Influences on cognition by immunosuppression and immunomodulation in multiple sclerosis

The relationship of cognitive impairment with neurological and psychiatric variables in multiple sclerosis patients

OBJECTIVE

Cognitive impairment (CI) in multiple sclerosis (MS) can develop any time. CI is associated with the degree of neuronal loss, but disease duration, fatigue, comorbid affective disorder, and drug dose may also affect cognition. Our aim was to assess which cognitive domain was disturbed primarily in mild MS patients and to see whether CI was related with clinical and psychiatric features.

METHOD

Neurological and psychiatric evaluation of 31 MS patients and 31 age, sex, and education-matched healthy controls were made with Structured Clinical Interview for Axis I Disorders (SCID-I). Depression, anxiety, functionality, fatigue, and disability scoring were determined with Hamilton Depression-Anxiety scales, Global Assessment of Functionality, Fatigue Severity and Expanded Disability Status Scales. Cognitive functions were assessed using Mini Mental, Serial Digit Learning, Verbal and Nonverbal Cancellation, Stroop and Rey Auditory Verbal Learning tests.

RESULTS

Retrieval from long-term memory and psychomotor speed were significantly worse in MS group. CI was correlated with disease duration, number of attacks, and physical disability but not with depression and anxiety severity. Disease duration predicted disturbances in recall and psychomotor speed, whereas fatigue and disability predicted depression.

CONCLUSION

Psychomotor speed and memory were primarily impaired in MS patients, and CI was closely associated with clinical aspects of MS rather than with depression and anxiety.

White matter dementia

White matter dementia (WMD) is a syndrome introduced in 1988 to highlight the potential of cerebral white matter disorders to produce cognitive loss of sufficient severity to qualify as dementia. Neurologists have long understood that such a syndrome can occur, but the dominance of gray matter as the locus of higher function has strongly directed neurobehavioral inquiry to the cerebral cortex while white matter has received less attention. Contemporary neuroimaging has been crucial in enabling the recognition of white matter abnormalities in a host of disorders, and the correlation of these changes with cognitive performance. Comprising about half the brain, white matter is prominently or exclusively involved in well over 100 disorders, in each of which white matter dysfunction can potentially cause or contribute to dementia. Neuropsychological findings from ten categories of white matter disorder lead to a convergence of findings that document remarkable neurobehavioral commonality among the dementias produced. More recently, the syndrome of mild cognitive dysfunction (MCD) has been introduced to expand the concept of WMD by proposing a precursor syndrome related to early white matter neuropathology. WMD and MCD inform the understanding of how white matter contributes to normal and abnormal cognition, and the specific neuroanatomic focus of these syndromes may enhance the diagnosis and treatment of many disabling disorders that do not primarily implicate the cerebral cortex. Forming essential connections within widely distributed neural networks, white matter is critical for rapid and efficient information transfer that complements the information processing of gray matter. As neuroimaging continues to advance, further information on white matter structure can be expected, and behavioral neurology will play a central role in elucidating the functional significance of these emerging data. By emphasizing the contribution of myelinated systems to higher function, the study of white matter and cognition represents investigation of the basic neuroscience of human behavior.

Quality of life in multiple sclerosis: effects of current treatment options

Multiple sclerosis is the most common non-traumatic neurodegenerative disease in adults. Most of the patients present with both physical and mental deficits which reflect the dissemination of the lesions in the central nervous system, produced by the inflammatory process. The incomplete recovery after relapses, the accumulation of new deficits and the progressive nature of the condition interfere with daily activities of individuals and have a negative impact on their well-being. Indeed, studies show that quality of life measurements are constantly lower in patients with multiple sclerosis. Estimation of health-related quality of life is being increasingly recognized as necessary when analysing the effectiveness of treatment modalities and for the follow up of patients with chronic diseases such as multiple sclerosis. Current immunomodulatory interventions that are shown to reduce the frequency of relapses and delay disease progression might also have a positive effect on quality of life measurements. Additive pharmacological agents that target cognitive impairments and common symptoms such as depression, fatigue and pain, along with life-style modifications and rehabilitation programmes are also important for the appropriate management that aims to improve quality of life.