Nerfs imaging in the eyes can be used to differentiate Parkinson’s disease and secondary forms of parkinsonism, according to a new study.
The study, “Cornean confocal microscopy differentiates patients with secondary parkinsonism from the idiopathic parkinson disease“, Was published in NPJ Parkinson’s disease.
Parkinson can cause anomalies in the nerves connecting the eyes and the brain
Parkinson’s disease is a neurodegenerative disorder caused by the dysfunction and death of brain cells which are responsible for the manufacture of chemical messenger dopamine. Parkinson’s is marked by motor symptoms such as slow motion, tremors, stiffness and balance problems. Most people with parkinson have idiopathic disease, which means that the underlying cause is not known.
Secondary Parkinsonism refers to health problems that can cause Parkinson -type motor symptoms, but are not in fact Parkinson’s disease. Secondary parkinsonism can develop due to drugs or toxins, or due to blood flow problems or liquid pressure in and around the brain. Since secondary parkinsonism is characterized by definition by symptoms similar to Parkinson’s disease, it can be difficult for clinicians to separate them.
Parkinson’s disease can cause anomalies in the nerves that connect the eyes to the brain, which are generally less affected in secondary parkinsonism. These nerves can be visualized using a technique called corneal confocal microscopy, or CCM. In this study, scientists in China have tested whether CCM could be used to distinguish reliably between real disease of Parkinson and secondary parkinsonism.
The CCM can have clinical utility as a rapid ophthalmic neuroimetry method to distinguish patients with (secondary parkinsonism) from (Parkinson’s disease).
The study included 45 people with idiopathic parkinson disease and 25 with secondary parkinsonism. The researchers found that Parkinson patients had a lower density of nerve fibers detected by the CCM than those with secondary parkinsonism. They also tended to have more protuberances in the shape of a branch on their nerves than those with secondary parkinsonism.
To test whether these CCM -based measures could distinguish the two conditions, the researchers calculated a statistical value called zone under the characteristic curve of the receiver’s operating (AUC). This is a statistical test of how a measure (in this case, CCM) can distinguish between two groups, parkinson or secondary parkinsonism in this study. AUC values can range from 0.5 to 1, with higher numbers reflecting better precision.
The AUC for the CCM in this study was 0.924, suggesting great precision to distinguish the true parkinson from secondary parkinsonism. Researchers noted that they could obtain better precision if they also included clinical measures such as evaluations of the severity of symptoms.
“The CCM can have clinical utility as a rapid method of ophthalmic neuroimetry to distinguish patients with (secondary parkinsonism) from (Parkinson’s disease),” concluded scientists.
