Breath Test Detects Early-Stage Parkinson's Disease

Parkinson's disease (PD) is a degenerative disease that destroys brain tissue and affects movement. It has four main symptoms: stiffness, shaking, slowness, and problems with coordination and balance. Other problems can also develop as the disease progresses, including fatigue, speech difficulties, disrupted sleep, memory problems, and depression.

The disease is complex and diverse and arises differently in different people. However, there are some common features, the main one being the dead dopamine-producing cells in a brain area called the substantia nigra. Dopamine is a brain chemical that carries messages that control movement and other functions. There are around 10 million people living with Parkinson's disease worldwide, including one million in the USA.

Scientists at the Technion - Israel Institute of Technology (Haifa, Israel) described for the first time a clinical trial to distinguish between de novo PD and control subjects using an electronic system for the detection of volatile molecules in exhaled breath (sensor array). They further determined for the first time the association to other common tests for PD diagnostics as smell, ultrasound, and nonmotor symptoms. The test group consisted of 29 PD patients after initial diagnosis by an experienced neurologist, compared with 19 control subjects of similar age who did not have the disease.

The breath-testing device contains an array of 40 sensors made of carbon nanotubes or gold nanoparticles. Each sensor had a different chemical attached that could bind certain volatile molecules in the breath, and this binding changed the electrical resistance of the sensor. The authors reported that the test was able to detect early-stage Parkinson's patients before medication and showed sensitivity, specificity, and accuracy values of the sensor array to detect PD from controls were 79%, 84%, and 81% respectively, in comparison with midbrain ultrasonography (93%, 90%, 92%) and smell detection (62%, 89%, 73%).

The authors concluded that although the device needs to be improved and validated by larger studies, they say that it has potential as a small, portable system to screen at-risk individuals without the need for highly trained specialists. The study was published online on July 10, 2018, in the journal ACS Chemical Neuroscience.

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Technion - Israel Institute of Technology