M. Jauß

An international Consensus Meeting to determine a standard in the examination technique for the detection of right-to-left shunt (RLS) using contrast transcranial Doppler sonography (TCD) led to the following recommendations to standardize the examination procedure: The patient should be prepared with an 18-gauge needle inserted into the cubital vein and should be in the supine position. Insonation of at least one middle cerebral artery (MCA) using TCD is performed. The contrast agent is prepared using 9 ml isotonic saline solution and 1 ml air mixed with a three-way stopcock by exchange of saline/air mixture between the syringes and injected as a bolus. In case of little or no detection of microbubbles (MB) in the MCA under basal conditions, the examination will be repeated using the Valsalva maneuver (VM). Contrast agent will be injected 5 s before the start of the VM; the overall VM duration should be 10 s. The patient should start the VM on examiner's command. The strength of the VM can be controlled by peak flow velocity of the Doppler curve. The time when the first MB appears at the MCA level will be noted. A four-level categorization according to the MB count should be applied: (1) 0 MB (negative result); (2) 1-10 MB; (3) >10 MB and no curtain, and (4) curtain. ('Curtain' refers to a shower of MB, where a single bubble cannot be identified.) The results should be documented for basal condition and VM testing separately. The clinical significance of the diagnosis of a RLS in a particular patient is not fully evaluated and requires further studies. A minimum amount of MB suggestive of a clinical relevant RLS is not yet established. It probably depends on interindividual differences in hemodynamics that are currently not fully understood. Transesophageal echocardiography remains the gold standard for detection of a patent foramen ovale or an atrial septum defect. However, TCD with a contrast agent has been turned out as a potential method to diagnose a RLS in several studies which have been published during the last years, and a RLS other than at the atrial level may be detected only by this method. Furthermore, the VM can be applied more comfortably and more reliably during Doppler examination than during transesophageal echocardiography.

OBJECTIVE: To report results of a randomized pilot clinical feasibility trial of endovascular cooling in patients with ischemic stroke. METHODS: Forty patients with ischemic stroke presenting within 12 hours of symptom onset were enrolled in the study. An endovascular cooling device was inserted into the inferior vena cava of those randomized to hypothermia. A core body temperature of 33 degrees C was targeted for 24 hours. All patients underwent clinical assessment and MRI initially, at days 3 to 5 and days 30 to 37. RESULTS: Eighteen patients were randomized to hypothermia and 22 to receive standard medical management. Thirteen patients reached target temperature in a mean of 77 +/- 44 minutes. Most tolerated hypothermia well. Clinical outcomes were similar in both groups. Mean diffusion-weighted imaging (DWI) lesion growth in the hypothermia group (n = 12) was 90.0 +/- 83.5% compared with 108.4 +/- 142.4% in the control group (n = 11) (NS). Mean DWI lesion growth in patients who cooled well (n = 8) was 72.9 +/- 95.2% (NS). CONCLUSIONS: Induced moderate hypothermia is feasible using an endovascular cooling device in most patients with acute ischemic stroke. Further studies are needed to determine if hypothermia improves outcome.

BACKGROUND AND PURPOSE: Because the timing and strategy of surgical intervention in massive cerebellar infarction remains controversial, we report our experience with the management of 52 such patients. METHODS: Case records, computed tomographic scans, surgical reports, and angiograms of 52 patients with space-occupying cerebellar infarction defined by computed tomographic criteria were reevaluated with regard to clinical course, etiology, therapeutic management, mortality, and functional outcome. RESULTS: In most cases clinical deterioration started on the third day after stroke, and a comatose state was reached within 24 hours. Sixteen patients were treated medically, and 30 by suboccipital craniectomy (22 plus ventriculostomy, 12 plus tonsillectomy). Ten patients primarily had ventriculostomy, which in 4 patients was supplemented by craniotomy because of continuing deterioration. Twenty-nine patients made a good recovery, 15 remained disabled, and 8 died. Even comatose patients had a 38% chance of a good recovery with decompressive surgery. Age older than 60 years (P = .0043) and probably initial brain stem signs (P = .0816) and a late clinical stage (P = .0893) were linked with a fatal or disabling outcome. CONCLUSIONS: Decompressive surgery should be the treatment of choice for massive cerebellar infarction causing progressive brain stem signs or impairment of consciousness.

BACKGROUND: Patent foramen ovale as a possible stroke risk factor can be diagnosed with transcranial Doppler sonography (TCD) by detecting intravenous contrast medium crossing from the right to the left atrium. The present study evaluates the reliability of this method. SUMMARY OF REPORT: We performed TCD and transesophageal echocardiography simultaneously in 50 patients using galactose microbubbles. We observed bubble signals passing the middle cerebral artery in 7 patients less than 20 seconds after injection; we found positive TCD tests in 14 patients using the Valsalva maneuver. With transesophageal echocardiography patent foramen ovale could be detected in 15 patients (sensitivity, 0.93; specificity, 1; P < .01). CONCLUSIONS: TCD with echo contrast is a reliable screening tool for patent foramen ovale. A standardized procedure including the Valsalva maneuver is essential to prevent false-negative results.