MS research update - 01 January 2010
- Tear fluid test offers alternative to lumbar puncture in CIS
- Brain stimulation techniques improves pain in people with MS
- Slower reaction times due to impaired attention span in MS
Tear fluid test offers alternative to lumbar puncture in CIS
In the case of a clinically islolated syndrome (CIS), the detection of oligoclonal bands (laboratory indicators) in the cerebrospinal fluid (CSF)- the fluid that fills and protects cavities in the brain and spinal cord - can be an important way of determining the likelihood of conversion to clinically definite MS. A lumbar puncture, the method that is used to extract the fluid is quite an invasive and unpleasant procedure.
Previous studies have suggested that oligoclonal bands in people with MS, may be detected in their tear fluid. The present study sought to determine whether oligoclonal bands could be detected with as much sensitivity in the tear fluid of people with CIS as they could be in the cerebrospinal fluid.
Both cerebrospinal fluid and tear fluid was collected for 69 people with CIS. 80% of individuals' samples that tested positive for oligoclonoal bands in the cerebrospinal fluid also tested positive in the tear fluid.
The study authors suggest that tear fluid analysis is highly sensitive to the detection of oligoclonal bands in people with CIS and if used as a preliminary test may make the use of the invasive and unpleasant lumbar puncture test unnecessary.
Calais G, Forzy G, Crinquette C, et al.
Tear analysis in clinically isolated syndrome as new multiple sclerosis criterion.
Multiple Sclerosis 2009; [Epub ahead of print].
Medline abstract
Brain stimulation techniques improves pain in people with MS
Neuropathic pain, or nerve pain, is a symptom commonly experienced by people with MS. There are several brain areas thought to be responsible for neuropathic pain including the motor cortex.
Anodal transcranial direct current stimulation is a brain stimulation technique that uses low amplitude direct currents applied via scalp electrodes to inject currents in the brain and affect the level of cortical activity. The aim of the present study was to determine whether daily sessions of anodal transcranial direct current stimulation applied over the motor cortex may be effective in reducing chronic neuropathic pain in people with MS. Study participants were divided into two groups: one of which received the active treatment; and one of which received a 'sham' treatment, over five consecutive days.
The participants were assessed for levels of pain at the beginning of the study, immediately after the end of treatment, and once a week for the following three weeks. The results of these assessments indicated that the 5-day course of anodal transcranial direct current stimulation, but not the sham treatment, was effective in reducing persistent pain scores. Furthermore, the improvements were seen in the assessments that took place in the three weeks following treatment, suggesting that the effect of the treatment outlasts the period of stimulation. The authors propose that anodal transcranial direct current stimulation might be a viable treatment option when pain medication has proven ineffective.
Mori F, Codeca C, Kusayanagi H, et al.
Effects of anodal transcranial direct stimulation on chronic neuropathic pain in patients with multiple sclerosis.
Journal of pain 2009; [Epub ahead of print].
Medline abstract
Slower reaction times due to impaired attention span in MS
Previous studies have observed slower reaction times in people with MS. There are a variety of factors that may be responsible for action slowing, which may relate to mental, cognitive, perceptual or motor impairment of some degree. The present study sought to determine the mechanisms that account for the slowing of actions. The study involved 20 people with multiple sclerosis and a group of 20 healthy comparators. The study participants took part in two reaction time tests: a simple reaction time test whereby they were prompted to push a button when a letter flashed up on a display screen; and a choice reaction time test whereby they had to base the decision of which of two buttons to press depending on whether the letter appeared on the left or right side of the screen.
The findings showed that simple reaction times were slower when compared against the healthy study participants. However, there was no significant difference between the two groups' reaction times on the choice reaction time test. The authors conclude that action slowing in people with MS is mainly due to attention impairment and subtle motor slowing; and that decision-making is preserved.
Stoquart-Elsankari, Bottin C, Roussel-Pieronne, et al.
Motor and cognitive slowing in multiple sclerosis: an attentional deficit?
Clinical Neurology and Neurosurgery 2009 [Epub ahead of print].
Medline abstract