Validity of the minimal assessment of cognitive function in multiple sclerosis (MACHMS)

Cognitive impairment occurs in roughly 50% of patients with multiple sclerosis (MS). It is well known that processing speed and episodic memory deficits are the most common neuropsychological (NP) sequelae in this illness. Consensus has emerged about the specific tests that prove most helpful for routine monitoring of MS associated cognitive impairment. The purpose of this study was to examine the validity of the Minimal Assessment of Cognitive Function in MS (MACFIMS), a recommended battery based on the findings of an international conference held in 2001. We tested 291 MS patients and 56 healthy controls. Frequencies of impairment paralleled those reported in previous work for both individual cognitive domains and general impairment. All tests were impaired in the MS group, and distinguished relapsing-remitting (RR) from secondary progressive (SP) course. Principle components analysis showed a distinct episodic memory component. Most of the MACFIMS tests discriminated disabled from employed patients. However, in regression models accounting for all NP tests, those emphasizing verbal memory and executive function were most predictive of vocational status. We conclude that the MACFIMS is a valid approach to routine NP assessment of MS patients. Future work is planned to determine its psychometric properties in a longitudinal study.