Cooperative study of hospital frequency and character of transient ischemic attacks. VIII. Risk factors.

A total of 969 (73%) of 1,328 patients with cases of suspected transient ischemic attacks (TIAs) who came to six institutions during a 21-month period were followed up. Factors were identified and prospectively analyzed for risk for further TIAs, stroke, and deatn. A history of multiple carotid artery TIAs was significantly related to further TIAs. A single TIA placed the patient at greater risk for early infarction. Older age, male sex, and unreliability to take dangerous medication were risk factors for cerebral infarction. Anticoagulant therapy, older age, male sex, diabetes mellitus, heart disease, abnormal ECG, and poor surgical risk were factors for death. The increased mortality associated with anticoagulants was confined to the older age group. While white patients treated with antiplatelet-aggregating agents had a lower mortality than those treated otherwise, this was not true amont black patients.

Cooperative study of hospital frequency and character of transient ischemic attacks.

Information was collected among six participating medial centers on frequency of performance and the percentage of abnormality of 30 tests performed on patients with complaints suggesting transient ischemic attacks (TIAs). A number of these were commonly performed and commonly exhibited abnormalities. Although the diagnosis of TIA is made by history and physical examination, these tests were of value in aiding the physician to determine possible causes of TIA, to detect risk factors of associated conditions, to rule out alternative diagnoses, and to assess the patient's ability to tolerate different types of therapy.

Cooperative study of hospital frequency and character of transient ischemic attacks. VI. Patients examined during an attack.

Examination during an episode of transient ischemic attack (TIA) was performed on 121 of 1,307 patients suspected of having a single type of TIA. This examination supported the diagnosis of TIA in 79 patients and contributed to the establishment of a diagnosis other than TIA in 42. Although the examination increased diagnostic reliability, it did not always result in a definite diagnosis. The most common neurologic findings during a TIA were weakness of an arm or side of the face. Important findings not suggested by history included visual defects and blood pressure fluctuation. Also unexpected were the absence of findings such as sensory deficits in the presence of sensory complaints, retinal emboli, and cardiac abnormalities. Severe arteriosclerotic disease was less evident, the attacks were longer and more severe, and monocular blindness was rare.

Cooperative study of hospital frequency and character of transient ischemic attacks. V. Symptom analysis.

All patients (1,328) suspected of having transient ischemic attacks (TIA) who came to six institutions during a 21-month period were identified. Symptoms and symptom complexes were related to the clinical diagnoses by cross-tabulation, factor analysis, and discriminant analysis. The diagnoses obtained by the discriminant analysis program were comparable to those of reviewing clinical neurologists. Symptoms of importance in the vertebral-basilar system (VBS) were bilateral visual blurring, diplopia, ataxia, and dizziness; In either carotid system (CAS), ipsilateral monocular visual disturbance anc contralateral weakness or sensory complaints; in the left CAS, language disturbances; and in those whose ultimate diagnosis was not TIA, loss of consciousness, confusion, and bilateral leg weakness. Patients with VBS TIAs have symptoms common to conditions that are not TIA and have a greater variety of symptoms and more combinations of symptoms than CAS TIA.

Cooperative study of hospital frequency and character of transient ischemic attacks. IV. The reliability of diagnosis.

All patients (1,328) suspected of having transient ischemic attacks (TIA) who came to six institutions over a 21-months period were identified. Each case was reviewed by a neurological investigator, and a definite diagnosis of TIA was supported in 39% and ruled out in 30%. The reliability of the neurologist's review diagnosis was assessed by three methods, and close agreement (84% to 93%) was obtained. Factors demonstrated to effect the diagnosis were historical information, neurological training of the examiners, type of symptom complex, presence of carotid artery bruits, and examination during an attack.

Cooperative study of hospital frequency and character of transient ischemic attacks. III. Variations in treatment.

Variations in therapy for patients with complaints suggesting transient ischemic attacks (TIAs) among six participating medical centers are described. Selected treatment, based on clinical interpretation of patient characteristics, varied widely among centers. Therefore, results cannot be attributed to specific treatment. Nevertheless, there was little difference between treatment categories and the likelihood of further TIAs. The mortality of the patients who had received anticoagulants was significantly higher (P less than .001) than those patients receiving other treatment. Possible reasons for these differences are discussed.

A cooperative study of hospital frequency and character of transient ischemic attacks. II. Performance of angiography among six centers.

Angiographic procedures were carried out on 36% of 1,328 patients suspected of having transient ischemic attacks (TIA). Among six participating centers, this ranged from 13% to 82%. This large difference might be related to the number of patients considered good surgical candidates and differences in the use of screening noninvasive diagnostic techniques. Arch studies, using catheter techniques, were performed most often. Although 13% of the patients had transient complications, permanent neurological deficits occurred in only 0.65%. Angiographic lesions were best correlated to clinical symptoms in those patients thought to definitely have carotid artery system TIA but were commonly seen in all other groups. Thus, clinical correlation was poor.

Cooperative study of hospital frequency and character of transient ischemic attacks. I. Background, organization, and clinical survey.

To better understand transient ischemic attacks (TIA), all patients (1,328) with TIA-like symptoms were identified at six participating institutions representing known variations in geography, referral patterns, and socioeconomic status. A total of 954 patients were observed for a mean of 14.3 months. Problems in diagnosis are defined, demographic information is summarized, and features of the histroy, examination, tests, and treatments are noted.