Abstracts

Rationale: Memory difficulty is a common complaint in both aging and epilepsy populations. Although patient reports are important in forming diagnoses and treatment recommendations, subjective memory difficulty fails to consistently predict objective memory impairment. Some studies have suggested that this discrepancy may be due to patients erroneously attributing other cognitive problems to memory difficulty. Clinically, we have observed that older adults with temporal lobe epilepsy (TLE) often complain of memory decline; however, on further querying, patients often describe word finding difficulty, and clinical assessment frequently identifies naming problems. We hypothesized that in older adults with TLE, subjective memory ratings would correlate more strongly with objective naming performance (i.e., word-finding) than with objective memory performance.

Methods: Participants were 33 TLE patients (20 left, 13 right) ages 56-87 (Age: 66.2 ± 8.2, Education: 15.2 ± 2.6, FSIQ: 105.3 ± 16.0). Subjective memory difficulty was assessed using the Quality of Life in Epilepsy Inventory (QOLIE-89) memory scale (6 Likert scale items, e.g., “in the past 4 weeks have you had any trouble with your memory?”). Objective naming was assessed with the Boston Naming Test (i.e., number correct within 20 seconds) and the Older Adult Auditory Naming (ANT; e.g., “where you go to borrow books”) and Visual Naming tests (VNT; i.e., naming pictured common objects). ANT and VNT scores were converted to z-scores using age- and education-stratified normative data. ANT and VNT scores included Response Time (RT), and Tip-of-the-tongue responses (TOT: delayed responses, i.e., items named 2-20 seconds plus items named after 20 seconds following a phonemic cue). Objective memory was assessed with the Rey Auditory Verbal Learning Test (delayed recall scaled score). Pearson correlations analyzed relations between subjective memory ratings, objective memory performance, and naming performance.

Results: Subjective memory ratings correlated significantly with performance on visual, but not auditory naming. Specifically, greater subjective memory difficulty was associated with slower RT (r = -0.35, p = 0.04) and a greater number of TOTs (r = -0.46, p = 0.007) on the VNT, and poorer accuracy on the BNT (r = 0.40, p = 0.02). The correlation between subjective and objective memory approached, but did not reach, significance (r = 0.38, p = 0.08).

Conclusions: As hypothesized, in this sample of older adults with TLE, memory complaints were more closely associated with word finding than with memory performance; however, this was restricted to visual naming. It may be the case that for TLE patients with increasing age, visual naming difficulty becomes more salient and therefore, associated with a subjective sense of memory decline.

Funding: Supported by NIH grant R01 NS 083976