Skip to main content

Neuropathology of Alzheimer's Disease

Image
By

Neuropathology of Alzheimer's Disease

Gross Brain Changes

The following are the gross changes in the brains of people with Alzheimer’s disease:
  1. Reduced weight of the brain
  2. Reduced cortical volume
  3. Dilated ventricles
  4. Deepening of sulci

Magnetic Resonance Imaging

On magnetic resonance imaging, the diagnostically most important finding is atrophy, especially of the medial temporal lobe. It affects the entorhinal cortex the earliest but then it spreads to other regions of the temporal lobe and limbic lobe for example hippocampus, amygdala, and parahippocampus. Later, the pathology extends to the parietal lobe and eventually causes global atrophy. It spares frontal lobes until the late stage. The progression of atrophy occurs in a similar pattern as the progression of neuropathology.

Dilated ventricles can show global atrophy, but the most reliable method is a direct measurement of volume. Expansion of the fissures is the indirect, and less reliable way to measure the atrophy. For Alzheimer’s disease, fissures/sulci in the temporal lobe and parietal lobe are more important.

>> Parietal atrophy relates to the early onset subtype of Alzheimer’s Dementia.

References

  1. Johnson, K. A., Fox, N. C., Sperling, R. A., & Klunk, W. E. (2012). Brain imaging in Alzheimer disease. Cold Spring Harbor perspectives in medicine, 2(4), a006213. doi:10.1101/cshperspect.a006213
  2. Alzheimer disease | Radiology Reference Article | Radiopaedia.org. (n.d.). Retrieved January 17, 2020, from https://radiopaedia.org/articles/alzheimer-disease-1

Comments

Post a Comment

Your Thoughts?

Popular posts from this blog

ADVOKATE: A Mnemonic Tool for the Assessment of Eyewitness Evidence

By
ADVOKATE: A Mnemonic Tool for Assessment of Eyewitness Evidence A tool for assessing eyewitness  ADVOKATE is a tool designed to assess eyewitness evidence and how much it is reliable. It requires the user to respond to several statements/questions. Forensic psychologists, police or investigative officer can do it. The mnemonic ADVOKATE stands for: A = amount of time under observation (event and act) D = distance from suspect V = visibility (night-day, lighting) O = obstruction to the view of the witness K = known or seen before when and where (suspect) A = any special reason for remembering the subject T = time-lapse (how long has it been since witness saw suspect) E = error or material discrepancy between the description given first or any subsequent accounts by a witness.  Working with suspects (college.police.uk)
Post a Comment
Read more

ICD-11 Criteria for Attention Deficit Hyperactivity Disorder (ADHD) 6A05

By
ICD-11 Criteria for Attention Deficit Hyperactivity Disorder (ADHD) 6A05 Attention deficit hyperactivity disorder is characterised by a persistent pattern (at least 6 months) of inattention and/or hyperactivity-impulsivity that has a direct negative impact on academic, occupational, or social functioning. There is evidence of significant inattention and/or hyperactivity-impulsivity symptoms prior to age 12, typically by early to mid-childhood, though some individuals may first come to clinical attention later. The degree of inattention and hyperactivity-impulsivity is outside the limits of normal variation expected for age and level of intellectual functioning. Inattention refers to significant difficulty in sustaining attention to tasks that do not provide a high level of stimulation or frequent rewards, distractibility and problems with organisation. Hyperactivity refers to excessive motor activity and difficulties with remaining still, most evident in structured situations that re...
Post a Comment
Read more

ICD-11 Criteria for Anorexia Nervosa (6B80)

By
ICD-11 Criteria for Anorexia Nervosa (6B80) Anorexia Nervosa is characterised by significantly low body weight for the individual’s height, age and developmental stage that is not due to another health condition or to the unavailability of food. A commonly used threshold is body mass index (BMI) less than 18.5 kg/m2 in adults and BMI-for-age under 5th percentile in children and adolescents. Rapid weight loss (e.g. more than 20% of total body weight within 6 months) may replace the low body weight guideline as long as other diagnostic requirements are met. Children and adolescents may exhibit failure to gain weight as expected based on the individual developmental trajectory rather than weight loss. Low body weight is accompanied by a persistent pattern of behaviours to prevent restoration of normal weight, which may include behaviours aimed at reducing energy intake (restricted eating), purging behaviours (e.g. self-induced vomiting, misuse of laxatives), and behaviours aimed at incr...
Post a Comment
Read more