The<unk>  or the masseter reflex is a stretch reflex used to test the status of a patient's trigeminal nerve (cranial nerve V) and to help distinguish an upper cervical cord compression from lesions that are above the foramen magnum. The mandible—or lower<unk> —is tapped at a downward angle just below the lips at the chin while the mouth is held slightly open. In response, the masseter muscles will<unk>  the mandible upwards. Normally this reflex is absent or very slight. However, in individuals with upper motor neuron lesions the<unk>  can be quite pronounced. The<unk>  can be classified as a dynamic stretch reflex. As with most other reflexes, the response to the stimulus is monosynaptic, with sensory neurons of the trigeminal mesencephalic nucleus sending axons to the trigeminal motor nucleus, which in turn innervates the masseter. This reflex is used to judge the integrity of the upper motor neurons projecting to the trigeminal motor nucleus. Both the sensory and motor aspects of this reflex are through CN V. It is not part of a standard neurological examination. It is performed when there are other signs of damage to the trigeminal nerve. The clinical presentation of cervical spondylotic myelopathy can be similar to multiple sclerosis (MS) or amyotrophic lateral sclerosis (ALS), however, a hyperactive<unk>  reflex suggests the pathology is above the foramen magnum. In other words, a normal<unk>  points the diagnosis toward cervical spondylotic myelopathy and away from MS or ALS.
Jaw jerk reflex
Tonic vibration reflex
Stretch reflex
Biceps reflex
Triceps reflex
Moro reflex
Tendon reflex
Plantar reflex