%0 Journal Article %J J Alzheimers Dis %D 2017 %T Challenges in Screening and Recruitment for a Neuroimaging Study in Cognitively Impaired Geriatric Inpatients. %A Apostolova, Ivayla %A Lange, Catharina %A Roberts, Anna %A Igel, Hans Joachim %A Mäurer, Anja %A Liese, Stephanie %A Estrella, Melanie %A Prasad, Vikas %A Stechl, Elisabeth %A Lämmler, Gernot %A Steinhagen-Thiessen, Elisabeth %A Buchert, Ralph %X

BACKGROUND: Neuroimaging-based biomarkers have the potential to improve etiological diagnosis of cognitive impairment in elderly inpatients. However, there is a relative lack of studies on neuroimaging-based biomarkers in hospitalized geriatric patients, as the vast majority of neuroimaging studies in dementia have focused on memory clinic outpatients. An important aspect of study planning is a priori estimation of the rate of screen failures.

OBJECTIVE: To report on the rate and causes of screen failures in a prospective study on the utility of neuroimaging (PET, MRI) for the etiological diagnosis of newly manifested cognitive impairment in acutely hospitalized geriatric patients.

METHODS: Ten acute care geriatrics clinics with 802 beds participated in the study. The potential recruitment rate had been estimated to 5 patients/100 beds/week.

RESULTS: Seventeen months of pre-screening resulted in 322 potential participants. 109 of these patients were enrolled, i.e., the screen failure rate was 66%. 58% of the screen failures were due to refusal of participation by the patient, most often due to lack of interest in clarifying the cause of the cognitive impairment or due to reluctance to engage in additional diagnostic procedures associated with physical stress. 42% of pre-screened patients were excluded because of violation of the eligibility criteria.

CONCLUSION: Enrollment for neuroimaging studies presents considerable additional challenges in acutely hospitalized geriatric patients compared to outpatient settings. Low rate of approaching potential candidates by attending geriatricians and a high rate of screen failures have to be anticipated in the study design.

%B J Alzheimers Dis %V 56 %P 197-204 %8 2017 %G eng %N 1 %1 http://www.ncbi.nlm.nih.gov/pubmed/27911313?dopt=Abstract %R 10.3233/JAD-160797 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Combination of Structural MRI and FDG-PET of the Brain Improves Diagnostic Accuracy in Newly Manifested Cognitive Impairment in Geriatric Inpatients. %A Ritter, Kerstin %A Lange, Catharina %A Weygandt, Martin %A Mäurer, Anja %A Roberts, Anna %A Estrella, Melanie %A Suppa, Per %A Spies, Lothar %A Prasad, Vikas %A Steffen, Ingo %A Apostolova, Ivayla %A Bittner, Daniel %A Gövercin, Mehmet %A Brenner, Winfried %A Mende, Christine %A Peters, Oliver %A Seybold, Joachim %A Fiebach, Jochen B %A Steinhagen-Thiessen, Elisabeth %A Hampel, Harald %A Haynes, John-Dylan %A Buchert, Ralph %X

BACKGROUND: The cause of cognitive impairment in acutely hospitalized geriatric patients is often unclear. The diagnostic process is challenging but important in order to treat potentially life-threatening etiologies or identify underlying neurodegenerative disease.

OBJECTIVE: To evaluate the add-on diagnostic value of structural and metabolic neuroimaging in newly manifested cognitive impairment in elderly geriatric inpatients.

METHODS: Eighty-one inpatients (55 females, 81.6±5.5 y) without history of cognitive complaints prior to hospitalization were recruited in 10 acute geriatrics clinics. Primary inclusion criterion was a clinical hypothesis of Alzheimer's disease (AD), cerebrovascular disease (CVD), or mixed AD+CVD etiology (MD), which remained uncertain after standard diagnostic workup. Additional procedures performed after enrollment included detailed neuropsychological testing and structural MRI and FDG-PET of the brain. An interdisciplinary expert team established the most probable etiologic diagnosis (non-neurodegenerative, AD, CVD, or MD) integrating all available data. Automatic multimodal classification based on Random Undersampling Boosting was used for rater-independent assessment of the complementary contribution of the additional diagnostic procedures to the etiologic diagnosis.

RESULTS: Automatic 4-class classification based on all diagnostic routine standard procedures combined reproduced the etiologic expert diagnosis in 31% of the patients (p = 0.100, chance level 25%). Highest accuracy by a single modality was achieved by MRI or FDG-PET (both 45%, p≤0.001). Integration of all modalities resulted in 76% accuracy (p≤0.001).

CONCLUSION: These results indicate substantial improvement of diagnostic accuracy in uncertain de novo cognitive impairment in acutely hospitalized geriatric patients with the integration of structural MRI and brain FDG-PET into the diagnostic process.

%B J Alzheimers Dis %V 54 %P 1319-1331 %8 2016 Oct 18 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/27567842?dopt=Abstract %R 10.3233/JAD-160380