Lymphomatosis cerebri presenting as rapidly progressive dementia.

BACKGROUND: As the population ages, the incidence of dementing illness is increasing. Accurate and timely diagnosis provides the best hope for instituting appropriate treatment and educating the patient and family members as to prognosis based upon likely etiology in a given patient. REVIEW SUMMARY: We present a case of an elderly patient referred to our tertiary-care center for further evaluation of a rapidly progressive dementia, whose definitive diagnosis was delayed by nonspecific MRI findings, presence of 14-3-3 protein in the CSF, and nonspecific cutaneous lesions. At brain biopsy, he was thought to have a diffusely infiltrating lymphoma, with distinctive immunohistochemical features. CONCLUSION: This case is notable in that it presents a patient with progressive dementia whose diagnosis of primary central nervous system lymphoma (PCNSL) was delayed because of the lymphoma's atypical diffusely infiltrating nature. Awareness of this unique presentation may hasten the time between clinical presentation, diagnosis, and subsequent treatment.

The utility of PET brain imaging in the initial evaluation of dementia.

Given the challenges and benefits of timely and accurate diagnosis of neurodegenerative disorders and the importance of appropriate subsequent treatments, physicians and patients alike desire tools that aid in diagnosing dementia as early and as precisely as possible. One of these tools may be functional brain imaging, specifically positron emission tomography (PET). Recent technological advancements, ongoing research studies, and approval for reimbursement by various insurance companies and Medicare, under certain circumstances, have led to an increased interest in the use of this tool in the evaluation of dementia. This article will review PET brain imaging in the initial assessment and diagnosis of dementia, including its place in current guidelines and role in diagnostic algorithms, its applicability in differentiating among various dementia syndromes and major psychiatric disorders, and some of the controversies surrounding its utility in general clinical practice.