INTRODUCTIONTranscranial Doppler (TCD) is an established tool for the non-invasive assessment of cerebral blood flow. Since TCD results vary with the skills and experience of the sonographer, it requires validation against contrast angiography. We evaluated the diagnostic accuracy of TCD against computed tomography angiography (CTA) and the feasibility of the latter as an additional screening tool in our acute ischaemic stroke patients.

MATERIALS AND METHODSOur stroke unit manages about 700 patients annually. Acute stroke patients undergo TCD for vascular assessment of major arteries of the circle of Willis. Randomly selected acute stroke patients with significant stenosis on TCD underwent high-resolution cranial CTA with multidetector helical scanner. CTA was performed within 24 hours of TCD and images were interpreted by a neuroradiologist blinded to TCD findings. An independent neurosonologist reevaluated TCD if CTA findings were contradictory. Additional information by either modality was also noted.

RESULTSFifteen patients (12 men, mean age 61 +/- 15years) with cerebral ischaemia and moderate (>50%) stenosis in > or =1 large intracranial arterial segment on routine TCD were evaluated by CTA. Compared with 21 segments of significant stenosis on CTA, TCD showed 16 true-positive, 3 false-positive and 5 false-negative results (sensitivity: 76.2%, positive predictive value: 84.2%). In 3 cases, TCD showed findings complementary to CTA (real-time embolisation, collateral flow patterns, evidence of distal M2 branch occlusion).

CONCLUSIONTCD in our neurovascular laboratory shows a satisfactory agreement with cranial CTA in evaluating patients with cerebral ischaemia. TCD can provide additional real-time dynamic findings complementary to information provided by CTA.

Aged ; Brain Ischemia ; diagnosis ; Cerebral Angiography ; Female ; Humans ; Male ; Middle Aged ; Pilot Projects ; Singapore ; Tomography, X-Ray Computed ; Ultrasonography, Doppler, Transcranial

Stroke is a major cause of death and disability in Singapore and many parts of the world. Chronic disease management programmes allow seamless care provision across a spectrum of healthcare facilities and allow appropriate services to be brought to the stroke patient and the family. Randomised controlled trials have provided evidence for efficacious interventions. After the management of acute stroke in a stroke unit, most stable stroke patients can be sent to their family physician for continued treatment and rehabilitation supervision. Disabled stroke survivors may need added home-based services. Suitable community resources will need to be harnessed. Clinic-based stroke nurses may enhance service provision and coordination. Close collaboration between the specialist and family physician would be needed to right-site patients and also allow referrals in either direction where necessary. Barriers to integration can be surmounted by trust and improved communication. Audits would allow monitoring of care provision and quality care enhancement. The Wagner model of chronic care delivery involves self-management support, shared clinical information systems, delivery system redesign, decision support, healthcare organisation and community resources. The key and critical feature is the need for an informed, activated (or motivated) patient, working in collaboration with the specialist and family physician, and a team of nursing and allied healthcare professionals across the continuum of care. The 3-year Integrating Services and Interventions for Stroke (ISIS) project funded by the Ministry of Health will test such an integrative system.
Delivery of Health Care, Integrated ; organization & administration ; Evidence-Based Medicine ; Humans ; Ischemic Attack, Transient ; Medicine ; Middle Aged ; Models, Organizational ; Neurology ; Primary Health Care ; Rehabilitation Nursing ; Singapore ; Specialization ; Stroke ; nursing ; Stroke Rehabilitation