Biomedical subjects

Naeem Dean

Publications and source records attributed to Naeem Dean.

6 recordsLinked to original sources

PubMed2005

The impact of a stroke prevention clinic in diagnosing modifiable risk factors for stroke.

OBJECTIVE: To evaluate the referral patterns of patients to a stroke prevention clinic (SPC) and to test the adequacy of prereferral diagnosis and management of modifiable risk factors for stroke. METHODS: We collected prospective data on consecutive patients referred to the SPC at University of Alberta Hospital in Edmonton, Alberta, Canada. Outcome measures included: alternate diagnoses to stroke or transient ischemic attack (TIA), uncontrolled or undiagnosed hypertension, hyperlipidemia and diabetes, therapies, and investigations leading to carotid endarterectomy. RESULTS: Two thousand and eleven patients were referred to SPC. Nearly 25% of the referrals originated from the emergency room and the rest from general physicians. Of the referrals, 68.7% were confirmed as TIA or stroke at the SPC. Among 1381 patients with TIA or stroke, 736 had history of hypertension. Uncontrolled hypertension was found in 265 patients (36.0% of those with hypertension: 95% CI: 32.5-39.5) while undiagnosed hypertension was found in 103 (15.9% of those without hypertension: 95%CI: 13.14-18.79). History of hyperlipidemia was present in 451 patients (32.6%) and 356 (78.9%: 95% CI: 75.2-82.69) of these patients were not at target for secondary prevention. Among 930 patients without history of hyperlipidemia, 739 (79.5%: 95% CI: 76.8-82.1) were diagnosed with hyperlipidemia through the SPC. Fasting blood glucose levels above 7.1 mmol/L in patients with and without history of diabetes were 221 (79.2%: 95% CI: 74.5-83.9) and 66 (6%: 95%CI: 4.6-7.4) respectively. CONCLUSIONS: Management of risk factors for stroke needs improvement. SPCs should consider actively managing the classical modifiable risk factors of stroke.

Adult↗

PubMed2005

Bedside emergency transcranial Doppler diagnosis of severe carotid disease using orbital window examination.

BACKGROUND: Identifying internal carotid artery (ICA) stenosis in the acute stroke setting can provide clinically useful information. Transcranial Doppler (TCD) through the orbital window is an easy test to perform and to track and identify different vessels. Previous TCD studies have suggested that a reversed ophthalmic artery (OA) flow is a useful collateral pattern to predict ICA disease. The authors sought to evaluate the TCD orbital window for predicting cervical ICA (cICA) stenosis in the setting of acute stroke and TIA. METHOD: Power M-mode/TCD was performed in acute stroke and transient ischemic attack patients at 2 institutions. Each orbital window depth was detected on M-mode and evaluated for the direction of flow and resistance pattern. Gold standard for comparison was carotid evaluation using carotid duplex, computed tomography angiogram, or conventional angiography. The assessment of cICA disease was categorized by degree of stenosis or occlusion. RESULTS: A total of 216 transorbital exams were performed in 117 patients. Twenty-five cICA occlusions and 8 critical cICA stenoses (>or=95%) were identified by gold standard imaging. Reversed OA flow at 50 to 60 mm depth revealed high specificity (100%; confidence interval [CI], 97.6%-100.0%) and good sensitivity (75%; CI, 53.3%-90.2%) for identifying cICA occlusion or critical stenosis (>or=95%). Low pulsatility index (<1.2) and mean flow velocity (<15 cm/s) discriminated critical severe ICA stenosis or occlusion when OA flow was anterograde with good sensitivity (87.2%) and specificity (95.2%). CONCLUSION: The reversed OA sign at 50 to 60 mm depth is very specific for identifying cICA occlusion or critical stenosis. When OA flow is anterograde, a low mean flow velocity or pulsatility index is also useful to identify cICA critical stenosis or occlusion.

Carotid Artery, Internal↗

PubMed2004

Current and future concepts in stroke prevention.

Stroke is a major cause of morbidity and mortality in an aging population. The current understanding of the pathophysiology of atherosclerotic diseases, the most common cause of stroke, and the evidence for existing therapeutic interventions for the prevention of stroke are presented. Specifically, we review the evidence for antiplatelet agents, anticoagulants, antihypertensive medications, lipid-lowering agents and carotid endarterectomy for stroke prevention.

Anticoagulants↗

PubMed2003

Improved detection of microbubble signals using power M-mode Doppler.

UNLABELLED: Background- Power motion-mode transcranial Doppler (TCD) (PMD) is a new, multigated technique that may simplify and enhance detection of embolus. We developed criteria for emboli detection using PMD. Then, we performed a blinded comparison of transcranial PMD with single-gate spectral TCD in TCD bubble study patients. METHODS: Patients with right-to-left shunt as detected with standard TCD were selected for this study. The international emboli criteria for spectral TCD were used. We defined novel PMD criteria for detecting emboli signature on PMD as follows: (1) signature at least 3 dB higher than the highest spontaneous PMD display of background blood flow; (2) embolic signature reflects motion in one direction at a minimum spatial extent of 7.5 mm and temporal extent of 30 ms; (3) embolus must traverse a prespecified depth. Each study was blindly assessed for microbubble signals (MBS) count on either modality. RESULTS: Thirty-six patients were included in the study. Mean age was 44.4 (SD 14.4), 50% were male, and median time from stroke onset to TCD bubble test was 12 days. Median MBS count in middle cerebral arteries (MCA) was 4 on both modalities. Spectral TCD MBS counts were highly correlated (rho=0.97) with PMD MBS counts in MCA and similarly in anterior cerebral arteries (ACA) (rho=0.79). When PMD microbubble counts in the ACA and MCA were summed, a clear 2-fold difference emerged between 2 modalities (P<0.001). CONCLUSIONS: When compared with spectral TCD, PMD detects more MBS with higher counts by identifying ACA as well as MCA emboli. Pitfalls of overcounting emboli with PMD can be avoided by following such criteria.

Adult↗

PubMed2003

Atrial myxoma as a cause of stroke: case report and discussion.

Cardiac myxoma is a source of emboli to the central nervous system and elsewhere in the vascular tree. However, nonspecific systemic symptoms and minor embolic phenomena may be overlooked in the absence of any history of cardiac problems. In this situation, cardiac investigations may not be performed, and diagnosis of this rare condition may be delayed until the onset of more significant embolic disease, such as stroke with functional impairment, as in the case reported here. The clinical presentation of cardiac myxoma is discussed, along with appropriate investigations and treatment, which may prevent such sequelae.

Echocardiography, Transesophageal↗

PubMed2002

"Malignant" carotid artery dissection.

PURPOSE: Carotid artery dissection resulting in occlusion or severe narrowing and massive intracranial embolism can result in life-threatening hemispheric ischemia. Aggressive endovascular and microsurgical measures may be necessary to salvage life and minimize stroke morbidity in this extreme situation. PATIENTS AND METHODS: We have treated two middle-aged women who presented within an hour of spontaneous cervical internal carotid artery (ICA) dissection causing hemiplegia, forced head and eye deviation, and declining consciousness. The first patient had a carotid occlusion through which a catheter could not be passed, so intracranial thrombolysis was achieved through a microcatheter navigated through the posterior circulation. Surgical intimectomy and thrombectomy of the dissected ICA was then carried out using an intraoperative Fogarty arterial embolectomy catheter passed up the dissected ICA, followed by endovascular stenting of the reopened cervical ICA. The second patient underwent intracranial microsurgical embolectomy and, after an unsuccessful attempt of stenting the dissected and severely narrowed cervical ICA, surgical reopening again with a Fogarty catheter. Both patients suffered basal ganglionic infarcts but most of the middle cerebral artery territories were preserved and the patients made satisfactory recoveries. CONCLUSIONS: "Malignant" carotid artery dissection causing occlusion or near occlusion with intracranial embolism is an important cause of severe and life-threatening hemispheric ischemia. Treatment should include aggressive endovascular and microsurgical interventions when the hemisphere is at risk.

Carotid Artery, Internal, Dissection↗