Is mobile teleconsulting equivalent to hospital-based telestroke services?

BACKGROUND AND PURPOSE: Telemedicine is increasingly used to provide acute stroke expertise for hospitals without full-time neurological services. Teleconsulting through mobile laptop computers may offer more flexibility compared with hospital-based services, but concerns about quality and technical reliability remain. METHODS: We conducted a controlled trial, allocating hospital-based or mobile teleconsulting in a shift-by-shift sequence and evaluating technical parameters, acceptability, and impact on immediate clinical decisions. Both types of telemedicine workstations were equipped with DICOM (Digital-Imaging-and-Communications-in-Medicine) viewer and videoconference software. The laptop connected by asymmetrical broadband UMTS (Universal-Mobile-Telecommunication-Systems) technology with a one-way spoke-to-hub video transmission, whereas the hospital-based device used landline symmetrical telecommunication, including a 2-way videoconference. RESULTS: One hundred twenty-seven hospital-based and 96 mobile teleconsultations were conducted within 2 months without any technical breakdown. The rates per allocated time were similar with 3.8 and 4.0 per day. No significant differences were found for durations of videoconference (mean: 11+/-3 versus 10+/-3 minutes, P=0.07), DICOM download (3+/-3 versus 4+/-3 minutes, P=0.19), and total duration of teleconsultations (44+/-19 versus 45+/-21 minutes, P=0.98). Technical quality of mobile teleconsultations was rated worse on both sides, but this did not affect the ability to make remote clinical decisions like initiating thrombolysis (17% versus 13% of all, P=0.32). CONCLUSIONS: Teleconsultation using a laptop workstation and broadband mobile telecommunication was technically stable and allowed remote clinical decision-making. There remain disadvantages regarding videoconference quality on the hub side and lack of video transmission to the spoke side.

Fischer-344 rats are unsuitable for the MCAO filament model due to their cerebrovascular anatomy.

Middle cerebral artery occlusion (MCAO) in Fischer-344 rats results in a small variance of infarct size. However, complications are frequent especially in aged Fisher-344 rats undergoing endovascular suture occlusion of the middle cerebral artery. Analyzing our experiences with 165 Wistar, 13 Sprague-Dawley and 10 F-344 rats, we compared the incidence of impossible thread advancement and subarachnoid hemorrhage, respectively. Magnetic resonance angiography (MRA) was applied to study the course of the internal carotid artery (ICA) in Fischer and Wistar rats. Finally, we performed a structured review of the literature from 1991 to 2005 evaluating reports on Fischer rats subjected to intraluminal filament MCAO. Complications like fruitless filament advancement or subarachnoid hemorrhage were found to be significantly more frequent in Fischer rats than in other strains. MRA revealed significantly more pronounced kinking of the ICA in F-344 than in Wistar rats. In seven publications available on filament MCAO in F-344 rats, complication rates of 50-100% were reported, corroborating our data. Surgical difficulties accompanied by high complication rates due to their cerebrovascular anatomy make Fischer rats unsuitable for filament MCAO. If the use of Fischer rats for studies on focal cerebral ischemia is indicated, other ischemia models than intraluminal suture occlusion should be chosen.

Ketamine/xylazine anesthesia for radiologic imaging of neurologically impaired rats: dose response, respiratory depression, and management of complications.

In vivo imaging of rats represents an important tool for outcome evaluation in research on stroke, brain trauma, and other neurologic diseases. Since sedation of animals is necessary to avoid artifacts, a mixture of ketamine and xylazine is frequently used for anesthesia. We assessed the suitable dosage of narcotics and its correlation to severe respiratory adverse events in 269 cases of ketamine/xylazine anesthesia in male Wistar rats for performance of magnetic resonance imaging after middle cerebral artery occlusion (MCAO) or sham surgery. Anesthesia depth was not measured. Anesthesia was efficacious in avoiding movement artifacts during imaging. Necessary dosage was lower if rodents were subjected to MCAO instead of sham surgery, if body weight was below baseline, and if time since surgery was short. If anesthesia was induced during the first 2 days after surgery in animals with body weight loss, necessary dose rates were 27% below doses required for rats more than 10 days post-surgery with body weight above baseline (91.4/8.3 versus 125.1/11.3 mg of ketamine/xylazine/kg). A dose adaptation scale for the prediction of necessary dose rates was developed. Apnea developed in 3.3% of all animals. Use of ketamine/xylazine anesthesia for imaging procedures is feasible and safe, though it is associated with a small risk of respiratory arrest. In case of apnea, inspiration can be provoked by a puff of air into the rat's pelt. If unsuccessful, endotracheal intubation and mechanical ventilation are needed until spontaneous breathing is restored or xylazine effects are antagonized.

Thrombolysis for stroke in the elderly.

INTRODUCTION: Systemic thrombolysis with intravenous recombinant tissue plasminogen activator (rt PA) for acute ischemic stroke had been licensed for patients up to 75 years in age in many European countries and was recently extended to 80 years. This age restriction results from the potential higher risk of cerebral bleeding in the elderly. The major rt PA trials included only 42 patients above 80 years showing a potential benefit from treatment. Further data is still rare. METHODS: Using our stroke database we identified all patients beyond 75 years with middle cerebral artery ischemia treated with intravenous rt PA in our stroke unit from 02/1999 until 07/2004. Clinical course and outcome until day 5 in addition to mortality after 3 and 6 months were analysed. RESULTS: Twenty-nine patients (80.8+/-4 years, 16 of them over 80 years old) met the inclusion criteria representing 21.2% of those receiving thrombolytic therapy. The median NIH-SS score on admission was 14 points. On day 5 after thrombolysis, 13/29 showed a good recovery (NIH-SS improvement >or=4 pts). The remaining exhibited only small or no benefit (n=11), deterioration (n=3) or died (n=2). A total of 3/29 patients developed non-symptomatic parenchymal hemorrhage or hemorrhagic transformation. One patient died due to space-occupying cerebral hemorrhage. Extracerebral bleeding was found in 3/29 requiring substitution in one. One other died for primary cardiac reasons. Median NIH-SS on day 5 was 10 points. Mortality after 3 and 6 months was 20.7%. We did not find factors predicting clinical outcome. Most importantly, there was no significant difference regarding outcome in patients 76--80 vs. 81--87 years old. DISCUSSION: Intravenous rt PA resulted in good neurological in-hospital outcome in almost 45% and six-months survival of almost 80% of the patients beyond 75 years. In 10.3% non-symptomatic and in 3.4% symptomatic cerebral bleeding was found. Thus, seniors beyond 75 and even beyond 80 years in good medical condition may benefit from systemic treatment with rt PA. Prospective studies are needed to clarify which part of the senior population might be most eligible for systemic thrombolysis.

The role of ECA transection in the development of masticatory lesions in the MCAO filament model.

In the intraluminal suture model of middle cerebral artery occlusion (MCAO) in the rat, lesions of the masticator muscles associated with impaired functional outcome occur. We evaluated the role of external carotid artery (ECA) transection. We assessed whether isolated interruption of an arterial or a venous connection to the ECA territory was sufficient to induce masticatory hypoperfusion and lesions. We also evaluated a direct access to the common carotid artery (CCA) with subsequent vascular closure with regard to its feasibility, frequency of masticatory lesions, complications, and cerebral ischemia. Cerebral and masticatory lesions and perfusion deficits were assessed by in vivo magnetic resonance imaging (MRI). Vessel patency was evaluated using computerized tomography angiography and histology. An interruption of arterial blood flow led to masticatory hypoperfusion. Masticatory lesions occurred in 6% of the rats. Access to and closure of the CCA were feasible in all animals, leading to moderate or severe vessel stenosis in 20%, and intraarterial thrombosis in 25% of the rats. Reproducible cerebral infarctions were obtained in all animals. In 24% of the rats, hyperintense MRI signal changes were observed in the ipsilateral temporal muscle. Thus, the induction of masticatory hypoperfusion and lesions by arterial transection supports the role of the ECA in this context. Direct access to the CCA with subsequent vessel closure led to stenosis in most animals. Preservation of ECA continuity was not suitable to fully prevent masticatory lesions.