Memory loss resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Moises Romo, M.D.
Overview
Amnesia is a condition in which memory is disturbed or lost. The causes of amnesia can be organic or functional. Organic causes include damage to the brain through trauma or disease or the use of certain (generally sedative) drugs. Functional causes are psychological factors, such as defense mechanisms. Hysterical post-traumatic amnesia is an example of this. Amnesia may also be spontaneous, in the case of transient global amnesia. This global type of amnesia is more common in middle-aged to elderly people, particularly males, and usually lasts less than 24 hours. Memory loss can be partial or total and is normally expected as we get older.
Causes
Life Threatening Causes
- Life-threatening causes include conditions that may result in death or permanent disability within 24 hours if left untreated. Most acute causes of amnesia are considered life-threatening, among them, are the following:
Common Causes
Diagnosis
- Shown below is an algorithm summarizing the diagnosis of amnesia according to the the American Academy of Neurology guidelines: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898682/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC535652/ https://www.aafp.org/afp/2005/0501/p1745.html
| Patient with amnesia | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Acute onset | Chronic onset | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Measure vitamin B12, and folic acid, and TSH | Abnormal? | Yes | Vitamin deficiency, hypothyroidism | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Fluctuating course, inattention, disorganized thinking, or altered level of consciousness? | Positive for SIGE CAPS questionary? | Yes | Depression | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Yes | No | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Delirium | Dementia | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Take history and perform physical examination | Take history and perform physical examination | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| History of head trauma? | Yes | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| No | Concussion, post-concussive amnesia | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Measure urine toxicology, CBC, creatinine, electrolites, and glucose to reveal cause | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Initial short term memory loss | Vascular risk factors, imaging evidence of cerebrovascular involvement | Young age, behavioral symptoms or language impairment | Bradikinesia or features of parkinsonism,
fluctuating cognition, visual hallucinations | Dementia occuring 1 year after onset of Parkinson disease | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| Alzheimer disease | Vascular dementia | Frontotemporal dementia | Dementia with Lewy bodies | Parkinson disease dementia | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Do's
- Perform laboratory testing is to exclude potentially reversible causes of amnesia. Initial tests should include a CBC, urine toxicology, thyroid function, folate, and vitamin B12 level. https://www.aafp.org/afp/2005/0501/p1745.html
- When a history of head trauma exists, perform an immediate non-contrasted CT scan of the head to rule out intracerebral hemorrage. Neuroimaging may diagnose vascular disease, normal pressure hydrocephalus, tumors, abscess. https://pubmed.ncbi.nlm.nih.gov/11342678/
- Perform a minimental status test on physical examination and pay especial attention in concentration domain. Minimental testing has the potential distinguish mild cognitive impairment from dementia. https://pubmed.ncbi.nlm.nih.gov/11342677/
- Always have in mind depression as a possible causant of memory impairmant. Depression is common cause of amnesia; a SIGE CAPS evaluation may disclose an underlying mood disorder. https://pubmed.ncbi.nlm.nih.gov/3235647/
Don'ts
- If alcoholism and thiamine deficiency is suspected, do not administer glucose before thiamine. Administration of glucose before thiamine may lead to Wernicke encephalopathy. https://jamanetwork.com/journals/jama/article-abstract/2682749#:~:text=%E2%80%94In%20his%20letter%2C%20Dr%20Marinella,statement%20describes%20only%204%20patients.