Spinal Cord: Clinical Applications Dr. Stuart Inglis
Tabes dorsalis, also known as syphilitic myelopathy, is a slow degeneration (specifically, demyelination) of the nerves in the dorsal funiculus of the spinal cord. In the slide preparation to the right, demyelination is responsible for the bleached appearance observed in the center of the image.
What would be the most likely presentation in tabes dorsalis? A. Loss of general motor function B. Loss of general sensation C. Loss of pain perception D. Loss of subconscious proprioception E. Loss of head and neck function
Dorsal Funiculus Fasisiculus Gracilis Fasisiculus Cuneatus Ascending tracts Heavily myelinated primary sensory fibers distributed to the body wall, appendages Fasisiculus cuneatus above T6 Fasisiculus gracilis below T6 Conveying tactile, vibratory, and proprioceptive information from ipsilateral side of body
Bonus: Assuming this is a section through the cervical spinal cord, what region of the body would be most affected? A. Lower B. Upper
A patient presents with a piercing stab wound that completely sections the right half of the spinal cord in the mid-thoracic region. What would be the expected clinical presentation? A. General sensation loss to the left side, loss of pain perception to the left side B. General sensation loss to the left side, loss of pain perception to the right side C. General sensation loss to the right side, loss of pain perception to the left side D. General sensation loss to the right side, loss of pain perception to the right side
Brown-Séquard syndrome is a loss of sensation and motor function (paralysis and anesthesia) that is caused by the lateral hemisection (cutting) of the spinal cord. It is named after physiologist Charles-Édouard Brown-Séquard, who first described the condition in 1850. This syndrome is rare as the trauma would have to be something that damaged the nerve fibres on just one half of the spinal cord. The classic cause is a stab wound in the back.
Syringomyelia is a generic term referring to a disorder in which a cyst or cavity forms within the spinal cord. A patient presents with syringomyelia, which is compressing the anterior white commissure. What is the likely presentation A. Bilateral loss of general and pain sensation B. Bilateral loss of general sensation, no loss in pain sensation C. Bilateral loss of pain sensation, no loss in general sensation D. Unilateral loss of general and pain sensation E. Unilateral loss of general sensation, no loss in pain sensation F. Unilateral loss of pain sensation, no loss in general sensation G. No appreciable losses
Cape Distribution
A 65 year old woman presents to hospital with left leg weakness, decreased proprioception on the left foot and leg, decreased pinprick sensation on the right leg. The most likely spinal cord lesion would to explain these symptoms would be: A. Anterior cord B. Hemilesion to the right side C. Central cord D. Brown-Sequard syndrome on the left side E. Posterior cord
Areflexia (loss of reflexes) of the lower limbs is most likely to occur with a fracture to which of the following vertebrae? A. C7 B. T2 C. L3 D. All of the above
Cauda Equina Syndrome Compression of nerves within cauda equina 2 0 to trauma, herniated disc, stenosis, tumors, infection LMN lesion pattern to variable levels Sensory/motor deficits to lower limbs Weakness, reduced reflexes Saddle/perineal paresthesia Bowel/bladder disturbances Loss of parasympathetics; urinary/fecal retention, overflow incontinence UMN lesion symptoms may also be present, if sacral cord affected
Upper vs. Lower Motoneuron Lesion
A 5-year old girl is seen in the ED who has trouble walking. Her mother says that she has been falling a lot. She sways from side to side when standing and walks with a wide-based gait. An exam also reveals nystagmus. The most likely site of a lesion causing these symptoms is the: A. corticospinal tract B. putamen C. superior cerebellar peduncle D. cerebellar vermis E. cerebellar nodulus F. middle cerebellar peduncle
Symptoms of Cerebellar Lesions Flocculus/Nodulus Vermis Cerebellar Hemisphere Vestibular Signs Truncal Ataxia upper/lower limb ataxia Falling Ataxic Gait Nystagmus Nausea, vertigo 4th ventricle tumors Ataxic Gait Alcohol, MS, tumor ataxic gait, intention, tremor, uncoordinated limb motion Tumor, infarct, MS Vestibular Signs Ataxia - truncal Ataxia upper/lower limbs
A 67-year old woman sees her physician because she says her right arm has been acting funny. She says when she is sitting quietly and reading, her right arm starts to shake and she can t stop it. She says when she reaches for a glass of water the shaking stops, so she didn t think this was too serious. She says she also has trouble getting out of her chair. She just can t seem to get her movement started. The most likely site of a lesion causing these symptoms is the: A. substantia nigra on the right B. substantia nigra on the left C. subthalamic nucleus on the right D. subthalamic nucleus on the left E. cerebellar hemisphere on the right
Basal Ganglia Circuit motor cortex
A 25-year old man is seen in the ED with the following symptoms: ability to raise his eye brow on the left side ability to close the left eye decreased nasolabial fold on the left inability to raise his lip on the left when smiling The most likely site of a lesion causing these symptoms is the: A. genu of internal capsule on the right B. motor cortex on the left C. facial nucleus on the right D. facial nucleus on the left E. facial nerve on the left
UMN Control of CN VII Lesions of corticobulbars on one side cause weakness or paralysis of the lower face on the opposite side: decreased nasolabial fold drooping mouth Lower face droop on side opposite lesion (usually + corticospinal deficit)
A 75-year old man presents with weakness of the right upper and lower limbs involving increased muscle tone and DTRs and Babinski sign on the right. Tactile sensation is normal on the body and face, but there is loss of pin prick sensation on the left side of the body. Which vessel is most likely to have caused these symptoms: A. right branch of the anterior spinal artery at the level of the caudal medulla B. right branch of the anterior spinal artery at the level of C4 C. left branch of the anterior spinal artery at the level of C4 D. right branch of the posterior spinal artery at the level of C4 E. left branch of the posterior spinal artery at the level of C4 F. left paramedian branch of the basilar artery
Supply to Spinal Cord Posterior spinal R L cst Anterior spinal
76 yo female with atrial fibrillation experienced sudden onset symptoms and was rushed to the hospital. During her workup in the ED imaging showed a lesion in the region indicated in the figure. Which of the following describes symptoms would you expect this woman to exhibit: R L
R L A. RT CN III weakness, LT loss of tactile sensation on body, LT loss of tactile/pain sensation face, LT limb weakness with increased muscle tone/dtr B. LT loss of tactile sensation on body, LT loss of tactile/pain sensation face, LT limb weakness with increased muscle tone/dtr C. RT CN III weakness, LT loss of tactile sensation on body, LT loss of tactile/pain sensation face, LT arm resting tremor and slowed movement D. RT CN III weakness, LT loss of tactile sensation on body, LT loss of tactile/pain sensation face, LT limb intention tremor, dysmetria E. RT CN III weakness, LT loss of tactile sensation on body, LT loss of tactile/pain sensation face, RT limb intention tremor, dysmetria
Pathways Communicating with Cerebellum dorsal spinocerebellar tract ventral spinocerebellar t
Take Home Message 1. Cerebellar symptoms are caused by damage to cerebellum, its peduncles or pathways. 2. Cerebellar damage produces motor deficits on same side of body. 3. Cerebellar signs fall into 2 categories: Vestibular - falling/ataxic gait, nystagmus Ataxia trunk - vermis limbs - hemisphere, peduncles, pathways Midbrain - crus cerebri red nuc area Pons - basilar (bottom 1/2) Spinal Cord/Medullaafferent tracts
The most likely blood vessel that would have caused this lesion is: R L A. basilar artery B. superior cerebellar artery C. posterior cerebral artery D. anterior choroidal artey E. AICA
Supply to Midbrain Posterior cerebral long circumferentials (or superior cerebellar) posterior cerebral paramedian short circumferentials