neuro-exam is About pathways.
In essences, neurological exam is to test different pathways as human body is a wired information highway.
There are longitudinal pathways from top down as well as pathways from front to back.
When a patient listens to your command to flex his left big toe with full strength, what is tested is the neurology pathway from right motor cortex to brain stem, cervical spine, thoracic spine and lumbar spine, sciatic nerve, tibial nerve and the nerve muscle junction then the muscles, the joints and bones of foot and toe dorsal flexion. What it means is all structures the nerve signal travels is in good function. This one single test yields so much information about so many systems. In term of return on your effort to obtain information, this neuro-exam is very rewarding.
If the same patient can flex and extend his thumb on command, then the arm is tested. Another set of nerve, muscle, bone and joints are tested. This way, all 4 extremity are examined now.
Next, gait can be tested, with Romberg test, sitting down, standing up, turning a corner, tandem walking, heel and toe walking. This is the summation of lower extremity motor/sensory test, balance/coordination/, gait, stationary and posture.
This set complete the top down test.
The next is front to back test. The visual testing serves this purpose.
Ask the patient to read aloud a paper or a magazine holding by their hands, then you have tested to frontal to back neuro pathway of the brain. This is because the visual signal comes in from the eyes and travels back to the occipital lobe of the brain. What is more, the reading test also evaluate the speech and language function and all but two cranial nerves (that is 1st and 11th CN) as well as attention, receptive and expressive speech function, a higher cortical function. Here, a single reading test give you so much information about the brain function.
A third test is auditory test which involves pathways from left to right.
A test such as finger ub next to a patient left ear travels first from the auditory nerve-CN 8th to ipsilateral cochlear nucleus then to contralateral superior olive nucleus. Further, the signal travels up to bilateral inferior colliculus which further relay the signal to medial geniculate body of the thalamus. From these thalamic nucleus, processed sound signal were projected to bilateral auditory cortex located in the upper posterior part of the temporal lobe around sylvian fissure.
All these tests takes about 5 minutes to do in office. These three test sets do not cover all neurological functions but it covers the basic life and motor functions. IF all tests are normal then it is highly likely the patient does not have neurological deficit. Documentation should describe the tests and how they were done. If there is any deficit then such must be further investigated. Refer the patient to a neurologist or if there is new deficit then the patient may need to be sent to ED for further management.