Biomedical subjects

Stephan Behrens

Publications and source records attributed to Stephan Behrens.

4 recordsLinked to original sources

PubMed2004

Early motor evoked potentials in acute stroke: adjunctive measure to MRI for assessment of prognosis in acute stroke within 6 hours.

BACKGROUND: In acute stroke, a magnetic resonance (MR) perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) mismatch (PWI>DWI mismatch) may indicate tissue at risk for infarction and poor prognosis. However, different to early enthusiasm about this surrogate marker, its validity has shown several drawbacks in individual patients. Rather than relying on imaging, we evaluated motor evoked potentials (MEP) as a measure of cerebral function in the acute stroke setting. METHODS: Thirteen patients with acute hemiparetic stroke underwent time to peak PWI and DWI within 6 h after onset as well as recordings of early MEP of first dorsal interosseous muscles. Outcome was assessed by the Unified Neurological Stroke Scale and Barthel Index at day 42. RESULTS: Of 8 patients with PWI>DWI mismatch, 4 patients with normal MEP had a good clinical outcome and 4 patients with absent or pathological MEP had an unfavourable outcome (p < 0.05, Fisher's exact test). In all patients without PWI>DWI mismatch, MEP findings predicted clinical outcome. Normal MEP at day 0--but not PWI/DWI findings--significantly correlated with a good clinical outcome. CONCLUSIONS: Early MEP recordings in acute stroke patients provide valid prognostic information; they may become more useful for specific treatment decisions than presently available MRI surrogate parameters.

Acute Disease↗

PubMed2003

Non-oral drug delivery in Parkinson's disease: a summary from the symposium at the 7th International Congress of Parkinson's Disease and Movement Disorders. 10-14 November 2002, Miami, FL, USA.

This symposium reviewed the issues of non-oral therapy in the late stage Parkinson's disease (PD). The accepted standard treatment of PD is oral levodopa or oral dopamine agonists. However, the long-term complications and limitations of this treatment might be improved by changing therapy from the present pulsatile stimulation to a more constant stimulation of central dopamine receptors. Stimulation of these receptors may be possible with non-oral drug delivery treatments. Many of these non-oral options have been evaluated during the last few decades to find a more continuous drug delivery. The non-oral treatment options include invasive measures such as intraduodenal levodopa, subcutaneous apomorphin and most recently, the non-invasive transdermal (patch) delivery system, with the novel dopamine agonist rotigotine (Aderis Pharmaceuticals Inc.). The benefits of the non-oral, more continuous dopaminergic treatment of PD needs to be demonstrated in clinical trials and long-term clinical practice, before they can be considered as potential replacements of the standard oral therapy.

Antiparkinson Agents↗

PubMed2002

Acceleration of cerebral blood flow velocity in a patient with sleep apnea and intracranial arterial stenosis.

Sleep apnea (SA) syndromes of different etiologies are known to induce complications including cardiovascular diseases and stroke. However, the exact mechanisms involved in cerebral ischemia remain obscure. We measured the cerebral blood flow velocities (CBFV) by means of transcranial Doppler sonography in an 81-year-old patient who presented with an acute ischemic stroke caused by an intracranial middle cerebral artery (MCA) stenosis in the presence of SA syndrome. During apnea episodes simultaneous recordings revealed reduced intra-arterial oxygen but increased carbon dioxide saturation. This resulted in an increased CBFV (220 to 320 cm/s) and suggested intermittent hemodynamic relevance of a structurally only moderate MCA stenosis. Intracranial artery stenosis can become hemodynamically significant due to episodic hypercapnia in patients with SA. This may cause ischemic infarction in the periphery of the related cerebral vascular territories.

Aged↗

PubMed2002

Improvement in stroke quality management by an educational programme.

Time after symptom onset in ischaemic stroke has to be as short as possible to increase success of treatment. We prospectively analysed latencies from symptom onset until the start of therapy and the rate of thrombolysis in 196 patients with suspected stroke sequentially admitted to the hospital before (6 weeks prior, n = 83) and after (n = 113) initiating an educational stroke programme (EP). A total of 345 dispatchers, paramedics, and emergency staff were trained, each person for at least 2 h. The mean pre-hospital time interval from symptom onset until admission was significantly decreased by nearly 2 h (p < 0.05). Thrombolytic therapy frequencies increased from 2 to 10.5% (p < 0.01) because the overall mean time interval from admission to the start of therapy significantly decreased (p < 0.01) by 69 min after the EP, with increasing numbers of patients suitable for acute stroke therapies within a 0- to 3-hour treatment window.

Aged↗