Transverse colon volvulus - a case report and literature review

SUMMARY

Transverse colon volvulus is a rare diagnosis, with less than 100 cases reported up to 2019. The condition is complicated by the absence of characteristic radiological findings and is typically diagnosed intraoperatively. It is a surgical emergency as the condition can lead to bowel necrosis and is associated with a mortality rate of up to 33%. Bowel resection is the treatment of choice, and if a megacolon is present a subtotal colectomy is recommended. Due to the rarity of transverse colon volvulus, limited data is available on the long-term outcome of patients.

Clinical determinants of dementia and mild cognitive impairment following ischaemic stroke: the Sydney Stroke Study

BACKGROUND

Dementia following stroke is common but its determinants are still incompletely understood.

METHODS

In the Sydney Stroke Study, we performed detailed neuropsychological and medical-psychiatric assessments on 169 patients aged 50-85 years, 3-6 months after a stroke, and 103 controls with a majority of both groups undergoing MRI brain scans. Stroke subjects were diagnosed as having vascular mild cognitive impairment (VaMCI) or vascular dementia (VaD) or no cognitive impairment by consensus. Demographic, functional, cerebrovascular risk factors and neuroimaging parameters were examined as determinants of dementia using planned logistic regression.

RESULTS

21.3% of subjects were diagnosed with VaD, with one case in those aged 50-59 years, 24% in those aged 60-69 years and 23% in those 70-79 years. There was no difference by sex. The prevalence of VaMCI was 36.7%. VaD subjects had lower premorbid intellectual functioning and had 0.9 years less education than controls. The VaD and VaMCI groups did not differ from the no cognitive impairment group on any specific cerebrovascular risk factor, however overall those with impairment had a greater number of risk factors. They did not differ consistently on depression severity, homocysteine levels and neuroimaging parameters (atrophy, infarct volume and number of infarcts) except for an excess of white matter lesions on MRI and greater number of infarcts in the VaD and VaMCI groups. On a series of logistic regression analyses, stroke volume and premorbid function were significant determinants of cognitive impairment in stroke patients.

CONCLUSION

Post-stroke dementia and MCI are common, especially in older individuals. Cerebrovascular risk factors are not independent risk factors for VaD, but stroke volume is a significant determinant of dementia. Premorbid functioning is a determinant of post- stroke impairment.

The neuropsychological profile of vascular cognitive impairment in stroke and TIA patients

OBJECTIVE

To characterize the neuropsychological profile of vascular cognitive impairment (VCI) and vascular dementia (VaD).

METHODS

The authors examined 170 patients with stroke or TIA at 3 to 6 months after the vascular event, and 96 age-matched healthy controls, with detailed neuropsychological and medical-psychiatric assessments, with a majority (66.7%) undergoing MRI brain scans. The subjects were diagnosed as having VaD, VCI, or no cognitive impairment by consensus. The neuropsychological tests were classified into cognitive domains, and composite z-scores adjusted for age and education.

RESULTS

VaD subjects had disturbance in all cognitive domains, with verbal memory, especially retention, being less affected. VCI subjects had similar but less severe disturbance. The domains that best discriminated cognitively impaired from unimpaired patients were abstraction, mental flexibility, information processing speed, and working memory. Cognitive impairment had a significant correlation with deep white matter hyperintensities, but not with volume and number of infarctions, even though the VaD subjects had larger infarct volumes than VCI subjects. The MRI variables did not provide additional discrimination between subgroups.

CONCLUSIONS

The cognitive deficits in VaD and VCI are characterized by disturbance of frontal functions, with less verbal memory impairment. VaD and VCI differ in severity but not pattern of disturbance. The brain lesions that best account for these deficits are noninfarct subcortical white matter and gray matter changes due to ischemia. The picture of VaD/VCI presented shows subcortical deficits embellished by cognitive deficits from cortical infarctions.

Rates of forgetting in Alzheimer dementia

Patients diagnosed with Alzheimer's disease (AD) were compared with healthy controls on a picture recognition task, a forced choice word recognition task, a forced choice design recognition task, a picture recall task and a stem completion task. Performance on recognition and word stem completion was assessed at 1, 10 and 20 min after exposure to experimental stimuli, as these are delays across which previous studies had suggested there might be differing forgetting rates. AD patients did not show significantly faster rates of forgetting relative to controls on picture recognition, design recognition, word recognition or stem completion, after levels of learning had been matched as closely as possible. Moreover, once initial learning was equated in a small number of subjects, there were no qualitative differences between AD patients and controls following inclusion and exclusion instructions on the stem completion task. In particular, those AD patients who were matched to controls for initial levels of "recollection" showed comparable forgetting rates in recollection (or cued recall). Although matching was more difficult for a picture recall task, both the main analysis and subgroup analysis indicated faster forgetting in the AD group than controls, suggesting a difference between "free recall" and recognition or cued recall measures, comparable with the finding in a parallel study of organic amnesia.