Reduced neuropsychologic measures as predictors of treatment outcome in patients with temporomandibular disorders

Aims: To determine via a prospective investigation whether the presence of neuropsychologic or cognitive deficiencies could be identified in patients with temporomandibular disorders (TMD) and used to predict treatment outcom e. This was based on the theory that measurable reductions in neuropsycholo gic and cognitive function might have a negative impact on treatment outcom e in patients with essentially nontraumatic TMD, as has been shown for pati ents with posttraumatic TMD. Methods: Various neuropsychologic, psychosocia l, and clinical parameters (including but not limited to the Peterson-Peter son Consonant Trigram Test and the California Verbal Learning Test) were us ed to pretest patients suffering from TMD prior to treatment. Patients were then entered into treatment, after which determination of treatment succes s was made both by the use of visual analog scales for pain and global tran sitional outcome measures (eg, "better," responders versus "same/worse," no nresponders). After determination of treatment success was made, treatment response was correlated with the various clinical, cognitive, and neuropsyc hologic test scores. Results: Overall, the nonresponders did worse in both the neuropsychologic and psychosocial assessments, with greater memory defi cits, sleep disturbances, depression, and fatigue and lower energy levels a s compared to responders. Among the best predictors of treatment outcome we re the Peterson-Peterson Consonant Trigram Test scores as well as the score s on the California Verbal Learning Test (ie, poorer test outcomes predicte d nonresponse). Neither responders nor nonresponders could be distinguished from one another based on clinical parameters of maximum interincisal open ing or muscle tenderness. Three psychosocial variables were also found to b e predictors of Poor outcome: sleep disturbance, fatigue, and income. Pretr eatment pain on chewing was also found to be a reliable predictor of poor t reatment outcome. Conclusion: We conclude that various neuropsychologic, ps ychosocial, and some clinical parameters may provide pretreatment predictio n of treatment outcome in an idiopathic TMD population.