A 49-year-old woman arrives at the office complaining of muscular weakness. The patient's right hand has been weakening for the previous three months. She's also been hallucinating. The patient's arms and legs are twitching and cramping. She has no sensory issues. The lower extremities muscles have increased tone and fasciculations on examination. There is atrophy of the interosseus muscles of the right hand as well as the bilateral intrinsic muscles of the foot. When the doctor touches the chin with the mouth slightly open, the jaw jerks up quickly. This response is mediated by which of the following cranial nerves?

Question

Quizplus · Accepted Answer

Eductional Objective: The jaw jerk reflex is a pathologic cranial nerve response that occurs in people with amyotrophic lateral sclerosis, which affects bilateral upper motor neuron lesions. The mandibular division of the trigeminal nerve mediates both the afferent and efferent pathways (CN V3).

A 49-Year-Old Woman Arrives at the Office Complaining of Muscular