Influence of personality on the relationship between gray matter volume and neuropsychiatric symptoms in multiple sclerosis.

OBJECTIVE: Research has revealed an association between personality traits and health outcomes, and in multiple sclerosis (MS), there are preliminary data showing a correlation between personality traits and brain volume. We examined the general hypothesis that personality influences the relationship between gray matter volume (GMV) and cognitive/neuropsychiatric MS features. METHODS: Participants were 98 patients with MS who underwent magnetic resonance imaging and were tested with the Symbol Digit Modalities Test and the Neuropsychiatric Inventory, the latter providing measures of depression and euphoria that can be characteristic of MS, that is, cheerful indifference and disinhibition. Personality traits were assessed with the NEO Five Factor Inventory. We examined the correlation between personality traits and both GMV and symptoms, and then modeled mediation and moderation influences on the relationships between GMV and cognitive/neuropsychiatric features. RESULTS: Linear regression modeling revealed that GMV (r = 0.54, p < .001) and NEO Five Factor Inventory low conscientiousness (r = 0.36, p = .001) were associated with cognitive function, but no mediator or moderator effects were observed. However, conscientiousness mediated the relationship between GMV and symptoms of euphoria (p = .002). The moderator analysis revealed a significant influence of high neuroticism on the GMV-euphoria relationship (p = .029). CONCLUSIONS: Low conscientiousness and high neuroticism are associated with neuropsychiatric complications in MS, and each influences the relationship between GMV and euphoria. The findings suggest that patients with low conscientiousness are at higher risk for MS-associated cognitive dysfunction and neuropsychiatric symptoms, a conclusion that has implications for the emerging role of personality in clinical neuroscience.

Cognitive impairment is associated with reduced bone mass in multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) has been associated with reduced bone mineral density (BMD), yet the underlying causes are not fully known. The recent discovery that bone homeostasis is directly regulated by the brain led us to hypothesize that it may be impaired by MS pathology. As cognitive impairment (CI) is a well-documented correlate of MS-related brain pathology, we tested the hypothesis that it is associated with reduced BMD. OBJECTIVE: We aimed to determine if CI is associated with reduced BMD in patients with MS. METHODS: We retrospectively studied the medical records of 56 patients with MS, ≤50 years old, with Expanded Disability Status Scale score ≤4.5 and with dual X-ray absorptiometry (DEXA) BMD measurement within 1 year of neuropsychological testing with a standard battery (MACFIMS). RESULTS: In total, 23 (41.1%) MS patients had osteopenia or osteoporosis. Mean femur BMD was significantly lower in patients with MS with CI (0.89±0.12 g/cm(2)) compared with intact patients (0.99±0.17 g/cm(2), p=0.009). In the cognitively impaired group, 59.3% had either osteopenia or osteoporosis, compared with 24.1% in the non-cognitively impaired group (odds ratio=4.57, p=0.008). CONCLUSION: CI is associated with reduced BMD in patients with MS, suggesting that central mechanisms involved in bone homeostasis may be directly impaired by MS-related inflammatory and neurodegenerative processes.

Outcome of intracranial electroencephalography monitoring and surgery in magnetic resonance imaging-negative temporal lobe epilepsy.

We evaluated the outcomes of intracranial electroencephalography (iEEG) recording and subsequent resective surgery in patients with magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE). Thirty-two patients were identified from the Mayo Clinic Epilepsy Surgery Database (Arizona, Florida, and Minnesota). Eight (25.0%) had chronic iEEG monitoring that recorded neocortical temporal seizure onsets; 12 (37.5%) had mesial temporal seizure onsets; 5 (15.6%) had independent neocortical and mesial temporal seizure onsets; and 7 (21.9%) had simultaneous neocortical and mesial seizure onsets. Neocortical temporal lobe seizure semiology was the only factor significantly associated with neocortical temporal seizure onsets on iEEG. Only 33.3% of patients who underwent lateral temporal neocorticectomy had an Engel class 1 outcome, whereas 76.5% of patients with iEEG-guided anterior temporal lobectomy that included the amygdala and the hippocampus had an Engel class 1 outcome. Limitations in cohort size precluded statistical analysis of neuropsychological test data.

Overall Memory Impairment Identification with Mathematical Modeling of the CVLT-II Learning Curve in Multiple Sclerosis.

The CVLT-II provides standardized scores for each of the List A five learning trials, so that the clinician can compare the patient's raw trials 1-5 scores with standardized ones. However, frequently, a patient's raw scores fluctuate making a proper interpretation difficult. The CVLT-II does not offer any other methods for classifying a patient's learning and memory status on the background of the learning curve. The main objective of this research is to illustrate that discriminant analysis provides an accurate assessment of the learning curve, if suitable predictor variables are selected. Normal controls were ninety-eight healthy volunteers (78 females and 20 males). A group of MS patients included 365 patients (266 females and 99 males) with clinically defined multiple sclerosis. We show that the best predictor variables are coefficients B3 and B4 of our mathematical model B3 ∗ exp(-B2 ∗ (X - 1)) + B4 ∗ (1 - exp(-B2 ∗ (X - 1))) because discriminant functions, calculated separately for B3 and B4, allow nearly 100% correct classification. These predictors allow identification of separate impairment of readiness to learn or ability to learn, or both.

Basal ganglia, thalamus and neocortical atrophy predicting slowed cognitive processing in multiple sclerosis.

Information-processing speed (IPS) slowing is a primary cognitive deficit in multiple sclerosis (MS). Basal ganglia, thalamus and neocortex are thought to have a key role for efficient information-processing, yet the specific relative contribution of these structures for MS-related IPS impairment is poorly understood. To determine if basal ganglia and thalamus atrophy independently contribute to visual and auditory IPS impairment in MS, after controlling for the influence of neocortical volume, we enrolled 86 consecutive MS patients and 25 normal controls undergoing 3T brain MRI and neuropsychological testing. Using Sienax and FIRST software, neocortical and deep gray matter (DGM) volumes were calculated. Neuropsychological testing contributed measures of auditory and visual IPS using the Paced Auditory Serial Addition Test (PASAT) and the Symbol Digit Modalities Test (SDMT), respectively. MS patients exhibited significantly slower IPS relative to controls and showed reduction in neocortex, caudate, putamen, globus pallidus, thalamus and nucleus accumbens volume. SDMT and PASAT were significantly correlated with all DGM regions. These effects were mitigated by controlling for the effects of neocortical volume, but all DGM volumes remained significantly correlated with SDMT, putamen (r = 0.409, p < 0.001) and thalamus (r = 0.362, p < 0.001) having the strongest effects, whereas for PASAT, the correlation was significant for putamen (r = 0.313, p < 0.01) but not for thalamus. We confirm the significant role of thalamus atrophy in MS-related IPS slowing and find that putamen atrophy is also a significant contributor to this disorder. These DGM structures have independent, significant roles, after controlling for the influence of neocortex atrophy.

Cognition and physical disability in predicting health-related quality of life in multiple sclerosis.

Many studies have shown that multiple sclerosis (MS) has a significant impact on patient health-related quality of life (HRQOL), but the relative contributions of physical versus cognitive disability are not well established. Most studies have relied on HRQOL outcomes that depend largely on patient mood, life satisfaction, and personal happiness. The Sickness Impact Profile (SIP) is a measure of HRQOL known for its relatively strong emphasis on task completion and activities of daily living. As such, the SIP may be less influenced by depression. We sought to determine the relative influence of physical disability and cognition, above and beyond demographic and disease variables, in predicting HRQOL. Patients (n = 132) and healthy controls (n = 26) underwent complete neuropsychological evaluation using the Minimal Assessment of Cognitive Function in MS (MACFIMS) battery and a series of self-report measures assessing depression, fatigue, and HRQOL. The SIP was also administered. Correlation analysis and group comparisons revealed significant associations between cognition and HRQOL outcomes. Logistic regression models comparing the Expanded Disability Status Scale (EDSS) and cognitive tests in predicting poor physical HRQOL retained both EDSS and Symbol Digit Modalities Test (SDMT) performance, while models predicting poor psychosocial and poor overall HRQOL retained only the SDMT. These findings support cognition as a significant predictor of overall HRQOL, psychosocial HRQOL, and, interestingly, physical HRQOL.