engleski

Role of Tc-99m HMPAO brain SPECT in the differential diagnosis of vascular and other dementias

Aim: The aim of this study was to examine the value and importance of brain SPECT in the differential diagnosis of cognitive decline. Establishing a correct diagnosis is often challenging and is frequently dependent solely on clinical evaluation. Functional neuroimaging is emerging as an additional clinicians’ aid in correctly diagnosing dementia patients and providing the appropriate therapy.Method: Sixty-nine patients (39 female)with various forms of newly reported cognitive decline were referred to our Department from November 2014 to March 2015, mostly (68%) with unspecified cognitive decline as a working diagnosis. Twelve patients (17%) were suspected to have Alzheimer’s disease (AD) and eight (11.6%) were assumed to have vascular dementia. Their mean age was 71 years (range 51-89). They underwent regional cerebral blood flow (rCBF) examination with single-photon emission computerized tomography (SPECT), using standardized EANM protocol.Results: Decreased perfusion in temporoparietal cortex, usually bilaterally, characteristic for AD, was found in 12% of patients. Patchy, irregular tracer uptake with significant reductions of rCBF in majority of cerebral regions, differing in size and severity, left to right asymmetries and even globally diminished perfusion with changes in the cerebellum, characteristic for vascular dementia (VD) was found in the majority of our patients, 52%.A third of our patients were reported to have the above mentioned AD perfusion pattern with the addition of nonuniform VD pattern, indicating a mixed dementia. Six patients had the perfusion pattern of frontotemporal and Lewy body dementia, and two had a normal finding. SPECT data were compared with clinical and psychometric data. A significant number of patients found to have mixed dementia had a positive history for high blood pressure (80%) and hyperlipoproteinemia (76%). A more specific diagnosis (AD, FTLD, LBD perfusion pattern, mixed dementia)was determined in 42% of patients. In 50 patients detailed follow-up was obtained, which indicated an altered clinical diagnosis in 23, and confirmation of the working diagnosis in additional 9 patients, with modification in patient management due to brain SPECT data in 64% of patients with follow up neurology exam.Conclusion: HMPAO brain SPECT has been presented as an immensely valuable functional neuroimaging method in differentiating patients with various cognitive decline symptoms. It presents an affordable and accessible tool which enables early and correct diagnosis and influences further patient management and therapy.

dementia, Tc-99m-HMPAO, vascular dementia, SPECT

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