A "prevalence-based," cross-sectional convenience sample of adults with active epilepsy attending the outpatient clinic of our tertiary epilepsy center was evaluated. Seizure-free patients and patients presenting with their first seizure were excluded. Direct and indirect costs were prospectively recorded over a three-month period using questionnaires and a patient diary. Cost driving factors were identified. RESULTS: One hundred one patients were included (40.7+/-15.2 years; disease duration: 18.1+/-15.3 years; 6 patients had focal epilepsy with simple partial seizures only, 28 with complex partial seizures, 43 with secondarily generalized tonic-clonic seizures; 20 had idiopathic generalized epilepsy with generalized tonic-clonic seizures). The total costs of epilepsy per patient were in average euro 2610+/-4200 over the three-month period. Direct cost contributed 39% to the total costs. Costs of anticonvulsant medication were the main contributor to the direct costs while indirect costs were caused mainly by losses due to early retirement. Cost driving factors included higher seizure frequency, longer disease duration, ictal falls, and situationally inappropriate complex behavior during or after the seizure. CONCLUSIONS: Indirect costs were higher than direct costs in adult patients with active epilepsy attending a German epilepsy center. Medication contributed the most to the direct costs and early retirement was the main factor for the indirect costs. The costs of poorly controlled epilepsy in this German study were above average of the European costs of epilepsy.

Adolescent↗
PubMed2005

Predictive value of electrocorticography in epilepsy patients with unilateral hippocampal sclerosis undergoing selective amygdalohippocampectomy.

The purpose of this study was to evaluate the predictive value of intraoperative electro-corticography (ECoG) in patients with unilateral hippocampal sclerosis (HS) undergoing transsylvian selective amygdalohippocampectomy (sAHE). ECoG was recorded before and after resection in 22 patients with medication-resistant mesial temporal lobe epilepsy. The sAHE was performed, regardless of ECoG findings. ECoG findings recorded from the mesiobasal temporal lobe (MTL) and lateral temporal lobe (LTL) before and after the sAHE were correlated with seizure outcome 12 months later. Ten patients had right-sided and 12 left-sided HS. Average age was 37.1 years. Pre-resection spikes were restricted to the MTL in 11 patients and to the LTL in one. In three patients spikes were recorded from MTL and LTL and in seven no spikes were recorded before the resection. Fifteen patients (68%) remained completely seizure-free and 19 (86%) were in Engel's class I post-operatively. Patients with pre-resection spikes restricted to the MTL (n = 11) remained seizure-free more frequently (9/11, 82%) compared with other patients (6/11, 55%; P = 0.36). Pre-resection ECoG may be helpful in the prediction of seizure outcome in patients undergoing sAHE for mesial temporal lobe epilepsy. A larger study including more than 100 patients is needed to determine the predictive value of ECoG in patients with mesial temporal lobe epilepsy.

Adolescent↗
PubMed2005

Weight change in monozygotic twins treated with valproate.

OBJECTIVE: To evaluate whether genetic factors contribute to weight gain associated with valproate (VPA) therapy. RESEARCH METHODS AND PROCEDURES: We retrospectively and prospectively evaluated five pairs of monozygotic twins concordant for epilepsy and treated with VPA regarding weight course. RESULTS: In all twin pairs, both twins showed similar weight courses under therapy with VPA. DISCUSSION: These results suggest that genetic factors may have an influence on the weight change induced by VPA. Further studies are necessary to obtain heritability estimates regarding this effect of VPA therapy and to identify the relevant genes.

Adolescent↗
PubMed2005

Reflex seizures in patients with malformations of cortical development and refractory epilepsy.

PURPOSE: Malformations of cortical development (MCDs) are usually highly epileptogenic, and their hyperexcitability could facilitate the occurrence of reflex seizures. We sought to characterize reflex seizures in patients with MCDs and refractory epilepsy. METHODS: Clinical, electrographic, and neuroimaging data were reviewed in eight patients with MCDs who had reflex seizures reproduced during presurgical evaluation. RESULTS: All eight patients had both reflex and spontaneous seizures. In six, however, drop attacks or axial myoclonic seizures occurred only upon specific sensory stimulation. Reflex seizures were induced by more than one type of stimulus in most patients, but anatomofunctional correlations could usually be invoked. Six patients had significant intellectual impairment. Surgical resection controlled seizures in two patients. CONCLUSIONS: Reflex seizures in patients with MCDs may be medically refractory and may often manifest as drop attacks or axial myoclonus. Surgical resection of focal lesions can bring reflex seizures under control. Putative mechanisms related to the relatively low frequency of reflex seizures in MCDs are discussed.

Adolescent↗
PubMed2005

A semiological classification of status epilepticus.

The classification of status epilepticus (SE) has been a subject of discussion for many years, yet no satisfactory agreement has been reached. Due to their complexity, status episodes often defy classification according to the current international classification scheme. The semiological seizure classification (SSC) has been in use in several epilepsy centers for more than a decade, and has proven to be a valid approach to the classification of epileptic seizures. Based on the detailed analysis of more than 100 episodes of SE documented with video-EEG recordings, the authors now present a proposal for a semiological classification of status epilepticus (SCSE). The SCSE reflects the assumption implied by all modern definitions of SE that "there are as many types of status as there are types of seizures" and relies on the same principles as the SSC, focusing on the main clinical manifestations and the evolution of the status episode. The clinical manifestations of SE are subdivided into semiological components and classified along three axes: the type of brain function predominantly compromised by the seizure activity, the body part involved, and the evolution over time. Each axis contains several subcategories, so that many different levels of accuracy are possible. The SCSE, just like the SSC, is meant to be part of a comprehensive epilepsy classification which classifies as independent variables (epileptogenic zone, ictal semiology, etiology, related medical conditions) the main features of the patient's epilepsy, allowing for each variable maximum flexibility.

Autonomic Nervous System↗
PubMed2005

A proposal for a five-dimensional patient-oriented epilepsy classification.

The recent proposal by the ILAE Task Force for Epilepsy Classification consists of a multi-axial syndrome-oriented approach. Epilepsy syndromes, as defined by the ILAE, group patients according to various, poorly defined parameters. The resulting syndromes have frequently no biological significance, with overlap among different syndromes and syndromes changing with age. Additionally, only a minority of patients can be classified syndromatically, and the axes of this classification system convey redundant information. We propose a five-dimensional, patient-oriented approach to classifying epilepsies. This approach shifts from the syndrome-oriented approach to a standard, neurological, methodological, patient-oriented approach, using independent criteria in each of the five dimensions. Similar to general neurology, the first step in each patient-physician encounter in epileptology is to take a history of the presenting symptoms and generate a hypothesis regarding the localization and etiology of the symptom within the nervous system. Therefore, the main dimensions of this classification consist of: 1) localization of the epileptogenic zone, 2) seizure semiology classified according to the semiological seizure classification, 3) etiology, 4) seizure frequency, and 5) related medical conditions. These dimensions characterize all of the information necessary for patient management, are independent parameters, and include more pertinent information with regards to patient management than the ILAE axes. All patients can be classified according to this five-dimensional system even at the initial patient encounter when no detailed test results are available. Information from clinical tests, such as MRI and EEG, are translated into the best possible working hypothesis at the time of classification, allowing for increasing precision of the classification as additional information becomes available. This patient-oriented classification envisions an epileptic seizure as an independent symptom of a central nervous system dysfunction due to different causes, with various cortical localizations, occurring at various frequencies, and in conjunction with other diseases and clinical symptoms.

Adult↗
PubMed2004

Levetiracetam influences human motor cortex excitability mainly by modulation of ion channel function--a TMS study.

PURPOSE: Levetiracetam (LEV) is a new compound with anticonvulsive efficacy in focal and generalized epilepsies. Recent in vitro studies suggest LEV to act as a selective N-type-calcium-channel blocker. METHODS: We used transcranial magnetic stimulation (TMS) in order to investigate if ion-channel blockade is relevant to the inhibitory CNS effects of LEV in vivo and if motor thresholds (MTs) are a valid TMS parameter to detect this mode of action. In a double blind, placebo-controlled, crossover study, the effects of single oral doses of 500 and 2000 mg LEV on motor thresholds, recruitment curves (REC), cortical induced silent period (CSP) and on intracortical inhibition (ICI) and facilitation (ICF) were studied in 10 healthy subjects. RESULTS: A significant increase of motor thresholds was noticed after 2000 mg LEV as compared to placebo. The recruitment curve showed a trend towards motor evoked potential (MEP) amplitude reduction after LEV. LEV had no significant effect on CSP or on intracortical excitability as measured by inhibition and facilitation. CONCLUSIONS: We conclude that the modulation of ion-channel function, reflected by motor threshold elevation and a trend towards recruitment curve suppression, is relevant to the inhibitory CNS effects of LEV in vivo, and therefore, may contribute to the anticonvulsive efficacy of LEV. GABAergic or glutamatergic mechanisms seem to be less important in vivo as measured by TMS.

Adult↗
PubMed2004

Ictal functional TCD for the lateralization of the seizure onset zone--a report of two cases.

Ictal functional transcranial Doppler sonography (I-fTCD) was used to lateralize the ictal onset zone in the presurgical evaluation of two patients with temporal lobe epilepsy. In one patient, I-fTCD and ictal SPECT were performed simultaneously during EEG-monitoring. In both patients, results were concordant with the ictal SPECT findings, PET and semiology. I-fTCD seems to be an interesting new method to non-invasively lateralize the seizure onset zone with high temporal resolution. I-fTCD and SPECT may give complementary information to lateralize the seizure onset zone.

Adult↗
PubMed2004

Status epilepticus and seizures induced by iopamidol myelography.

PURPOSE: To report that iopamidol myelography can induce status epilepticus (SE) in patients carrying the diagnosis of symptomatic epilepsy and to estimate the incidence of seizures in patients undergoing iopamidol myelography. METHODS: We retrospectively identified all patients with seizures/SE associated with 1350 iopamidol myelographies during the last 5 years at our institution. The impact of cervical versus lumbar myelography was analysed. RESULTS: Induced by iopamidol myelography two non-epileptic patients suffered from first generalised tonic-clonic seizures and a 67-year-old women with symptomatic epilepsy after a remote ischemic stroke developed a generalised tonic-clonic seizure evolving into a dialeptic and right nystagmus SE (i.e. complex focal status) of 5-hour duration. The incidence of seizures in non-epileptic patients was 0.15%. The incidence of seizure induction for lumbar myelography was lower than for myelographies that included the cervical subarachnoid space. CONCLUSIONS: Iopamidol myelography (especially if cervical) is associated with a risk of seizures in non-epileptic individuals and can induce SE in patients with epilepsy. Patients should be informed about the risk of seizure induction.

Aged↗
PubMed2004

Hypocalcemic generalised seizures as a manifestation of iatrogenic hypoparathyroidism months to years after thyroid surgery.

Hypoparathyroidism is a relatively common side effect of a thyroidectomy and leads to hypocalcemia. Carpopedal spasm and tetany are typical manifestations and usually occur within weeks after surgery. The first signs can be less typical and include movement disorders such as chorea, as well as symptoms of increased intracranial pressure or epileptic seizures. We describe two cases with generalised tonic-clonic seizures as the first manifestation of postoperative hypoparathyroidism, appearing months and years after thyroidectomy. Iatrogenic hypoparathyroidism needs to be considered in the differential diagnosis of adult-onset, generalised, tonic-clonic seizures even if the thyroidectomy was performed years earlier.

Adult↗
PubMed2003

Sleep but not hyperventilation increases the sensitivity of the EEG in patients with temporal lobe epilepsy.

PURPOSE: To evaluate the relative impact of 3 and 5 min of hyperventilation (HV) and different sleep stages on the sensitivity of the interictal EEG in focal epilepsy. METHODS: We examined 20 patients with temporal lobe epilepsy (TLE, 85%) or extratemporal epilepsy during EEG-monitoring. We compared 6 min EEG (12 epochs of 30s) during/after each: (a) waking; (b) 5 or 3 min of HV; (c) sleep stages 1, 2, 3/4 and REM regarding the frequency of epileptiform discharges (ED). The Wilcoxon matched pairs signed rank test was used. The main endpoint was the comparison of 5 min of HV with sleep stage 2. RESULTS: During sleep stage 2, ED were more frequent than during/after 5 min of HV (P=0.002). Compared to the waking EEG, all NREM-sleep stages activated ED. Sleep stage 2 was associated with the strongest activation. There was no difference between the waking state and REM-sleep. Compared to the waking EEG, neither 3 nor 5 min of HV showed an activation of ED. CONCLUSION: In patients with TLE, sleep stage 2 shows a significantly higher sensitivity for ED than 5 min of HV. Compared to the waking EEG, HV showed no activating effect on ED. These results suggest that in patients with the clinical diagnosis of TLE (and possibly other focal epilepsies) measures to record sleep stage 2 (such as sleep deprivation) should be increased whereas HV appears to be dispensable in this setting.

Adult↗
PubMed2003

Language lateralization in patients with temporal lobe epilepsy: a comparison of functional transcranial Doppler sonography and the Wada test.

This study prospectively investigates whether noninvasive functional transcranial Doppler sonography (fTCD) is a useful tool to determine hemispheric language lateralization in the presurgical evaluation of patients with medically intractable temporal lobe epilepsy (TLE). fTCD results were compared with the Wada test as the gold standard. Wada test and fTCD were performed in 13 patients suffering from TLE. fTCD continuously measured blood flow velocities in both middle cerebral arteries, while the patient was performing a cued word generation task. During the Wada test, spontaneous speech, comprehension, reading, naming, and repetition were investigated. A laterality index (LI) was obtained by both procedures. Due to a lack of an acoustic temporal bone window, fTCD could not be performed in two patients (15%). In 9 of the remaining 11 patients hemispheric language dominance was found on the left side, in 1 patient on the right side, and 1 patient showed bihemispheric language representation. In all patients fTCD and the Wada test were in good agreement regarding hemispheric language lateralization, and the LI of both techniques were highly correlated (r = 0.776, P = 0.005). fTCD gives predictions of hemispheric language dominance consistent with the Wada test results even in children, patients with low IQ, and nonnative speakers. It is an alternative to the Wada test in determining language lateralization in patients with temporal lobe epilepsy.

Adolescent↗