Biomedical subjects

Michaela Stampfer-Kountchev

Publications and source records attributed to Michaela Stampfer-Kountchev.

5 recordsLinked to original sources

PubMed2007

Abnormal responses to repetitive transcranial magnetic stimulation in multiple system atrophy.

We studied the response of the motor cortex to brief trains of suprathreshold repetitive transcranial magnetic stimulations (rTMS) in patients with the Parkinson-variant of multiple system atrophy (MSA-P) and compared it to patients with idiopathic Parkinson's disease (PD) and healthy controls. Eight subjects were studied in each group, and patients were matched for disease severity as assessed by Hoehn & Yahr stages. rTMS was delivered at rest and during low-level contractions in trains of 10 stimulations at 5 Hz, and stimulation intensity was set to result in an motor evoked potential (MEP) in the first dorsal interosseus muscle of 0.5 to 1.0 mV. In MSA-P, MEP amplitude at rest was already reduced after the second stimulus and remained so, while it did not change in PD and controls. During contraction, MEP size did not change during the train in any group. The silent period that followed the last stimulus was of similar duration as the first stimulus in MSA-P, but was increased in PD and controls. These findings indicate that abnormal inhibition occurs within the motor cortex in MSA-P, despite dopaminergic treatment and indicate differences in cortical dysfunction between MSA-P and PD. We suggest that these abnormalities reflect the motor cortex pathology found in MSA-P.

Electromyography↗

PubMed2006

Progression of multiple system atrophy (MSA): a prospective natural history study by the European MSA Study Group (EMSA SG).

The disease-specific Unified Multiple System Atrophy Rating Scale (UMSARS) has been developed recently and validated for assessing disease severity in multiple system atrophy (MSA). Here, we aimed at (1) assessing rates of disease progression in MSA and (2) validating UMSARS for sensitivity to change over time. Impairment was assessed at two time points 12 months apart using UMSARS Part I (historical review), UMSARS Part II (motor examination), as well as measures of global disease severity, including UMSARS Part IV, Hoehn and Yahr (HY) Parkinson's disease staging, Schwab England Activities of Daily Living (SE ADL), and a three-point global Severity Scale (SS3). Fifty patients (male:female ratio, 1:0.9; possible MSA, 16%; probable MSA, 84%; MSA-parkinsonian, 58%; MSA-cerebellar, 42%) were assessed twice with an interval of 12.3 months. UMSARS II scores progressed by 57.3% (P<0.0001) and UMSARS I scores by 35.6% (P<0.0001) in relation to the respective baseline scores with no differences between motor subtypes, diagnostic categories and gender. Significant inverse correlations between (1) UMSARS I or UMSARS II progression and (2) baseline disability measures (i.e., the respective UMSARS or SS3 scores) and disease duration were found. Furthermore, the increases in HY staging, SE ADL and SS3 correlated significantly with UMSARS I, UMSARS II, and UMSARS IV progression. This report is the first prospective study showing rapid annual UMSARS rates of decline in MSA. Our data contribute to the ongoing validation process of UMSARS, and they facilitate the planning and implementation of future neuroprotective intervention trials.

Adult↗

PubMed2006

Health-related quality of life in multiple system atrophy.

Although multiple system atrophy (MSA) is a neurodegenerative disorder leading to progressive disability and decreased life expectancy, little is known about patients' own evaluation of their illness and factors associated with poor health-related quality of life (Hr-QoL). We, therefore, assessed Hr-QoL and its determinants in MSA. The following scales were applied to 115 patients in the European MSA-Study Group (EMSA-SG) Natural History Study: Medical Outcome Study Short Form (SF-36), EQ-5D, Beck Depression Inventory (BDI), Mini-Mental state examination (MMSE), Unified MSA Rating Scale (UMSARS), Hoehn & Yahr (H&Y) Parkinson's disease staging scale, Composite Autonomic Symptom Scale (COMPASS), and Parkinson's Disease Sleep Scale (PDSS). Forty-six percent of patients had moderate to severe depression (BDI > or = 17); Hr-QoL scores on the SF-36 and EQ-5D were significantly impaired. Pain, the only domain with similar scores in MSA and published PD patients, was reported more frequently in patients with MSA-P (predominantly parkinsonian motor subtype) than MSA-C (predominantly cerebellar motor subtype; 76% vs. 50%; P = 0.005). Hr-QoL scores correlated most strongly with UMSARS motor, COMPASS, and BDI scores but not with MMSE scores, age at onset, or disease duration. The COMPASS and UMSARS activities of daily living scores were moderate-to-strong predictors for the SF-36 physical summary score and the BDI and UMSARS motor scores for the SF-36 mental summary score. This report is the first study to show that Hr-QoL is significantly impaired in MSA. Although not all possible factors related to impaired Hr-QoL in MSA could be assessed, autonomic dysfunction, motor impairment, and depression were most closely associated with poor Hr-QoL, and therapeutic management, therefore, should concentrate upon these aspects of the disease.

Anxiety↗

PubMed2004

How chronic inflammation can affect the brain and support the development of Alzheimer's disease in old age: the role of microglia and astrocytes.

A huge amount of evidence has implicated amyloid beta (A beta) peptides and other derivatives of the amyloid precursor protein (beta APP) as central to the pathogenesis of Alzheimer's disease (AD). It is also widely recognized that age is the most important risk factor for AD and that the innate immune system plays a role in the development of neurodegeneration. Little is known, however, about the molecular mechanisms that underlie age-related changes of innate immunity and how they affect brain pathology. Aging is characteristically accompanied by a shift within innate immunity towards a pro-inflammatory status. Pro-inflammatory mediators such as tumour necrosis factor-alpha or interleukin-1 beta can then in combination with interferon-gamma be toxic on neurons and affect the metabolism of beta APP such that increased concentrations of amyloidogenic peptides are produced by neuronal cells as well as by astrocytes. A disturbed balance between the production and the degradation of A beta can trigger chronic inflammatory processes in microglial cells and astrocytes and thus initiate a vicious circle. This leads to a perpetuation of the disease.

Aging↗

PubMed2003

Multiple system atrophy: an update.

Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder that usually manifests in the early sixth decade of life and progresses relentlessly with a mean survival of 9 years. Clinically, MSA is dominated by autonomic/urogenital failure, which may be associated with either levodopa (L-dopa) -unresponsive parkinsonism in 80% of cases (MSA-P subtype) or with cerebellar ataxia in 20% of cases (MSA-C subtype). Pathologically, MSA is characterized by a neuronal multisystem degeneration and abnormal glial cytoplasmic inclusions containing alpha-synuclein aggregates. Pharmacological treatment of motor features is disappointing except for a transient L-dopa response in a minority of MSA-P patients. In contrast, autonomic and urogenital features of MSA should be identified early on, because they can be treated effectively in many instances. Neuroprotective strategies are presently unavailable, however, two multicentre European trials have been launched to evaluate the effects of riluzole and human recombinant growth hormone on disease progression in MSA. Clearly, further randomised, controlled trials are required to identify effective symptomatic or neuroprotective agents in MSA. Several in vivo models have become available to allow a careful preselection of candidate agents. Several research groups have been formed in Europe (EMSA-SG, NNIPPS) and United States (NAMSA-SG), providing a framework for coordinated trial activity in MSA.

Animals↗