Memory Performance is Related to Language Dominance as Determined by the intracarotid amobarbital procedure

Objective The goal of this study was to explore the relationship between language and memory lateralization in patients with epilepsy undergoing the intracarotid amobarbital procedure. Methods In 386 patients, language lateralization and memory lateralization as determined by laterality index (LI) were correlated with each other. Results Language lateralization and memory lateralization were positively correlated (r = 0.34, P \u3c 0.01). Correlations differed depending on the presence and type of lesion (χ2 = 7.98, P \u3c 0.05). LIs correlated significantly higher (z = 2.82, P \u3c 0.05) in patients with cortical dysplasia (n = 41, r = 0.61, P \u3c 0.01) compared with the group without lesions (n = 90, r = 0.16, P \u3e 0.05), with patients with hippocampal sclerosis falling between these two groups. Both memory (P \u3c 0.01) and language (P \u3c 0.01) LIs were higher in right- compared with left-sided lesions. Conclusion Correlation of language and memory is more pronounced in patients with structural lesions as compared with patients without lesions on MRI

Frequency of seizures and epilepsy in neurological HIV-infected patients

SummaryBackgroundInfection with the human immunodeficiency virus (HIV) is associated both with infections of the central nervous system and with neurological deficits due to direct effects of the neurotropic virus. Seizures and epilepsy are not rare among HIV-infected patients. We investigated the frequency of acute seizures and epilepsy of patients in different stages of HIV infection. In addition, we compared the characteristics of patients who experienced provoked seizures only with those of patients who developed epilepsy.MethodsThe database of the Department of Neurology, University of Münster, was searched for patients with HIV infection admitted between 1992 and 2004. Their charts were reviewed regarding all available sociodemographic, clinical, neurophysiological, imaging and laboratory data, therapy and outcome. Stage of infection according to the CDC classification and the epileptogenic zone were determined.ResultsOf 831 HIV-infected patients treated in our department, 51 (6.1%) had seizures or epilepsy. Three of the 51 patients (6%) were diagnosed with epilepsy before the onset of the HIV infection. Fourteen patients (27%) only had single or few provoked seizures in the setting of acute cerebral disorders (eight patients), drug withdrawal or sleep withdrawal (two patients), or of unknown cause (four patients). Thirty-four patients (67%) developed epilepsy in the course of their HIV infection. Toxoplasmosis (seven patients), progressive multifocal leukencephalopathy (seven patients) and other acute or subacute cerebral infections (five patients) were the most frequent causes of seizures. EEG data of 38 patients were available. EEG showed generalized and diffuse slowing only in 9 patients, regional slowing in 14 patients and regional slowing and epileptiform discharges in 1 patient. Only 14 of the patients had normal EEG. At the last contact, the majority of the patients (46 patients=90%) were on highly active antiretroviral therapy (HAART). Twenty-seven patients (53%) were on anticonvulsant therapy (gabapentin: 14 patients, carbamazepine: 9 patients, valproate: 2 patients, phenytoin: 1 patient, lamotrigine: 1 patient). Patients with only provoked seizures had no epilepsy risk factors except HIV infection, and were less likely to be infected via intravenous drug abuse.ConclusionsSeizures are a relevant neurological symptom during the course of HIV infection. Although in some patients seizures only occur provoked by acute disease processes, the majority of patients with new onset seizures eventually develops epilepsy and require anticonvulsant therapy. Intravenous drug abuse and the presence of non-HIV-associated risk factors for epilepsy seem to be associated with the development of chronic seizures in this patient group

Visual Naming Performance after ATL Resection: Impact of Atypical Language Dominance.

Purpose- To characterize the interaction between language dominance and lateralization of the epileptic focus for pre- and postoperative Boston Naming Test (BNT) performance in patients undergoing anterior temporal lobectomy (ATL). Methods- Analysis of pre- and postoperative BNT scores depending on lateralization of language as measured by the intracarotid amobarbital procedure (IAP) versus lateralization of the temporal lobe epileptic focus. Results- Changes between pre- and postoperative BNT performance depended on epilepsy lateralization (effect size = 0.189) with significant decrease in patients undergoing left ATL. Subgroup analysis in these showed that postoperative decline in BNT scores was significant in patients with atypical (n = 14; p \u3c 0.05), but did not reach statistical significance in patients with left language dominance (n = 36; p = 0.09). Chi-square test revealed a trend of higher proportions of patients experiencing significant postsurgical deterioration in naming performance in atypical (57.1%) as compared to left language dominance (30.6%; p = 0.082). Surgical failure was also associated with greater decline of BNT scores and was more common in atypical than in left language dominant patients (χ2 (1, n = 98) = 4.62, p = 0.032). Age of onset, duration of epilepsy, and seizure frequency had no impact on changes in BNT performance. Conclusion- Atypical language dominance is a predictor of change in visual naming performance after left ATL and may also impact postsurgical seizure control. This should be considered when counseling surgical candidates

Akute tubulointerstitielle Nephritis bei HIV-Erkrankung

We report about a patient with human immunodeficiency virus infection who developed acute renal failure after therapy with atazanavir. Renal biopsy showed acute interstitial nephritis. After discontinuing medication with atazanavir serum creatinine level decreased spontaneously without steroids. The different etiologies of acute renal failure in patients with human immunodeficiency infection are discussed. Die Fallbeschreibung illustriert den Verlauf eines akuten Nierenversagens bei einer Atazanavir-assoziierten akuten tubulointerstitiellen Nephritis bei HIV-Erkrankung im CDC-Stadium B2. Nach Absetzen des Virostatikums Atazanavir war das akute Nierenversagen unter konservativer Therapie ohne Einsatz von Steroiden reversibel. Die Differenzialdiagnose des akuten Nierenversagens bei HIV-Erkrankung wird dargestellt

The Inflammatory Chemokine CXCL10 Modulates Synaptic Plasticity and Neuronal Activity in the Hippocampus

Chemokines, a family member of cytokines, have been shown to play a major role in central nervous system inflammation. Among other chemokines, CXCR3 and its ligand CXCL10 are involved in the pathophysiology of several neuroinflammatory conditions. Most of these conditions are also associated with an increased incidence of seizure or epilepsy. Using age-matched wild-type (WT), as well as CXCR3-receptor-deficient (CXCR3-KO) mice, the present study aimed to investigate the effect of the chemokine CXCL10 and its receptor CXCR3 on synaptic plasticity as well as neuronal activities in hippocampal brain slices. Using field potential and intracellular recordings, the effect of exogenous CXCL10 on tetanus-induced long-term potentiation (LTP) as well as the neuronal spike activity was evaluated in hippocampal CA1 area. Exogenous application of CXCL10 enhanced LTP in WT mice, whereas it exerted no significant effect on CXCR3-KO mice. During intracellular recordings of spontaneous spike activity, exogenous application of CXCL10 significantly enhanced the amplitude, duration, and after-hyperpolarization of action potentials in slices obtained from WT mice compared to CXCR3-KO mice. In addition, CXCR3-KO mice exhibited a lower GABA A -mediated excitation in hippocampal CA1 neurons compared to WT mice. These data show that the inflammatory chemokine CXCL10, probably via its receptor CXCR3, modulates neuronal activity and synaptic plasticity in the hippocampus. CXCL10 may be involved in seizures observed during neuroinflammatory diseases such as meningitis and encephalitis

The Effect of Head Model Simplification on Beamformer Source Localization

Beamformers are a widely-used tool in brain analysis with magnetoencephalography (MEG) and electroencephalography (EEG). For the construction of the beamformer filters realistic head volume conductor modeling is necessary for accurately computing the EEG and MEG leadfields, i.e., for solving the EEG and MEG forward problem. In this work, we investigate the influence of including realistic head tissue compartments into a finite element method (FEM) model on the beamformer's localization ability. Specifically, we investigate the effect of including cerebrospinal fluid, gray matter, and white matter distinction, as well as segmenting the skull bone into compacta and spongiosa, and modeling white matter anisotropy. We simulate an interictal epileptic measurement with white sensor noise. Beamformer filters are constructed with unit gain, unit array gain, and unit noise gain constraint. Beamformer source positions are determined by evaluating power and excess sample kurtosis (g2) of the source-waveforms at all source space nodes. For both modalities, we see a strong effect of modeling the cerebrospinal fluid and white and gray matter. Depending on the source position, both effects can each be in the magnitude of centimeters, rendering their modeling necessary for successful localization. Precise skull modeling mainly effected the EEG up to a few millimeters, while both modalities could profit from modeling white matter anisotropy to a smaller extent of 5–10 mm. The unit noise gain or neural activity index beamformer behaves similarly to the array gain beamformer when noise strength is sufficiently high. Variance localization seems more robust against modeling errors than kurtosis