SECTIONS OF THE BRAINSTEM ANATOMY, SURGICAL BRAINSTEM PROCEDURES AND CRANIAL NERVE MONITORING Thalamus James Watt, BS, CNIM, R.EP.T Midbrain MSET 2017 Pons Medulla Oblongata CRANIAL NERVES 1. OLFACTORY NERVE 1. Olfactory 7. Facial 2. Optic 8. Vestibulocochlear • Sensory 3. Oculomotor 9. Glossopharyngeal • Not monitored during surgery 4. Trochlear 10.Vagus • Origin - Telencephalon Trigeminal Spinal Accessory 5. 11. • Nuclei - Anterior olfactory nucleus 6. Abducens 12.Hypoglossal THE BIG PICTURE THE BIG PICTURE Optic Canal - II Superior Orbital Fissure - III, IV, V1 and V(1) Foramen Rotundum - V(2) Foramen Ovale - V(3) Internal Acoustic Meatus - VII & VIII Jugular Foramen - IX, X, XI Hypoglossal Canal - X THE BIG PICTURE THE BIG PICTURE Optic Canal - II Optic Canal - II Superior Orbital Fissure - III, IV, V1 and V(1) Superior Orbital Fissure - III, IV, V1 and V(1) Foramen Rotundum - V(2) Foramen Rotundum - V(2) Foramen Ovale - V(3) Foramen Ovale - V(3) Internal Acoustic Meatus - VII & VIII Internal Acoustic Meatus - VII & VIII Jugular Foramen - IX, X, XI Jugular Foramen - IX, X, XI Hypoglossal Canal - X Hypoglossal Canal - X THE BIG PICTURE THE BIG PICTURE Optic Canal - II Optic Canal - II Superior Orbital Fissure - III, IV, V1 and V(1) Superior Orbital Fissure - III, IV, V1 and V(1) Foramen Rotundum - V(2) Foramen Rotundum - V(2) Foramen Ovale - V(3) Foramen Ovale - V(3) Internal Acoustic Meatus - VII & VIII Internal Acoustic Meatus - VII & VIII Jugular Foramen - IX, X, XI Jugular Foramen - IX, X, XI Hypoglossal Canal - X Hypoglossal Canal - X THE BIG PICTURE THE BIG PICTURE Optic Canal - II Optic Canal - II Superior Orbital Fissure - III, IV, V1 and V(1) Superior Orbital Fissure - III, IV, V1 and V(1) Foramen Rotundum - V(2) Foramen Rotundum - V(2) Foramen Ovale - V(3) Foramen Ovale - V(3) Internal Acoustic Meatus - VII & VIII Internal Acoustic Meatus - VII & VIII Jugular Foramen - IX, X, XI Jugular Foramen - IX, X, XI Hypoglossal Canal - X Hypoglossal Canal - X 2. OPTIC NERVE 3. OCULOMOTOR • Mainly motor • Spontaneous and triggered • Sensory EMG monitored during • Monitored using Flash Visual Evoked surgery Potentials during surgery • Origin - Anterior aspect of • Origin - Retina Midbrain • • Nucleus - Lateral geniculate nucleus Nucleus - Oculomotor nucleus, Edinger-Westphal nucleus 3. OCULOMOTOR 3. OCULOMOTOR • Mainly motor • Mainly motor • Spontaneous and triggered • Spontaneous and triggered EMG monitored during EMG monitored during surgery surgery • Origin - Anterior aspect of • Origin - Anterior aspect of Midbrain Midbrain • Nucleus - Oculomotor • Nucleus - Oculomotor nucleus, Edinger-Westphal nucleus, Edinger-Westphal nucleus nucleus 3. OCULOMOTOR 3. OCULOMOTOR • Mainly motor • Mainly motor • Spontaneous and triggered • Spontaneous and triggered EMG monitored during EMG monitored during surgery surgery • Origin - Anterior aspect of • Origin - Anterior aspect of Midbrain Midbrain • Nucleus - Oculomotor • Nucleus - Oculomotor nucleus, Edinger-Westphal nucleus, Edinger-Westphal nucleus nucleus 3. OCULOMOTOR 3. OCULOMOTOR • Mainly motor • EMG monitored from • Spontaneous and triggered EMG monitored during • Inferior Rectus Muscle surgery • Nerve also innervates • Origin - Anterior aspect of • Superior Rectus Muscle Midbrain • Medial Rectus Muscle • Nucleus - Oculomotor nucleus, Edinger-Westphal • Inferior Oblique Muscle nucleus 3. OCULOMOTOR 4. TROCHLEAR NERVE • EMG monitored from • Inferior Rectus Muscle • Motor • Nerve also innervates • Spontaneous and triggered EMG monitored during surgery • Superior Rectus Muscle • Origin - Dorsal aspect of Midbrain • Medial Rectus Muscle • Nucleus - Trochlear nucleus • Inferior Oblique Muscle Yingling 4. TROCHLEAR NERVE 4. TROCHLEAR NERVE • Motor • Motor • Spontaneous and triggered EMG • Spontaneous and triggered EMG monitored during surgery monitored during surgery • Origin - Dorsal aspect of Midbrain • Origin - Dorsal aspect of Midbrain • Nucleus - Trochlear nucleus • Nucleus - Trochlear nucleus 4. TROCHLEAR NERVE 4. TROCHLEAR NERVE • Motor • Motor • Spontaneous and triggered EMG • Spontaneous and triggered EMG monitored during surgery monitored during surgery • Origin - Dorsal aspect of Midbrain • Origin - Dorsal aspect of Midbrain • Nucleus - Trochlear nucleus • Nucleus - Trochlear nucleus 4. TROCHLEAR NERVE 4. TROCHLEAR NERVE • EMG monitored from • EMG monitored from • Superior Oblique Muscle • Superior Oblique Muscle Yingling 6. ABDUCENS NERVE 6. ABDUCENS NERVE • Mainly Motor • Mainly Motor • Spontaneous and triggered EMG • Spontaneous and triggered EMG monitored during surgery monitored during surgery • Origin - floor of the fourth ventricle in • Origin - floor of the fourth ventricle in the Pons the Pons • Nucleus - Abducens nucleus • Nucleus - Abducens nucleus 6. ABDUCENS NERVE 6. ABDUCENS NERVE • Mainly Motor • Mainly Motor • Spontaneous and triggered EMG • Spontaneous and triggered EMG monitored during surgery monitored during surgery • Origin - floor of the fourth ventricle in • Origin - floor of the fourth ventricle in the Pons the Pons • Nucleus - Abducens nucleus • Nucleus - Abducens nucleus 6. ABDUCENS NERVE 6. ABDUCENS NERVE • Mainly Motor • Spontaneous and triggered EMG monitored during surgery • EMG monitored from • Origin - floor of the fourth ventricle in • Lateral Rectus Muscle the Pons • Nucleus - Abducens nucleus 6. ABDUCENS NERVE EYE MOVEMENTS • EMG monitored from • Lateral Rectus Muscle Yingling 5. TRIGEMINAL NERVE 5. TRIGEMINAL NERVE • Mixed Sensory and Motor • Mixed Sensory and Motor • Motor component monitored during • Motor component monitored during surgery using spontaneous and triggered surgery using spontaneous and triggered EMG EMG • Sensory component monitored using • Sensory component monitored using trigeminal SEPs and blink reflex trigeminal SEPs and blink reflex • Origin - Pons • Origin - Pons • Nucleus - Trigeminal nucleus • Nucleus - Trigeminal nucleus 5. TRIGEMINAL NERVE 5. TRIGEMINAL NERVE • Mixed Sensory and Motor • Mixed Sensory and Motor • Motor component monitored during • Motor component monitored during surgery using spontaneous and triggered surgery using spontaneous and triggered EMG EMG • Sensory component monitored using • Sensory component monitored using trigeminal SEPs and blink reflex trigeminal SEPs and blink reflex • Origin - Pons • Origin - Pons • Nucleus - Trigeminal nucleus • Nucleus - Trigeminal nucleus 5. TRIGEMINAL NERVE 5. TRIGEMINAL NERVE • Mixed Sensory and Motor • Mixed Sensory and Motor • Motor component monitored during • Motor component monitored during surgery using spontaneous and triggered Superior Orbital Fissure surgery using spontaneous and triggered EMG EMG Foramen Rotundum • Sensory component monitored using • Sensory component monitored using trigeminal SEPs and blink reflex trigeminal SEPs and blink reflex Foramen Ovale • Origin - Pons • Origin - Pons • Nucleus - Trigeminal nucleus • Nucleus - Trigeminal nucleus 5. TRIGEMINAL NERVE 5. TRIGEMINAL NERVE • Mixed Sensory and Motor • Motor component monitored during surgery using spontaneous and triggered EMG • Sensory component monitored using trigeminal SEPs and blink reflex • Origin - Pons V1 - Opthalmic V2 - Maxillary V3 - Mandibular • Nucleus - Trigeminal nucleus 5. TRIGEMINAL NERVE 7. FACIAL NERVE • Mixed sensory and motor • EMG monitored from muscles of • Motor component monitored using mastication spontaneous and triggered EMG monitored during surgery • Temporalis • Origin - Cerebellopontine angle • Masseter • Nucleus - Facial nucleus, solitary nucleus, superior salivary nucleus 7. FACIAL NERVE 7. FACIAL NERVE • Mixed sensory and motor • Mixed sensory and motor • Motor component monitored using • Motor component monitored using spontaneous and triggered EMG spontaneous and triggered EMG monitored during surgery monitored during surgery • Origin - Cerebellopontine angle • Origin - Cerebellopontine angle • Nucleus - Facial nucleus, solitary nucleus, • Nucleus - Facial nucleus, solitary nucleus, superior salivary nucleus superior salivary nucleus 7. FACIAL NERVE 7. FACIAL NERVE • Mixed sensory and motor • Mixed sensory and motor • Motor component monitored using • Motor component monitored using spontaneous and triggered EMG spontaneous and triggered EMG monitored during surgery monitored during surgery • Origin - Cerebellopontine angle • Origin - Cerebellopontine angle • Nucleus - Facial nucleus, solitary nucleus, • Nucleus - Facial nucleus, solitary nucleus, superior salivary nucleus superior salivary nucleus 7. FACIAL NERVE 7. FACIAL NERVE • Mixed sensory and motor • Mixed sensory and motor • Motor component monitored using • Motor component monitored using spontaneous and triggered EMG spontaneous and triggered EMG monitored during surgery monitored during surgery • Origin - Cerebellopontine angle • Origin - Cerebellopontine angle • Nucleus - Facial nucleus, solitary nucleus, • Nucleus - Facial nucleus, solitary nucleus, superior salivary nucleus superior salivary nucleus 7. FACIAL NERVE 7. FACIAL NERVE • Mixed sensory and motor • Mixed sensory and motor • Motor component monitored using • Motor component monitored using spontaneous and triggered EMG spontaneous and triggered EMG monitored during surgery monitored during surgery • Origin - Cerebellopontine angle • Origin - Cerebellopontine angle • Nucleus - Facial nucleus, solitary nucleus, • Nucleus - Facial nucleus, solitary nucleus, superior salivary nucleus superior salivary nucleus 7. FACIAL NERVE 7. FACIAL NERVE • • Mixed sensory and motor EMG monitored from • • Motor component monitored using Temporal