![]() ![]() ![]() Patients with anterograde amnesia may have episodic, semantic, or both types of explicit memory impaired for events after the trauma that caused the amnesia. Damage to specific areas can result in reduced or eliminated ability to encode new explicit memories, giving rise to anterograde amnesia. Initially, it is present in the limbic cortices it may then spread to the adjacent frontal and temporal lobes. How HSV gains access to the brain is unknown the virus shows a distinct predilection for certain parts of the brain. There are several types of encephalitis: one such is herpes simplex encephalitis (HSV), which, if left untreated, can lead to neurological deterioration. Illness, though much rarer, can also cause anterograde amnesia if it causes encephalitis, which is the inflammation of brain tissue. It may also be caused by a PTSD, a shocking event, or an emotional disorder. A second cause is a traumatic brain injury in which damage is usually done to the hippocampus or surrounding cortices. This has also been recorded in non-benzodiazepine sedatives or " z-drugs" which act on the same set of receptors such as zolpidem (also known as Ambien), eszopiclone (also known as Lunesta), and zopiclone (also known by brand names Imovane and Zimovane). This disorder is usually acquired in one of four ways: One cause is benzodiazepine drugs such as midazolam, flunitrazepam, lorazepam, temazepam, nitrazepam, triazolam, clonazepam, alprazolam, diazepam, and nimetazepam all of these are known to have powerful amnesic effects. Certain authors claim the deficit in temporal context memory is more significant than the deficit in semantic learning ability (described below). In addition, patients have a diminished ability to remember the temporal context in which objects were presented. This supports the notion that declarative and procedural memory are consolidated in different areas of the brain. no conscious memory of completing the maze exists), the patients still had a working procedural memory (learning done unconsciously through practice). concluded despite having no declarative memory (i.e. Despite having no memory of having completed the maze the day before, unconscious practice of completing the same maze over and over reduced the amount of time needed to complete it in subsequent trials. He, along with other patients with anterograde amnesia, were given the same maze to complete day after day. ![]() One extensively studied anterograde amnesiac patient, codenamed H.M., demonstrated that despite his amnesia preventing him from learning new declarative information, procedural memory consolidation was still possible, albeit severely reduced in power. ![]() For instance, they are able to remember and in some cases learn how to do things such as talking on the phone or riding a bicycle, but they may not remember what they had eaten earlier that day for lunch. In most cases of anterograde amnesia, patients lose declarative memory, or the recollection of facts, but they retain nondeclarative memory, often called procedural memory. In cases of pure anterograde amnesia, patients have recollections of events prior to the injury, but cannot recall day-to-day information or new facts presented to them after the injury occurred. Usually, some capacity for learning remains, although it may be very elementary. In the other case, which has been studied extensively since the early 1970s, patients often have permanent damage, although some recovery is possible, depending on the nature of the pathophysiology. In the case of drug-induced amnesia, it may be short-lived and patients can recover from it. Some with severe cases have a combined form of anterograde and retrograde amnesia, sometimes called global amnesia. People with anterograde amnesic syndromes may present with widely varying degrees of forgetfulness. To a large degree, anterograde amnesia remains a mysterious ailment because the precise mechanism of storing memories is not yet well understood, although it is known that the regions of the brain involved are certain sites in the temporal cortex, especially in the hippocampus and nearby subcortical regions. Both can occur together in the same patient. This is in contrast to retrograde amnesia, where memories created prior to the event are lost while new memories can still be created. In neurology, anterograde amnesia is the inability to create new memories after the event that caused amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. ![]()
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