Therapists can evaluate cranial nerves at an initial consultation which provides the therapist a window into the patient’s neurological status and the location of the insult. It makes reading the neurologist’s consult clear and the therapist’s objectives more to the point. As therapists, we most often encounter cranial nerve deficits after a traumatic event, stroke, or diagnosis of a brain mass. Close attention to where the cranial nerves arise and their respective pathways through the brain will localize the event and the differential diagnosis for the neurologist and neurosurgeon.
Cranial Nerves: A Sign of an Emergency
When working with a patient in the ICU, it is especially important to be evaluating cranial nerves that affect the eye and tongue. The therapist and the RN may be the first line of defense for a sudden change in status 3-4 days immediately following a stroke. There often can be a dramatic increase in cytotoxic swelling or intraventricular extension which can build into a life threatening emergency.
During this time, an alerted level of consciousness and a change in cranial nerve function are among the first telling signs. We may be called on to inform the neurologist or neurosurgeon of the change for prompt treatment. Even once past this window of danger, physical and occupational therapists are called to evaluate safety and disposition for outpatient or inpatient rehab. If it is not clear to you how the patient’s vision has been compromised and how it affects them, you can send them home with a high risk for falls during ambulation or activities of daily living (ADLS).
3rd, 4th, and 6th Cranial Nerve Palsies
The most common patient complaint that I encounter is of double vision, however many do not show exasperation over their problem. I am often surprised by the patients non-complaint of their eyelid (ptosis) from a 3rd cranial nerve palsy following a subarachnoid hemorrhage (SAH). If you do not know where to start learning, go with the your most seen patient complaint.
Remember that practice makes perfect. The more you evaluate a normal patient’s cranial nerve functions, the more you can identify real problems. So do not be discouraged to always examine and clear every neurologic patient’s cranial nerves. If you can identify a normal eye’s extraocular movements, then it is easier to see a problem on the first exam. Need practice or are not sure what you are seeing; do not be afraid to ask for help with this task.
Ask the neurologist for tips, an experienced therapist, or a well-practiced neurologic trained nurse on the unit. Once you get the hang of it, you will have the confidence to know that you are sending your patient home with a safe plan, or to acute rehab with a need to learn how to accommodate their mobility and adls to their new visual limits. Remember, that we are often the gatekeepers to discharging a patient home, and no one wants a patient to repeat a fall and need a second hospitalization or surgery. The risks are too high to ignore.
There are three essential take aways. First, do not ignore the patient’s eyes as this the most frequent cranial nerve dysfunction we will encounter. Real life is at times unforgiving. A new field of vision deficit or double vision is a dangerous thing with a car, hot stove, or cooking knife. I often have to caution my patients about not using hot stoves and knives until they are cleared by a therapist in outpatient.
Second, know how to distinguish each cranial nerve palsy, there may be life threatening signs that you may encounter days after a stroke. They will need prompt attention by the neurosurgeon. Third, and most critically, we are often the gatekeepers to clearing a patient for discharge to home or inpatient rehab.
We should be skilled at knowing how each palsy and resultant deficit affects their daily skills and remember to test those situations in our evaluation. Just because a client can walk or do basic tasks in a sterile hospital setting does not mean they are safe. Critically evaluate and ask what are their real life needs. Most people drive, complete complex household chores, and walk on uneven surfaces either at home or at work.