The clock drawing test is an important contribution to the Mini Mental State Examination in screening for cognitive impairment.

BACKGROUND: The clock drawing test (CDT) and the Mini Mental State Examination (MMSE) are frequently used screening instruments for cognitive impairment, however, the precise contribution of the CDT to the MMSE is largely unknown. METHODS: We studied patients with subjective cognitive impairment (SCI, n = 481), mild cognitive impairment (MCI, n = 628) and Alzheimer's disease (AD, n = 1099). Discrimination between patients was examined with multiple logistic regression, adjusted for age, sex, and education. Four groups were constructed based on a normal/abnormal MMSE (cut-off <24/30) versus normal/abnormal CDT (cut-off ≤2/3). Visually rated medial temporal lobe atrophy (MTA) on CT was used as parameter of neurodegeneration. RESULTS: The CDT significantly contributed to the MMSE in discriminating SCI from both MCI and AD patients. Our four group analyses showed that of those patients with a normal MMSE and incorrectly classified as SCI, an abnormal CDT could significantly identify 10.0% as MCI and 13.2% as AD. Among those with an abnormal MMSE, the percentage AD patients shifted from 53.1% to 82.1% due to an abnormal CDT. Presence of an abnormal CDT was significantly related to MTA increase, regardless of the MMSE score. CONCLUSION: The CDT is an important additional screening tool to the MMSE. An abnormal CDT with a normal MMSE is an indicator for cognitive impairment. An abnormal CDT in combination with an abnormal MMSE can be considered as an indicator of disease progression.

Education as Proxy for Cognitive Reserve in a Large Elderly Memory Clinic: 'Window of Benefit'.

BACKGROUND: The role of cognitive reserve (CR) to explain individual differences in cognitive functioning is unclear in memory clinic patients. OBJECTIVE: To examine the cross-sectional effect of CR on cognition in relation to levels of neurodegeneration in a large elderly single-center memory clinic population. METHODS: We included patients with subjective cognitive impairment (SCI, n = 481), mild cognitive impairment (MCI, n = 628) or Alzheimer's disease (AD, n = 1,099). Education was used as proxy for CR and visually rated medial temporal lobe atrophy (MTA) on CT was used as parameter of neurodegeneration. Relations between CR, cognition, and MTA were analyzed with multiple linear regression adjusted for age, sex, and cerebral atrophy. In addition, we examined if education affects the relation between MTA and cognition using an interaction variable. RESULTS: Education was significantly related to all measures of cognition including subtests with an explained variance of education as a determinant of cognition of 11%. More highly educated patients had more advanced levels of MTA at the same level of cognition. All these results were stronger or only present in demented compared to non-demented patients but appeared no longer significant in those with lowest overall cognition. The interaction effect was significant indicating that with more advanced MTA, less cognitive decline was shown in higher educated patients. CONCLUSION: Education is a very strong determinant of cognition in an elderly memory clinic population. The positive effect of education was stronger in demented than in non-demented patients but disappeared in those with the lowest cognitive scores indicating a "window of CR benefit".

Clinician-patient communication during the diagnostic workup: The ABIDE project.

INTRODUCTION: We aimed to describe clinician-patient communication in the diagnostic process of memory clinics, specifically clinician behavior known to facilitate knowledgeable participation of patients during consultations. METHODS: In this multicenter, observational study, we audio-recorded routine diagnostic consultations of 41 clinicians and 136 patients/caregivers at eight memory clinics. Patients/caregivers completed surveys after each audiotaped consultation. We used a study-specific coding scheme to categorize communication behavior. RESULTS: Clinicians often provided information on (results of) diagnostic testing. They infrequently invited questions and/or checked understanding. Clinician behavior to involve patients in decision-making about diagnostic testing was limited. Of note, patients/caregivers rarely expressed their information or involvement preferences. Yet, approximately, one quarter of them would have liked to receive more information. DISCUSSION: Involving patients more explicitly by means of shared decision-making could benefit the quality of care provided in memory clinics because it enables clinicians to attune the diagnostic workup to the individual patient's needs.

Cerebral White Matter Lesions have Low Impact on Cognitive Function in a Large Elderly Memory Clinic Population.

BACKGROUND: Evidence suggests that cerebral white matter lesions (WML) play a role in cognitive decline. OBJECTIVE: To assess the impact of cerebral WML on cognitive function relative to absence or presence of medial temporal atrophy (MTA) in a large single-center memory clinic population. METHODS: Patients included had subjective cognitive impairment (SCI, n = 333), mild cognitive impairment (MCI, n = 492) and Alzheimer's disease (AD, n = 832). The relationships between visually rated WML (Fazekas scale, 0-3) on brain Computed Tomography and CAMCOG memory and non-memory function were investigated with regression analysis adjusted for age, gender and education in combined patient groups. We assessed possible interaction versus addition effects of these relationships with visually rated MTA (Scheltens scale). RESULTS: The highly statistical significant relationship between WML and memory function was no longer significant when MTA was taken into account. However, the strong significant relationship between WML and non-memory function remained significant after adjustment for MTA, but the explained variance attributed to WML was only 1.3%. There was no interaction between WML and MTA on CAMCOG test scores. In addition, shown by a 2×2 factorial model by presence versus absence of WML and MTA, WML affected non-memory function only in the presence of MTA. CONCLUSION: Our data suggest that presence of WML is associated with lower non-memory cognitive function but this effect is conditional on the presence of pre-existing MTA. The very small explained variance suggests little impact of WML to the clinical profile of a memory clinic patient.

Practical use of visual medial temporal lobe atrophy cut-off scores in Alzheimer's disease: Validation in a large memory clinic population.

OBJECTIVE: To provide age-specific medial temporal lobe atrophy (MTA) cut-off scores for routine clinical practice as marker for Alzheimer's disease (AD). METHODS: Patients with AD (n = 832, mean age 81.8 years) were compared with patients with subjective cognitive impairment (n = 333, mean age 71.8 years) in a large single-centre memory clinic. Mean of right and left MTA scores was determined with visual rating (Scheltens scale) using CT (0, no atrophy to 4, severe atrophy). Relationships between age and MTA scores were analysed with regression analysis. For various MTA cut-off scores, decade-specific sensitivity and specificity and area under the curve (AUC) values, computed with receiver operator characteristic curves, were determined. RESULTS: MTA strongly increased with age in both groups to a similar degree. Optimal MTA cut-off values for the age ranges <65, 65-74, 75-84 and ≥85 were: ≥1.0, ≥1.5, ≥ 2.0 and ≥2.0. Corresponding values of sensitivity and specificity were 83.3% and 86.4%; 73.7% and 84.6%; 73.7% and 76.2%; and 84.0% and 62.5%. CONCLUSION: From this large unique memory clinic cohort we suggest decade-specific MTA cut-off scores for clinical use. After age 85 years, however, the practical usefulness of the MTA cut-off is limited. KEY POINTS: • We suggest decade-specific MTA cut-off scores for AD. • MTA cut-off after the age of 85 years has limited use. • CT is feasible and accurate for visual MTA rating.