Characterization of rebound depolarization in hippocampal neurons.

Rebound depolarization (RD) following hyperpolarizing pulses is found in several neuronal cell types where it takes part in the regulation of neuronal firing behavior. During whole-cell current and voltage clamp recordings in slice preparations, we investigated the modulation of RD by different stimulation patterns and its underlying ionic currents in rat CA1 pyramidal cells. RD was mainly carried by the hyperpolarization-activated cation current I(h) (about two-third) and T-type calcium currents (about one-third), respectively.

Blood-brain barrier disruption by low-frequency ultrasound.

Background And Purpose: A recent study showed a dramatic increase in cerebral hemorrhage comprising atypical locations with low-frequency ultrasound-mediated recombinant tissue plasminogen activator-thrombolysis in humans. Here, we provide a possible explanation for this phenomenon by a side effect observed in a study using the similar ultrasound device.

Methods: The study was originally undertaken to investigate by transcranial Doppler sonography, positron emission tomography and perfusion MRI whether transcranial application of wide-field low-frequency ultrasound (300 kHz) improves cerebral hemodynamics in patients with cerebral small vessel disease.

Safety and therapeutical benefit of hemicraniectomy combined with mild hypothermia in comparison with hemicraniectomy alone in patients with malignant ischemic stroke.

Introduction: Both for hemicraniectomy and for hypothermia, several reports describe a beneficial effect in patients with malignant supratentorial cerebral ischemia. We compared the safety and the clinical outcome in patients with a malignant supratentorial infarction who were treated with hemicraniectomy alone (HA) or received a combination therapy with hemicraniectomy and hypothermia of 35 degrees C (HH), respectively.

Methods: In a prospective and randomized study, 25 consecutive patients were treated after an ischemic infarction of more than two thirds of one hemisphere by HA (n=13 patients) or the HH combination therapy (n=12 patients).

Transcranial low-frequency ultrasound-mediated thrombolysis in brain ischemia: increased risk of hemorrhage with combined ultrasound and tissue plasminogen activator: results of a phase II clinical trial.

Background: Clinical studies using ultrasound at diagnostic frequencies in transcranial Doppler devices provided encouraging results in enhancing thrombolysis with tissue plasminogen activator (tPA) in acute stroke. Low-frequency ultrasound does not require complex positioning procedures, penetrates through the skull better, and has been demonstrated to accelerate thrombolysis with tPA in animal experiments in wide cerebrovascular territories without hemorrhagic side effects. We therefore conducted the first multicenter clinical trial to investigate safety of tPA plus low-frequency ultrasound (300 kHz).

Separating functional and structural damage in persistent vegetative state using combined voxel-based analysis of 3-D MRI and FDG-PET.

Functional and structural damage in postanoxic persistent vegetative state (PVS) was analysed using 18fluorodeoxyglucose PET (FDG-PET) coregistered to 3-D MRI in combination with morphometric 3-D MRI analysis (voxel-based morphometry, VBM). In five patients in late stages of non-traumatic PVS, combined analysis using statistical parametric mapping (SPM2) was performed to compare metabolic impairment and structural loss. FDG-PET showed widespread hypometabolism at p<0.

Activation of a residual cortical network during painful stimulation in long-term postanoxic vegetative state: a 15O-H2O PET study.

Survivors of prolonged cerebral anoxia often remain in the persistent vegetative state (PVS). In this study, long-term PVS patients were investigated by 15O-H(2)O PET to analyze their central processing of pain. The study was approved by the local Ethics Committee, the experiments were performed in accordance with the Helsinki Declaration of 2000.

[Clinical symptomatology, diagnostics, and treatment in patients with tuberculous meningoencephalitis].

Background: Tuberculous meningoencephalitis (TBM) is still associated with a high mortality. The relative rareness of TBM in Western European countries and the accompanying heterogeneous and unspecific clinical symptoms often result in a delayed diagnosis.

Patients And Methods: We present six HIV-negative patients (age 37-72 years) with a laboratory-confirmed or clinically probable diagnosis of TBM.

Primary stenting as emergency therapy in acute basilar artery occlusion.

In three patients with acute occlusion of the basilar artery intra-arterial fibrinolysis resulted in only partial recanalization and revealed severe stenosis as the underlying cause. Application of micro-stents without previous dilatation resulted in vessel re-opening. Two patients had an excellent clinical outcome.

Transcranial color-coded sonography in basilar artery stenting.

Basilar artery (BA) stenting is an emerging technique with promising results in revascularization of severe arteriosclerotic stenoses. Because of the limitations associated with other noninvasive techniques, we applied transcranial color-coded sonography (TCCS) in the follow-up. Successful stent application in two cases of acute basilar occlusion caused by thrombosis on pre-existing severe midbasilar stenoses was initially confirmed by angiography.