TIA英语教学分析课件.pptVIP

Transient Ischemic Attack (TIA) Definition A TIA is a brief, reversible episode of focal, nonconvulsive ischemic neurologic deficit lasting less than 24 hours. Recurrent TIAs with identical pattern are warning signs that a stroke may happen soon. TIA- Pathogenesis The mechanisms are not fully understood. Microembolization Vascular spasm, stenosis or compression Hemodynamic disorders and abnormal blood constituents Others (arteritis, subclavian steal syndrome ) TIA-Pathogenesis Microembolization hypothesis Microembolus （a small blood clot） Cause: stenosis of BA Symptoms: paroxysmal vertigo, vomiting, diplopia TIA-Pathogenesis VA TIA-Pathogenesis The mechanism is not fully understood. But they might be thought of as follows: Microembolization Vascular spasm, stenosis or compression Hemodynamic disorders and abnormal blood constituents Others (arteritis, subclavian steal syndrome ) TIA-Clinical features Age: middle-aged and old people. Sex: male female. Risk factors : hypertension, atherosclerosis, diabetes, etc. Basic clinical features: Sudden onset; Transient episode (24h); Reversible course (no sequelae); Focal neurologic deficits. TIA- Focal neurologic deficits Anterior circulation Posterior circulation (carotid arteries) (vertebrobasilar arteries) ▲ Contralateral weakness Aphasia ★ Amaurosis fugax ★ Contralateral sensory loss Contralateral homonymous hemianopia Any combination of the above ▲ Vertigo, nausea, vomiting ★ Diplopia ★ Drop attacks ★ Dysarthria / dysphagia Unilateral / bilateral or crossed paresis or sensory loss Visual loss Ataxia / unsteadiness Any combination of the above ▲ Most common features ★ Most useful distinguishing features TIA-Diagnosis Depend upon history in most cases. Pathogenic diagnosis ： To explore the underling causes of TIAs ！ TIA- Differential diagnosis Partial seizures Méniere disease Migraine