Cranial Nerves Introduction
Perhaps more than any other part of the neurologic exam, cranial nerve testing can raise “red flags” that suggest specific neurologic dysfunction rather than a systemic disorder. For example, many medical conditions cause lethargy, unsteadiness, headaches, or dizziness. However, any of these symptoms together with cranial nerve abnormalities strongly suggests brainstem dysfunction as the cause (see Neuroanatomy Through Clinical Cases 3e, Chapters 12, 13 and 14). Careful testing of the cranial nerves, therefore, can reveal crucial information to help pinpoint disorders in the nervous system. While learning to test the cranial nerves, refer to Neuroanatomy Through Clinical Cases 3e, Figure 2.22 and Table 2.5.