What is the difference between parkinsons and huntingtons disease

Researchers are focusing on abnormal proteins that could be causing the brain damage associated with these three neurological diseases.

Is an abnormal protein the cause of Alzheimer’s, Parkinson’s, and Huntington’s diseases?

A group of researchers is looking into that question.

If successful, their research could lead to diagnostic tools and new treatments that could be used on all three of these deadly neurological ailments.

The findings from the scientists at Loyola University Chicago were published late last month in the journal Acta Neuropathologica.

“A possible therapy would involve boosting a brain cell’s ability to degrade a clump of proteins and damage vesicles,” explained Edward Campbell, PhD, study senior author, and an associate professor at Loyola, in a statement. “If we could do this in one disease, it’s a good bet the therapy would be effective in the other two diseases.”

Read more: Get the facts on Alzheimer’s disease »

Neurodegenerative diseases are basically caused by the death of cells in the brain.

In Alzheimer’s, this destruction primarily destroys memory.

In Parkinson’s and Huntington’s, it primarily affects movement.

Despite those effectual differences, the Loyola researchers say they may have discovered a common thread among the trio of diseases.

In all three ailments, previous research has suggested that proteins that are abnormally folded form clumps inside brain cells.

Different proteins have been implicated in each of the three diseases. In Alzheimer’s, it’s tau. In Parkinson’s, it’s alpha-synuclein. In Huntington’s, it’s huntingtin.

The Loyola researchers concluded that these different proteins behave in the same way when they enter brain cells.

They said these proteins invade vesicles, small compartments that are encased in membranes.

The proteins damage those membranes, allowing them to then invade a cell’s cytoplasm and cause even more destruction.

The researchers said the damaged cells try to gather the ruptured vesicles and protein clumps together to destroy them. However, the proteins are resistant to the degradation.

“The cell’s attempt to degrade the proteins is somewhat like a stomach trying to digest a clump of nails,” Campbell said.

Read more: The stages of Parkinson’s disease »

Experts in these fields told Healthline this particular research does provide some encouragement.

James Hendrix, director of global science initiatives at the Alzheimer’s Association, said although the three diseases involve different proteins and have different effects on the brain, there is still some commonality.

He likened it to studying the motors of cars, airplanes, and boats. Although they’re different modes of transport, they still have similar engines.

“It’s valuable to have this cross talk. You don’t want to work in a silo,” Hendrix told Healthline. “A discovery in one area can revolutionize another field.”

George Yohrling, PhD, the senior director of mission and scientific affairs at the Huntington’s Disease Society of America, agrees.

“They’re looking at what’s going on at the cellular level. What cellular machinery is being disrupted,” he told Healthline.

“It gets down to the cellular level,” added Hendrix. “If you can understand what’s going wrong, you might be able to prevent that mechanism from happening.”

A breakthrough is sorely needed for all these diseases.

Late last month, the Centers for Disease Control and Prevention (CDC) announced that the death rate from Alzheimer’s in the United States increased 55 percent between 1999 and 2014.

In addition, about 50,000 people in the United States are diagnosed with Parkinson’s every year. An estimated 500,000 Americans are living with the disease.

Huntington’s usually afflicts people while they are in their 30s and 40s. Most people die 15 to 20 years after diagnosis.

Yohrling and Hendrix both said finding a treatment that worked for all three diseases would be a truly fantastic thing.

“That would be wonderful,” said Yohrling.

“That would be pretty amazing,” added Hendrix.

Read more: Get the facts on Huntington’s disease »

Case Study: Late-Onset Huntington’s Presents Like Parkinson’s Disease

Man, 56, showed Parkinson's-like symptoms at diagnosis

What is the difference between parkinsons and huntingtons disease

What is the difference between parkinsons and huntingtons disease

What is the difference between parkinsons and huntingtons disease

A 56-year-old man with undiagnosed late-onset Huntington’s disease presented with Parkinson’s disease-like symptoms, including bradykinesia, or slowness of movement, a case study reported.

He was correctly diagnosed after clinicians learned of a family history of Huntington’s and ordered genetic testing.

Given the diagnosis, the researchers recommended that Huntington’s disease be considered when older patients with a family history of Huntington’s show Parkinson’s-like symptoms.

“Some patients can initially present atypical movements other than the usual symptoms, such as parkinsonism, ataxia [poor muscle control], and dystonia [involuntary muscle contractions],” the team wrote.

The case study, “Atypical parkinsonism can be a presenting feature of late-onset Huntington’s disease,” was published in the journal Clinical Case Reports.

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What is the difference between parkinsons and huntingtons disease

Huntington’s disease vs Parkinson’s: similar symptoms

Huntington’s disease is caused by defects in the huntingtin (HTT) gene. These mutations lead to an expansion of CAG nucleotides, which are building blocks of DNA. Typically, the HTT gene CAG expansion contains 10 to 35 repeats, but in people with Huntington’s disease, it may be repeated from 36 to more than 120 times.

These genetic defects lead to an imbalance in dopamine levels in the brain. Dopamine is a neurotransmitter, or nerve cell signaling molecule, that plays an essential role in body movements.

Unusually high dopamine levels are thought to cause chorea — abrupt movements that are irregular and unpredictable. In the later stages of the disease, dopamine levels can drop, which can ease chorea but then show symptoms similar to Parkinson’s disease, a movement disorder characterized by abnormally low dopamine levels. This can often lead to a misdiagnosis.

Now, researchers based at the Shahid Beheshti University of Medical Science, in Iran, described the case of a man in his mid-50s with undiagnosed Huntington’s who was treated for Parkinson’s-like symptoms.

The man had undergone treatment for depression for eight years before gradually developing other symptoms that all appeared to be signs of Parkinson’s disease. These symptoms included speech impairment, walking difficulties, an urgent need to urinate, constipation, memory problems, and frequent falling.

His medical records showed no history of brain inflammation, known as encephalitis, or exposure to toxic substances. Nor had the man received medications designed to lower dopamine or block dopamine receptors.

Notably, his now-deceased father had Huntington’s disease, as did his sister, who carried 42 CAG repeats.

On examination, the patient had an expressionless face and eye movements that were slow in all directions but more prominent vertically. His upper and lower extremities were rigid, and he showed slowness of movement, called bradykinesia, also consistent with Parkinson’s.

During the exam, he showed repetitive hand movements and could not stand for more than three minutes to measure blood pressure. His speech was unclear, high-pitched, and whiny, and he also had significant cognitive impairment.

MRI scans demonstrated generalized atrophy, or shrinkage of the brain, which was more prominent in the temporal lobes and caudate nucleus. That area of the brain typically has the heaviest nerve damage in Huntington’s.

Because of his family history of Huntington’s, he underwent genetic testing, which demonstrated 39 CAG repeats in the HTT gene.

He had been treated with medications for dementia (donepezil), to control body movements (amantadine, sold as Gocovri), and to prevent seizures (valproate sodium).

The team added the standard Parkinson’s therapy levodopa; a precursor molecule converted to dopamine in the brain. The dose was gradually increased from 25 mg three times per day to 100 mg three times daily, and amantadine also was increased.

Treatment led to mild improvement in bradykinesia, rigidity, and gait.

The researchers noted that this was the fifth reported case of late-onset Huntington’s that presented with Parkinson’s-like symptoms.

Huntington’s disease “should be considered as a differential diagnosis of patients with atypical parkinsonism, especially if family history is positive,” the researchers concluded.

About the Author

What is the difference between parkinsons and huntingtons disease

Steve Bryson, PhD Steve holds a PhD in biochemistry from the Faculty of Medicine at the University of Toronto, Canada. As a medical scientist for 18 years, he worked in both academia and industry, where his research focused on the discovery of new vaccines and medicines to treat inflammatory disorders and infectious diseases. Steve is a published author in multiple peer-reviewed scientific journals and a patented inventor.

Can Huntington's be misdiagnosed as Parkinson's?

In the later stages of the disease, dopamine levels can drop, which can ease chorea but then show symptoms similar to Parkinson's disease, a movement disorder characterized by abnormally low dopamine levels. This can often lead to a misdiagnosis.

What disease mimics Huntington's?

Autosomal-dominant diseases that can mimic HD are HD-like 2, C9orf72 mutations, spinocerebellar ataxia type 2, spinocerebellar ataxia type 17 (HD-like 4), benign hereditary chorea, neuroferritinopathy (neurodegeneration with brain iron accumulation type 3), dentatorubropallidoluysian atrophy and HD-like 1.

What are 3 symptoms of Huntington's disease?

The first symptoms of Huntington's disease often include:.
difficulty concentrating..
memory lapses..
depression – including low mood, a lack of interest in things, and feelings of hopelessness..
stumbling and clumsiness..
mood swings, such as irritability or aggressive behaviour..

What disease has the same symptoms as Parkinson's disease?

Conditions that Mimic Parkinson's.
Essential Tremor. Essential tremor (ET) is a tremor involving the hands or forearms that occurs when the limbs are active. ... .
Normal Pressure Hydrocephalus. ... .
Dementia with Lewy Bodies. ... .
Multiple System Atrophy. ... .
Corticobasal Syndrome. ... .
Progressive Supranuclear Palsy..