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Biomedical subjects

Mathias Bartels

Publications and source records attributed to Mathias Bartels.

17 recordsLinked to original sources
PubMed2006

Clinical efficacy and cognitive side effects of bifrontal versus right unilateral electroconvulsive therapy (ECT): a short-term randomised controlled trial in pharmaco-resistant major depression.

BACKGROUND: In most studies right unilateral electroconvulsive therapy (ECT) has been shown to cause fewer cognitive side effects but less antidepressant efficacy compared with bi(fronto)temporal ECT at certain intensities. AIMS: To compare the short-term efficacy and side effects of right unilateral ECT and bifrontal ECT. METHODS: In a double-blind randomised controlled clinical trial, 92 patients diagnosed with pharmaco-resistant major depression received either six right unilateral ECT treatments (250% stimulus intensity of titrated threshold) or six bifrontal ECT (150% of threshold) treatments over a 3-week period. Concomitant psychotropic medications were continued during ECT treatments. The severity of depression and cognitive status was assessed prior to the first ECT and one day after the sixth ECT using the 21-item Hamilton Depression Rating Scale and the modified Mini Mental State Examination. RESULTS: Eight patients did not complete the course of the study due to minor side effects or withdrawal of consent. The mean Hamilton Depression score decreased from 27 to 17 points in both groups of 46 patients, resulting in 12 responders (primary endpoint defined as a decrease >50%) in each patient group (95% confidence interval for the odds ratio from 0.35 to 2.8). There was no reduction in the modified Mini Mental State score (mean score 86 of 100 points). CONCLUSIONS: Both bifrontal and right unilateral electrode placements in ECT were reasonably safe and moderately efficacious in reducing symptoms of pharmaco-resistant major depression.

Adult↗
PubMed2006

BDNF serum and CSF concentrations in Alzheimer's disease, normal pressure hydrocephalus and healthy controls.

Alzheimer's disease (AD) and normal pressure hydrocephalus (NPH) are common forms of dementia in the elderly. Recent findings have suggested an involvement of brain-derived neurotrophic factor (BDNF) in the pathogenesis of AD. BDNF is an endogenous protein involved in the maintenance of neuronal function, synaptic plasticity and structural integrity in the adult brain. BDNF serum and cerebrospinal fluid (CSF) concentrations were assessed by a sensitive ELISA in 27 AD patients in comparison to 9 NPH patients and 28 age-matched healthy controls (10 CSF samples). We found a significant decrease of BDNF serum concentration in AD (18.6ng/ml) and NPH patients (18.1ng/ml) as compared to healthy controls (21.3ng/ml; p=0.041/p=0.017). BDNF serum concentrations did not correlate with CSF levels, age or MMSE scores both in AD and NPH patients. In unconcentrated CSF samples, BDNF could be detected in AD patients in 8/27 cases (29.6%; mean of 4.6pg/ml), in NPH patients in 1/9 cases (11.1%; mean of 6.4pg/ml) and in the control subjects in 5/10 cases (50%; mean of 1.6pg/ml) with no significant differences as regards mean concentration and frequency of detectable BDNF in CSF. The decrease of BDNF serum levels in AD and NPH may reflect a lack of trophic support and thus contribute to progressive degeneration in both diseases. In contrast to serum, CSF seems to be no useful source to determine BDNF in AD or NPH because of too low concentrations. Further examinations have to follow to elucidate the potential sources and the meaning of reduced BDNF levels in the blood in AD and NPH.

Aged↗
PubMed2006

Altered lymphocyte distribution in Alzheimer's disease.

The contribution of immunological factors in the etiopathogenesis of Alzheimer's disease (AD) is increasingly noted. Apart from cerebral immunological findings, peripheral changes of the immune systems have been reported including lymphocyte function and subset distribution. As data still remain inconsistent, we investigated a sample of 43 patients with AD and of 34 healthy age-matched controls. Distribution of the T-, B- and NK cell subsets was determined by flow cytometry (FACS). We found a significant decrease of CD3(+) lymphocytes as well as of CD19(+) lymphocytes. A slight increase of the CD4(+) and a decrease of the CD8(+) subpopulation could be observed, without significant change of the CD4(+)/CD8(+) ratio. CD16(+)56(+) cells were not altered. Our findings of decreased T- and B-Cell numbers in AD sustain the hypothesis of a general decline of immune activity in AD. A putative association with premature immunosenescence in AD and possible pathogenetic implications are discussed.

Aged↗
PubMed2005

Decline of immune responsiveness: a pathogenetic factor in Alzheimer's disease?

The involvement of immunological alterations in the pathogenesis of Alzheimer's disease (AD) is widely discussed. Hitherto, findings on systemic immunological alterations are inconsistent. We measured the concentrations of the pro-inflammatory cytokines IL-1beta, IL-2, IL-6, and TNF-alpha, and of the soluble receptors sIL-2r, sIL-6r, and sTNF-alphar, in cerebrospinal fluid (CSF) and serum of 20 Alzheimer patients and 21 controls. Moreover, we studied levels of the pro-inflammatory IL-6, Il-12, IFN-gamma, and TNF-alpha, and of the anti-inflammatory IL-5 and IL-13 in stimulated blood cell cultures from 27 AD patients and 25 controls. The levels in CSF and serum were diminished in AD or under detection limit. In mitogen-stimulated blood cultures we found a significant decrease of pro- and anti-inflammatory cytokines in the AD group. Our data suggest a general decline of immune responsiveness in AD. Based on the recent research, an impaired immune response may be considered as a pathogenetically relevant factor in AD. With respect to the putative role of ageing in AD, we assume a premature immunosenescence contributing to the Alzheimer's pathology.

Aged↗
PubMed2005

Hashimoto's encephalopathy presenting with bipolar affective disorder.

OBJECTIVE: We report on a rare case of Hashimoto's encephalopathy associated with a bipolar affective disorder. CASE REPORT: A 32-year-old woman presented with a bipolar affective disorder and Hashimoto's thyroiditis. Neurological investigations (magnetic resonance imaging of the brain and cerebrospinal fluid) did not reveal any pathological findings except for a pathological electroencephalogram (EEG). Despite consequent antidepressant treatment, the patient remitted only in conjunction with normalization of the EEG after short-term treatment with high doses of prednisolone. CONCLUSION: In treatment resistant courses of disorders, the thorough clinical and laboratory investigation of our patient revealed a very efficient treatment strategy. Cases of Hashimoto's encephalopathy associated with the occurrence of a manic episode and hence with bipolar disorder are rare; this is the first reported case. However, clinicians should be alert to this possibility.

Adult↗
PubMed2004

Pausing for thought: engagement of left temporal cortex during pauses in speech.

Pauses during continuous speech, particularly those that occur within clauses, are thought to reflect the planning of forthcoming verbal output. We used functional Magnetic Resonance Imaging (fMRI) to examine their neural correlates. Six volunteers were scanned while describing seven Rorschach inkblots, producing 3 min of speech per inkblot. In an event-related design, the level of blood oxygenation level dependent (BOLD) contrast during brief speech pauses (mean duration 1.3 s, SD 0.3 s) during overt speech was contrasted with that during intervening periods of articulation. We then examined activity associated with pauses that occurred within clauses and pauses that occurred between grammatical junctions. Relative to articulation during speech, pauses were associated with activation in the banks of the left superior temporal sulcus (BA 39/22), at the temporoparietal junction. Continuous speech was associated with greater activation bilaterally in the inferior frontal (BA 44/45), middle frontal (BA 8) and anterior cingulate (BA 24) gyri, the middle temporal sulcus (BA 21/22), the occipital cortex and the cerebellum. Left temporal activation was evident during pauses that occurred within clauses but not during pauses at grammatical junctions. In summary, articulation during continuous speech involved frontal, temporal and cerebellar areas, while pausing was associated with activity in the left temporal cortex, especially when this occurred within a clause. The latter finding is consistent with evidence that within-clause pauses are a correlate of speech planning and in particular lexical retrieval.

Adult↗
PubMed2004

[Liaison psychiatry in the prison of Rottenburg (Germany)].

The aim of this study was to get an idea of the need of psychiatric therapy in a prison. We report on the period May 2000 to January 2002. 60 medical files with the sociodemographic variables and the psychiatric diagnosis were evaluated. 45 % of the examined prisoners had a diagnosis of drug- or alcohol dependency and 31.3 % had a diagnosis of a schizophrenia. In 26.7 % the therapy was successful and the prisoners improved. This results show a great need of psychiatric therapy in a prison. Also in a prison improvements in the course of psychic disturbances are possible.

Adult↗
PubMed2004

Electroconvulsive therapy dosage in continuation/maintenance electroconvulsive therapy: when is a new threshold titration necessary?

Treatment effects and side effects of electroconvulsive therapy (ECT) depend on the level of applied energy in relation to the individual patient's seizure threshold. The threshold is known to increase during a course of frequently repeated ECT treatments and to return to baseline 6 months after cessation of treatment. In continuation ECT, however, as well as after early relapses, the interval between treatments is often longer than a few days but shorter than 6 months. Seizure thresholds for such cases have not been examined. We retrospectively examined 19 patients who had undergone repeated ECT treatments that had been separated by intervals of at least 14 days. We found significant changes in seizure duration, as measured by EEG and the cuff technique, when treatments were separated by durations exceeding 60 days. This is compatible with a decrease in seizure threshold or a loss of anticonvulsant action after 2 months and indicates the necessity to retitrate seizure threshold after this time.

Depressive Disorder↗
PubMed2003

Autoantibodies to serotonin in serum of patients with psychiatric disorders.

Antibodies to serotonin in serum were investigated by ELISA in patients with paranoid schizophrenia (N=27), schizoaffective psychosis (N=38), depression (N=67), Alzheimer's disease (N=21), chronic alcoholism (N=43), rheumatoid arthritis (N=25), and multiple sclerosis (N=16), and in healthy volunteers (N=60). Increased antibody reactivity to serotonin was found in schizoaffective psychosis, chronic alcoholism, and rheumatoid arthritis. Decreased antibody reactivity to serotonin was found in multiple sclerosis and depression. These anti-serotonin antibodies belong to the class of so-called natural autoantibodies. Alterations of these natural autoantibodies could indicate a disturbance to the immune system. It is possible that these antibodies could also influence receptor function. Autoantibodies to neurotransmitters in a wide spectrum of psychiatric disorders have not previously been reported.

Adolescent↗
PubMed2003

Brain regions sensitive to the face inversion effect: a functional magnetic resonance imaging study in humans.

Perception of upright faces relies on configural processing. Therefore recognition of inverted, compared to upright faces is impaired. In a functional magnetic resonance imaging experiment we investigated the neural correlate of a face inversion task. Thirteen healthy subjects were presented with a equal number of upright and inverted faces alternating with a low level baseline with an upright and inverted picture of an abstract symbol. Brain activation was calculated for upright minus inverted faces. For this differential contrast, we found a signal change in the right superior temporal sulcus and right insula. Configural properties are processed in a network comprising right superior temporal and insular cortex.

Adult↗
PubMed2003

Why are smiles contagious? An fMRI study of the interaction between perception of facial affect and facial movements.

In human communication there is often a close relationship between the perception of an emotionally expressive face and the facial response of the viewer himself. Whereas perception and generation of facial expressions have been studied separately with functional imaging methods, no studies exist on their interaction. We combined the presentation of emotionally expressive faces with the instruction to react with facial movements predetermined and assigned. fMRI was used in an event related design to examine healthy subjects while they regarded happy, sad, or neutral faces and were instructed to simultaneously move the corners of their mouths either (a). upwards or (b). downwards, or (c). to refrain from movement. The subjects' facial movements were recorded with an MR-compatible video camera. Movement latencies were shortened in congruent situations (e.g. the presentation of a happy face and combined with upward movements) and delayed in non-congruent situations. Dissonant more than congruent stimuli activated the inferior prefrontal cortex and the somatomotor cortex bilaterally. The congruent condition, in particular when seeing a happy face, activated the medial basotemporal lobes (hippocampus, amygdala, parahippocampal region). We hypothesize that this region facilitates congruent facial movements when an emotionally expressive face is perceived and that it is part of a system for non-volitional emotional facial movements.

Adult↗
PubMed2003

Transient suppression of tinnitus by transcranial magnetic stimulation.

It has been proposed that tinnitus is associated with an irregular activation of the temporoparietal cortex. If this activity is a functionally relevant component of the tinnitus-related network, a virtual temporary lesion of this area should result in transient reduction of tinnitus. To test this hypothesis, we applied 10Hz repetitive transcranial magnetic stimulation to eight scalp and four control positions in 14 patients with chronic tinnitus. Stimulation of left temporoparietal cortex significantly reduced tinnitus (Friedman analysis of variance, p < 0.05; compared with control), indicating that secondary auditory areas can be critical for tinnitus perception, perhaps as a consequence of maladaptive cortical reorganization.

Adult↗
PubMed2003

Successful episodic memory retrieval of newly learned faces activates a left fronto-parietal network.

It is easier to recognize a familiar face than a newly learned face. The neural basis of familiar face recognition has been elucidated in functional imaging and lesion studies. Behavioural and neuropsychological data indicate, however, that brain systems involved in episodic retrieval of familiar and newly learned faces are distinct. In our study, 12 subjects viewed 30 novel faces in an encoding session. In the study condition, event-related functional magnetic resonance imaging (fMRI) was used to compare brain activation during correct recognition of the recently learned faces to that observed during correct rejection of unknown control faces. Differences were present in the left inferior parietal (BA 40) and left medial frontal/anterior cingulate (BA 32/9) cortex. These two regions may be part of a pathway in the dorsal visual stream, responsible for a "feeling of familiarity" in contrast to the ventral pathway in the temporal lobes, which is mainly involved in the recognition of personal identity.

Adult↗
PubMed2003

The neural correlates of perceiving one's own movements.

Feedforward mechanisms are important for movement control. They may also contribute to the identification of self-produced actions by attenuating the sensory consequences of self-produced movements. In our study, subjects opened and closed their hand slowly and continuously (0.5 Hz). This movement was filmed with an MRI compatible video camera and projected online onto a screen, viewed by the subject while BOLD contrast was measured with fMRI. The temporal delay between movement and feedback was parametrically varied (0-200 ms). In each trial, subjects judged whether there was a delay or not. There was a positive correlation between the extent of the temporal delay and activation in the right posterior superior temporal cortex (pSTS) and a negative correlation in the left putamen. A second analysis addressed the neural correlates of subjective judgement under conditions of uncertainty. This contrast showed a differential activation in the cerebellum. These results support the assumption of a forward model implying that predictions generated in motor areas attenuate sensory areas. They also suggest that efference copy mechanisms are not located within specific brain areas but are implemented as a specific form of interaction between perceptual and motor areas depending on the modalities and the type of actions involved. Further, conscious detection of small temporal deviations might be based on signals generated in the cerebellum which provide fine-grained temporal information. These results might be useful to refine theories about the role of forward mechanisms in the emergence of disorders of the self, such as in schizophrenia.

Adult↗
PubMed2002

Enhancement of human cortico-motoneuronal excitability by the selective norepinephrine reuptake inhibitor reboxetine.

It has been proposed that norepinephrine plays a critical role in the modulation of cortical excitability, which in turn is thought to influence functional recovery from brain lesions. The purpose of the present experiments was to determine if it is possible to modulate cortical excitability with the selective norepinephrine reuptake inhibitor reboxetine in intact humans. Recruitment curve and intracortical facilitation, assessed by transcranial magnetic stimulation, were increased after oral intake of 8 and 4 mg reboxetine, in the absence of changes in motor threshold, intracortical inhibition, M-response, F-wave or H-reflex. These results demonstrate that reboxetine enhances cortical excitability and raise the possibility that it could act as a plasticity enhancing substance potentially useful in combination with neurorehabilitative strategies geared to enhance neurorehabilitation.

Adrenergic Uptake Inhibitors↗
PubMed2002

T-wave response: a sensitive test for latent alcoholic polyneuropathy.

To date, the H-reflex is the most sensitive test to measure nerve conduction velocity in alcoholic polyneuropathy. Analogous to the H-reflex, we investigated the T-wave response from the soleus muscle using a hand-held reflex hammer. Twenty-four inpatients suffering from chronic alcoholism and 24 healthy volunteers were recruited. All probands had a careful neurological examination and were graded (PNP-classifications). The T- and H-reflexes were measured. In the clinical examination, only a few patients exhibited symptoms of alcoholic PNP. However, when the autonomic nervous system was also tested, 50% exhibited signs of alcoholic PNP. Both the T- and H-reflex responses were pathologically retarded, indicating latent alcoholic PNP in 60% of the patients. Thus the main finding in our study is the difference between clinical and electrophysiological examinations: only a few of the patients had neurological symptoms for alcoholic PNP but 14 patients (60%) exhibited a so-called latent, subclinical alcoholic PNP by showing delayed reflex latencies. Measuring the T-wave proved to be a simple and painless screening method for diagnosis and monitoring of alcoholic PNP. Among the clinical tests the best indicator for alcoholic PNP was the test for autonomous alcoholic PNP.

Adult↗