Superficial siderosis: a potential diagnostic marker of cerebral amyloid angiopathy in Alzheimer disease

Abstract BACKGROUND AND PURPOSE: Superficial siderosis of the central nervous system results from chronic bleeding in the superficial layers of the cortex and spinal cord. In cerebral amyloid angiopathy (CAA), there is amyloid deposition in meningeal and meningo-cortical arteries and capillaries, predisposing them to rupture. CAA is frequently associated with Alzheimer disease (AD). METHODS: We report a series of 3 AD patients with MRI evidence of superficial siderosis. Two had neuropathological examination confirming superficial siderosis, AD, and CAA. CONCLUSIONS: Superficial siderosis should be recognized within the spectrum of AD with CAA and considered as a possible antemortem diagnostic feature

Decreased olfactory discrimination is associated with impulsivity in healthy volunteers

In clinical populations, olfactory abilities parallel executive function, implicating shared neuroanatomical substrates within the ventral prefrontal cortex. In healthy individuals, the relationship between olfaction and personality traits or certain cognitive and behavioural characteristics remains unexplored. We therefore tested if olfactory function is associated with trait and behavioural impulsivity in nonclinical individuals. Eighty-three healthy volunteers (50 females) underwent quantitative assessment of olfactory function (odour detection threshold, discrimination, and identifcation). Each participant was rated for trait impulsivity index using the Barratt Impulsiveness Scale and performed a battery of tasks to assess behavioural impulsivity (Stop Signal Task, SST; Information Sampling Task, IST; Delay Discounting). Lower odour discrimination predicted high ratings in non-planning impulsivity (Barratt Non-Planning impulsivity subscale); both, lower odour discrimination and detection threshold predicted low inhibitory control (SST; increased motor impulsivity). These fndings extend clinical observations to support the hypothesis that defcits in olfactory ability are linked to impulsive tendencies within the healthy population. In particular, the relationship between olfactory abilities and behavioural inhibitory control (in the SST) reinforces evidence for functional overlap between neural networks involved in both processes. These fndings may usefully inform the stratifcation of people at risk of impulse-control-related problems and support planning early clinical interventions

Irrational beliefs and the anxiety disorders

This study investigated the levels of irrationality reported by a clinical sample of anxiety disorder patients, including simple and social phobics, panic disorder patients, agoraphobics, and obssessive compulsive patients. The levels of irrationality were compared between these groups and a group of normal control subjects, using the Rational Behavior Inventory (RBI). Agoraphobic patients were significantly less rational than control subjects on six of the RBI's subfactors and the total score of the Inventory. Patients in all diagnostic categories except simple phobia were significantly different from control subjects on the projected misfortune subfactor, and patients in all categories except simple phobia and panic disorder were significantly different from controls on the total RBI score. There were only four instances where patients in anxiety disorder categories significantly differed from each other in levels of irrationality. The implications of these findings, methodological limitations, and directions for future research are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43981/1/10942_2005_Article_BF01076187.pd