Extremely Low Prevalence of Amyloid Positron Emission Tomography Positivity in Parkinson's Disease without Dementia.

BACKGROUND: Most cases of dementia with Lewy bodies (DLB) show Alzheimer's disease pathology-like senile plaques and neurofibrillary tangles. Several studies have also revealed a high prevalence of positive amyloid imaging with positron emission tomography (PET) in DLB and moderate prevalence in Parkinson's disease (PD) with dementia. However, it remains unclear in PD without dementia as to when the brain ß amyloid (Aß) burden begins and progresses. Our study aimed to determine the prevalence of Aß deposition in PD without dementia using amyloid PET. METHODS: This was a cross-sectional study on 33 patients with PD without dementia, of whom 21 had normal cognition and 12 met the criteria for PD-mild cognitive impairment. All subjects underwent neuropsychological assessment and [18F] florbetaben (FBB) PET. RESULTS: All subjects had Lewy body-related disorders, displaying a significantly reduced myocardial [123I] metaiodobenzylguanidine uptake. The cortical FBB-binding pattern in all subjects, including APOE e4 carriers, suggested negative Aß deposition. CONCLUSION: Patients with PD without dementia exhibit an extremely low prevalence of Aß positivity compared with those reported in cognitively normal elderly controls. Further longitudinal imaging studies and long-term follow-up are needed; however, our findings provide novel insights for understanding Aß metabolism in PD.

Fatal intracranial hemorrhage after intravenous thrombolytic therapy for acute ischemic stroke associated with cancer-related nonbacterial thrombotic endocarditis.

Nonbacterial thrombotic endocarditis (NBTE) is associated with hypercoagulability in patients with inflammatory states such as cancer and autoimmune diseases. Cardiac vegetations caused by NBTE often lead to life-threatening systemic thromboembolism that most frequently affects the brain, spleen, and kidneys. A 54-year-old woman diagnosed with ovarian cancer suddenly developed back pain and left hemiparesis. Although intravenous alteplase (rt-PA) therapy was administered to treat hyperacute ischemic infarction detected by magnetic resonance imaging, intracranial hemorrhage occurred in the left hemisphere several hours later as the patient started to lose consciousness. Transthoracic echocardiography then detected aseptic vegetations on the mitral and aortic valves, indicating NBTE associated with ovarian cancer. Because therapies for NBTE are limited to heparinization and control of underlying diseases, thrombolytic therapy for acute embolic stroke in NBTE has not yet been validated. We postulated that thrombolytic therapy for cancer-related NBTE might easily cause hemorrhagic complications because cancer-related NBTE is often similar to the state of disseminated intravascular coagulation.

q-Space Myelin Map imaging for longitudinal analysis of demyelination and remyelination in multiple sclerosis patients treated with fingolimod: A preliminary study.

BACKGROUND: Fingolimod (FTY) is an oral sphingosine-1-phosphate receptor modulator that reduces relapse and slows brain atrophy in multiple sclerosis (MS) patients. In addition, FTY has been shown to enhance remyelination in certain animal models. OBJECTIVE: To analyze feasibility of a novel q-space Myelin Map imaging to monitor demyelination and remyelination under FTY treatment in MS patients. METHODS: Treatment outcomes of 24 consecutive MS patients treated with FTY were analyzed. A longitudinal analysis of q-space Myelin Map imaging was performed in a subset of these patients. RESULTS: During the treatment course (average of 16.1months), 10 patients (42%) exhibited improvement on the Expanded Disability Status Scale (EDSS) or maintained disability-free state ("optimal responders"). The average baseline age and EDSS score were significantly younger and milder in optimal responders compared to the rest of patients. A pilot longitudinal q-space Myelin Map study in 8 patients (including 4 optimal responders) showed that optimal responders tended to show signs of remyelination while exhibiting no newly evolved demyelinated lesions. CONCLUSION: FTY may improve disability in younger patients with milder MS, and absence of demyelination activity and presence of remyelination activity may in part be associated with such improvement. q-Space Myelin Map imaging is a clinically feasible modality to monitor demyelination and remyelination in MS patients.