Memory disorders and dementias

Memory disorders can be classified either as transient or persistent. This chapter provides a brief overview of transient neurological amnesias such as transient global amnesia (TGA) and transient epileptic amnesia (TEA), before moving on to persistent memory disorders, using vignettes to demonstrate the cognitive effects of conditions like Korsakoff syndrome and herpes encephalitis. The remainder of the chapter focuses on various forms of dementia, beginning with an exploration of the various types of Alzheimer’s disease and moving on to less common dementias, such as vascular cognitive disorder and variant Creutzfeldt–Jakob disease, with vignettes and sub-sections on management and prognosis. Dementias associated with movement disorders, such as corticobasal syndrome and spinocerebellar ataxia (SCA), are explored, followed lastly by various transient psychogenic amnesias, the basis of which is not neurological, but psychological.

High occurrence of impaired emotion recognition after ischemic stroke

Introduction Deficits of emotion recognition after ischemic stroke are often overlooked by clinicians, and are mostly not spontaneously reported by patients. However, impaired emotion recognition after stroke negatively affects the ability to return to work and the quality of life. It is still unknown how often impairments of emotion recognition occur shortly after ischemic stroke. We aimed to estimate the occurrence of impaired emotion recognition after ischemic stroke and to characterise these patients with impaired emotion recognition. Patients and methods Two hundred thirty patients were included, derived from a prospective study of cognitive recovery. Five weeks after ischemic stroke a neuropsychological assessment was performed, including an emotion recognition task (i.e. Ekman 60-faces test). Emotion recognition was regarded as impaired if the total score was below the fifth percentile for a large independent reference sample. Results Emotion recognition was impaired in 33.5% of patients. Patients with impaired emotion recognition were more likely to have an abnormal Montreal Cognitive Assessment during hospitalisation, and 5 weeks after their stroke, a higher proportion of them had a vascular cognitive disorder (VCD). Even 20% of patients without VCD had impaired emotion recognition. Discussion: Emotion recognition was often impaired after ischemic stroke. This is clinically relevant, since impaired emotion recognition negatively impacts social functioning. Conclusion: Even when there was no cognitive disorder in traditional cognitive domains, emotion recognition was impaired in 1 out of 5 patients. Clinicians should systematically ask patients and their caregivers about deficits in emotion recognition, and, if needed, test for these deficits.

Idiopathic Normal-Pressure Hydrocephalus: Diagnostic Accuracy of Automated Sulcal Morphometry in Patients With Ventriculomegaly

BACKGROUND Idiopathic normal-pressure hydrocephalus (iNPH) is a treatable cause of gait and cognitive impairment. iNPH should be differentiated from ventriculomegaly secondary to brain atrophy to choose the best therapeutic option (ventriculoperitoneal shunt vs medical management). OBJECTIVE To determine the diagnostic accuracy of automated sulcal morphometry to differentiate patients with iNPH from patients with ventriculomegaly of neurodegenerative origin. METHODS Thirty-eight consecutive patients with iNPH (shunt responsive n = 31, nonresponsive n = 7), 35 with vascular cognitive disorder, and 25 age- and sex-matched healthy controls were prospectively included and underwent cognitive evaluation and 3T brain magnetic resonance imaging. Sulcal opening of 10 sulci of interest was retrospectively measured using an automated surface-based approach from the 3-dimensional T1-weighted images. Receiver-operating characteristic curve analyses determined the best parameter to identify iNPH patients. RESULTS The best parameter to discriminate shunt-responsive iNPH from patients with vascular cognitive disorder and healthy controls was the ratio between calcarine sulcus and cingulate sulcus opening with an area under the curve of 0.94 (95% CI: 0.89, 0.99). A cut-off value of 0.95 provided the highest sensitivity (96.8%) and specificity (83.3%). CONCLUSION This preliminary study showed that automated sulcal morphometry may help the neurosurgeon to identify iNPH patients and to exclude other causes of ventriculomegaly.

Vascular Cognitive Disorder

The term vascular cognitive disorder (VCD) refers to a heterogeneous group of disorders in which the primary feature is cognitive impairment attributable to cerebrovascular disease (CVD). This includes not only vascular dementia (VaD) but also cognitive impairment of insufficient severity to meet diagnostic criteria for dementia. VCD is recognized as the second most common cause of dementia after Alzheimer's disease (AD), but prevalence rates vary widely according to the diagnostic criteria employed. There have been recent attempts to standardize diagnostic criteria. VCD incorporates a range of neuropathological mechanisms including poststroke impairment, small and large vessel disease, and cases of mixed-pathology, with CVD interacting with AD and other neuropathologies. Recent neuroimaging data have improved our understanding of the etiology of VCD. Symptomatic treatments for VaD have modest benefit and there is increased focus on the primary and secondary preventative benefits of vascular risk factor control.

A Role for New Brain Magnetic Resonance Imaging Modalities in Daily Clinical Practice: Protocol of the Prediction of Cognitive Recovery After Stroke (PROCRAS) Study (Preprint)

BACKGROUND Cognitive impairment is common after acute ischemic stroke, affecting up to 75% of the patients. About half of the patients will show recovery, whereas the others will remain cognitively impaired or deteriorate. It is difficult to predict these different cognitive outcomes. OBJECTIVE The objective of this study is to investigate whether diffusion tensor imaging–based measures of brain connectivity predict cognitive recovery after 1 year, in addition to patient characteristics and stroke severity. A specific premise of the Prediction of Cognitive Recovery After Stroke (PROCRAS) study is that it is conducted in a daily practice setting. METHODS The PROCRAS study is a prospective, mono-center cohort study conducted in a large teaching hospital in the Netherlands. A total of 350 patients suffering from an ischemic stroke who screen positive for cognitive impairment on the Montreal Cognitive Assessment (MoCA<26) in the acute stage will undergo a 3Tesla-Magnetic Resonance Imaging (3T-MRI) with a diffusion-weighted sequence and a neuropsychological assessment. Patients will be classified as being unimpaired, as having a mild vascular cognitive disorder, or as having a major vascular cognitive disorder. One year after stroke, patients will undergo follow-up neuropsychological assessment. The primary endpoint is recovery of cognitive function 1 year after stroke in patients with a confirmed poststroke cognitive disorder. The secondary endpoint is deterioration of cognitive function in the first year after stroke. RESULTS The study is already ongoing for 1.5 years, and thus far, 252 patients have provided written informed consent. Final results are expected in June 2019. CONCLUSIONS The PROCRAS study will show the additional predictive value of diffusion tensor imaging-based measures of brain connectivity for cognitive outcome at 1 year in patients with a poststroke cognitive disorder in a daily clinical practice setting. REGISTERED REPORT IDENTIFIER RR1-10.2196/9431