Determination of hemispheric dominance with mental rotation using functional transcranial Doppler sonography and FMRI.

BACKGROUND AND PURPOSE: the aim of this study was to investigate specific activation patterns and potential gender differences during mental rotation and to investigate whether functional magnetic resonance imaging (fMRI) and functional transcranial Doppler sonography (fTCD) lateralize hemispheric dominance concordantly. METHODS: regional brain activation and hemispheric dominance during mental rotation (cube perspective test) were investigated in 10 female and 10 male healthy subjects using fMRI and fTCD. RESULTS: significant activation was found in the superior parietal lobe, at the parieto-occipital border, in the middle and superior frontal gyrus bilaterally, and the right inferior frontal gyrus using fMRI. Men showed a stronger lateralization to the right hemisphere during fMRI and a tendency toward stronger right-hemispheric activation during fTCD. Furthermore, more activation in frontal and parieto-occipital regions of the right hemisphere was observed using fMRI. Hemispheric dominance for mental rotation determined by the 2 methods correlated well (P= .008), but did not show concordant results in every single subject. CONCLUSIONS: the neural basis of mental rotation depends on a widespread bilateral network. Hemispheric dominance for mental rotation determined by fMRI and fTCD, though correlating well, is not always concordant. Hemispheric lateralization of complex cortical functions such as spatial rotation therefore should be investigated using multimodal imaging approaches, especially if used clinically as a tool for the presurgical evaluation of patients undergoing neurosurgery.

Real-time visualization of altered gastric motility by magnetic resonance imaging in patients with Parkinson's disease.

Gastrointestinal motility is frequently affected in Parkinson's disease (PD) and has even been reported in early stages of PD. We hypothesized that gastric motility can be assessed in vivo by real-time magnetic resonance imaging (MRI), an established, noninvasive method. After an overnight fast and a standardized test meal, 10 patients with PD (six drug naïve, four treated) and 10 healthy volunteers underwent real-time MRI scanning of the stomach. Gastric motility was quantified by calculating the gastric motility indices (GMI) from transversal oblique und sagittal oblique MRI scans. There was a trend toward a decreased gastric motility in patients with PD compared with healthy controls (Mann-Whitney test, P 0.059). This difference in peristalsis was due to a significant reduction in the amplitude of peristaltic contractions (P 0.029) and not to a decelerated velocity of the peristaltic waves (P 0.97). Real-time MRI allows direct visualization of gastric motility in PD. In this pilot study, a relatively high interindividual variability impaired accurate separation of our PD sample from healthy controls. The trend toward decreased gastric motility is in accordance with previous studies that investigated gastric motility in patients with PD using other methods. Our study provides first demonstration of a possible underlying mechanism for disturbed gastric motility in PD (reduced amplitude of contractions versus altered velocity of peristaltic waves). Further studies in drug-naïve PD patients are required to determine the discriminatory power and validity of this technique in PD.

Six months of postmarketing experience with adjunctive lacosamide in patients with pharmacoresistant focal epilepsy at a tertiary epilepsy center in Germany.

We report our 6 months of experience with adjunctive lacosamide in 25 patients with pharmacoresistant focal epilepsy. Baseline characteristics of our patients were similar to those of the populations in the three clinical trials that evaluated lacosamide for refractory focal epilepsy. One patient experienced sustained seizure freedom for 5 months; two more patients had nonsustained periods of seizure freedom of 1 and 4 months. A total of eight patients (32%) reported a greater than 50% reduction in seizure frequency. Thirteen patients (52%) reported side effects during the titration, mostly dizziness, fatigue, nausea, and gait instability. In five patients (20%), these disappeared during the maintenance phase and/or with dose reduction. Two patients lost more than 10% of their body weight. Otherwise, in terms of efficacy and adverse effects, our data mirror the profile of lacosamide described in the three clinical trials. Substantial weight loss may occur in individual patients.

Recurrent alcohol-induced seizures in a patient with chronic alcohol abuse.

Seizures related to alcohol are a common finding, and are usually attributed to alcohol withdrawal, or to a neurotoxic effect of ethanol leading to seizures that are unrelated to acute alcohol consumption or withdrawal. However, there is also evidence for a third kind of alcohol-related seizure: alcohol-induced seizures. We describe a 36-year-old patient who, during the years from 1996-2006, was admitted 27 times with alcohol-induced seizures that occurred during alcohol consumption. Excluding one documented withdrawal seizure, serum ethanol levels at admission were 3.24 +/- 0.67%. There were no seizures that were unrelated to alcohol consumption. This case report supports the evidence of a seizure-provoking effect of ethanol that should be considered in the diagnosis and treatment of patients with alcohol-dependency and seizures.

Lack of differences of motorcortical excitability in the morning as compared to the evening in juvenile myoclonic epilepsy--a study using transcranial magnetic stimulation.

We used transcranial magnetic stimulation (TMS) in patients with juvenile myoclonic epilepsy (JME) and healthy controls to characterise motorcortical excitability in the morning as compared to the evening. Intra- and interindividual comparisons in JME-patients and controls showed no significant differences of any TMS parameter. The expected rise of the resting motor thresholds (RMT) in JME-patients taking anticonvulsants could not be detected which may indicate a decreased RMT in JME-patients.

Excitability of the motor cortex during ovulatory and anovulatory cycles: a transcranial magnetic stimulation study.

OBJECTIVE: The pathophysiology of catamenial diseases such as epilepsy is unclear. Therefore, we investigated changes in cortical excitability during anovulatory and ovulatory cycles. PATIENTS AND METHODS: Using transcranial magnetic stimulation (TMS), eight healthy women were investigated during anovulatory and 12 during ovulatory cycles. On days 8, -14, -7 and 2 of the cycle, resting motor threshold (RMT), cortical silent period (CSP), intracortical inhibition (ICI) and intracortical facilitation (ICF) were investigated. Repeated-measures analysis of variance (anova) and nonparametric methods were used for statistical analysis. RESULTS: A trend was seen for group by phase interaction regarding ICI (F = 2.5, P = 0.10). ICI varied during anovulatory cycles (median: 51.0% on day 8; 45.3% on day -14, 51.0% on day -7, and 28.6% on day 2; P = 0.040), mainly because of an increased inhibition on day 2. ICI was more pronounced in anovulatory cycles on day -14 (P = 0.021), -7 (P = 0.048) and 2 (P = 0.018) compared to ovulatory women who did not show intraindividual changes (P = 0.56). RMT, CSP and ICF showed no significant changes during anovulatory or ovulatory cycles. CONCLUSIONS: The results suggest fluctuations in cortical excitability during anovulatory cycles, possibly due to the withdrawal of 'excitatory' oestrogens that initiate menses in anovulatory cycles.

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.