Biomedical subjects

Iris-Katharina Penner

Publications and source records attributed to Iris-Katharina Penner.

3 recordsLinked to original sources

PubMed2006

Therapy-induced plasticity of cognitive functions in MS patients: insights from fMRI.

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system whose pathological mechanisms are still not completely understood. Physical as well as cognitive deterioration are consequences within the disease process that have an extensive impact on the patient's quality of life. Therefore, understanding the functional background of spontaneous as well as induced remission is of high relevance. Studies on visualization of therapeutic effects of pharmacological or cognitive treatment by functional magnetic resonance imaging (fMRI) are still rare. From fMRI studies on focal brain lesions hypotheses on mechanisms of brain reorganization can be derived. This contribution will first give an overview of the existing studies using fMRI in MS, on cognitive decline, on cognitive treatment studies and its therapeutic effects on behavioural readouts in MS, and on therapy-induced brain plasticity and its possible visualization by fMRI. Results of a study on correlating the effects of cognitive training with changes in brain organization in patients with mild to severe cognitive impairment will be reported.

Cognition↗

PubMed2006

Retraining attention in MS.

Cognitive decline is frequently observed in multiple sclerosis (MS) and has a major impact on quality of life. Therefore it would be important to offer therapeutic strategies to the patients. In the past, several studies were conducted on pharmacological or cognitive treatment. However, there is currently no specific treatment for cognitive decline and the studies published so far report heterogeneous results. The present paper focuses on the cognitive treatment strategies by reviewing and discussing the few studies that have been carried out in this area. In addition, results of a recently completed fMRI study on the visualization of cognitive training effects will be reported. This review clearly points out that further research in this area is needed to clarify the effects of cognitive intervention. Larger sample sizes and standardized neuropsychological outcome measures as well as standardized training tools are required to allow for comparisons between different studies and to improve our understanding of cognitive decline and the processes of cognitive recovery in MS.

Attention↗

PubMed2003

Analysis of impairment related functional architecture in MS patients during performance of different attention tasks.

More than 50 % of patients with multiple sclerosis (MS) suffer from cognitive deficits. Attention is one of the most frequently affected cognitive functions. It has been shown that MS patients suffer from a specific but not necessarily from a generalized decrease in performance and that different severity grades of impaired attentional processing can be distinguished. Little is known about patterns of brain activation in MS patients with different grades of attentional deficits. The objective was to examine if different severity grades in attentional impairment are reflected by altered patterns of brain activation in specific attention tasks. In the present study cerebral activation induced by three attention tasks of different complexity was assessed in 14 MS patients and seven healthy controls by functional MRI (fMRI). Based on their performance on the tests recorded off-line with a computerized test battery and during the fMRI investigation, patients were classified as mildly and severely impaired. MS patients with mild impairment showed increased and additional activation of brain areas which were in part not activated in normal subjects. Those were located mainly in the frontal cortex and posterior parietal cortex. This effect decreased with increasing task complexity and was strongest for the alertness task. In MS patients with severe impairment no additional activation was found in prefrontal structures and activation in the premotor cortex was not significantly different from controls. These findings suggest that compensation in MS patients is in part achieved by functional integration of frontal and parietal association areas. The extent of compensation seems to depend on the brain's capacity to access additional brain structures. Exhaustion of this capacity may finally lead to severe cognitive impairment.

Adult↗