A rating system for prompt clinical diagnosis of ischemic stroke.

BACKGROUND: When a CT scan is not available, an early accurate clinical diagnosis of ischemic stroke is essential to initiate prompt therapy. Our objective was to construct a clinical index that is easy to use when stroke patients are first evaluated at the hospital, to identify those who probably are experiencing an acute ischemic episode. The study was conducted at a university-affiliated medical referral center and two community general hospitals in Mexico. METHODS: Clinical records were reviewed for 801 patients with sudden onset of a focal or global neurologic dysfunction, presumably of vascular origin lasting more than 24 h. Eligibility criteria for this study were admission to the hospital within the first 24 h after symptomatic onset, CT scan diagnosis between 24 and 72 h, and age >45 years. Ischemic stroke included cases of arterial brain infarction, while nonischemic stroke included subarachnoid or intraparenchymatous hemorrhage, mass lesion, venous infarction, and in cases without a CT scan evidence that could explain the clinical manifestations. Data excerpted for analysis were age, sex, history of diabetes mellitus or previous stroke/transient ischemic attack (TIA), time of onset of symptoms, presence of headache, vomiting, neck stiffness, hemiplegia, leukocytosis or atrial fibrillation, diastolic blood pressure, and Glasgow coma scale (GCS) rating. Two multivariable analyses were used: 1) step-wise multiple logistic regression (SMLR), and 2) conjunctive consolidation (CC). RESULTS: After appropriate exclusions, the study proceeded with 83 ischemic and 42 nonischemic stroke patients. With SMLR, six variables were selected as predictive for ischemic stroke, including neck stiffness, diastolic blood pressure, previous history of stroke/TIA, hemiplegia, GCS, and atrial fibrillation. An appropriate sum of weighted ratings had a positive predictive value (PPV) of 100% for ischemic stroke. With consolidated categories, the PPV was 97% when patients had the following: no neck stiffness; no atrial fibrillation but history of stroke/TIA and GCS > or =12, or no neck stiffness but atrial fibrillation. CONCLUSIONS: Among patients with acute stroke, clinical data can be used to identify a group with a high probability of ischemic stroke. There are slightly different results between both methods; while SMLR includes the four variables selected by CC, the latter included neither diastolic blood pressure nor hemiplegia/hemiparesia. However, CC results seem easier to understand and interpret than with SMLR.

Predictive value of signs and symptoms in the diagnosis of subarachnoid hemorrhage among stroke patients.

Clinical diagnosis of subarachnoid hemorrhage (SAH) is frequently misdiagnosed with intracerebral hemorrhage (ICH) or cerebral infarction (CI), which delays appropriate referral. This study was undertaken to create a clinical index to select, among stroke patients, those with the highest probability of having a SAH. Clinical data of patients with acute stroke were evaluated with the X2 and the Fisher exact test; a p value < 0.05 was considered significant. Significant variables were included in a "log-lineal regression analysis" where those with an odds ratio (OR) 95% confidence limits not including the unit were considered to construct an index using the odds ratio coefficient (C). The results indicated that of 197 records which were included, 22 cases of SAH and 175 of ICH or CI were demonstrated. Kappa coefficients for observer variation in clinical data retrieval was 0.91. After "log-lineal regression analysis" was carried out the following variables were significant: neck stiffness (C = 3, OR = 21); lack of focal neurologic signs (C = 2, OR = 6.88); and age < or = 60 years (C = 1.5, OR = 4.35). A fourth variable, seizures (C = 1, OR = 3.25), was marginally significant (p = 0.07), but added predictive value to the index. The positive predictive values of the sum of the coefficients were: 0 = 0%; 1-2 = 3%; 2.5-3.5 = 21%; 4-5 = 40%; 6.5 = 75%; 7.5 = 100%. In conclusion, when a stroke patient shows neck stiffness, or any combination of young age, lack of focal neurologic signs or seizures (a score > or = 2.5, the index has a 91% sensitivity and 82% specificity), he/she must be referred to a tertiary care center.