Vascular Dementia (VaD) is defined as the loss of cognitive function resulting from ischemic, ischemic-hypoxic, or hemorrhagic brain lesions as a result of cardiovascular diseases and cardiovascular pathologic changes. See, e.g., G. C. Roman, Med. Clin. North. Am., 86, pp. 477-99 (2002). VaD is a chronic disorder and the symptoms of VaD include cognitive loss, headaches, insomnia and memory loss. VaD may be caused by multiple strokes (MID or poststroke dementia) but also by single strategic strokes, multiple lacunes, and hypoperfusive lesions such as border zone infarcts and ischemic periventricular leukoencephalopathy (Binswanger's disease). See, G. C. Roman, supra. In Asian countries such as China, Japan and Korea, VaD is observed in over 60% of patients with dementia. Primary and secondary prevention of stroke and cardiovascular disease decreases the burden of VaD.
Treatment of VaD involves control of risk factors (i.e., hypertension, diabetes, smoking, hyperfibrinogenemia, hyperhomocystinemia, orthostatic hypotension, cardiac arrhythmias). See, G. C. Roman, supra. Researchers have also investigated whether hormone replacement therapy and estrogen replacement therapy could delay the onset of dementia in women. See, E. Hogervorst et al., Cochrane Database Syst. Rev., 3, CD003799 (2002). Although there has been evidence that aspirin is widely prescribed for VaD, there is very limited evidence that aspirin is effective in treating patients with VaD. See, P. S. Williams et al., Cochrane Database Syst. Rev., 2, CD001296 (2000). Nimodipine has been implicated as a drug demonstrating short-term benefits in VaD patients, but has not been justified as a long-term anti-dementia drug. See, J. M. Lopez-Arrieta and J. Birks, Cochrane Database Syst. Rev., 3, CD000147 (2002). Further, clinical efficacy data of piracetam does not support the use of this drug in the treatment of dementia or cognitive impairment. L. Flicker and G. Grimley Evans, Cochrane Database Syst. Rev., 2, CD001011 (2001). Thus, an agent that is effective in treating VaD is highly desired in the market.
USPTO Backgrounds
USPTO Backgrounds