PubMed Health⌕ Search

Biomedical subjects

L R Caplan

Publications and source records attributed to L R Caplan.

At least 19 recordsLinked to original sources
PubMed2004

Assessment: transcranial Doppler ultrasonography: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

OBJECTIVE: To review the use of transcranial Doppler ultrasonography (TCD) and transcranial color-coded sonography (TCCS) for diagnosis. METHODS: The authors searched the literature for evidence of 1) if TCD provides useful information in specific clinical settings; 2) if using this information improves clinical decision making, as reflected by improved patient outcomes; and 3) if TCD is preferable to other diagnostic tests in these clinical situations. RESULTS: TCD is of established value in the screening of children aged 2 to 16 years with sickle cell disease for stroke risk (Type A, Class I) and the detection and monitoring of angiographic vasospasm after spontaneous subarachnoid hemorrhage (Type A, Class I to II). TCD and TCCS provide important information and may have value for detection of intracranial steno-occlusive disease (Type B, Class II to III), vasomotor reactivity testing (Type B, Class II to III), detection of cerebral circulatory arrest/brain death (Type A, Class II), monitoring carotid endarterectomy (Type B, Class II to III), monitoring cerebral thrombolysis (Type B, Class II to III), and monitoring coronary artery bypass graft operations (Type B to C, Class II to III). Contrast-enhanced TCD/TCCS can also provide useful information in right-to-left cardiac/extracardiac shunts (Type A, Class II), intracranial occlusive disease (Type B, Class II to IV), and hemorrhagic cerebrovascular disease (Type B, Class II to IV), although other techniques may be preferable in these settings.

Adolescent↗
PubMed2001

A three-item scale for the early prediction of stroke recovery.

BACKGROUND: Accurate assessment of prognosis in the first hours of stroke is desirable for best patient management. We aimed to assess whether the extent of ischaemic brain injury on magnetic reasonance diffusion-weighted imaging (MR DWI) could provide additional prognostic information to clinical factors. METHODS: In a three-phase study we studied 66 patients from a North American teaching hospital who had: MR DWI within 36 h of stroke onset; the National Institutes of Health Stroke Scale (NIHSS) score measured at the time of scanning; and the Barthel Index measured no later than 3 months after stroke. We used logistic regression to derive a predictive model for good recovery. This logistic regression model was applied to an independent series of 63 patients from an Australian teaching hospital, and we then developed a three-item scale for the early prediction of stroke recovery. FINDINGS: Combined measurements of the NIHSS score (p=0.01), time in hours from stroke onset to MR DWI (p=0.02), and the volume of ischaemic brain tissue on MR DWI (p=0.04) gave the best prediction of stroke recovery. The model was externally validated on the Australian sample with 0.77 sensitivity and 0.88 specificity. Three likelihood levels for stroke recovery-low (0-2), medium (3-4), and high (5-7)-were identified on the three-item scale. INTERPRETATION: The combination of clinical and MR DWI factors provided better prediction of stroke recovery than any factor alone, shortly after admission to hospital. This information was incorporated into a three-item scale for clinical use.

Activities of Daily Living↗
PubMed2001

Diffusion-weighted imaging and National Institutes of Health Stroke Scale in the acute phase of posterior-circulation stroke.

BACKGROUND: Occlusive disease of the posterior circulation represents a heterogeneous group of strokes that differ in etiology, clinical presentation, and prognosis. Computed tomography provides suboptimal visualization of posterior-circulation infarcts. Anatomic definition of traditional magnetic resonance imaging sequences has been used for clinicoradiologic correlation in patients with posterior-circulation disease. These studies focused on the subacute rather than the acute phase of ischemia. Lesion volumes on diffusion-weighted imaging (DWI) and perfusion imaging were found to have a good correlation with 24-hour National Institutes of Health stroke scale (NIHSS) score in ischemia of the anterior circulation. Correlation between NIHSS score and lesion volume in posterior-circulation infarcts is unknown. OBJECTIVES: To investigate whether DWI is useful for clinicoradiologic correlation of posterior-circulation ischemia within 24 hours after symptom onset and whether NIHSS score correlates with lesion volumes in patients with posterior-circulation stroke. PATIENTS AND METHODS: In a database analysis of 631 patients with stroke from June 26, 1996, to July 30, 1999, 115 patients (18%) had symptoms of posterior-circulation ischemia by imaging and clinical criteria. Among these 115, we included all patients (n = 40) who underwent DWI within 24 hours from symptom onset (mean, 9.7 +/- 7.1 hours). All 40 patients also underwent magnetic resonance angiography and T2-weighted imaging. Seventy-five did not meet inclusion criteria: in 45, magnetic resonance imaging was performed more than 24 hours after symptom onset; 12 did not have DWI; in 11 patients, symptoms resolved within 24 hours; 6 had hemorrhages; and 1 had a border zone infarct. RESULTS: An acute lesion on DWI corresponding to the patient's symptoms was detected in all 40 patients, 16 (40%) of whom had detectable acute lesions on T2-weighted images. The lesions on DWI were larger in 11 of the 16 patients with positive T2-weighted images. Acute lesion volume did not correlate with NIHSS score (n = 40; rho = 0.30; P =.06, Spearman rank) also when DWI lesion volumes were divided by cause and territory. CONCLUSIONS: Diffusion-weighted imaging is more effective than T2-weighted imaging in patients with acute posterior-circulation strokes. The DWI lesion volume did not significantly correlate with NIHSS score, suggesting that NIHSS is more weighted toward anterior-circulation stroke symptoms.

Acute Disease↗
PubMed2001

Convulsive-like movements in brainstem stroke.

BACKGROUND: Involuntary convulsive-like movements sometimes occur in patients with brainstem strokes. These movements vary in nature, frequency, and trigger, including fasciculation-like, shivering, jerky, tonic-clonic, and intermittent shaking movements. Some are interpreted as decerebrate postures or seizures. It is important to recognize this type of motor phenomenon since it may be a diagnostic clue for early diagnosis and treatment of brainstem strokes. DESIGN: Case report and review of the literature OBSERVATION: A 72-year-old-man presented with impaired consciousness and jerks of the upper limbs mimicking seizures. These episodes consisted of brief clonic contractions of the proximal and distal upper extremities. They were observed in paroxysms lasting for 3 to 5 seconds. Magnetic resonance imaging showed large midpontine infarction. Magnetic resonance angiography revealed the absence of basilar artery blood flow. No seizure discharges were observed in the electroencephalogram. Anticoagulation with intravenous heparin was started. Two days after admission, the patient had a cardiac arrest and died. We review the frequency and nature of convulsive-like movements in brainstem stroke in the literature. CONCLUSIONS: Movements associated with brainstem lesions are not easily differentiated from convulsions. Unexpected onset and inexperience of the observers limit the characterization of this phenomenon. Convulsive-like movements in brainstem stroke may occur more frequently than reported. Early detection of this motor phenomenon may have practical implications.

Aged↗
PubMed2001

Evidence-based treatment of patients with ischemic cerebrovascular disease.

The results of trials that study patients with defined lesions (atrial fibrillation without valvular heart disease, various severities of carotid artery stenosis in the neck, intracranial artery stenosis) are very helpful for clinicians caring for patients with those conditions. On the other hand, trials that group all patients with brain ischemia together are not very helpful. Modern technology now makes it possible to define quickly and safely: (1) the location, nature, and severity of causative cerebrovascular, cardiac, and aortic lesions; (2) blood constituents and coagulability; and, (3) the presence, location, and severity of ischemic brain damage. As in all medicine, treatment should be aimed at the cause of disease, not the time course and severity of present damage. Clearly, more trials are needed in patients who have been studied thoroughly using modern technology. Until then, clinicians must understand the context of the trial data to determine if the results are applicable to Mr. or Ms. Jones, and the patients sitting before them in the office or in the hospital bed.

Angioplasty↗
PubMed2001

Southern Buenos Aires stroke project.

BACKGROUND: Ethnic differences and vascular risk factors are the major determinants of stroke subtypes. Nevertheless, specific data from undeveloped countries is difficult to obtain. Natives from South America may have a higher frequency of penetrating small vessel disease and hemorrhagic stroke. However, there are few studies in South America supporting these findings. OBJECTIVE: We analyze demographic, ethnic, risk factors, clinical characteristics, and stroke subtypes in all patients with acute stroke admitted to our hospital. METHODS: We studied all consecutive acute stroke patients admitted to the Ramos Mejia Hospital in Buenos Aires from 1997 to 1999. Our hospital serves a determined population of Southern Buenos Aires. Data were collected prospectively on patients' admission in a form especially designed for this study including vascular risk factors, clinical features, epidemiological characteristics, and neuroradiological findings. Stroke subtypes were determined according to the TOAST classification. RESULTS: Among 361 acute stroke patients, 31% had hemorrhagic stroke. It was more frequent among Natives (34%) than Caucasians (27%) (P<0.002). Ischemic stroke subtypes were as follows: 105 (42%) patients had lacunar, 31 (12%) atherosclerotic stroke, 53 (21%) cardioembolic infarction, and 16 (6%) other causes of stroke. Forty-five (18%) patients were classified as undetermined. Small vessel disease was higher among Caucasians (35%) than Natives (24%). CONCLUSIONS: Penetrating artery disease (42%) and intracranial hemorrhage (31%) were the most common stroke subtypes, being more frequent than reported in the literature. Natives had significantly higher frequency of hemorrhagic stroke than Caucasians.

Acute Disease↗