Syndrome confusionnel du sujet âgé : les difficultés d'un diagnostic facile

Confusion is a frequent psychiatric and behavioural manifestation of diffuse cerebral injury found in elderly patients that are severely ill or stressed. The hyperactive form is often recognised because of the psychomotor agitation. However, the hypoactive form is most frequent and has a worse prognosis. Despite, it is often under-recognised. Among contributing factors, anticholinergic agents and drug interactions are significant. Identification and treatment of the underlying cause of delirium is essential with a focus on non pharmacological approach. Antipsychotic agents are reserved for severe forms and where non pharmacological intervention fracases

Glia: initiators and progressors of pathology in Parkinson\u27s disease

Background: Glia are traditionally known as support cells for neurons, and their role in neurodegeneration has been largely considered secondary to neuronal dysfunction. We review newer concepts on glial function and assess glial changes in Parkinson\u27s disease (PD) at the time of disease initiation when α-synuclein is accumulating in brain tissue but there is limited neuronal loss, and also as the disease progresses and neuronal loss is evident. Results: Of the two main types of astrocytes, only protoplasmic astrocytes are involved in PD, where they become nonreactive and accumulate α-synuclein. Experimental evidence has shown that astrocytic α-synuclein deposition initiates the noncell autonomous killing of neurons through microglial signaling. As the disease progresses, more protoplasmic astrocytes are affected by the disease with an increasing microglial response. Although there is still controversy on the role microglia play in neurodegeneration, there is evidence that microglia are activated early in PD and possibly assist with the clearance of extracellular α-synuclein at this time. Microglia transform to phagocytes and target neurons as the disease progresses but appear to become dysfunctional with increasing amounts of ingested debris. Only nonmyelinating oligodendroglial cells are affected in PD, and only late in the disease process. Conclusions: Glial cells are responsible for the progression of PD and play an important role in initiating the early tissue response. In particular, early dysfunction and α-synuclein accumulation in astrocytes causes recruitment of phagocytic microglia that attack selected neurons in restricted brain regions causing the clinical symptoms of PD

The role of astrocytes in parkinson\u27s disease

2014 Springer International Publishing Switzerland. All rights reserved. Unlike other disorders, astrocytes in regions undergoing neurodegeneration in patients with Parkinson\u27s disease do not become reactive. Instead gray matter protoplasmic astrocytes accumulate α-synuclein, withdraw their processes from damaged neurons, and show altered expression of constituent proteins, including PINK-1, parkin, and DJ-1 (gene products associated with recessive Parkinson\u27s disease). These and other gene products are normally up-regulated in astrocytes by disease states. Combined, these data suggest that protoplasmic astrocytes lose their protective function in patients with Parkinson\u27s disease, leaving neurons vulnerable to perturbations and insults they would normally be protected from. Recent work also shows that astrocytes are able to take up and metabolize L-DOPA, the drug of choice for standard therapy for Parkinson\u27s disease. It is therefore possible that ongoing astrocytic dysfunction may compromise the efficacy of L-DOPA therapy. These unique astrocytic responses to the disease process and current main therapy support the concept that astrocytes play a critical, under-recognized role in the initiation, progression, and treatment response of patients with Parkinson\u27s disease