In one embodiment, a system for finger-to-thumb crease testing includes a patient interface configured to attach to a thumb of a patient, the patient interface including a touch sensor configured to sense contact between a finger of the patient and the touch sensor, the touch sensor being positioned on the patient interface in a location at which it overlies a distalmost thumb crease of the thumb when the patient interface is attached, and a control module in electrical communication with the patient interface, the control module being configured to count a number of times the patient successfully taps the touch sensor with the finger.