The amnesic syndrome is characterized by a prominent disorder of recent memory, in the absence of the generalized intellectual impairment observed in dementia or the impaired consciousness seen in delirium.
The condition usually results from lesions in the posterior hypothalamus and nearby midline structures, but occasionally results from bilateral hippocampal lesions.
It is often described as Korsakov’s syndrome, after the Russian neurologist who first described the clinical features, or as the Wernicke–Korsakov syndrome, because the amnesic syndrome may accompany an acute neurological syndrome described by Wernicke (Wernicke’s encephalopathy) characterized by impairment of consciousness, memory defect, disorientation, ataxia, and ophthalmoplegia.
The prominent causal factor in most cases appears to be thiamine deficiency.
- Recent memory severely impaired
- Remote memory spared
- Disorientation in time
- Other cognitive functions preserved further damage.
The patient can recall events immediately after they have occurred, but cannot do so even a few minutes thereafter.
Thus, on the standard clinical test of remembering an address, immediate recall is good but grossly impaired 10 minutes later.
One consequence of the profound disorder of memory is an associated disorientation in time.
Gaps in memory are often filled by confabulation. The patient may give a vivid and detailed account of recent activities that, on checking, turn out to be inaccurate. It is as though he cannot distinguish between true memories and the products of his imagination or recollection of events from times other than those he is trying to recall. Such a patient is often suggestible; in response to a few cues from the interviewer, he may give an elaborate account of taking part in events that never happened. Other cognitive functions, including remote memory, are relatively well preserved. Unlike the patient with dementia, the patient with an amnesic syndrome seems alert and able to reason or hold an ordinary conversation, so that the interviewer may at first be unaware of the extent of the memory disorder.
- Alcohol abuse is the most frequent cause, and seems to act by causing a deficiency of thiamine.
- carbon monoxide poisoning
- vascular lesions
- tumours of the third ventricle.
Prognosis is better when the condition is due to thiamine deficiency, provided that thiamine treatment was started promptly.
1. Anacardium : beneficial medicine when there is marked loss of memory. The person needing it does not retain anything in his memory. He loses power of recollection completely. It may happen all of a sudden. It is a well indicated for memory loss after stroke and after some sort of fright
2. Cicuta : person fails to recognize anybody and is unable to remember what has happened recently. His memory goes blank for hours or days together. To him everything appears strange. He is confused and mixes up the present with the past. It is a useful medicine when memory loss follows seizure.
3. Nux Moschata : loss of memory and a person doesn’t recognise surrounding, places and streets previously well known to him. He seems to be lost somewhere when spoken to. He gives answers which have no reference to questions asked to him. While speaking he is also unable to use appropriate words and stops many a times in between the lines and changes the speech because of his inability to use right and accurate words. It is also indicated when there is entire loss of memory of his past life.
4. Alumina : Persons needing it are unable to recollect things. They have great confusion of mind. They make makes mistakes in speaking and writing. While speaking they use words not meant to be used. They also are incapable of following up an idea.
5. Agathis Americana : People who need it retain memory for past events but are forgetful for everyday things. They are also forgetful for words and mixes up words or use wrong letters. Forgetfulness about what they were about to do or say may also be there.
6. Absinthium Artemisia : Its use is mainly recommended for cases where memory loss arise after epileptic fit.It is indicated when there is forgetfulness about what has recently happened before and after fit
7. Cannabis Indica : sudden loss of memory and have poor short term memory. There is complete forgetfulness about recent thought, speech, ideas and action .