Psychiatric diagnoses and cognitive impairment in pediatric multiple sclerosis.

BACKGROUND: Pediatric multiple sclerosis (MS) represents approximately 5% of the MS population; information regarding clinical features is slowly accumulating. Cognitive and psychiatric impairments frequently occur, but remain poorly understood. OBJECTIVES: To describe psychiatric diagnoses among children with MS referred for psychiatric assessment and their relation to cognitive impairment. METHODS: Forty-five pediatric MS patients (aged 8 to 17 years) were referred for outpatient psychiatric evaluation including a psychiatric interview (K-SADS), a clinician-based global assessment of functioning (Children's Global Assessment Scale, CGAS), a neurologic examination including the Expanded Disability Status Scale (EDSS), and a neuropsychological test battery. RESULTS: The most common categories of psychiatric diagnoses were anxiety disorders (n=15), attention deficit hyperactivity disorder (ADHD, n=12), and mood disorders (n=11). Cognitive impairment was classified in 20/25 (80%) of patients meeting criteria for a psychiatric disorder versus 11/20 (55%) of those without psychiatric disorder (p=0.08). Those diagnosed with anxiety or mood disorder had the highest frequency of cognitive impairment, with a significantly higher rate when compared with those with psychiatric diagnoses in other categories (p=0.05). CONCLUSIONS: A variety of psychiatric diagnoses can occur in children with pediatric MS. Many of these children also had cognitive impairment, particularly those in the mood and anxiety groups.

Metabolomic approach to human brain spectroscopy identifies associations between clinical features and the frontal lobe metabolome in multiple sclerosis.

Proton magnetic resonance spectroscopy ((1)H-MRS) is capable of noninvasively detecting metabolic changes that occur in the brain tissue in vivo. Its clinical utility has been limited so far, however, by analytic methods that focus on independently evaluated metabolites and require prior knowledge about which metabolites to examine. Here, we applied advanced computational methodologies from the field of metabolomics, specifically partial least squares discriminant analysis and orthogonal partial least squares, to in vivo (1)H-MRS from frontal lobe white matter of 27 patients with relapsing-remitting multiple sclerosis (RRMS) and 14 healthy controls. We chose RRMS, a chronic demyelinating disorder of the central nervous system, because its complex pathology and variable disease course make the need for reliable biomarkers of disease progression more pressing. We show that in vivo MRS data, when analyzed by multivariate statistical methods, can provide reliable, distinct profiles of MRS-detectable metabolites in different patient populations. Specifically, we find that brain tissue in RRMS patients deviates significantly in its metabolic profile from that of healthy controls, even though it appears normal by standard MRI techniques. We also identify, using statistical means, the metabolic signatures of certain clinical features common in RRMS, such as disability score, cognitive impairments, and response to stress. This approach to human in vivo MRS data should promote understanding of the specific metabolic changes accompanying disease pathogenesis, and could provide biomarkers of disease progression that would be useful in clinical trials.

Multiple white matter tract abnormalities underlie cognitive impairment in RRMS.

Diffusion tensor imaging (DTI) is a sensitive tool for detecting microstructural tissue damage in vivo. In this study, we investigated DTI abnormalities in individuals with relapsing remitting multiple sclerosis (RRMS) and examined the relations between imaging-based measures of white matter injury and cognitive impairment. DTI-derived metrics using tract-based spatial statistics (TBSS) were compared between 37 individuals with RRMS and 20 healthy controls. Cognitive impairment was assessed with three standard tests: the Symbol Digit Modalities Test (SDMT), which measures cognitive processing speed and visual working memory, the Rey Auditory Verbal Learning Test (RAVLT), which examines verbal memory, and the Paced Auditory Serial Addition Test (PASAT), which assesses sustained attention and working memory. Correlations between DTI-metrics and cognition were explored in regions demonstrating significant differences between the RRMS patients and the control group. Lower fractional anisotropy (FA) was found in RRMS participants compared to controls across the tract skeleton (0.40 ± 0.03 vs. 0.43 ± 0.01, p<0.01). In areas of reduced FA, mean diffusivity was increased and was dominated by increased radial diffusivity with no significant change in axial diffusivity, an indication of the role of damage to CNS myelin in MS pathology. In the RRMS group, voxelwise correlations were found between FA reduction and cognitive impairment in cognitively-relevant tracts, predominantly in the posterior thalamic radiation, the sagittal stratum, and the corpus callosum; the strongest correlations were with SDMT measures, with contributions to these associations from both lesion and normal-appearing white matter. Moreover, results using threshold-free cluster enhancement (TFCE) showed more widespread white matter involvement compared to cluster-based thresholding. These findings indicate the important role for DTI in delineating mechanisms underlying MS-associated cognitive impairment and suggest that DTI could play a critical role in monitoring the clinical and cognitive effects of the disease.

Pediatric multiple sclerosis: what we know and where are we headed?

Multiple Sclerosis (MS), an autoimmune mediated disease of the central nervous system, has historically been considered a disease of young adulthood. However, there has been increasing recognition that the disease can occur in adolescence and even early childhood and recent years have witnessed a surge of studies documenting the clinical features of the disease as it pertains to this young population. The purpose of this article is to review the literature on MS in childhood and adolescence, including the clinical presentation of the disease in this group, neuropathology and pathogenesis, magnetic resonance imaging findings, as well as neuropsychological and psychosocial considerations.

Cognitive impairment occurs in children and adolescents with multiple sclerosis: results from a United States network.

In the largest sample studied to date, we measured cognitive functioning in children and adolescents with pediatric multiple sclerosis (n = 187) as well as those with clinically isolated syndrome (n = 44). Participants were consecutively enrolled from six United States Pediatric Multiple Sclerosis Centers of Excellence. Participants had a mean of 14.8 ± 2.6 years of age and an average disease duration of 1.9 ± 2.2 years. A total of 65 (35%) children with multiple sclerosis and 8 (18%) with clinically isolated syndrome met criteria for cognitive impairment. The most frequent areas involved were fine motor coordination (54%), visuomotor integration (50%), and speeded information processing (35%). A diagnosis of multiple sclerosis (odds ratio = 3.60, confidence interval = 1.07, 12.36, P = .04) and overall neurologic disability (odds ratio = 1.47, confidence interval = 1.10, 2.10, P = .03) were the only independent predictors of cognitive impairment. Cognitive impairment may occur early in these patients, and prompt recognition is critical for their care.

Multiple sclerosis-associated fatigue.

Fatigue is an extremely prevalent issue for multiple sclerosis (MS) patients. Fatigue can affect quality of life, depression, anxiety, motor function and sleep patterns. There are a number of available rating scales designed to detect and assess fatigue. However, the pathophysiology of fatigue is still not completely understood and the treatment of this symptom remains difficult. A number of clinical trials for fatigue in MS have shown some benefit with different interventions, including medication, physical activity and cognitive-behavioral therapy. Nonetheless, further research and the development of more targeted therapies are needed to improve the management of fatigue.