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Summary: Objectives: Despite the introduction of combined antiretroviral therapy (cART), the prevalence of HIV-associated neurocognitive disorders (HANDs) remains high. Aim of the study was to investigate the potential relationship between ophthalmic artery resistance index (OARI), a marker of subclinical cerebrovascular disease, and cognitive performance. Methods: We performed a cross-sectional cohort study by consecutively enrolling HIV-infected patients during routine outpatient visits. All subjects underwent a comprehensive neuropsycological battery and ultrasonographic assessment of OARI. Patients were classified as cognitively impaired if they showed decreased cognitive function involving at least two ability domains. OARI was considered abnormal if above 0.72 at left or right side. Factors associated with cognitive performance were evaluated by linear and logistic regression analysis. Results: A total of 116 patients [78.4% males, median age 44 years (IQR 37–49), 13.8% with past AIDS-defining events, median CD4 482 cells/μL (IQR 352–690), 79.3% with HIV RNA <20 copies/mL] were enrolled. A hundred-thirteen (97.4%) subjects were on cART of which 88.5% on current regimen from one year. Fifty-four (46.6%) patients were classified as cognitively impaired. ROC curves indicated that the most discriminant left and right OARI values for predicting a mild cognitive impairment were >0.72 (AUC = 0.73, sensitivity 61.8%, specificity 81.4%, p < 0.001) and >0.71 (AUC = 0.72, sensitivity 69.1%, specificity 71.2%, p < 0.001), respectively. Multivariate analysis showed that OARI >0.72 (OR 4.7, p = 0.001) was independently associated with increased risk of cognitive impairment. Moreover, education (β = −0.18, p = 0.005), Zung depression score (β = +0.05, p = 0.021) and an abnormal OARI (β = +1.46, p = 0.002) were independently associated with an increased number of pathological performances. Evaluating separately each cognitive domain, an abnormal OARI confirmed an independent association with lower performance in attention and executive functions (p = 0.003) and in psychomotor speed (p = 0.010). Conclusions: Increased OARI was associated with lower cognitive performance in HIV-infected patients. These findings suggest a potential role of subclinical cerebrovascular disease in the pathogenesis of HAND. [Copyright &y& Elsevier]

Abstract: An impairment for verbs has been described in patients with Parkinson''s disease (PD), suggesting that a disruption of frontal–subcortical circuits may result in dysfunction of the neural systems involved in action–verb processing. A previous study suggested that deep brain stimulation (DBS) of the subthalamic nucleus (STN) during verb generation may affect the ability to select from many competing lexical alternatives. In this study, 12 PD patients who had undergone bilateral STN DBS and completed an 8-year follow-up and 14 matched normal controls were administered action and object naming tasks and verb and noun reading tasks. Their responses were recorded using a microphone, resulting in a signal that marked the onset of the verbal response and allowed to measure response times (RTs). Accuracy was scored manually. Results: Overall performance in naming (independently of stimulation): In naming task controls were faster and more accurate than PD patients. In both groups, performance (accuracy and RTs) was worse on action naming than object naming. PD patients were significantly slower than controls in naming actions. Effect of stimulation: Compared with the OFF stimulation condition, in ON stimulation condition PD patients showed improved performance on object and action naming tasks (increased accuracy, faster RTs), with a decreased number of semantic errors. Some evidence also emerged that action naming in the ON stimulation condition improved more than object naming. On noun and verb reading tasks, although accuracy was at ceiling in both groups and no significant difference was observed in RTs for nouns and verbs, PD patients were slower than controls. Conclusions: Our findings suggest that STN DBS may improve lexical search in PD patients. We hypothesize that STN stimulation may facilitate the motor components involved in naming and reading tasks (increased speed of speech onset), resulting in shorter RTs in both naming and reading and, to some extent, in increased accuracy in naming due to fewer omissions (no response within the 7500ms time limit). However, to account for greater accuracy in naming due to decreased number of semantic errors in the ON stimulation condition, we hypothesize that STN stimulation restores the activity of the corticostriatal circuits involved in selection processes of a target word among different alternatives. [Copyright &y& Elsevier]

Abstract: We studied five patients with semantic memory disorders, four with semantic dementia and one with herpes simplex virus encephalitis, to investigate the involvement of semantic conceptual knowledge in object use. Comparisons between patients who had semantic deficits of different severity, as well as the follow-up, showed that the ability to use objects was largely preserved when the deficit was mild but progressively decayed as the deficit became more severe. Naming was generally more impaired than object use. Production tasks (pantomime execution and actual object use) and comprehension tasks (pantomime recognition and action recognition) as well as functional knowledge about objects were impaired when the semantic deficit was severe. Semantic and unrelated errors were produced during object use, but actions were always fluent and patients performed normally on a novel tools task in which the semantic demand was minimal. Patients with severe semantic deficits scored borderline on ideational apraxia tasks. Our data indicate that functional semantic knowledge is crucial for using objects in a conventional way and suggest that non-semantic factors, mainly non-declarative components of memory, might compensate to some extent for semantic disorders and guarantee some residual ability to use very common objects independently of semantic knowledge. [Copyright &y& Elsevier]

Abstract: We describe five patients with corticobasal degeneration who had apraxia with an ideational component and reduced action/verb naming ability. Patients also had difficulty in a series of tasks devised to explore the conceptual representation of actions associated with manipulable objects, such as action recognition, action miming and pantomime recognition; however, their ability to name manipulable objects was comparatively preserved. According to the current interpretation of ideational apraxia [De Renzi, E., & Lucchelli, F. (1988). Ideational apraxia. Brain, 111, 1173–1185] we considered the patients’ apraxic disorder as the motor expression of decay of the action representation and we hypothesized that this may also have contributed to the action-naming deficit. The results are discussed within a “multimodal model” of semantic memory in which the concept of action is seen as the product of the integration between sensorial and motor attributes. We suggest that corticobasal degeneration might offer a unique opportunity to validate this model because it is typically characterized by a frontoparietal damage [Gibb, W. R., Luthert, P. J., & Marsden, C. D. (1989). Corticobasal degeneration. Brain, 1, 1171–1192] that prevents integration of sensory and motor information. We conclude that the selective impairment of action/verb should also be studied from the point of view of a movement disorder and not only in terms of a lexical-semantic deficit. [Copyright &y& Elsevier]