Boundary extension as a tool for detection of cognitive change among individuals with mild cognitive impairment: A preliminary study.

OBJECTIVES: Recent neuropathological research suggests that recognition memory supported by familiarity rather than recollection may be the earliest cognitive change in course of Alzheimer's disease (AD). Nonetheless, the findings on the issue of familiarity capacity in the prodromal AD remain inconsistent. Boundary extension (BE), in which the view recollected by the subject covers a wider angle than was actually observed, is a form of false memory. Given that BE occurs implicitly and automatically, it may be a candidate for assessing familiarity functioning in cases of AD. This was the issue explored in the current study. METHODS: One-hundred and six participants comprising a younger adult group (YA, n = 40), a healthy older adult group (OA, n = 40), and a group of patients with mild cognitive impairment (MCI, n = 26) underwent testing for BE and neuropsychological functions. Parts of OA and MCI underwent analysis for plasma tau levels. Receiver-operating characteristic analysis was used to assess memory associated with familiarity and recollection among participants. RESULTS: The OA and MCI groups could be differentiated by the degree of familiarity associated with BE, wherein the latter group displayed minimal familiarity. Among OAs, familiarity was positively associated with education level. We observed a correlation between plasma tau levels and various neuropsychological functions. Most of the associations between plasma tau levels and neuropsychological functions were mediated by education level. CONCLUSIONS: Our findings indicate that BE could detect early decline in familiarity and assess preserved cognitive functions in aging.

Asymptomatic cerebral aneurysm in stroke patients eligible for intravenous thrombolytic therapy.

PURPOSE: To report two cases of acute ischemic stroke with anterior communicating artery aneurysm presented to emergency room within 3 hours after onset, and to review the literature. CASE REPORT: Two cases of previously unreported anterior communicating artery aneurysm were candidates for intravenous thrombolysis for their acute stroke. Recombinant tissue plasminogen activator was eventually withdrawn by other reasons. The aneurysms presented as nodular lesions with slightly increased density just above sellae turcica on non-contrasted computed tomography and were later diagnosed by magnetic resonance angiography. CONCLUSION: Asymptomatic cerebral aneurysm could be undiagnosed by non-contrasted computed tomography.Careful reading at selected regions can reduce pitfalls. Computed tomographic angiography and magnetic resonance angiography are alternative screening tools for thrombolysis if available in ER.The composite effect of r-tPA on cerebral aneurysms is still uncertain. A more inclusive definition of cerebral aneurysms and miscellaneous vascular anomalies in current criteria of thrombolysis is recommended.

Young stroke, cardiac myxoma, and multiple emboli: a case report and literature review.

Cardiac myxoma is a source of emboli to the vascular tree, especially to the central nervous system. Although it is rare, its early recognition is particularly important because of its unique clinical features of subsequently leading to intracerebral or subarachnoid hemorrhage, even brain metastases, and its potential for surgical cure. Missing the diagnosis may lead to devastating results, including stroke, even sudden death. A 40-year-old male with no other conventional vascular risk factors such as hypertension, diabetes or hyperlipidemia presented with right hemiplegia, global aphasia, vomiting, and fever. Infarction over the left middle cerebral artery was disclosed on magnetic resonance imaging study, and echocardiogram showed a huge mass, about 5cm in size, on the mitral valve which was histopathologically proved to be a cardiac myxoma. He also presented with multiple emboli to the kidneys and the left eye. There is uncertainty about the role of anticoagulation. The treatment of choice remains surgical excision of the cardiac myxoma which may lead to normalization of serum interleukin-6 levels and resolution of constitutional symptoms, and the intracranial aneurysms may regress and resolve.