G Hagemann

Universitätsklinikum Jena, Jena, Thuringia, Germany

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Publications (65)204.75 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Here, we demonstrate a first case of tick-borne encephalitis (TBE) associated with an isolated reversible splenial corpus callosum lesion (IRSL) and highlight the wide range of different clinical entities in which such alterations have been observed. A 42-year-old man showed fever, cephalgia and mild disturbance of coordination and gait. Diagnosis was ascertained by slight CSF-pleiocytosis and positive TBE-IgG as well as by positive intrathekal specific antibody index on follow-up. MRI demonstrated a single ovoid hyperintensity in T2 and DWI with reduction in ADC in the splenium of corpus callosum which was abrogated in follow-up after 6 weeks. Most entities of IRSL presented with excellent prognosis, including our novel case of TBE. We discuss different possible pathomechanisms and the so far unexplained propensity of the splenium for such alterations. Clinicians should be familiar with this phenomenon to avoid unnecessary diagnostic or therapeutic efforts.
    Clinical neurology and neurosurgery 03/2011; 113(5):430-3. · 1.30 Impact Factor
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    ABSTRACT: There is increasing evidence for hormone-dependent modification of function and behavior during the menstrual cycle, but little is known about associated short-term structural alterations of the brain. Preliminary studies suggest that a hormone-dependent decline in brain volume occurs in postmenopausal, or women receiving antiestrogens, long term. Advances in serial MR-volumetry have allowed for the accurate detection of small volume changes of the brain. Recently, activity-induced short-term structural plasticity of the brain was demonstrated, challenging the view that the brain is as rigid as formerly believed. We used MR-volumetry to investigate short-term brain volume changes across the menstrual cycle in women or a parallel 4 week period in men, respectively. We found a significant grey matter volume peak and CSF loss at the time of ovulation in females. This volume peak did not correlate with estradiol or progesterone hormone levels. Men did not show any significant brain volume alterations. These data give evidence of short-term hormone-dependent structural brain changes during the menstrual cycle, which need to be correlated with functional states and have to be considered in structure-associated functional brain research.
    PLoS ONE 01/2011; 6(2):e14655. · 3.53 Impact Factor
  • G Hagemann, J Zinke, M Fuchs, O W Witte
    Der Nervenarzt 12/2010; 81(12):1498-500. · 0.80 Impact Factor
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    ABSTRACT: We report the case of a patient with idiopathic generalized epilepsy who ten years after the onset of his epilepsy also developed recurring nocturnal paroxysmal episodes reminiscent of his seizure semiology. Video monitoring and polysomnography revealed episodes of nocturnal groaning. Escalation of antiepileptic treatment was avoided.
    Epileptic disorders: international epilepsy journal with videotape 06/2010; 12(2):136-7. · 1.17 Impact Factor
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    ABSTRACT: Gait disturbances are frequent in older patients and lead to immobility, falls, and increased mortality. In gerontoneurologic patients a higher prevalence of risk factors for gait disturbances and falls has to be attributed due to neurodegenerative diseases, dementia, delirium, or psychotropic medication. The potential of neurological expertise to contribute to the evaluation and treatment of falls and gait disorders in geriatric patients is still not fully exploited. Sometimes a fall can be an index event to the diagnosis of the underlying disorder. This review, therefore, focuses on the relationship between falls, gait, and neurological diagnosis. It helps to find the correct diagnosis of the underlying disease as one major step in the management of gait disorders and fall prevention. From a pragmatic point of view falls can be classified according to loss or preservation of consciousness. Gait disturbances should be differentiated into gait disorders with and without cognitive impairment. Although gait impairments are influenced by multifactorial parameters, this differentiation may help to find a diagnosis and also to initiate an appropriate, disease-specific therapy. In addition, every fall patient has to be analyzed individually according to his individual risk factors, which all can potentially be influenced to improve mobility and to reduce falls.
    Clinical neurology and neurosurgery 05/2010; 112(4):265-74. · 1.30 Impact Factor
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    ABSTRACT: Arteriosclerosis related stenosis in the carotid bulb causes autonomic imbalance, likely due to carotid chemoreceptor and baroreceptor dysfunction. The latter are associated with increased cerebrovascular and cardiovascular mortality. Chemoreceptor and baroreceptor dysfunction is also involved in the origin of central sleep apnea syndrome (CSA) in different clinical entities. We hypothesized that CSA is associated with stenosis of the internal carotid artery (ICA). The mechanism of this association is an autonomic imbalance induced by stenosis-mediated chemoreceptor and baroreceptor dysfunction. Cross-sectional prospective study. University-based tertiary referral sleep clinic and research center. Fifty-nine patients with various degrees of asymptomatic extracranial ICA (elCA) (n = 49) and intracranial ICA (ilCA) stenosis (n = 10) were investigated. Polysomnography to detect CSA and analysis of spontaneous heart rate variability (HRV) to detect autonomic imbalance. CSA occurred in 39% of the patients with elCA stenosis but was absent in patients with ilCA stenosis. CSA was present in patients with severe elCA stenosis of > or = 70% on one side. Independent predictors for CSA were severity of stenosis, asymmetric distribution of stenosis between both elCA and autonomic imbalance, namely a decrease of parasympathetic tone. The specific constellation of HRV-parameters indicated increased chemoreceptor sensitivity and impaired baroreflex sensitivity. CSA indicates autonomic dysfunction in patients with asymptomatic elCA stenosis. Detection of CSA may help to identify asymptomatic patients with an increased risk of cerebrovascular or cardiovascular events who particularly benefit from carotid revascularization.
    Sleep 03/2010; 33(3):327-33. · 5.10 Impact Factor
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    ABSTRACT: The clinical differentiation between stroke and seizure is usually straightforward but postictal neurological deficits can be mistaken for stroke in case no detailed medical history is available. Up to now, the imaging findings of Todd's paresis are not well described. This case report demonstrates that postictal paresis can be accompanied by a reversible global hemispheric hypoperfusion as measured with perfusion MRI indicating transient but profound cerebrovascular dysfunction in postictal paresis. Extensive postictal perfusion changes must be discriminated from emerging stroke to avoid potentially harmful therapy like thrombolysis. Further investigations are warranted to clarify the role of cerebrovascular dysfunction in the pathophysiology of postictal paresis.
    Epilepsy research 03/2010; 89(2-3):355-9. · 2.48 Impact Factor
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    ABSTRACT: To assess and visualize gravitational effects on brain morphology and the position of the brain within the skull by magnetic resonance (MR) morphometry in order to identify confounding effects and possible sources of error for accurate planning of neurosurgical interventions. Three-dimensional MR imaging data sets of 13 healthy adults were acquired in different positions in the scanner. With a morphometric approach, data sets were evaluated by deformation field analysis and the brain boundary shift integral. Distortions of the brain were assessed comparing right versus left and prone versus supine positioning, respectively. Two effects could be differentiated: 1) greatest brain deformation of up to 1.7 mm predominantly located around central brain structures in the lateral direction and a less pronounced change after position changes in posterior-anterior direction, and 2) the brain boundary shift integral depicted position-dependent brain shift relative to the inner skull. Position-dependent effects on brain structure may undermine the accuracy of neuronavigational and other neurosurgical procedures. Furthermore, in longitudinal MR volumetric studies, gravitational effects should be kept in mind and the scanning position should be rigidly controlled for.
    Neurosurgery 02/2010; 66(2):376-84; discussion 384. · 2.53 Impact Factor
  • G. Hagemann, J. Zinke, M. Fuchs, O.W. Witte
    Der Nervenarzt 01/2010; 81(12). · 0.80 Impact Factor
  • Georg Hagemann, Ilia Mois Aroyo
    Archives of neurology 05/2009; 66(4):534-5. · 7.58 Impact Factor
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    Sleep Medicine 09/2008; 10(5):592-3. · 3.49 Impact Factor
  • Gynakologe. 01/2008; 41(6):427-435.
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    ABSTRACT: Während der Schwangerschaft sind schwere Notfälle mit nicht ansprechbaren, komatösen oder generalisiert krampfenden Patientinnen selten, aber mit hoher Mortalität und Morbidität verbunden. Die häufigsten Ursachen sind Epilepsie, Eklampsie, Hyperventilationstetanie, Hypoglykämie, Ketoazidose, Sinusvenenthrombose und Schlaganfälle, die häufiger während Schwangerschaft und Wochenbett auftreten. Die Erstversorgung umfasst die kardiopulmonale Stabilisierung, stabile Linksseitenlagerung, Glukosezufuhr und anfallsdurchbrechende Medikation. Eine rasche Differenzialdiagnostik ist wegweisend für das weitere Management und die Verhinderung von schweren maternalen und fetalen Komplikationen. Emergencies involving coma and seizures are rare events during pregnancy but are associated with high morbidity and mortality. Common conditions include epilepsy, eclampsia, hypoglycemia, diabetic ketoacidosis, hyperventilation, and stroke, which have a higher incidence during pregnancy and the postpartum period. First-line therapy consists of cardiopulmonary stabilization, left lateral position, glucose, and antiepileptic drugs. Prompt diagnosis is important for further management to avoid severe maternal and fetal complications.
    Der Gynäkologe 01/2008; 41(6):427-435.
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    ABSTRACT: Non-convulsive status epilepticus (NCSE) is characterized by continuous or recurrent, generalized or focal epileptiform activity on the electroencephalogram and diverse clinical symptoms with alterations of mental state and vigilance. NCSE is not rare but certainly under diagnosed. There is some debate about how aggressive NCSE should be treated, as high dose anticonvulsants maybe partially responsible for the morbidity and mortality of patients with NCSE. We hypothesized that levetiracetam (LEV) as a well tolerated, highly effective new anticonvulsant, may be a safe treatment option. We retrospectively analyzed all (8) patients with NCSE who received levetiracetam from our database, compared with 11 patients with NCSE treated with conventional intravenous status medication as controls. These eight patients showed a marked clinical improvement with final cessation of ictal EEG-activity and clinical symptoms of NCSE after initiation of LEV within 3 days (mean 1.5 days). The response to conventional treatment was similarly effective but there were severe side effects whereas no relevant side effects in the LEV-treated group were noticed. A long-term follow up (6-36 months from discharge) revealed six patients with a persisting reduction in seizure frequency on medication with LEV. One patient changed the anticonvulsive medication because of inefficacy and one died from other causes than epilepsy 2 months after discharge from hospital. We found no significant differences in hospitalisation time, time in intensive care unit and outcome between the LEV group and the control group. This retrospectively acquired data suggests that LEV may be a well tolerated, effective treatment option in NCSE. This highlights the need for a prospective controlled study to further elucidate the utility of LEV in the treatment of NCSE, particularly as an intravenous formulation is now available.
    Epilepsy Research 04/2007; 73(3):238-44. · 2.24 Impact Factor
  • Klinische Neurophysiologie 01/2007; 118(4). · 0.33 Impact Factor
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    ABSTRACT: Neonatal freeze lesions in newborn rats induce focal malformations of the cerebral cortex mimicking human polymicrogyria which is a common cause of epilepsy and neuropsychological deficits in children and adults. Experimental and clinical studies demonstrated hyperexcitability in the malformation itself and peridysplastic cortex associated with a widespread imbalance of excitatory and inhibitory function and extensive alterations in cortical connectivity. We investigated the integrity of functional cortical inhibition using a paired pulse paradigm in brain slice preparations of adult freeze-lesioned rats. In contrast to previous electrophysiological studies focusing on the dysplastic cortex and the ipsilateral hemisphere, we here mapped both hemispheres. Extracellular field potentials were evoked by application of double pulses at the border of layer VI/white matter and recorded in layer II/III. Evaluation of the ratio of the field potential amplitudes at different recording positions allowed an assessment of regional functional inhibition. Using this approach, we observed a significant reduction of functional inhibition in the somatosensory cortex of the contralateral hemisphere, whereas only slight alterations were detected in the ipsilateral lesion surround. Our results provide evidence that focal cortical malformations not only impair cortical excitability in the ipsilateral hemisphere but also induce a disinhibition of the contralateral cortex.
    Experimental Neurology 10/2006; 201(1):270-4. · 4.65 Impact Factor
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    ABSTRACT: This report presents the imaging findings of an unusual case of Epstein-Barr virus (EBV) encephalitis. A young man presented with a short-lasting history of febrile infection, neuropsychologic deficits, ataxia, and seizures. MR imaging revealed fully reversible signal intensities (T2, diffusion-weighted imaging with a decreased apparent diffusion coefficient) in the splenium of the corpus callosum and both posterior hemispheres. EBV infection must be added to the list of differential diagnoses of (reversible) splenial lesions.
    American Journal of Neuroradiology 09/2006; 27(7):1447-9. · 3.17 Impact Factor
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    ABSTRACT: Decompressive craniectomy after space occupying infarction of the middle cerebral artery (MCA) tends to decrease mortality and increase functional outcome. The aim of this retrospective study was to evaluate mortality rates and functional outcome in our centre and to identify predictors of prognosis. The charts of 30 consecutive patients (6 women, 24 men, mean age 59.3 +/- 11.0 years) who underwent craniectomy after space occupying MCA-infarction from 1996 to 2002 were analyzed. Functional outcome was assessed by semistructured telephone interview as Barthel-Index, modified Rankin scale and extended Barthel-Index. Five patients (mean age 67.2 +/- 6.1 years) died within 5.2 +/- 2.4 days (range 2-8 days) after the first symptoms due to herniation. Nine patients (mean age 63.1 +/- 7.1 years) died 141.0 +/- 92.5 days (range 40-343) after stroke onset due to internal complications. 16 patients survived (mean surviving time 2.1 +/- 1.5 years, mean age 54.1 +/- 11.4 years). Mortality was related to age and the number of risk factors/comorbidity, and functional outcome was dependent on the number of risk factors/comorbidity. Our small observational, retrospective study suggests that hemicraniectomy in patients with space occupying MCA-infarction decreases mortality rate and increases functional outcome. Further randomized trials may prove useful to better define the indications, timing and prognosis for this procedure.
    Acta Neurochirurgica 02/2006; 148(1):31-7; discussion 37. · 1.55 Impact Factor
  • Aktuelle Neurologie - AKTUEL NEUROL. 01/2006; 33.
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    ABSTRACT: Electrophysiological studies of human cortical dysplasia and rodent models revealed widespread hyperexcitability in the malformation itself as well as in its vicinity. We here analyzed the initiation of paroxysmal epileptiform activity using optical imaging of neuronal activity in rats with cortical malformations induced by neonatal freeze lesions. Brain slice preparations were incubated with the voltage-sensitive dye RH795 and neuronal activity was monitored using a fast-imaging photodiode array combined with standard field potential recordings. Spontaneous paroxysmal epileptiform activity emerged in all slices from animals with cortical malformations and sham-operated controls 20-40 min after omission of extracellular Mg(2+). Following electrophysiological and optical recordings, slices were histochemically processed. Using this approach, the present study demonstrated that in animals with freeze-lesion-induced focal cortical malformations, paroxysmal epileptiform activity always emerged from the dysplastic cortex and then spread to adjacent areas through superficial layers. This distribution of initiation sites was significantly different to sham-operated controls in which epileptogenic foci were located in various cytoarchitectonic areas. The present study indicates that following global changes in excitability, the dysplastic cortex itself is the main initiation site of paroxysmal epileptiform activity in animals with focal cortical malformations.
    Experimental Neurology 05/2005; 192(2):288-98. · 4.65 Impact Factor

Publication Stats

1k Citations
204.75 Total Impact Points

Institutions

  • 2004–2011
    • Universitätsklinikum Jena
      Jena, Thuringia, Germany
    • Charité Universitätsmedizin Berlin
      • Department of Psychiatry and Psychotherapy
      Berlin, Land Berlin, Germany
  • 2010
    • HELIOS Klinikum Berlin-Buch
      Berlín, Berlin, Germany
  • 2002–2010
    • Friedrich-Schiller-University Jena
      • Klinik für Neurologie
      Jena, Thuringia, Germany
  • 1993–2003
    • Heinrich-Heine-Universität Düsseldorf
      • Neurologische Klinik
      Düsseldorf, North Rhine-Westphalia, Germany