Correlation between Cognitive Functions and Nitric Oxide Levels in Patients with Dementia

Abstract

Dementia is defined as a clinical syndrome characterized by acquired loss of cognitive and emotional abilities, severe enough to interfere with daily functioning and quality of life. Event related potentials (ERP) are sensitive to task variables that relate to cognitive behavior. They might be altered in patients with disorders of cognition such as dementia. Application of the P300 ERP component to the study of cognitive disorders provides a means of quantifying the level of mental impairment. At high levels, nitric oxide (NO), which is produced by microglia due to induction of nitric oxide synthase (NOS), is neurotoxic and may play a role in neurodegeneration. In our study an attempt has been made to record ERP in patients of mild and moderate dementia and to correlate their findings with nitric oxide levels in CSF and serum. Twenty patients with dementia were selected as cases and 20 subjects as controls, which were further subdivided according to the age groups. Both dementia cases and controls were assessed by minimental state examination (MMSE) and clinical dementia rating scale (CDRS) for evaluating the degree of dementia. It was observed that the MMSE score was reduced in demented cases. P300 latency was significantly delayed in mild and moderate cases of dementia. However, no change was seen in NO levels of cerebrospinal fluid (CSF) and serum in dementia cases and controls. A negative correlation was found between MMSE and P300 latency. Hence we conclude that cognitive impairment in demented patients is reflected in P300 latency but not in NO levels in CSF and serum.

Mechanism of Oxidative Stress and Synapse Dysfunction in the Pathogenesis of Alzheimer’s Disease: Understanding the Therapeutics Strategies

“…Liu et al [25] suggested that generation of reactive nitrogen species (RNS) and ROS triggers oxidative stress and eventually leads to neuronal damage. Thus, the increased free radical generation may ultimately lead to synaptic dysfunction which is an important pathophysiological component of AD [26]. Moreover, Kamat et al [10] also suggest that oxidative stress causes cognitive deficiency, neurofibrillary tangle (NFT)-like pathological changes, and oxidative stress as seen in AD pathology via tau hyperphosphorylation.…”

IL-1<i>β</i>, TNF-<i>α </i>and <i>Sambucus nigra</i> Reactive Serum Proteins as Biomarkers of Mild Cognitive Impairment and Alzheimer Disease Progression

“…We find an increase in serum nitric oxide in the MCI patients and a decrease in AD. This is probably the consequence of the increased iNOS expression that we observe in the MCI patients, interestingly patients with AD show lower serum concentrations of NO [30] [31] [33] [34], which are not secondary to a decrease or disappearance of iNOS. It is possible that the lack of arginine that has been reported in AD patients [35] is the cause of such a decrease.…”