A: CNVII – Facial Nerve provides motor innervation to muscles of facial expression. CNV – Trigeminal Nerve is separated into 3 branches. V1 is ophthalmic, V2 is maxillary, and V3 is mandibular. V1 and V2 provide sensory information while V3 provides motor input.

C, D. CN III and IV exit from the midbrain. CN V, VI, VII, VII exit from the pons. The remaining cranial nerves exit from the medulla.

D. Trigeminothalamic pathway is responsible for reflexive head movement in response to stimuli. The medial lemniscus pathway carries information regarding touch, pressure, and vibration from the body. The spinothalamic pathway carries pain and temperature information from the body.

A. An INO is caused by a lesion of the medial longitudinal fasciculus (MLF). The MLF is responsible for coordinating the conjugate movement of eyes with associated head/neck movements. A lesion to the MLF causes an INO – loss of ipsilateral adduction and a contralateral nystagmus.

D. The hypothalamus is responsible for regulating body temperature, hunger, and sleep. The epithalamus contains the pineal gland which regulates circadian rhythms. The thalamus acts as a relay station for sensory input to different cortical regions. The subthalamus and basal ganglia communicate to control muscle movement.

D. Optic disc drusen are HYPERreflective on B scan ultrasound.

B. An optic nerve coloboma is caused by the incomplete closure of the fetal fissure during development. The degree of visual impairment varies depending on severity and location. The defect is most commonly located in the inferior nasal region of the disc.

C. The lesion is most likely located in the temporal lobe. To recall, think “pie in the sky”. If these findings were in the inferior field, it is suggestive of a lesion in the parietal lobe.