Memory loss resident survival guide

Memory loss Resident Survival Guide Microchapters
Overview
Causes
Diagnosis
Do's
Don'ts

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Moises Romo, M.D.

Synonyms and keywords: approach to amnesia, approach to dementia, amnesia workup, dementia workup, approach to pseudodementia, pseudodementia workup

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

• Death or permanent disability may occur within 24 hours if left untreated. Most acute causes of amnesia are considered life-threatening, among them, are the following:
  • Electrolyte imbalances
  • Head trauma
  • Hypoglycemia
  • Infections
  • Intoxications

Common Causes

• Alzheimer disease.
• Vascular dementia
• Frontotemporal dementia
• Vitamin deficiency
• Depression

Diagnosis

Shown below is an algorithm summarizing the diagnosis of amnesia according to the the American Academy of Neurology guidelines:

Patient with amnesia

Acute onset

Chronic onset

Measure vitamin B12, and folate, 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

Severe disimpairment in social functioning?

No

Normal aging

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's disease

Do's

• Perform laboratory testing to exclude potentially reversible causes of amnesia. Initial tests should include a CBC, urine toxicology, thyroid function, folate, and vitamin B12 level.
• 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.
• 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.
• Always have in mind depression as a possible cause of memory impairmant. Depression is common cause of amnesia; a SIGE CAPS evaluation may disclose an underlying mood disorder.

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.