Binswanger's disease (Part II): Pathogenesis of subcortical arteriosclerotic encephalopathy and its relation to other dementing processes

An exploratory study of delayed flash visual evoked potential P2 wave latency in subcortical arteriosclerotic encephalopathy

BACKGROUND

Patients with cognitive dysfunction may present with significantly prolonged the P2 wave latency of flash visual evoked potential. However, no studies have been reported on whether the P2 wave latency of flash visual evoked potential is prolonged in patients with subcortical arteriosclerotic encephalopathy (SAE).

OBJECTIVE

To examine the relationship between flash visual evoked potential P2 wave latency (FVEP-P2 wave latency) and cognitive impairment in patients with SAE.

METHODS

Overall, we recruited 38 SAE patients as the observation cohort (OC) and 34 healthy volunteers as the control cohort (CC). We measured the FVEP-P2 wave latency for both groups. The SAE patients' cognitive abilities were evaluated via mini-mental state examination (MMSE) and the association between the latency of FVEP-P2 and MMSE score was explored by Pearsons´s correlation test.

RESULTS

There is no significant difference between OC (21 males and 17 females; 68.6 ± 6.7 years of age and 9.6 ± 2.8 years of education) and CC (19 males and 15 females; 65.3 ± 5.9 years of age and 10.1 ± 2.6 years of education) in gender and age composition and education level. The FVEP-P2 wave latency of the CC group was (108.80 ± 16.70) ms and the OC FVEP-P2 wave latency was (152.31 ± 20.70) ms. The OC FVEP-P2 wave latency was significantly longer than the CC (P < 0.05). In terms of MMSE scores, the MMSE scores of CC was (28.41 ± 2.34), and that of OC was (9.08 ± 4.39). Compared to the CC, the OC MMSE score was significantly lower (P < 0.05). In addition, the FVEP-P2 wave latency was inversely related to the MMSE (r = -0.4465, P < 0.05) in SAE patients.

CONCLUSION

The FVEP-P2 wave latency wave latency was significantly prolonged in SAE patients and strongly associated with the degree of cognitive dysfunction.

Cerebral small vessel disease and Alzheimer's disease

Cerebral small vessel disease (CSVD) is a group of pathological processes with multifarious etiology and pathogenesis that are involved into the small arteries, arterioles, venules, and capillaries of the brain. CSVD mainly contains lacunar infarct or lacunar stroke, leukoaraiosis, Binswanger's disease, and cerebral microbleeds. CSVD is an important cerebral microvascular pathogenesis as it is the cause of 20% of strokes worldwide and the most common cause of cognitive impairment and dementia, including vascular dementia and Alzheimer's disease (AD). It has been well identified that CSVD contributes to the occurrence of AD. It seems that the treatment and prevention for cerebrovascular diseases with statins have such a role in the same function for AD. So far, there is no strong evidence-based medicine to support the idea, although increasing basic studies supported the fact that the treatment and prevention for cerebrovascular diseases will benefit AD. Furthermore, there is still lack of evidence in clinical application involved in specific drugs to benefit both AD and CSVD.

Vascular endothelial growth factor inhibitors and cognitive impairment: evidence and controversies

INTRODUCTION

Chemotherapy-induced cognitive impairment, or 'chemobrain,' has been well established in the literature. However, neurocognitive toxic effect induced by targeted therapies such as anti-angiogenic agents is poorly investigated. Recently, emerging evidence suggests vascular endothelial growth factor (VEGF) to have a possible role in brain cognition giving rise to concerns whether VEGF inhibitors (VEGFIs) may induce neurotoxic effect on cancer patients' cognitive function.

AREAS COVERED

The aim of this review was to evaluate the plausible mechanisms underlying VEGF and cognition, and to highlight the evidence and controversies surrounding the cognitive issues associated with the use of VEGFIs.

EXPERT OPINION

This review paper has brought attention to the potential cognitive issues associated with the use of VEGFIs and has added a new, unexplored dimension to the problem of cancer treatment-related cognitive changes. However, the lack of evidence warrants the need for more well-designed studies to quantify the prevalence and severity of VEGFI-induced cognitive impairment in the cancer population, and to establish the role of VEGF in human cognitive function.

Global ischemia and behavioural deficits

Global cerebral ischemia in rodents is an established model in experimental research on cerebral ischemia which is characterized morphologically by a selective neuronal damage in the hippocampus, striatum and cortex. Using this model many studies have been performed to examine the pathophysiology of ischemic neuronal damage. Based upon these results it has been analysed whether substances which interact with the pathophysiological processes reduce the ischemic neuronal damage. Besides the morphological changes global ischemia leads to functional changes which can be assessed by behavioural studies. The Morris water maze examines the animals' abilities to learn, remember and go to a place in space only defined by its position relative to distal extramaze cues. In this test ischemic animals display a deficit in spatial learning as revealed by an increase in latency and in swim distance in the escape trials and a deficit in spatial memory as shown by reduced quadrant time and crossings over the former platform position during the probe trial. In several studies it could be demonstrated that neuroprotective strategies which reduce ischemic neuronal damage also attenuate or even completely prevent the ischemia-induced behavioural deficits in the water maze. Transplantation of fetal tissue which can also be used to achieve morphological recovery following global ischemia results in an amelioration of the ischemia-induced deficit. Thus, the water maze can clearly show that transplanted tissue can be functionally relevant. Data from the water maze seem to be a valuable completion to morphology which is especially important with respect to the relevance of experimental studies for clinical trials.