Amnesia..........

**counselor** Mon Oct 15, 2012 11:01 am

Amnesia

From greek to-mnesis (non-memory), indicates the severe impairment of memory and selective long-term (MLT), independent of stimulus type (verbal or non-verbal) or the sensory modality of presentation of the same, in relation to a pathological event, such as a head injury, poisoning or a vascular disorder. Characteristic of amnesic disorder is, as the law formulated by Ribot, preserve, contrary to the course of storage, the data acquired in the distant past, leaving decay first discuss what a recent acquisition. The a. There are two components of varying severity: retrograde amnesia for events preceding the onset of the disease because of the disorder of memory and anterograde amnesia for events after the onset of morbid fact. When the two disorders are associated, it is called anterograde amnesia-back. The a. retrograde can be global when it extends to all the past, when lacunar is limited to limited periods of time. The subject amnesic, if not distracted, may be able to remember for a few seconds, sometimes for a few minutes, limited amount of information: the span of immediate memory for sequences of digits or for phrases presented aurally is, usually, within the limits of the norm. In the A., Therefore, the information should have access to a short-term memory (MBT) working, but could not be moved to the MLT. However, in the. anterograde greatly limits the ability to capture and record new information, while the retrograde does not allow into consciousness engrams previously set. The a. can be generalized because it affects all the memories, selective when it refers specifically to a particular material mnemonic, systematized when they are not the memories that refer to specific people or events. The latter category includes psychogenic amnesia, which refer to events of great emotional and affective significance and are seen in some personality disorders. The clinical picture of the patient's amnesia is characterized by the difficulty of recognizing people I met not long ago, the spatial and temporal orientation, even with regard to the actions, the space and the location of the objects of everyday life. The past memories are lost in a more or less wide: the earliest memories are often preserved. The pathology of memory is extremely debilitating and sufferers rarely able to live independently. The a. is associated with lesions of the brain structures that are part of the circuit of Papez cortico-subcortical (hippocampus, fornix, mammillary bodies, beam mammillo-thalamic, anterior thalamus, cingulate gyrus). The main related anatomical of a. are, in fact, represented by: a) bilateral lesions in the temporal regions mesial and hippocampus; b) lesions situated in diencephalic structures and, in particular, in the mammillary bodies and medial back in the nucleus of the thalamus; c) bilateral lesions per revolution Track or fornix can lead to faulty memory or less associated with transient confusional states milder than the injuries mentioned above. Rarely, a. is produced by unilateral lesions and, in this case, is associated with lesions of the left hemisphere.[center]