Neurologic examinations are unique in medicine. Unlike other fields of medicine in which one can touch (surgery, orthopedics) or see the disease (eg, dermatology, ophthalmology), neurologic conditions often manifest in cryptic ways. Which is why simple clinical examination done with basic tools (reflex hammer, tuning fork, pin…) are always relevant for initial evaluation.
Touch Diagnostics is a small startup that has created four iPhone applications that provide a new way to administer some of the neurologic exams:
- Nystagmus is a disorder with periodic rhythmic, involuntary movement of the eyes. One of the ways to test for it is by using a ‘Optokinetic Drum‘, which relies on the response of the eye to continuously moving pattern that has contrasting elements. Now the drum can be expensive and comes with real-world problems (storage, disinfection etc.). OKN+™ is a simple app that replaces the drum for $2.99.
- In Finger Oscillation Test, individuals are instructed to tap their index finger as quickly as possible for few seconds, keeping the hand and arm stationary. It measures motor speed and helps determine particular areas of the brain that may be damaged. $2.99 DigiTap™ is replacement of older devices for this test.
- Reaction time is a simple measurement (in milliseconds) between the presentation of a stimulus and the elicited response. The results can be used to assess fatigue, concussion, sobriety, etc. ReAct™ does that for $2.99.
- Tremors are unintentional movements, and sometime these micro-vibrations are too small to notice with naked eye. For $3.99, TremorTracer™ provides a way to perform some subjective tremor tests (like Archimedes Spirals in which patient tries to trace a line inside a spiral space)
Okay, so these apps are not exactly cut for the top 25 list on iTunes. And they may never gain traction amongst the myriad of health-related apps out there. The clinical value of doing these tests, although foundational, is also no match for a CT scan. A neurologist I spoke with was quick to point out that doing these test the old-fashioned way doesn’t take much time, and the results are not that crucial anyway (for clinical course of action).
Regardless, I like the way these apps cleverly digitize a small subset of real clinical tests even when the hardware (i.e. the iPhone) was never intended for clinical applications. There will be a time in future when these smart computing devices open up to third-party hardware add-ons like scopes or sensors- temperature, pulse oximeter, etc. Then this would be a valid and viable genre of applications. Till then, we need to ‘fit the test to the device’ rather than the other way around.