Brain Stem Anterior View Posterior View 3 4 9,10,11 5 Adducent Facial colliculus 7 & 8th 12 Striae Medullare

Case.1 A 55 year old overweight man was brought to the emergency room unconscious after he had collapsed while loading a truck.After he regained consciousness, an exam revealed a paresis of both right limbs with a Babinski sign on the right. The patient's tongue deviated to the left upon protrusion, and he had no vibratory sense on the right side of the body. These findings suggest. A lesion in the medial medulla A lesion in the medial pons An infract PICA A lesion in the lateral medulla

Case cont…2 A 35-year-old visits hospital because of severe headache. The patient says that the headache, which seems to be localized area behind his ears, it has been intermittent but persistent since he was involved in the baseball game while on his vacation. Shortly after he returned from his vacation, he made an appointment with his family physician because he was worried about the headache and the fact that he had developed noticeable clumsiness. When physician questioned, he mentioned unusual frequent bouts of nausea and vertigo. Physical examination reveals mild hoarseness of voice and some difficulty swallowing oral secretions. The left side of his face is affected by Horner’s syndrome, He has decreased sensitivity to light touch on the left side of his face, flattening of the left nasolabial fold, and paresis of the left soft palate. Finger to nose testing shows left sided Dysmetria. When asked to walk across the examining room, his gait is ataxic and he deviates to the left. There is diminished pain and thermal sensation on the right side. Reflexes are symmetric. There is no Babinski reflex, and the remainder of the motor and sensory examination is normal.

Case Cont….3 Which one of the following vessels should be the primary suspect? Middle cerebral artery Internal carotid artery at the cavernous sinus Superior cerebellar artery Posterior inferior cerebellar artery Anterior communicating artery

Case cont…4 45 year-old women with a history of high blood pressure experienced a sudden onset of Dizziness, nausea, and vomiting. She was brought to the emergency room where a neurological Exam revealed horizontal nystagmus, Dysphagia and hoarseness. Absent of gag reflex on the left. Alteration of taste sensations from the tongue. Analgesia and thermal anesthesia on the left side of the face . Analgesia and thermal anesthesia on the right side of the body. Homer’s syndrome and significant hearing loss on the left as compared to the right

Case cont…5 The dysphagia and hoarseness in this case are to due to lesion of which structure? Dorsal motor nucleus of vagus Nucleus solitarius Nucleus ambigus Inferior salivatory nucleus Superior salivatory nucleus

Case cont 6…. The analgesia and thermal anesthesia on the left side of the face in this case most likely Resulted from a lesion of which structure? The trigeminal nerve The Mesencephalic nucleus of trigeminal The principal (chief) nucleus of The spinal tract of trigeminal The trigeminal ganglia

Level Nuclei Midbrain III, IV, mesencephalic V Pons V (main nucleus) Caudal pons VI, VII Ponto-medullary junction VIII Medulla N. of the descending tract of V. N. ambiguus N. tractus solitarius Motor X XII Cervical cord XI

Medial Medullary Syndrome Medial Medullary Syndrome/ Inferior Alternating Hemiplegia (branches of anterior spinal artery occlusion) contralateral hemiplegia of arm & leg (pyramid—corticospinal fibers) contralateral loss position sense, vibration, discriminatory touch (medial lemniscus) deviation of tongue to ipsilateral side when protruded; muscle atrophy (CN XII hypoglossal nerve in medulla or CN XII nucleus)

Lateral medullary Syndrome (Wallenberg's) contralateral body pain & temp loss (anterolateral system/spinothalamic tract) ipsilateral face pain & temp loss (spinal trigeminal tract & nucleus) dysphagia, soft palate paralysis, hoarseness, diminished gag reflex (nucleus ambiguus, roots of 9th and 10th nerves) ipsilateral Horner’s Syndrome (myosis, ptosis, anhydrosis) (descending hypothalamospinal fibers) nausea, diplopia, vertigo, nystagmus (vestibular nuclei—CN 8) ataxia to the ipsilateral side (restiform body & spinocerebellar fibers)

Case 7.. A 46-year-old woman presents to her physician with "double vision" and is unable to adduct her right eye on attempted left lateral gaze. Convergence is intact. Both direct and consensual light reflexes are normal. Which of the following structures is most likely to be affected? Left oculomotor nerve Medial longitudinal fasciculus Right abducent nerve Right oculomotor nerve Right trochlear nerve

Case 8.. A patient with a bullet wound to the head is referred to you for neurological examination. Upon entering the hospital room you find the patient on a respiratory and cardiac monitor. You have difficulty arousing the patient and once awake you note the following: Right pupil is constricted; there is medial strabismus of the right eye and upon attempted right lateral gaze the left eye fails to adduct; loss of pain and temperature sensitivity on the right side of the face and left side of the body; deafness of the right ear; a pronounced intention tremor in the right arm and leg. The deep tendon reflexes on the right side are not as brisk as those on the left and there appears to be a complete facial paralysis on the right side.   The likely site for this lesion is: The left internal capsule The right caudal pons The left cerebellar hemisphere The left side of the midbrain at the level of the superior colliculus The right side of the medulla at the level of the dorsal column nuclei

Pontine Syndromes (paramedian branches of basilar artery occlusion) Medial Pontine Syndrome/ Middle Alternating Hemiplegia (paramedian branches of basilar artery occlusion) contralateral hemiplegia of arm & leg (corticospinal fibers in basilar pons) contralateral loss/decrease of proprioception, vibration, discriminative touch (medial lemniscus) ipsilateral lateral rectus muscle paralysis (abducens nerve fibers or nucleus—CN 6) paralysis of conjugate gaze toward side of lesion Medial Strabismus (paramedian pontine reticular formation/pontine gaze center)  

Lateral Pontine Syndrome ) .   *note: combination of symptoms varies with caudal to rostral level of lesion* ataxia, unsteady gait, fall toward side of lesion (middle & superior cerebellar peduncles—caudal & rostral pons lesions) vertigo, nausea, nystagmus, deafness, tinnitus, vomiting (vestibular & cochlear nerves and nuclei—CN 8) ipsilateral paralysis of facial muscles (facial motor nucleus—CN 7—caudal pons lesions) ipsilateral paralysis of mastication muscles (trigeminal motor nucleus— CN 5—midpontine lesions) ipsilateral Horner’s Syndrome (descending hypothalamospinal fibers) ipsilateral face pain & temp loss (spinal trigeminal tract & nucleus) contralateral body pain & temp loss (anterolateral system/spinothalamic tract) paralysis of conjugate gaze (paramedian pontine reticular formation—mid to caudal pons lesions) (Long circumferential branches of basilar artery occlusion)

Case 9 Jones likes to play golf. Usually he is a very competitive member of the team UK , but his game has been off lately. He has been unable to maintain his well-practiced grip on his favorite clubs (particularly with his right hand), causing the club to slip out of alignment as he begins his swing. Additionally, as all great golfers know, maintaining visual contact with the ball is critical to accurate placement of the ball on the green. Peter has begun to complain that he sometimes sees two balls (double vision), and that occasionally he swings at the ‘wrong’ one. He has been unable to keep his eyes on the ball as he swings and he has not been able to watch it as it sails to its destination. Today has been particularly hot, and the entire team becoming fatigued as they near the final hole. It’s at this point that one of the partners who is a neurologist notices that June's left eye is crossed. On further examination Neurologist noticed fallowing

Case 9 Left eye is crossed (diplopia); an inability to move the Left to the left. He has Spastic paralysis of the right upper and right lower limb muscles. His left side of the body seems to be functioning normal.

Case 10 60 year old woman suddenly remarked that she was seeing double and felt a weakness in her left arm and leg. Her husband noticed that her right eyelid was drooping. At the hospital, she was awake, oriented, and articulate. Her visual fields were normal but here right eye deviated to the right. On attempted lateral gaze to the left only the left eye responded; only the left eye constructed in response to light. Upon smiling, there was a minor weakness on the left. The gag, corneal, and jaw jerk reflexes were normal as were the sensory examinations of the face and body. Motor strength was normal in the extremities on the right but reduced on the left especially in the arm where there was a heightened biceps reflex and resistance to passive stretch.   Where is the site of lesion? a) Cerebellum b) Substantia nigra c) Mid brain d) None of above.

Mid-Brian @ Superior colliculus

Mid-Brian @ Superior colliculus

Medial Midbrain (Weber) Syndrome/ Superior Alternating Hemiplegia (paramedian branches of P1 segment of PCA occlusion) 1.contralateral hemiplegia of arm & leg corticospinal fibers in crus cerebri) ipsilateral paralysis of eye movement, oriented down & out, pupil dilated & fixed (oculomotor nerve—CN 3) 2. Central Midbrain Lesion (Claude Syndrome) contralateral ataxia and tremor of cerebellar origin (red nucleus & cerebellothalamic fibers) 3. Benedikt Syndrome: includes both regions, both sets of symptoms from above