Allen score in clinical diagnosis of intracranial hemorrhage

Allen score is a validated weighted linear score for clinical distinction between hemorrhagic and ischemic stroke. As the prevalence of hemorrhagic stroke differs between Caucasian and Chinese populations, and the predictive value of any diagnostic score depends greatly on the prevalence of disease being considered, we tried to verify prospectively this score among the Chinese living in Taiwan.

From 1 April to 31 August 1993, all patients with acute stroke syndrome, who visited the emergency room at Veterans General Hospital-Taichung, were studied prospectively. Clinical features were recorded thoroughly to calculate the Allen score. The diagnosis was all confirmed by computed tomography (CT) of the head.

Totally 255 stroke cases were identified. The types of the stroke were cerebral infarction in 186 subjects (73%), cerebral hemorrhage in 64 subjects (25%), and subarachnoid hemorrhage in 5 subjects (2%). Seventy-five cases were excluded because of the lack of clinical details for calculation. Thus, 180 patients were included. When a cut-off of 4 or 24 was taken into account, the sensitivity of Allen score for diagnosing a hemorrhage was 67%, specificity 100%, accuracy 93%, positive predictive value 100%, and negative predictive value 91%.

Although Allen score can be used for epidemiological studies of incidence and outcome in stroke as well as for a first bedside screening to decide the priority of patients for CT, it is not safe enough as a guide for anticoagulant or thrombolytic therapy. Its validity should be verified before use in a given population other than the Caucasian.