Spatial navigational impairments in hydrocephalus

Whilst much is known about the neuropathological consequences of hydrocephalus, there have been comparatively few studies of the cognitive impairments associated with it. Studies using standardised tests of cognitive function have identified a general pattern of impairments, with patients exhibiting particular difficulty on tests of spatial memory and executive function. A strong prediction is that these deficits are likely to affect daily wayfinding behaviour, and we report a study of spatial and navigational abilities in a group of patients with hydrocephalus but without spina bifida. Participants completed a range of experimental tasks assessing spatial cueing behaviour, landmark memory and route-learning, and idiothetic path integration. This patient group was compared to a control sample matched on verbal, spatial, and intelligence measures, and hydrocephalus was found to be associated with relative impairments in each of the tasks. Patients exhibited reduced sensitivity to spatial cueing, less accurate route-learning, poorer memory for landmark objects, and less accurate spatial updating (with particular impairments in the calculation of heading). Overall, these data represent the first empirical demonstration of navigational impairments in hydrocephalus, and we suggest some of the cognitive, neural, and individual differences factors that may contribute to the pattern of performance reported.     

The role of the perirhinal cortex and hippocampus in learning, memory, and perception

One traditional and long-held view of medial temporal lobe (MTL) function is that it contains a system of structures that are exclusively involved in memory, and that the extent of memory loss following MTL damage is simply related to the amount of MTL damage sustained. Indeed, human patients with extensive MTL damage are typically profoundly amnesic whereas patients with less extensive brain lesions centred upon the hippocampus typically exhibit only moderately severe anterograde amnesia. Accordingly, the latter observations have elevated the hippocampus to a particularly prominent position within the purported MTL memory system. This article reviews recent lesion studies in macaque monkeys in which the behavioural effects of more highly circumscribed lesions (than those observed to occur in human patients with MTL lesions) to different subregions of the MTL have been examined. These studies have reported new find-ings that contradict this concept of a MTL memory system. First, the MTL is not exclusively involved in mnemonic processes; some MTL structures, most notably the perirhinal cortex, also contribute to perception. Second, there are some forms of memory, including recognition memory, that are not always affected by selective hippocampal lesions. Third, the data support the idea that regional functional specializations exist within the MTL. For example, the macaque perirhinal cortex appears to be specialized for processing object identity whereas the hippocampus may be specialized for processing spatial and temporal relationships.     

Acute Alcohol Co‐Ingestion and Hospital‐Treated Deliberate Self‐Poisoning: Is There an Effect on Subsequent Self‐Harm?

The aim of this study was to determine the relationship between alcohol co‐ingestion in an index deliberate self‐poisoning (DSP) episode with repeated DSP and subsequent suicide. A retrospective cohort study was conducted involving 5,669 consecutive index presentations to a toxicology service following DSP between January 1, 1996, and October 31, 2010. Records were probabilistically matched to National Coronial Information System data to identify subsequent suicide. Index DSPs were categorized on co‐ingestion of alcohol, and primary outcomes analyzed were repetition of any DSP, rates of repeated DSP, time to first repeat DSP, and subsequent suicide. Co‐ingestion of alcohol occurred in 35.9% of index admissions. There was no difference between those who co‐ingested alcohol (ALC+) and those who did not co‐ingest alcohol (ALC?) in terms of proportion of repeat DSP, number of DSP events, or time to first repeat DSP event. Forty‐one (1.0%) cases were probabilistically matched to a suicide death; there was no difference in the proportion of suicide between ALC+ and ALC? at 1 or 3 years. There was no significant relationship between the co‐ingestion of alcohol in an index DSP and subsequent repeated DSP or suicide. Clinically, this highlights the importance of mental health assessment of patients that present after DSP, irrespective of alcohol co‐ingestion at the time of event.     

Relationship-Based Home Visiting Services for Families Affected by Substance Use Disorders: A Qualitative Study

Journal of Child and Family Studies - Home visiting programs face many challenges when providing evidence-based services to families affected by substance use disorders (SUDs). We conducted...     

The role of the perirhinal cortex and hippocampus in learning, memory, and perception.

One traditional and long-held view of medial temporal lobe (MTL) function is that it contains a system of structures that are exclusively involved in memory, and that the extent of memory loss following MTL damage is simply related to the amount of MTL damage sustained. Indeed, human patients with extensive MTL damage are typically profoundly amnesic whereas patients with less extensive brain lesions centred upon the hippocampus typically exhibit only moderately severe anterograde amnesia. Accordingly, the latter observations have elevated the hippocampus to a particularly prominent position within the purported MTL memory system. This article reviews recent lesion studies in macaque monkeys in which the behavioural effects of more highly circumscribed lesions (than those observed to occur in human patients with MTL lesions) to different subregions of the MTL have been examined. These studies have reported new findings that contradict this concept of a MTL memory system. First, the MTL is not exclusively involved in mnemonic processes; some MTL structures, most notably the perirhinal cortex, also contribute to perception. Second, there are some forms of memory, including recognition memory, that are not always affected by selective hippocampal lesions. Third, the data support the idea that regional functional specializations exist within the MTL. For example, the macaque perirhinal cortex appears to be specialized for processing object identity whereas the hippocampus may be specialized for processing spatial and temporal relationships.