Vascular cognitive impairment: Advances and trends.

The presence of vascular neurocognitive impairment (whatever the severity) is always associated with a functional impact and increased risk of dependency and institutionalization. However, vascular cognitive impairment remains underdiagnosed, and the mechanisms underlying post-stroke cognitive disorders are still poorly understood. However, the advent of new criteria and a standardized international neuropsychological battery is expected to lead to improved diagnosis and management, and the development of novel techniques (such as brain imaging and amyloid PET) should improve our understanding of the mechanisms underlying vascular cognitive impairment and help to identify potential targets for therapy.

Neuropsychological assessment and cerebral vascular disease: the new standards.

Vascular cognitive impairment (VCI) includes vascular dementia (VaD), vascular mild cognitive impairment (VaMCI) and mixed dementia. In clinical practice, VCI concerns patients referred for clinical stroke or cognitive complaint. To improve the characterization of VCI and to refine its diagnostic criteria, an international group has elaborated a new standardized evaluation battery of clinical, cognitive, behavioral and neuroradiological data which now constitutes the reference battery. The adaption of the battery for French-speaking subjects is reported as well as preliminary results of the on-going validation study of the GRECOG-VASC group [Clinical Trial NCT01339195]. The diagnostic accuracy of various screening tests is reviewed and showed an overall sub-optimal sensitivity (<0.8). Thus, the general recommendation is to perform systematically a comprehensive assessment in stroke patients at risk of VCI. Furthermore,the use of a structured interview has been shown to increase the detection of dementia. In addition to the well known NINDS-AIREN criteria of VaD, criteria of VCI have been recently proposed which are based on the demonstration of a cognitive disorder by neuropsychological testing and either history of clinical stroke or presence of vascular lesion by neuroimaging suggestive of a link between cognitive impairment and vascular disease. A memory deficit is no longer required for the diagnosis of VaD as it is based on the cognitive decline concerning two or more domains that affect activities of daily living. Both VaMCI and VaD are classified as probable or possible. These new criteria have yet to be validated. Considerable uncertainties remain regarding the determinant of VCI, and especially the lesion amount inducing VCI and VaD. The interaction between lesion amount and its location is currently re-examined using recent techniques for the analysis of MRI data. The high frequency of associated Alzheimer pathology is now assessable in vivo using amyloid imaging. The first studies showed that about a third of patients with VaD due to small vessel disease or with poststroke dementia have amyloid PET imaging suggestive of AD. These new techniques will examine the interaction between vascular lesions and promotion of amyloid deposition. Although results of these on-going studies will be available in few years, these data indicate that efforts should be done in clinical practice to reduce underdiagnosis of VCI; VCI should be examined using a specific protocol which will be fully normalized soon for French-speaking patients; the sub-optimal sensitivity of screening tests prompts to use a structured interview to grade Rankin scale and to perform systematically a comprehensive assessment in stroke patients at risk of VCI; poststroke dementia occurring after 3 months poststroke may be preventable by treatment of modifiable vascular risk factors and secondary prevention of stroke recurrence according to recent recommendations.

[Identification errors and delusions of false identification in Alzheimer's disease: a regional survey]. / Troubles de l'identification et délires d'identité dans la maladie d'Alzheimer: une enquête régionale.

INTRODUCTION: Misidentification syndromes are the main symptoms in Alzheimer's disease. Underlain by complex cognitive, agnosic, and amnesic disturbances of degenerative etiology, they can be expressed by misidentification delusions, as in psychoses. To date, research has focused on identification disturbances of persons selected according to various definitions. OBJECTIVE: Our main objective was to evaluate the frequency of identification disturbances among patients suffering from Alzheimer's disease within the current conditions of diagnosis and treatment. The secondary objective aimed to establish a detailed analysis of symptoms and clinical correlations, and evaluate the effects of the troubles on the caregiver. METHODS: We conducted a regional survey using a questionnaire designed for the caregiver, proposed to the 60 geriatric doctors and neurologists in the Poitou-Charentes region of France, for all patients suffering from Alzheimer's disease (defined according to DSM IV criteria) seen between June 1st and August 31st of 2003. Statview software was used for statistical analysis. RESULTS: The survey was completed for 104 patients: 69.5 percent women and 30.5 percent men, with a mean age of 79 years. The majority of the patients were seen by a neurologist and presented an average cognitive deficiency (MMS ranging from 11 to 20). An identification disturbance, whether or not it was delusional, all domains included, was found in 81.6 percent of the patients and was related to a more severe cognitive deficiency and greater hardship on the part of the caregiver. DISCUSSION: We observed a high prevalence of identification disturbance, which can be explained by the systematic and exhaustive search for identification disturbance. The most frequent disturbance concerned the identification of places, whereas self-identification was less often affected; the authentic Capgras delusion was found less often. CONCLUSION: The study of identification disturbances in Alzheimer's disease can contribute to a better understanding of the cognitive, psychopathological, and physiopathological aspects of the disease as well as to a better knowledge and better care for the patient.

[Crossed aphasia disclosed by central auditory disorder]. / Aphasie croisée révélée par un trouble central de l'audition.

A 80-year-old woman, right-handed, suddenly felt the impression to be deaf. Besides, she presented language disorders of aphasic type relating to a sensorial transcortical aphasia. The case meets the diagnostic criteria for crossed aphasia. The magnetic resonance imaging showed a right temporo-parietal infarct. There was no sensorial or peripheral auditive disorder and no auditory agnosia of non verbal modality. During the evolution, the aphasic symptoms diminished partially and the subjective auditory deficit of the left ear continued. The integrated auditory evaluation (neuroacoustic test, study of auditory gnosia, dichotic listening test, evoked cortical auditory potentials) allowed the evidence of the characteristic disturbances of a right hemianacousia: loss of left hear in dichotic audition, decrease of amplitude of evoked right cortical auditory potentials. In the light of theories concerning auditory integration, one can explain this evolution. The initial aphasic comprehension disturbance expresses the alteration of the linguistic treatment of auditory information of the dominant hemisphere, here the right hemisphere. Subsequently, the linguistic disturbance regresses largely, letting persist the change of general auditory treatment. The representation of this general auditory treatment is hemispheric bilateral, the only right hemispheric damage shall result in hemianacousia.