Key Difference – Huntington’s Disease vs Alzheimer’s
Huntington’s disease is a cause of chorea, usually appearing in the middle years of life and later becoming complicated with psychiatric and cognitive abnormalities. Alzheimer’s disease is a neurodegenerative condition of the brain, which is characterized by the atrophy of brain tissues and it has been identified as the most common cause of dementia. In Huntington’s disease, there is a predominant motor impairment which is not observed in the Alzheimer’s disease. This is the key difference between Huntington’s disease and Alzheimer’s.
CONTENTS
1. Overview and Key Difference
2. What is Huntington’s Disease
3. What is Alzheimer’s
4. Similarities Between Huntington’s Disease and Alzheimer’s
5. Side by Side Comparison – Huntington’s Disease and Alzheimer’s in Tabular Form
6. Summary
What is Huntington’s Disease?
Huntington’s disease is a cause of chorea usually appearing in the middle years of life and later becoming complicated with psychiatric and cognitive abnormalities. A CAG trinucleotide repeat expansion has been identified to be the cause of this condition. An inverse relationship has been speculated between the number of repeat units and the age of onset, with over 60 repeat units in the cases of juvenile onset. There is a tendency for the successive generations to have an earlier onset and a more severe disease than previous generations.
Figure 01: Huntington’s Disease
There is no disease-modifying drug at present. Progressive neurodegeneration leads to dementia and death after 10-20 years.
What is Alzheimer’s?
Alzheimer’s disease is the most common cause of dementia.
Clinical Features of Alzheimer’s
The key clinical features of this condition are,
- Memory impairment
- Difficulty with words
- Apraxia
- Agnosia
- Frontal executive function- impairment in planning, organizing, and sequencing
- Visuospatial difficulties
- Difficulties with orientation in space and navigation
- Posterior cortical atrophy
- Personality
- Anosognosia
Although the vast amount research carried out on this subject has not been able to find the exact cause of the disease, it has unveiled a lot about the molecular pathology related to the disease progression. Deposition of beta-amyloid in amyloid plaques and the formation of tau-containing neurofibrillary tangles are the hallmark features of Alzheimer’s disease. Laying down of amyloid in the cerebral blood vessels can give rise to amyloid angiopathy
First degree relatives have a two times higher risk of getting Alzheimer’s than the normal population. Mutations in the following genes are the cause of autosomal dominant forms of the Alzheimer’s disease.
- Amyloid precursor protein
- Presenilin 1 and 2
- E4 allele of apolipoprotein E
Figure 02: Alzheimer’s
Risk Factors
- Advanced age
- Head trauma
- Vascular risk factors
- Family history
- Genetic predisposition
Whenever there is a clinical suspicion of Alzheimer’s disease, a CT scan of the brain is carried out; this will show degenerative changes such as atrophy in the presence of Alzheimer’s disease.
Management
There is no definitive treatment for Alzheimer’s disease.
Cholinesterase inhibitors can be given to control the neuropsychiatric manifestations such as depression. Memantatidine has also proven to be effective in controlling the disease progression and symptoms. Anti-depressants are prescribed when necessary along with the drugs such as zolpidem that can that can minimize the sleep disturbances.
What is the Similarity Between Huntington’s Disease and Alzheimer’s
- Both conditions cause dementia.
What is the Difference Between Huntington’s Disease and Alzheimer’s?
Huntington’s Disease vs Alzheimer’s |
|
| Huntington’s disease is a cause of chorea usually appearing in the middle years of life and later becoming complicated with psychiatric and cognitive abnormalities | Alzheimer’s disease is a neurodegenerative condition of the brain which is characterized by the atrophy of brain tissues, and it has been identified as the most common cause of dementia. |
| Impairment | |
| In Huntington’s disease, there is a predominant motor impairment. | In Alzheimer’s disease, cognitive impairment is more prominent. |
| Clinical Features | |
| The patient usually has chorea along with other cognitive abnormalities such as dementia. |
|
| Management | |
| There is no disease-modifying drug at present. Progressive neurodegeneration leads to dementia and death after 10-20 years. | There is no definitive treatment for the Alzheimer’s disease.
Cholinesterase inhibitors can be given to control the neuropsychiatric manifestations such as depression. Memantatidine has also proven to be effective in controlling the disease progression and symptoms. Anti-depressants are prescribed when necessary along with the drugs such as zolpidem that can that can minimize the sleep disturbances. |
Summary – Huntington’s Disease vs Alzheimer’s
Huntington’s disease is a cause of chorea usually appearing in the middle years of life and later becoming complicated with psychiatric and cognitive abnormalities whereas Alzheimer’s disease is a neurodegenerative condition of the brain which is characterized by the atrophy of brain tissues. Alzheimer’s has been identified as the most common cause of dementia. In Huntington’s, the motor component is predominantly impaired, but in Alzheimer’s, cognitive functions are predominantly impaired. This is the major difference between Huntington’s and Alzheimer’s.
Reference:
1.Kumar, Parveen J., and Michael L. Clark. Kumar & Clark clinical medicine. Edinburgh: W.B. Saunders, 2009.
Image Courtesy:
1. “Huntington” By Frank Gaillard – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Alzheimers brain” By National Institutes of Health – (Public Domain) via Commons Wikimedia