BackgroundTo assess and compare the effectiveness and costs of Phototest, Mini Mental State Examination (MMSE), and Memory Impairment Screen (MIS) to screen for dementia (DEM) and cognitive impairment (CI).MethodsA phase III study was conducted over one year in consecutive patients with suspicion of CI or DEM at four Primary Care (PC) centers. After undergoing all screening tests at the PC center, participants were extensively evaluated by researchers blinded to screening test results in a Cognitive-Behavioral Neurology Unit (CBNU). The gold standard diagnosis was established by consensus of expert neurologists. Effectiveness was assessed by the proportion of correct diagnoses (diagnostic accuracy [DA]) and by the kappa index of concordance between test results and gold standard diagnoses. Costs were based on public prices and hospital accounts.ResultsThe study included 140 subjects (48 with DEM, 37 with CI without DEM, and 55 without CI). The MIS could not be applied to 23 illiterate subjects (16.4%). For DEM, the maximum effectiveness of the MMSE was obtained with different cutoff points as a function of educational level [k = 0.31 (95% Confidence interval [95%CI], 0.19-0.43), DA = 0.60 (95%CI, 0.52-0.68)], and that of the MIS with a cutoff of 3/4 [k = 0.63 (95%CI, 0.48-0.78), DA = 0.83 (95%CI, 0.80-0.92)]. Effectiveness of the Phototest [k = 0.71 (95%CI, 0.59-0.83), DA = 0.87 (95%CI, 0.80-0.92)] was similar to that of the MIS and higher than that of the MMSE. Costs were higher with MMSE (275.9 ± 193.3€ [mean ± sd euros]) than with Phototest (208.2 ± 196.8€) or MIS (201.3 ± 193.4€), whose costs did not significantly differ. For CI, the effectiveness did not significantly differ between MIS [k = 0.59 (95%CI, 0.45-0.74), DA = 0.79 (95%CI, 0.64-0.97)] and Phototest [k = 0.58 (95%CI, 0.45-0.74), DA = 0.78 (95%CI, 0.64-0.95)] and was lowest for the MMSE [k = 0.27 (95%CI, 0.09-0.45), DA = 0.69 (95%CI, 0.56-0.84)]. Costs were higher for MMSE (393.4 ± 121.8€) than for Phototest (287.0 ± 197.4€) or MIS (300.1 ± 165.6€), whose costs did not significantly differ.ConclusionMMSE is not an effective instrument in our setting. For both DEM and CI, the Phototest and MIS are more effective and less costly, with no difference between them. However, MIS could not be applied to the appreciable percentage of our population who were illiterate.

Background: Subthalamic nucleus deep brain stimulation (STN-DBS) improves motor function in selected patients with Parkinson’s disease (PD) but can be associated with variable changes in cognitive functions. Methods: We studied 21 patients selected for STN-DBS and compared 6-month clinical and neuropsychological outcomes between those who underwent surgery (n = 9) and those who voluntarily refused it (n = 12). Results: Motor and quality of life outcomes were markedly superior in the STN-DBS group versus controls. A wide neuropsychological battery was administered, and the whole sample showed a statistically significant worsening in phonemic verbal fluency, time to perform the Trail Making Test part B, Digit Symbol score of WAIS-III and color-naming score of the Stroop Test. In comparison to controls, a trend to a slightly worse deterioration in phonemic verbal fluency was observed in the STN-DBS patients and was significantly correlated with reductions in the l-dopa-equivalent daily dose (r = 0.850, p = 0.007). Conclusion: Our study confirms the safety of STN-DBS from a cognitive standpoint; a reduction in verbal fluency at 6 months after surgery can also be related to PD progression and medication reduction.

OBJECTIVES - Determine whether bilateral subthalamic nucleus stimulation (STN-DBS) in Parkinson's disease (PD) is associated with an increase in neuropeptide Y (NPY) and/or resistance to inhibition by leptin in relation to post-surgery weight gain. MATERIALS AND METHODS - This prospective study included 20 patients who underwent bilateral STN-DBS and 17 who refused surgery. Data were obtained at baseline, 3 and 6 months on neurological and nutritional status, including determination of body mass index (BMI) and serum NPY and leptin levels. RESULTS -  NPY and leptin levels changed over time, with a distinct pattern. The BMI increase at 6 months was greater in the surgical group (5.5 ± 6.3% vs 0.5 ± 3.5%; P = 0.035). Medical group exhibited a reduction in leptin level (-2.0 ± 4.3 ng/ml) and a consequent increase in NPY level (72.4 ± 58.7 pmol/ml). However, STN-DBS patients showed an increase in leptin (3.1 ± 5.0 ng/ml; P = 0.001 vs medical group) and also in NPY (12.1 ± 53.6 pmol/ml; P = 0.022 vs medical group) levels, which suggests resistance to inhibition by leptin. Rise in NPY level correlated with higher stimulation voltages. CONCLUSIONS -  Bilateral STN-DBS causes disruption of the melanocortin system, probably related to diffusion of the electric current to the hypothalamus. This mechanism may in part explain the weight gain of patients with PD after surgery.

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BackgroundIlliteracy, a universal problem, limits the utilization of the most widely used short cognitive tests. Our objective was to assess and compare the effectiveness and cost for cognitive impairment (CI) and dementia (DEM) screening of three short cognitive tests applicable to illiterates.MethodsPhase III diagnostic test evaluation study was performed during one year in four Primary Care centers, prospectively including individuals with suspicion of CI or DEM. All underwent the Eurotest, Memory Alteration Test (M@T), and Phototest, applied in a balanced manner. Clinical, functional, and cognitive studies were independently performed in a blinded fashion in a Cognitive Behavioral Neurology Unit, and the gold standard diagnosis was established by consensus of expert neurologists on the basis of these results. Effectiveness of tests was assessed as the proportion of correct diagnoses (diagnostic accuracy [DA]) and the kappa index of concordance (k) with respect to gold standard diagnoses. Costs were based on public prices at the time and hospital accounts.ResultsThe study included 139 individuals: 47 with DEM, 36 with CI, and 56 without CI. No significant differences in effectiveness were found among the tests. For DEM screening: Eurotest (k = 0.71 [0.59–0.83], DA = 0.87 [0.80–0.92]), M@T (k = 0.72 [0.60–0.84], DA = 0.87 [0.80–0.92]), Phototest (k = 0.70 [0.57–0.82], DA = 0.86 [0.79–0.91]). For CI screening: Eurotest (k = 0.67 [0.55–0.79]; DA = 0.83 [0.76–0.89]), M@T (k = 0.52 [0.37–0.67]; DA = 0.80 [0.72–0.86]), Phototest (k = 0.59 [0.46–0.72]; DA = 0.79 [0.71–0.86]). There were no differences in the cost of DEM screening, but the cost of CI screening was significantly higher with M@T (330.7±177.1€, mean±sd) than with Eurotest (294.1±195.0€) or Phototest (296.0±196.5€). Application time was shorter with Phototest (2.8±0.8 min) than with Eurotest (7.1±1.8 min) or M@T (6.8±2.2 min).ConclusionsEurotest, M@T, and Phototest are equally effective. Eurotest and Phototest are both less expensive options but Phototest is the most efficient, requiring the shortest application time.

The Fototest is free from educational influence and shows appropriate test-retest and inter-rater reliabilities, as well as a high internal consistency. Therefore, it is a suitable psychometric instrument to be used in the follow-up of patients with cognitive impairment or dementia, especially in contexts where evaluators are not the same on different occasions, or with patients of low educational level.

The Fototest showed adequate validity for CI and DEM in general Neurology clinics in an extensive and wide geographical area.

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