Mini-Mental State Examination Test Scores Research Articles

Conversion between the Rowland Universal Dementia Assessment Scale and Mini-Mental State Examination test scores in majority and minority populations.

Despite the Rowland Universal Dementia Assessment Scale (RUDAS) having significant advantages as a cognitive screening tool, particularly for minority populations, the Mini-Mental State Examination (MMSE) test is the most widely used test for cognitive screening in Alzheimer's disease (AD). This study aimed to develop a conversion table to predict MMSE scores from observed RUDAS scores, allowing an easy-to-use method to compare both screening tests. The equipercentile equating method was used to develop the conversion table using a training sample consisting of cognitively intact participants and individuals with early-stage AD. The resulting conversion table was validated in two samples, comprising participants from majority and minority populations assessed in Spanish. The conversion table demonstrated excellent reliability with intraclass correlation coefficients of.92 in both validation samples. This study provides a conversion table between RUDAS and MMSE scores, improving the comparability of these cognitive screening tools for use in clinical and research purposes.

The relationship between uric acid levels, cognition and inflammation in a cohort of elderly subjects.

Uric acid (UA) is the most powerful antioxidant found among human body fluids. With this effect, UA protects neurons from oxidant effects and ensures the continuation of the structure and functions of neuronal tissue. However, UA has effects on the immune system. This study aims to explain the relationship between UA, cognitive level and inflammation in cases with a wide spectrum of cognitive function. A total of 67 women and 62 men who applied to the psychiatry outpatient clinic to obtain a health report were evaluated. The cognitive states of the individuals were determined with the mini-mental state examination test (MMSE). Additionally, serum uric acid levels and simple inflammatory parameters such as CRP, sedimentation, neutrophil-lymphocyte ratio (NLR), and monocyte-lymphocyte ratio (MLR) were measured. According to the MMSE results, two groups were created. Those with an MMSE score of 24 or above formed the first group, and those with an MMSE score below 24 formed the second group. While a statistically significant positive strong correlation was found between UA and MMSE in all individuals, negative correlations were found between UA and NLR and MLR in men. UA was found to be significantly lower in the group with MMSE scores below 24 and NLR values were higher in the same group. According to these results, UA seems to have a protective effect on cognitive functions. This situation manifests itself more clearly in men. At physiological concentrations, UA may have an anti-inflammatory effect. It appears that there are complex interactions between UA, cognition, and inflammation. Particularly, men appear to be more susceptible to UA effects.

Comparison of DBFS with MoCA and MMSE tools for MCI screening.

Mild cognitive impairment (MCI) has been associated with many diseases. The MCI could be a marker for the early diagnosis of certain diseases. Early detection of MCI could be beneficial for restoration of cognitive reserves. One hundred and five subjects were included in the study, underwent the Digital Brain Function Screen (DBFS) test as well as the Montreal Cognitive Assessment (MoCA) test and 73 subjects took the Mini-Mental State Examination (MMSE) test. DBFS test and retest was taken by 16 subjects. The test scores of DBFS tool showed significant positive correlation with MoCA and MMSE test scores. In conclusion, the DBFS tool could be an effective digital tool which can overcome the disadvantages of traditional tools of screening MCI like MoCA and MMSE.

The prevalence of sarcopenic obesity and its relationship with type 2 diabetes in a nursing home.

Diabetes mellitus (DM), sarcopenia, and sarcopenic obesity (SO) in the elderly were related to frailty, morbidity, and mortality. The aim of this study was to determine the contribution of diabetes mellitus to the prevalence of SO in a nursing home residents. This cross-sectional study included 397 old-aged (≥65 years) nursing home residents dwelling in Darulaceze Directorate Kayısdagı Campus of Istanbul. Exclusion criteria included <65 years of age, residing for less than a month, acute medical problems, and severe cognitive impairment (mini-mental state examination test score ≤10). Demographic characteristics, anthropometric measurements, nutritional status, and handgrip strength were evaluated for each participant. Sarcopenia was defined according to the European Working Group on Sarcopenia in Older People (EWGSOP) II criteria and obesity was defined with body mass index (BMI) ≥30 kg/m2. SO was the concomitant existence of sarcopenia and obesity together. Mean age of the participants was 77.95±7.94 (65-101) years (n=397). The prevalence of probable sarcopenia was significantly higher in non-obese patients when compared to obese (48.1% vs. 29.3%, p=0.014), which was similar after the exclusion of malnourished residents. In DM patients (n=63), the prevalence of obesity, probable sarcopenia and sarcopenic obesity were 30.2%, 42.2%, and 13.3%, which were 20.4%, 43.2%, and 6.5% in non-DM residents, respectively. Although they did not reach statistical significance, obesity and sarcopenic obesity were more prevalent among diabetic patients in a nursing home.

Predicting Mini-Mental State Examination Scores Using Electroencephalography Signal Features

Purpose: The purpose of this study is to use linear and non-linear features extracted from Electroencephalography (EEG) signal to predict the Mini-Mental State Examination (MMSE) test score by machine learning algorithms.&#x0D; Materials and Methods: First, the MMSE test was taken from 20 subjects that were referred with the initial diagnosis of dementia. Then, the brain activity of subjects was recorded via EEG signal. After preprocessing this signal, various linear and non-linear features are extracted from it that are used as input to machine learning algorithms to predict MMSE test scores in three levels.&#x0D; Results: Based on the experiments, the best classification result is related to the Long Short-Term Memory (LSTM) network with 68% accuracy.&#x0D; Conclusion: Findings show that by using machine learning algorithms and features extracted from EEG signal the MMSE scores are predicted in three levels. Although deep neural networks require a lot of data for training, the LSTM network has been able to achieve the best performance. By increasing the number of subjects, it is expected that the classification results will also increase.

The Association Between Cancer and Alzheimer's-Type Neuropathology: A Community-Based Cohort Study

Background: Cancer and Alzheimer's disease are common diseases in aging populations. Intriguingly, prior research has reported a lower incidence of Alzheimer's disease dementia among individuals with a history of cancer. Both are prevalent and lethal conditions. The current study was conducted to investigate the association of cancer history with neuropathological and cognitive features. Methods: Data were drawn from elderly, longitudinally evaluated participants in a community-based cohort study of aging and dementia who came to autopsy at the University of Kentucky Alzheimer's Disease Research Center. The data were linked to the Kentucky Cancer Registry, which is a population-based state cancer surveillance system, to obtain cancer-related data. We examined the relationship between cancer history, clinical dementia diagnoses, Mini-Mental State examination test scores, and neuropathological features using inverse probability weighting to address confounding and selection bias. Results: Included participants (n = 785) had a mean ±SD age of death of 83.8 ±8.6 years; 60.1% were female. Positive cancer history was determined in 190 (24.2%) participants. The prevalence of at least one APOE ε4 allele was lower among participants with cancer history compared to cancer-free participants (32.6% vs 42.0%, P = 0.0063). Participants with cancer history had lower odds of MCI/Dementia, and higher cognitive test scores (e.g., comparing MMSE scores evaluated at six and &amp;lt; two years prior to death., P &amp;lt; 0.001). Cancer history was also associated with reduced odds of intermediate (III/IV) or severe (V/VI) Braak Neurofibrillary tangle stages, moderate/frequent neuritic plaques, moderate/frequent diffuse plaques, and moderate/severe cerebral amyloid angiopathy (all P&amp;lt;0.05). By contrast, TDP-43, √é±-synuclein, and cerebrovascular pathologies were not associated with cancer history. Conclusion: In this study, we showed that cancer history was associated with a lower burden of Alzheimer's disease pathology and clinical dementia. These findings provide an additional basis of support for prior epidemiological research reporting a protective association between cancer and Alzheimer's disease-type dementia.

Effect of low-level laser therapy (LLLT) on cognitive impairment among patients with chronic schizophrenia: a double-blind randomized placebo-controlled clinical trial.

Low-level laser therapy (LLLT) is a noninvasive technique used in different medical fields. It has been applied in different medical areas such as wound healing, traumatic brain injuries, neurological disorders, cognitive disorders, Alzheimer's disease, pain, and arthritis, with different results. We studied the effectiveness of LLLT on cognitive impairment in patients with chronic schizophrenia. A randomized controlled double-blind clinical trial was performed in a men's chronic treatment center, in Razi Psychiatric Hospital, in Tehran, Iran. We screened the cognitive impairment by Mini-Mental State Examination (MMSE). Positive And Negative Syndrome Scale (PANSS) was also used to assess the patients' positive and negative symptoms. Seventeen consenting patients were randomly allocated to the treatment arm, and 15 to the sham treatment control arm. The mean age of the control and treated patients was 49.47 ± 6.99 and 50.24 ± 7.69, respectively. No significant difference in PANSS and MMSE test scores was detected in both groups after the 6th session and after 2months of follow-up after laser therapy. The positive and negative scales and agitation and excitement levels did not change significantly in either group. Nevertheless, the depression/anxiety subscale in the PANSS test showed a significant reduction after 6 sessions but did not persist after 2months. No improvement in cognitive impairment or the positive and negative symptoms was detected after LLLT in patients with chronic schizophrenia. Trial registration: IRCT 20210520051349N1.

An elaborative NMR based plasma metabolomics study revealed metabolic derangements in patients with mild cognitive impairment: a study on north Indian population.

Mild cognitive impairment (MCI) is transition phase between cognitive decline and dementia. The current study aims to investigate altered metabolic pattern in plasma of MCI for potential biomarkers. MCI (N= 50) and healthy controls (HC, N = 50) age group 55-75years were screened based on Mini Mental State Examination Test (MMSE) and diffusion tensor imaging (DTI imaging). The MMSE score of MCI was significantly lower (25.74 ± 1.83) compared to healthy control subjects (29 ± 1). The MCI patients exhibit significant changes in white matter integrity in the right frontal lobe, right temporal lobe, left frontal lobe, forcep major, fornix, corpus callosum. Further, the plasma samples of twenty seven MCI patients (N= 27) and twenty HC subjects (N= 20; having no significant differences in any demographics) were analyzed using 1H NMR based metabolomics approach. Consistent with many previous reports, the levels of several plasma metabolites were found to be elevated in MCI patients compared to healthy controls. Further univariate and multivariate ROC curve analyses provided three plasma metabolites as a diagnostic panel of biomarker for MCI; which are lysine, glycine, and glutamine. Overall, the results of this study will help to improve the diagnostic and prognostic strategies of MCI in addition to improving our understanding about disease pathogenesis. We believe that the over-nutritional metabolic phenotype of MCI needs to be targeted for developing future dietary interventions so that the progression of MCI can be limited. Metabolic derangements associated with Mild Cognitive Impairment.

Cognitive impairment related to arterial stiffness in cardiovascular disease patients with severe periodontitis

Severe periodontal disease (SPD) associated with systemic peripheral inflammation, cognitive impairment (CI) and arterial stiffness (AS) has been recognized. The aim of this study was to investigate whether CI and arterial stiffness (AS) occur in cardiovascular disease (CVD) patients with SPD. A crosssectional case-control study included hospitalized patients with CVD. Demographic characteristics, CVD and atherogenic risk factors were recorded. SPD was diagnosed by clinical and radiographic dental examinations. Dental clinical attachment level (CAL) and CAL % were recorded. A Mini-Mental State Examination test (MMSE) assessed cognition, a MMSE score of &lt; 27 was set as the cut-off point of CI; a score ≥ 27 was considered as no CI. Patients were categorized into: MMSE&lt; 27 in the three models. The risk of having MMSE &lt; 27 increased an average of 2.404-fold for each 1-unit increase in PWV. SPD and AS had significant and independent associations on the risk for development CI. MMSE negatively correlated with CAL% (r=0.69) and PWV (r=0.70). PWV positively correlated with CAL% (r=0.67). Serum VCAM-1 levels were higher in SPD with lower MMSE scores. In conclusion, SPD increases the risk of development of cognitive decline in CVD patients. PWV was directly associated with the risk of cognitive decline. These findings denote a significant opportunity to improve periodontal health in order to avert CI in CVD patients.

Cognitive impairment screening using m-health: an android implementation of the mini-mental state examination (MMSE) using speech recognition.

This paper describes an implementation of an Android application that allows cognitive functions to be tested. The application consists of a slightly modified Mini Mental state Examination (MMSE) test that provides examiner assistance in diagnosing cognitive impairments. The application deploys speech recognition techniques to allow easy and automated scoring of the test. The test results and test-related information are stored in a database providing easy access to data for follow-up and analysis, resulting in overall benefits to the examiner workflow. A small-scale pilot study of 5 months duration was conducted in a nursing home where 15 residents were tested with the MMSE app test and with the (paper) MMSE test with the aim of determining the agreement between the two test methods. The final MMSE test scores, with a maximum score of 30, agree; the differences have a mean of 0.1, a standard deviation of 2.1 and fall in a [- 4, + 4] range as is illustrated in a Bland-Altman analysis. From examiner reflections, the motoric skills of the participant are indicated to contribute strongly to the time benefit of the assessment itself. The findings of this study suggest that the mobile digital version of the slightly modified MMSE test has the potential to be used as an attractive alternative for the conventional paper version of the test.

Tau Protein in Oral Mucosa and Cognitive State: A Cross-sectional Study.

Neurodegenerative diseases are characterized by the presence of abnormal aggregates of proteins in brain tissue. Among them, the presence of aggregates of phosphorylated Tau protein (p-Tau) is the hallmark of Alzheimer’s disease (AD) and other major neurodegenerative disorders such as corticobasal degeneration and frontotemporal dementia among others. Although Tau protein has previously been assumed to be exclusive to the central nervous system, it is also found in peripheral tissues. The purpose of this study was to determine whether there is a differential Tau expression in oral mucosa cells according to cognitive impairment. Eighty-one subjects were enrolled in the study and classified per Mini-Mental State Examination test score into control, mild cognitive impairment (MCI), and severe cognitive impairment (SCI) groups. Immunocytochemistry and immunofluorescence revealed the presence of Tau and four p-Tau forms in the cytoplasm and nucleus of oral mucosa cells. More positivity was present in subjects with cognitive impairment than in control subjects, both in the nucleus and cytoplasm, in a speckle pattern. The mRNA expression of Tau by quantitative real-time polymerase chain reaction was higher in SCI as compared with the control group (P < 0.01). A significantly higher percentage of immunopositive cells in the SCI group was found via flow cytometry in comparison to controls and the MCI group (P < 0.01). These findings demonstrate the higher presence of p-Tau and Tau transcript in the oral mucosa of cognitively impaired subjects when compared with healthy subjects. The feasibility of p-Tau quantification by flow cytometry supports the prospective analysis of oral mucosa as a support tool for screening of proteinopathies in cognitively impaired patients.

Quality of recovery after anaesthesia measured with QoR-40: a prospective observational study

QoR-40, a 40-item questionnaire on quality of recovery from anaesthesia, has been shown to measure health status after surgery. Our aim was to evaluate the incidence of poor quality of recovery in our Post Anaesthesia Care Unit and to compare their QoR-40 scores before surgery and 3 months later. A prospective observational study was conducted in adult patients consecutively admitted from 18 June to 12 July 2012. The follow-up period was 3 months. We exclude patients submitted to cardiac surgery, neurosurgery, obstetric surgery and with a mini-mental state examination test score lower than 25. The primary endpoint was quality of recovery measured with the validated Portuguese for Portugal version of the QoR-40 before surgery (T0), 24h after surgery (T1) and 3 months after (T2). A total of 114 patients completed the study. Mean QoR-40 score was 169 and patients with poor quality of recovery were identified if their QoR-40 score was lesser than 142. This occurred in 26 patients (24%). Global median scores for patients with poor quality of recovery were lower at T0 (121 vs. 184, p<0.001), at T1 (120 vs. 177, p<0.001) and at T2 (119 vs. 189, p<0.001). Patients with poor quality of recovery had lower quality of life. This fact may allow earlier and more effective interventions, in order to improve quality of life after surgery. Beside its utility after surgery, QoR-40 may be important prior to surgery to identify patients who will develop a poor quality of recovery.

Quality of recovery after anaesthesia measured with QoR-40: a prospective observational study

BackgroundQoR-40, a 40-item questionnaire on quality of recovery from anaesthesia, has been shown to measure health status after surgery. Our aim was to evaluate the incidence of poor quality of recovery in our Post Anaesthesia Care Unit and to compare their QoR-40 scores before surgery and 3 months later. MethodsA prospective observational study was conducted in adult patients consecutively admitted from 18 June to 12 July 2012. The follow-up period was 3 months. We exclude patients submitted to cardiac surgery, neurosurgery, obstetric surgery and with a mini-mental state examination test score lower than 25. The primary endpoint was quality of recovery measured with the validated Portuguese for Portugal version of the QoR-40 before surgery (T0), 24h after surgery (T1) and 3 months after (T2). ResultsA total of 114 patients completed the study. Mean QoR-40 score was 169 and patients with poor quality of recovery were identified if their QoR-40 score was lesser than 142. This occurred in 26 patients (24%). Global median scores for patients with poor quality of recovery were lower at T0 (121 vs. 184, p<0.001), at T1 (120 vs. 177, p<0.001) and at T2 (119 vs. 189, p<0.001). ConclusionPatients with poor quality of recovery had lower quality of life. This fact may allow earlier and more effective interventions, in order to improve quality of life after surgery. Beside its utility after surgery, QoR-40 may be important prior to surgery to identify patients who will develop a poor quality of recovery.

Assessing cognitive changes in the elderly: Reliable Change Indices for the Mini‐Mental State Examination

The diagnosis of dementia includes evidence of decline in cognitive functioning over time measured by objective cognitive tasks. Normative data for changes adjusted for the impact of socio-demographic factors on cognitive test performance are lacking to interpret changes in Mini-Mental State Examination (MMSE) test scores. As part of the German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe Study), a sample of 1090 cognitively healthy individuals, aged 75 years and older, was assessed at 1.5-year intervals over a period of 4.5 years using the MMSE. Age- and education-specific Reliable Change Indices (RCIs) were computed. Age and education were significantly associated with MMSE test performance, and gender indicated no impact. Across different age and education subgroups, changes from at least 2 up to 3 points indicated significant (i.e., reliable) changes in MMSE test scores at the 90% confidence level. Furthermore, the calculation of RCIs for individual patients is demonstrated. This study provides age- and education-specific MMSE norms based upon RCI methods to interpret cognitive changes in older age groups. The computation of RCI scores improves the interpretation of changes in MMSE test scores by controlling for measurement error, practice effects, or regression to the mean.

AMACR mutations cause late-onset autosomal recessive cerebellar ataxia

Progressive cerebellar disorders presenting in late middle age often have a structural, toxic, inflammatory, or endocrine basis. Having excluded these causes, many patients are given a clinical diagnosis of multiple systems atrophy type C, or idiopathic late-onset cerebellar ataxia, and not investigated further. Here we describe a sporadic cerebellar syndrome leading to the diagnosis of a rare metabolic disorder with important implications for treatment. ### Case report. A 58-year-old man presented with an 8-year history of gait unsteadiness, slurred speech, a few tonic/clonic seizures, and a decline in short-term memory. There was no relevant family history or consanguinity. On examination, he had a cerebellar dysarthria with appendicular and gait ataxia. Deep tendon reflexes were preserved, and plantar responses flexor. His Mini-Mental State Examination test score was 19/23 at 51 years of age, and 21/30 at age 58, with an Addenbrooke cognitive assessment of 61/100. Routine hematology, thyroid function, vitamin E, B12, and copper studies were normal. CSF examination revealed normal protein content, cell count, and no oligoclonal bands. Urinary amino and organic acids, hexosaminidase, and acylcarnitines were normal. Echocardiography was normal. An EEG showed a mild generalized …

Higher Serum Vitamin D3 Levels Are Associated with Better Cognitive Test Performance in Patients with Alzheimer’s Disease

Background/Aims: Recent studies suggest that vitamin D metabolites may be important for preserving cognitive function via specific neuroprotective effects. No large studies have examined the association between vitamin D status and cognition. Methods: In this cross-sectional study, we analyzed the serum 25-hydroxyvitamin D₃ levels and Mini-Mental State Examination (MMSE) test scores of 225 older outpatients who were diagnosed as having probable Alzheimer’s disease (AD). In addition to the 25-hydroxyvitamin D₃ levels, we analyzed the serum vitamin B₁, B₆ and B₁₂ levels. Results: An association was found between MMSE test scores and serum 25-hydroxyvitamin D₃ levels, with a β-coefficient of 0.05 (p = 0.01). Vitamin-D-sufficient patients had significantly higher MMSE scores as compared to vitamin-D-insufficient ones. No association was found with the other serum vitamin levels. Conclusions: These data support the idea that a relationship exists between vitamin D status and cognition in patients with probable AD. However, given the cross-sectional design of this study, no causality can be concluded. Further prospective studies are needed to specify the contribution of vitamin D status to the onset and course of cognitive decline and AD.

Cognitive and emotional changes in neurobrucellosis

To determine cognitive and emotional changes among neurobrucellosis patients. The patients with neurobrucellosis and controls with brucellosis without neurologic involvement were included in the study. Neurobrucellosis was diagnosed by the following criteria: (i) symptoms or clinical findings compatible with neurobrucellosis, including headache, confusion, mental and emotional changes; (ii) isolation of Brucella spp. from CSF and/or demonstration of antibodies to Brucella > or = 1/4 in the CSF; (iii) the presence of lymphocytosis, increased protein and decreased glucose levels in the CSF; and (iv) clinical improvement with appropriate treatment. Two psychiatrists interviewed the patients, and performed the Hamilton Depression Rating Scale (HDRS) tests and Mini-Mental State Examination (MMSE) tests. Thirty-four neurobrucellosis cases and 30 patients with brucellosis without neurological involvement were studied. The mean age was 41 years, 12 (41%) patients were female, 13 (46%) patients were farmers, and 7 (25%) patients were housewives. Among the neurobrucellosis cases, before the antibiotic therapy, the mean MMSE test score was 21.6, one week after the therapy 22.7, and two weeks after the therapy 24.3 (p=0.024, and p<0.001, respectively). At the day of admission before therapy, the mean of HDRS test was 9.9, one week after therapy it was 7.8, and two weeks after therapy it was 5 (p=0.014, and p<0.001, respectively). The cognitive and emotional disturbances among neurobrucellosis patients were documented by MMSE and HDRS tests. These disorders improve by antibiotic therapy, without any anti-depressive or anti-psychotic therapy.

Psychometric Properties of the Folstein Mini-Mental State Examination

Criterion-referenced (Livingston) and norm-referenced (Gilmer-Feldt) techniques were used to measure the internal consistency reliability of Folstein's Mini-Mental State Examination (MMSE) on a large sample (N = 418) of elderly medical patients. Two administration and scoring variants of the MMSE Attention and Calculation section (Serial 7s only and WORLD only) were investigated. Livingston reliability coefficients (rs) were calculated for a wide range of cutoff scores. As necessary for the calculation of the Gilmer-Feldt r, a factor analysis showed that the MMSE measures three cognitive domains. Livingston's r for the most widely used MMSE cutoff score of 24 was .803 for Serial 7s and .795 for WORLD. The Gilmer-Feldt internal consistency reliability coefficient was .764 for Serial 7s and .747 for WORLD. Item analysis showed that nearly all of the MMSE items were good discriminators, but 12 were too easy. True score confidence intervals should be applied when interpreting MMSE test scores.

Cognitive status correlates with neuropathologic stage in Parkinson disease

To study the association of cognitive status with the stages of a published neuropathologic staging procedure for sporadic Parkinson disease (PD) in a cohort of 88 patients with PD from a single neurologic unit. None had received the clinical diagnosis of dementia with Lewy bodies (DLB). The authors assessed Lewy neurites/bodies (LNs/LBs) immunoreactive for alpha-synuclein semiquantitatively in sections from 18 brain regions. In silver-stained sections and sections immunostained for tau and beta-amyloid protein, the authors semiquantitatively evaluated comorbidities potentially contributing to cognitive decline, e.g., Alzheimer disease (AD), argyrophilic grain disease (AGD), and cerebral vascular disease. The authors analyzed four Mini-Mental State Examination (MMSE) subgroups ranging from marginally impaired cognition to severe dementia using nonparametric tests. It was possible to assign all patients to one of the PD stages. MMSE scores correlated with neuropathologic stages (p < 0.005) and this association showed a linear trend (p < 0.025). Median MMSE test scores for women were lower than those for men. Cognitively impaired individuals displayed higher stages of AD-related neurofibrillary pathology (p < 0.05) and beta-amyloid deposition (p < 0.05) than cognitively unimpaired persons. MMSE scores did not correlate significantly with AGD, disease duration, age at disease onset, or age at death. Hoehn and Yahr scores, however, correlated with PD stages (p < 0.0005) and MMSE scores (p < 0.0005). The decrease in median Mini-Mental State Examination scores between PD stages 3 to 6 indicates that the risk of developing dementia increases with disease progression. In some individuals, however, cognitive decline can develop in the presence of mild Parkinson disease-related cortical pathology and, conversely, widespread cortical lesions do not necessarily lead to cognitive decline.

Pain threshold and tolerance in Alzheimer's disease

We tested both pain thresholds and pain tolerance in patients with Alzheimer's disease (AD) by means of phasic and tonic noxious stimuli. In the first case, electrical stimulation was used, whereas in the second case arm ischemia was studied. By comparing AD patients with normal subjects of the same age, we found no differences in stimulus detection and pain thresholds, whereas a clearcut increase in pain tolerance was present in AD patients. The severity of AD was assessed by means of the Mini Mental State Examination test (MMSE) and the spectral analysis of the electroencephalogram (EEG). There was a straightforward correlation between MMSE scores and pain tolerance such that the more severe the cognitive impairment the higher the tolerance to pain. In addition, analysis of the EEG power spectra indicated that patients with low alpha and high delta peaks showed an increase in pain tolerance to both electrical stimulation and ischemia. These findings show that, whereas the sensory-discriminative component of pain is maintained in AD patients, pain tolerance is altered and depends on cognitive and affective factors. Thus, pain tolerance is tightly related to the severity of the disease according to the rule, `the more severe the MMSE and EEG changes, the higher the tolerance to pain'.