5/18/2023 0 Comments Retrograde amnesia![]() ![]() Isolated RA is associated with a visible thalamic lesion. Individuals with focal brain damage have minimal RA. A case study of DH revealed that the patient was unable to provide personal or public information, however there was no parahippocampal or entorhinal damage found. This could be described as a psychogenic form of amnesia with mild anterograde and retrograde loss. In addition, Focal RA in particular, has also been used to describe an RA situation in which there is a lack of observable physical deficit as well. These terms are used to describe a pure form of RA, with an absence of anterograde amnesia (AA). It is very rare to find stable RA, since improvement generally takes place among patients.įocal, Isolated, and Pure Retrograde Amnesia RA can also progress, as in the case of Korsakoff syndrome and Alzheimer’s disease, due to the ongoing nature of the damage. The fact that damage to the hippocampal formation no longer causes RA, suggests that other brain structures are able to function more independently. ![]() It suggests that the hippocampal formation is only used in systematic consolidation for a temporary and short period of time, until long-term consolidation takes place by other brain structures. Recovery often takes place after the onset of RA, which the Standard model accounts for. However, memory loss can also be selective or categorical, manifested by a person’s inability to remember events related to a specific incident or topic. Generally, this is a more severe type of amnesia known as global or generalized amnesia. In extreme cases, the individual may completely forget who he or she is. For example, older memories are consolidated over time and in various structures of the brain, including Wernicke’s area and the neocortex, making retrieval through alternate pathways possible.Īs previously mentioned, RA commonly results from damage to the brain regions most closely associated with episodic and declarative memory, including autobiographical information. Thus, the brain can learn to be independent of the impaired hippocampus, but only to a certain extent. Plasticity of the brain is when rewiring occurs because of brain damage, finding different neural pathways and not relying on the damaged structures. Difficulties in studying this region of the brain extend to its duties in comprehension, naming objects, verbal memory, and other language functions. Right side lesions in particular, result in impaired recall of non-verbal material, such as music and drawings. Damage to this region of the brain can result in impaired organization and categorization of verbal material, disturbance of language comprehension, and impaired long-term memory. Aside from helping to consolidate memory with the hippocampus, the temporal lobes are extremely important for semantic memory. The temporal lobes are essential for semantic and factual memory processing. However, this structure appears to be involved in episodic memory recall. The diencephalon and the surrounding areas’ role in memory is not well understood. Amnesic patients with damage to the hippocampus are able to demonstrate some degree of unimpaired semantic memory despite loss of episodic memory due to spared parahippocampal cortex. Its main responsibility is making information go from short-term memories into long-term stores. The hippocampus deals largely with memory consolidation, in particular episodic memory. ![]() The most commonly affected areas are associated with episodic and declarative memory such as the hippocampus, the diencephalon, and the temporal lobes. RA is often temporally graded, consistent with Ribot’s Law: more recent memories closer to the traumatic incident are more likely to be forgotten than more remote memories. Retrograde amnesia (RA) is a loss of access to events and information of the past after the onset of disease or injury. ![]()
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