Pain and Cognition in Multiple Sclerosis

Objective

The goal of the present study was to examine the relationship between pain and cognition in patients with multiple sclerosis.

Design

Cross-sectional.

Setting

Nursing home and personal environment of the investigators.

Subjects

Two groups of participants were included: 91 patients with multiple sclerosis and 80 matched control participants.

Methods

The level of pain was measured by the following pain scales: Number of Words Chosen-Affective, Colored Analogue Scale for pain intensity and suffering from pain, and the Faces Pain Scale. Mood was tested by administering the Beck Depression Inventory and the Symptom Check List-90 anxiety and depression subscale. Global cognitive functioning was assessed by the Mini Mental State Examination. Memory and executive functions were assessed by several neuropsychological tests.

Results

Multiple sclerosis (MS) patients scored significantly lower than control participants on the majority of the neuropsychological tests. The MS patients experienced more pain compared with control participants, despite the fact that they were taking significantly more pain medication. No significant correlation was observed between cognition and pain in MS patients. Verbal working memory explained 10% of pain intensity (trend). Mood appeared to be a significant predictor of pain in patients with multiple sclerosis.

Conclusion

The lack of a relationship between cognition and pain might be explained by the fact that, compared with control participants, patients with multiple sclerosis activate other non-pain-related areas to perform executive functions and memory tasks.

Chronic pain in "probable" vascular dementia: preliminary findings

BACKGROUND

In a previous study, the levels of pain reported by patients with "possible" vascular dementia (VaD) were higher than those reported by older individuals without dementia.

OBJECTIVE

To examine experienced pain in patients with "probable" VaD, confirmed by brain imaging.

STUDY DESIGN

Observational, cross sectional.

SETTING

Nursing home.

METHODS

The participants were 20 nursing home residents (14 females, 6 males) who met the NINDS-AIREN criteria for "probable" VaD and 22 nursing home residents with a normal mental status (18 females, 4 males). The patients were in a mild to moderate stage of dementia. All of the participants were suffering from arthritis/arthrosis or osteoporosis. Global cognitive functioning was measured by the Mini-Mental State Examination. Pain was assessed by the Coloured Analogue Scale (CAS: original and modified version) and the Faces Pain Scale. The Geriatric Depression Scale and the Symptom Checklist-90 were used to assess mood.

RESULTS

The main finding was that, after controlling for mood, the pain levels indicated by patients with "probable" VaD (M = 102.32; standard deviation [SD] = 53.42) were significantly higher than those indicated by the control group (M = 59.17; SD = 38.75), only according to the CAS modified version (F[1,29]) = 5.62, P = 0.01, η2  = 0.16).

CONCLUSION

As VaD patients may experience greater pain than controls, it is essential for prescribers to be aware of the presence of this neuropathology if these patients are to receive adequate treatment.