"You can't teach an old dog new tricks" is clearly repeated by an elderly man who's family got concerned he was having a stroke when they noticed some gait ataxia. EMS does a quick Cincinnati Stroke Scale and doesn't detect any deficits, 12 lead looks normal, and blood glucose is within normal limits. Should he be evaluated in the emergency room? Should EMS be concerned about a central lesion? Does a negative Cincinnati mean the patient is not having a CVA?
I would argue that while the FAST exam is a great tool for the public to quickly identify stroke symptoms, as healthcare professionals, we should be performing a more thorough neurological exam. Our service a few years ago did extensive training on the NIH stroke scale. Our goal was to speak the same language as the hospitals in which we were taking and delivering patients from. The issue of subjectivity and intra-operator reliability comes into question whenever I discuss the NIHSS. I would argue that the exact score is not as important as is the relay of information & communication between providers.
The Cincinnati Stroke Scale has been proven to be very sensitive in detecting large vessel occlusions. However there are subsets of ischemic lesions that will not be detected during this exam. It also pays to note that we are not just looking for strokes. We are looking for acute neurological deficits. The diagnostic momentum to exclude a stroke, may lead you to miss a pertinent finding.
"Aint No Body Got Time For That!"
The argument that typically comes up when we discuss performing an assessment of the cranial nerves is "it takes too long!" I had my friend Chip Lange from the TOTAL EM podcast record a video of him performing the complete neuro exam he uses in the emergency room.
Chip isn't just asking random memorized questions. He is carefully assessing each cranial nerve in an attempt to build a better clinical picture.
Check out Chip Lange's Podcast/ Blog http://www.totalem.org/emergency-professionals
The most important part of a neurological exam is not just going through the motions, but understanding and trending the findings. For example, if my patient with vertigo has one eye that moves vertically asymmetrical from the other, I am going to be concerned about a cerebellar infarct. If my exam reveals vertigo only with movement, I may be more likely to believe its contributed to a benign peripheral vestibulopathy (BPV).
The Cranial Nerve Challenge
For the next 12 shifts I would recommend adding a new cranial nerve to each patient assessment you do. Spend that day studying how to test it, what it does, and where it receives its blood supply. Just like acquiring a 12 lead does nothing physically for the patient if you don't know how to read it, a neuro exam without a proper understanding is a waste of time.
CN Functions
Day 1- Olfactory Smell
Day 2- Optic Vision
Day 3-Oculomotor Muscle of the eye
Day 4-Trochlear Superior oblique eye muscle
Day 5- Trigeminal Sensory from the face and mouth; motor to muscles of mastication (chewing)
Day 6- Abducens Lateral rectus eye muscle
Day 7- Facial Facial expressions, salivary glands, and lacrimal glands
Day 8 - Vestibulocochlear Equilibrium & hearing
Day 9 - Glossopharyngeal Swallowing
Day 10 - Vagus Sensations from visceral organs, and parasympathetic motor regulation or visceral organs
Day 11- Accesory Serves muscles that move head, neck, & shoulders
Day 12- Hypoglossal Serves muscles of the tongue