Brain areas that are involved in cognition and mood also play a role in pain processing. This present study examined the relationship between chronic pain and cognition (executive functions and memory), while controlling for mood, in cognitively intact older persons and in patients with early Alzheimer' s disease who suffered from arthrosis/arthritis.
Pain intensity and pain affect were assessed by the Colored Analogue Scale for Pain Intensity and for Pain Affect, the Faces Pain Scale (FPS) and the Number of Words Chosen-Affective. Level of depression and anxiety were evaluated by questionnaires. Executive functions and memory were assessed by neuropsychological tests.
There were no significant correlations between specific cognitive functions, pain intensity and pain affect were lacking in the cognitively intact older persons. Cognition, in particular memory, appeared to be related to depressive symptoms. In contrast, a significant positive correlation was observed between executive functions, pain intensity and pain affect measured by the Faces Pain Scale in the Alzheimer' s disease group. It was concluded that although older persons with depression were excluded, in studies on pain and cognition one should control for the presence of depressive symptoms in older persons with and without dementia. (Scherder EJ, Eggermont L, Plooij B, Oudshoorn J, Vuijk PJ, Pickering G, Lautenbacher S, Achterberg W, Oosterman J: Relationship between chronic pain and cognition in cognitively intact older persons and in patients with Alzheimer' s disease. The need to control for mood. Gerontology. 54(1):50-8, 2008).
This study evaluated the validity of traditional pain behaviors (guarding, bracing, rubbing, grimacing, and sighing) in persons with and without cognitive impairment and chronic low back pain.
Thirty-seven cognitively intact and 40 cognitively impaired participants with and without chronic low back pain were studied. Forty-six of the participants were pain free, and 31 had chronic low back pain.Participants with chronic low back pain exhibited significantly higher levels of grimacing and guarding than pain-free participants. Intact subjects exhibited fewer guarding and rubbing behaviors but a higher number of bracing behaviors than cognitively impaired participants.
These results support the utility of facial grimacing in assessing pain in patients with mild to moderate cognitive impairment and call into question the validity of guarding and rubbing in assessing pain in persons with mild to moderate cognitive impairment. (Shega JW, Rudy T, Keefe FJ, Perri LC, Mengin OT, Weiner DK: Validity of pain behaviors in persons with mild to moderate cognitive impairment. Journal of the American Geriatrics Society. 56(9):1631-7, 2008).