Dementia and memory loss

Normal aging vs pathology Posted by Ahmad Azizov on September 25, 2020

Dementia 

This is a disorder that can be seen with cognitive impairment or memory loss. Dementia is chronic, permanent and slowly changing.

  • Normal ageing
    • Negative test scores on cognitive assessment tests 
    • High level of functionality
    • Trouble remembering names or losing objects 
  • Mild cognitive impairment (MCI) 
    • Positive test scores on cognitive assessment tests 
    • Level of daily function mostly maintained
  • Dementia 
    • Positive test scores on cognitive assessment tests 
    • Functional status significantly decreased - need assistance to do basic tasks 

There are a number of reversible causes of dementia and to rule these out a few lab tests can be useful:

Table 1. Investigations to rule out reversible causes of Dementia
Investigation Reasoning
TSH/T4 Hypothyroidism
Basic metabolic panel - CR, BUN Kidney function
LFTs Cirrhosis
Vitamin B12 levels B12 deficiency 
RPR Neurosyphilis 
Depression  Common after the loss of a spouse
CT Hydrocephalus, hematomas 
MRI Strokes, Creutzfeldt-Jakob Disease

Reversible causes are treated accordingly. 

Types of dementia 

  • Alzheimer's disease
    • The pathophysiology involves plaques and tau protein tangles 
    • Symptoms 
      • Memory loss observed first 
      • Down syndrome patients have a higher incidence (chromosome 21 involvement) 
      • Social skills preserved 
      • Personality changes and disinhibition are late-stage signs
    • Diagnosis 
      • Clinical diagnosis 
      • CT or MRI 
        • Can show diffuse atrophy 
    • Treatment 
      • Supportive 
  • Pick's disease = front temporal dementia 
      • Phineas Gage had personality changes after the destruction of his frontal lobe 
    • Involvement of frontal and temporal lobes 
    • Symptoms 
      • Initially personality changes and social disinhibition (hypersexual, aggressive) 
      • Later on, the memory losses occur 
    • Diagnosis 
      • Clinical 
      • Imaging
        • Frontotemporal degeneration
    • Treatment 
      • Supportive 
  • Lewy body dementia = Parkinson's 
    • Symptoms 
      • Few Parkinsonian symptoms with dementia 
      • Dementia predominates 
      • Visual hallucinations 
    • Diagnosis 
      • Clinical 
      • Autopsy after death 
      • MRI 
        • Not required but can show the atrophy of substantial nigra 
    • Treatment 
      • Supportive 
  • Vascular dementia  
    • Series of "mini-strokes"
    • Symptoms 
      • Stepwise decline in function after vascular infarcts 
    • Diagnosis 
      • Clinical 
      • CT 
        • Evidence of vascular infarcts 
    • Treatment 
      • Focused on stroke recovery and stroke prevention 
      • Otherwise supportive 
  • Creutzfeldt-Jakob Disease
    • "Mad cow disease" - caused by prions in undercooked meat 
    • Most patients with Creutzfeldt-Jakob disease acquire this disease from mutations and not undercooked meat
    • Symptoms 
      • Myoclonus and dementia in a young (30s/40s) person 
    • Diagnosis 
      • MRI 
    • Treatment 
      • Supportive 
      • Most patients die within 6 months from suicide or infections 
  • Normal-pressure hydrocephalus 
    • The brain feels an increased intracranial pressure (ICP)
    • Symptoms 
      • Wet
        • Urinary incontinence 
      • Wobbly 
        • Ataxia with walking 
      • Weird 
        • Dementia 
    • Diagnosis 
      • CT 
        • Hydrocephalus 
      • Lumbar puncture 
    • Treatment 
      • VP shunt after lumbar puncture 

Amnesia 

This is a disorder that involves memory loss without cognitive impairment. 

Movie Memento 

Delirium 

This is a disorder that can be seen with cognitive impairment or memory loss. Delirium is acute and very obvious to tell. The course of this condition is intermittent and is usually followed by a trigger such as a UTI (very common, alcohol intake, anesthesia). Unlike dementia, delirium is reversible if the primary trigger is treated. 

  • Causes - acronym
    • I Watch Death 
      • Infections – PUS, pneumonia, urinary, skin/soft tissue, CNS
      • Withdrawl – often unintentional, from alcohol, sedatives, barbiturates
      • Acute metabolic changes – altered pH, hypo/hyper Na+ Ca++, acute liver or renal failure
      • Trauma – brain injury, subdural hematoma
      • CNS pathology – post-ictal, stroke, tumour, brain metastasis
      • Hypoxia – CHF, anemia
      • Deficiencies – thiamine, niacin, B12 (e.g. chronic G and T alcoholics)
      • Endocrinopathies – hypo-/hyper-cortisol, hypoglycemia
      • Acute vascular – hypertensive encephalopathy, septic hypotension
      • Toxins and Drugs – especially anticholinergics, opioids, benzodiazepines
      • Heavy metals
    • DIMSO 
      • Drugs and alcohol
        • benzodiazepines (e.g. lorazepam)
        • zolpidem
        • opioids (e.g. morphine or hydrocodone)
        • anticholinergics (e.g. Benadryl)
        • corticosteroids
        • central antihypertensive (e.g clonidine)
        • fluoroquinolones (ciprofloxacin)
      • Infection - lungs, UTI, ulcers
      • Metabolic - TSH, B12, glucose, electrolyte
      • Structural - CNS, Cardiac

All information provided on this website is for educational purposes and does not constitute any medical advice. Please speak to you doctor before changing your diet, activity or medications. 


Written by
Ahmad Azizov Member since April 2020
Interested in Vascular surgery resident at Western U

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