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 roomunconscious after he had collapsed while loading a truck.After heregained consciousness, an exam revealed a paresis of both right limbswith a Babinski sign on the right. The patient's tongue deviated to theleft upon protrusion, and he had no vibratory sense on the right side ofthe 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 cont2 A 35-year-old visits hospital because of severe headache. The patient says that theheadache, which seems to be localized area behind his ears, it has beenintermittent but persistent since he was involved in the baseball game while on hisvacation. Shortly after he returned from his vacation, he made an appointmentwith his family physician because he was worried about the headache and the factthat he had developed noticeable clumsiness. When physician questioned, hementioned unusual frequent bouts of nausea and vertigo. Physical examinationreveals mild hoarseness of voice and some difficulty swallowing oral secretions.The left side of his face is affected by Horners syndrome, He has decreasedsensitivity to light touch on the left side of his face, flattening of the left nasolabialfold, and paresis of the left soft palate. Finger to nose testing shows left sidedDysmetria. When asked to walk across the examining room, his gait is ataxic andhe deviates to the left. There is diminished pain and thermal sensation on the rightside. Reflexes are symmetric. There is no Babinski reflex, and the remainder of themotor 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 cont4 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. Homers syndrome and significant hearing loss on the left as compared to the right Case cont5 The dysphagia and hoarseness in this case are to due to lesion ofwhich 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 inthis 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/ InferiorAlternating Hemiplegia (branches of anterior spinal artery occlusion) contralateral hemiplegia of arm & leg (pyramidcorticospinal fibers) contralateral loss position sense, vibration,discriminatory touch (medial lemniscus) deviation of tongue to ipsilateral side whenprotruded; muscle atrophy (CN XII hypoglossal nerve in medulla orCN 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 10thnerves) ipsilateral Horners Syndrome (myosis, ptosis,anhydrosis) (descending hypothalamospinal fibers) nausea, diplopia, vertigo, nystagmus (vestibular nucleiCN 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: Rightpupil is constricted; there is medial strabismus of the right eye and upon attempted rightlateral gaze the left eye fails to adduct; loss of pain and temperature sensitivity on the rightside of the face and left side of the body; deafness of the right ear; a pronounced intentiontremor in the right arm and leg. The deep tendon reflexes on the right side are not as briskas 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 nucleusCN 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 oflesion* ataxia, unsteady gait, fall toward side of lesion (middle & superior cerebellar pedunclescaudal & rostral pons lesions) vertigo, nausea, nystagmus, deafness, tinnitus, vomiting (vestibular &cochlear nerves and nucleiCN 8) ipsilateral paralysis of facial muscles (facial motor nucleusCN 7caudalpons lesions) ipsilateral paralysis of mastication muscles (trigeminal motor nucleus CN 5midpontine lesions) ipsilateral Horners Syndrome (descending hypothalamospinal fibers) ipsilateral face pain & temp loss (spinal trigeminal tract & nucleus) contralateral body pain & temp loss (anterolateral system/spinothalamictract) paralysis of conjugate gaze (paramedian pontine reticular formationmid 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 theteam UK , but his game has been off lately.He has been unable to maintainhis 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 theball is critical to accurate placement of the ball on the green.Peter hasbegun to complain that he sometimes sees two balls (double vision), and thatoccasionally he swings at the wrong one.He has been unable to keep hiseyes on the ball as he swings and he has not been able to watch it as it sailsto its destination.Today has been particularly hot, and the entire teambecoming fatigued as they near the final hole.Its at this point that one ofthe partners who is a neurologist notices that June's left eye is crossed. On further examinationNeurologistnoticed fallowing Case 9 Left eye is crossed (diplopia); an inability to move the Left to the left. He has Spastic paralysis of the rightupper 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 herleft 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 eyedeviated to the right. On attempted lateral gaze to the left only the left eye responded; onlythe left eye constructed in response to light. Upon smiling, there was a minor weakness onthe left. The gag, corneal, and jaw jerk reflexes were normal as were the sensoryexaminations of the face and body. Motor strength was normal in the extremities on theright but reduced on the left especially in the arm where there was a heightened biceps reflexand 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 nerveCN 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