Background: Deep Brain Stimulation of the Subthalamic Nucleus (STN-DBS) is an effective treatment for Parkinson's disease (PD), but only few studies investigated its long-term efficacy. Furthermore, little is known about the role of PD-subtype on STN-DBS long-term outcome.Objective: To report the results of a long-term follow-up (mean 11 years, range 10-13) on 26 patients bilaterally implanted in two centres. Methods:Patients were assessed preoperatively and 1, 5 and 11 years after the implant by the Unified Parkinson's Disease Rating Scale (UPDRS) and a battery of neuropsychological tests. Stimulation parameters, drugs dosages, non-motor symptoms and adverse events were also recorded.Results: At 11 years, stimulation significantly improved the motor symptoms by 35.8%, as compared to the preoperative off-state. Motor complications were well controlled, with a 84.6% improvement of dyskinesias and a 65.8% improvement of motor fluctuations. Despite this, the UPDRS-II-on score worsened by 88.5%, mainly for the worsening of poorly levodopa-responsive symptoms. More than 70% of the patients performed in the normal range in most of the neuropsychological tests, despite the development of dementia in 22.7%. Age at disease onset, axial subscore in off-condition and presence of REM behaviour disorder at baseline were found to be associated with a higher risk of developing disability over time. Conclusions:Our study confirms the long-term safety and efficacy of STN-DBS in PD. Nevertheless, the functionality of patients worsens over time, mainly for the onset and progression of levodopa-resistant and non-motor symptoms. The role of PD-subtype seems to be relevant in the long-term outcome.

Background: The assessment of semantic memory may be a useful marker to identify individuals with mild cognitive impairment (MCI) who will progress to Alzheimer’s disease (AD) in the early stages of the disease. Objective: The aim of this five-year follow-up longitudinal study is to assess whether semantic assessment could predict progression in MCI. Methods: A population of MCI (N = 251); mild (N = 178) and moderate AD (N = 114); and a sample of healthy participants (HP; N = 262) was investigated. The five-year follow-up of the MCI group was completed by 178 patients. Semantic and episodic memory measures were used, including a measure of the discrepancy between categorical and phonological verbal fluency, the semantic–phonological delta (SPD). The main outcome was the progression of MCI due to AD to dementia. Results: A general linear model showed a significant effect of diagnosis on SPD (Wilks’ Lambda = 0.591; p <  0.001). The estimated marginal means were –0.91 (SE = 0.185) in HP, –1.83 (SE = 0.187) in MCI, –1.16 (SE = 0.218) in mild AD, and –1.02 (SE = 0.275) in moderate AD. Post-hoc comparisons showed a significant difference between MCI and HP (p <  0.001). The follow-up was completed by 178 MCI individuals. SPD in MCI patients who progress to dementia was significantly lower than in MCI that will not progress (p = 0.003). Together with the Mini-Mental State Examination, the SPD was the only measure with a significant predicting effect at the five-years follow-up (p = 0.016). Conclusion: The SPD indicate the impairment of semantic memory in individuals with underlying AD at the MCI early stage, reflecting the early involvement of perirhinal and entorhinal cortices in the earliest stages of AD neuropathological process.

Extradural motor cortex stimulation is a safe procedure. After 12 months, the patients demonstrated a moderate improvement of motor symptoms (particularly axial symptoms) and quality of life.

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Several studies, showing that attention disorders during encoding reduce later memory performance, have stressed the critical role of attention for the formation of durable memory traces. Accordingly, some studies suggest that attentive disturbances, together with declarative memory defects, can constitute the earliest cognitive disorders in Alzheimer's disease. Therefore, the analysis of these disorders can contribute to identify different forms of dementia and to detect demented patients characterized by a faster cognitive decline. In this study, we report the normative data (gathered in a large Italian population) of a short test that assess the ability to detect stimuli characterized by a conjunction of features: the 'Multiple Features Targets Cancellation' task (MFTC). Our sample of 465 subjects was composed by urban and rural people. Multiple linear regression analyses revealed significant relation of false alarms with age and educational level, and of time of execution with age, educational level and gender. Regression analyses on accuracy scores did not show any significant correlation with demographics variables. Based on non-parametric techniques, cutoff scores were obtained on the corrected scores of the patients, and equivalent scores were derived for each measure. The MFTC task represents a useful tool that explores attentional disorders (and in particular conjunction search disturbances) and that could be helpful both in discriminating different forms of dementia and to detect mild cognitive impairment patients at risk of conversion to dementia.