Handwriting Changes as a Diagnostic Tool for Parkinson’s?

A study from the University of Haifa, Israel, states that changes in handwriting could be an effective tool for the diagnosis of Parkinson’s disease.

Parkinson’s disease (PD) is a progressive neurodegenerative disorder that results from the depletion of the neurotransmitter dopamine in the brain. PD is the second most common neurodegenerative disorder after Alzheimer’s disease. Approximately, 7-10 million individuals are reported to be afflicted with PD globally.

The symptoms of PD occur as a result of the death of the neurons (brain cells) in localized brain structures, called the substantia nigra and locus coeruleus. These neurons normally produce dopamine, a neurotransmitter that acts as a chemical signal to brain regions responsible for motor activity. Patients with PD experience symptoms such as impaired movement and posture, leading to the characteristic tremors and rigidity associated with PD.

Diagnosis of PD is generally done by clinical assessment of symptoms reported by the affected individual or family member, taken together with a neurological examination and neuroimaging studies. Since clinical symptoms appear in a relatively advanced stage of the disease, many individuals in the early stages of PD may go undiagnosed. Early diagnosis could lead to better neurological intervention to delay the onset of disease, but the diagnosis is hampered by mild symptoms. Therefore, the study in discussion is significant since it brings a simple, yet powerful tool for diagnosing PD patients by analyzing their handwriting.

For the study, 20 PD patients in early stages of the disease, and 20 healthy subjects were engaged. They were required to write their names and copy down an address using a special pen with pressure-sensitive sensors. The writing was done on paper, which was attached to a digitizer (an electronic tablet). Mean pressure and mean velocity were measured for each task. For each stroke of the pen, spatial and temporal characteristics were measured as well. The results showed that:

• When compared to healthy controls, those with PD exerted more pressure on the paper while writing;
  
• The letters of individuals with PD were more crowded and smaller;
  
• PD patients took more time to form the letters and words;
  
• The time the pen was in the air between letters and words was significantly higher in PD patients;
  
• With this test, the researchers could identify PD with 97.5% accuracy.

In the words of the lead author, Dr. Rosenblum, the time the pen is in the air is very significant. “This finding is particularly important because while the patient holds the pen in the air, his mind is planning his next action in the writing process, and the need for more time reflects the subject’s reduced cognitive ability. Changes in handwriting can occur years before a clinical diagnosis and, therefore, can be an early signal of the approaching disease,” says Dr. Rosenblum in the Israel 21C News report.

These findings pave the way for an early diagnosis of PD by a simple and objective tool. Diagnosis of PD in the early stages could lead to better management of the disease, thereby improving the quality of life of individuals suffering from the condition.

Written by Mangala Sarkar, Ph.D.

Primary References

Rosenblum, S., Samuel, M., Zlotnik, S., Erikh, I., & Schlesinger, I. (2013). Handwriting as an objective tool for Parkinson’s disease diagnosis. Journal of Neurology, 260(9), 2357-2361.

Scientists discover handwriting can diagnose Parkinson's. (n.d.). Retrieved August 13, 2015, from http://www.israel21c.org/scientists-discover-handwriting-can-diagnose-parkinsons/

DoveMed Resource

Parkinson's Disease (PD). (n.d.). Retrieved August 13, 2015, from http://www.dovemed.com/parkinsons-disease-pd/

Additional References

Statistics on Parkinson's. (n.d.). Retrieved August 13, 2015, from http://www.pdf.org/en/parkinson_statistics