Tracts and lesions vignettes

Question 1

How to identify what the most likely Pathology of the lesion?

Answer 1

1. What is the Level of the lesion?
   Supratentorial (ST) Cerebral hemispheres
   Posterior fossa (PF) Brainstem, Cerebellum
   Spinal (S) Spinal cord, Nerve roots
   Peripheral (P) Peripheral nerve, Muscles
   More than one level
2. What Side of the nervous system is involved?
3. Is the lesion a form of Mass or Non-mass?
   Mass (M) Focal and Progressive
   Non-mass (N) Focal and Non-Progressive, or Diffuse and Non-Progressive
   Indeterminate (I) Transient (fainting, TIA)
4. What is the most likely Pathology of the lesion?
   Vascular (V) (V) Acute (less than 24 hrs evolution)
   Inflammatory (I) (I) Subacute (1 day – 1 month)
   Neoplasm (N) (N) Focal and Chronic (>1 month)
   Degenerative (D) (D) Diffuse and Chronic (>1 month)
   Other (O) (I) Intoxication
   (C) Congenital
   (A) Autoimmune and Allergic
   (T) Traumatic
   (E) Endocrine and Metabolic

Question 2

Segmental vs intersegmental findings

Answer 2

Intersegmental findings - these depend on involvement of the major descending motor (corticospinal and corticobulbar) and ascending sensory (dorsal column/medial lemniscal and spinothalamic) pathways.

Segmental findings - these involve specific components (segments) of the CNS or periphery and have the most localizing value.

Question 3

A 68-year-old, right-handed man noted heaviness in his left upper extremity while reading a newspaper. He tried to stand up but he could not support his weight on his left lower extremity. He was able to call for help. When his wife came to the room, she noted that the left side of his face was sagging.

Answer 3

ST, R, N, V

Question 4

A 6-year-old, right-handed girl with known congenital heart disease began to complain of headaches. Several days later, the severity of the headaches increased, and she was noted to have a left hemiparesis and a left homonymous hemianopia.

Answer 4

ST, R, M, I

Question 5

A 54-year-old, right-handed woman noted some difficulty in expressing her thoughts. This difficulty was mild, and she paid little attention to it. Weeks later, she complained of clumsiness and weakness in her right upper and lower extremities, but the results of an examination by her physician were considered to be normal. Headaches appeared several months later, along with increasing right-sided weakness. She was also aware of an inability to see the right half of the visual field with either eye.

Answer 5

ST, L, M, N

Question 6

A 46-year-old, left-handed woman suddenly noted the onset of a severe bitemporal-occipital headache. On lying down, she became violently ill, with nausea and vomiting. She complained of a stiff neck. She was taken immediately to the hospital, where she was noted to be somnolent, but to respond appropriately when stimulated. She could move all four extremities with equal facility. Her level of consciousness deteriorated, and she became deeply comatose.

Answer 6

M, D, N, V

Question 7

A 4-year-old, right-handed boy complained of a sore throat, chills, and fever. He was put to bed and given Tylenol (acetaminophen) and fluids. The next morning, he complained of headache and an increasingly stiff neck. His temperature was 105oF (40.5oC). When seen at a physician’s office later that afternoon, he was difficult to arouse. He was confused and delirious when stimulated. He held his neck rigid but moved his extremities on command.

Answer 7

M, D, N, I

Question 8

A 50-year-old, right-handed woman, formerly an executive secretary for a local banker, underwent neurologic evaluation because she had had a marked personality change during the last several months. Her memory was poor. She could no longer do even simple calculations, and she had difficulty in following commands. She seemed ill informed about current events and no longer seemed interested in her personal appearance. Results of the rest of the examination were unremarkable.

Answer 8

ST, D, N, D

Question 9

A 54-year-old, right-handed woman suddenly became dizzy, with nausea and vomiting. Examination revealed dysarthria, difficulty in swallowing (with weakness of the left palate), loss of pinprick sensation over the left side of the face and the right side of the body, and marked ataxia on using the left extremities.

Answer 9

PF, L, N, V

Question 10

A 62-year-old right-handed man began to note generalized muscle cramps that he attributed to a charley horse. In the ensuing months, he became aware of weakness in his upper and lower extremities, and some difficulty in speaking and swallowing. Examination revealed muscle weakness and atrophy, and fasciculations of nearly all muscle groups, with no sensory changes. The sign of Babinski was present bilaterally.

Answer 10

M, D, N, D

Question 11

A 68-year-old, right-handed man noted the sudden onset of severe pain in the chest and abdomen. Almost immediately after the pain, he became weak and was unable to support any weight on his right lower extremity. Examination revealed marked weakness of the right lower extremity, with a decrease in the perception of pinprick in the left extremity and side to about the level of the umbilicus.

Answer 11

S, R, N, V

Question 12

A 46-year-old right-handed woman noted (in the absence of back pain) gradually increasing pain and numbness extending down her right leg. After these symptoms had been present for 12 months, she consulted her physician, who found slight weakness of the plantar-flexor muscles, absent ankle reflex, and decreased sensation in the posterior aspect of the leg – all on the right side.

Answer 12

P, R, M, N

Question 13

A 19-year-old man was involved in an automobile accident 4 months earlier. He sustained only minor bruises about the head and face. When he returned to school in the fall, he seemed to be uninterested in his schoolwork and began to complain of headaches. He dragged his right foot when he walked and used his right hand clumsily. He had a slight droop to the right side of his face.

Answer 13

ST, L, M, O

Question 14

A 72-year-old man awakened one morning and noted that he was unable to speak clearly. He wanted to ask for help but could utter only the words ‘go now’. His wife noted some weakness of the right side of his face and right upper and lower extremities. He seemed unable to answer the questions that his wife posed to him.

Answer 14

ST, L, N, V

Question 15

A 26-year-old man awoke and noted that all the muscles on the left side of his face seemed to be paralyzed. Sensation was normal, although he was aware of an inability to taste on the left side of his tongue. He had no other difficulties. Six weeks later, he noted gradual and continued improvement.

Answer 15

P, L, N, V

Question 16

A 42-year-old man noted over a period of several years the onset of ringing in his right ear and loss of hearing in that ear. In addition, he experienced right facial weakness and decreased sensation. In the weeks before his examination, he noted stiffness and weakness of his left upper and lower extremities.

Answer 16

PF, R, M, N

Question 17

A 24-year-old woman was involved in an automobile accident. When examined, she had complete loss of sensation from the upper extremity downward. She could not move her hands or lower extremities, and had no sensation below the armpits. She was incontinent.

Answer 17

S, M, N, O

Question 18

A 64-year-old woman for no apparent reason began to experience pain beginning in her back and encircling the right side of her chest about the level of her breast. A rash later appeared in the same distribution. She continued to have pain in that region, and sensation in that region was greatly diminished.

Answer 18

P, R, N, I

Question 19

A 46-year-old woman began to experience pain beginning in her back and encircling the left side of her chest about the level of her breast. No rash was present. Her symptoms increased over several months but remained localized in a rather circumscribed region of her chest. She was concerned about heart trouble. In addition, she complained of difficulty in walking. Her left lower extremity seemed to be weak and stiff, and at times the left leg and foot felt numb.

Answer 19

S, L, M, N

Question 20

A 64-year-old woman slipped on an icy walk, falling forward and striking her forehead. She had a brief convulsion immediately after the fall, was unresponsive for less than 1 minute, and awakened with a severe generalized headache and nausea, but no vomiting. In addition to being perplexed about the circumstances of the fall, she could not recall the previous few hours. She was awake and oriented, and had no abnormalities on neurologic examination. Tenderness and a scalp contusion were apparent at the site of the impact, and there were abrasions on her right cheek.

Answer 20

ST, D, I, O

Question 21

Syringomyelia (central cord syndrome)?

A 41-year-old right-handed female complained of progressive loss of sensation in both upper extremities for approximately 3 years. She was in perfectly good health until 3 years prior to examination when she noted that she had lost some feeling in the area under her right armpit. Since that time, her symptoms have been slowly progressive with involvement of the entire right hand. More recently, she noted similar sensations in the left hand and upper extremity, and up over the back of her neck and head. When asked to further define her sensory loss, she stated that although rubbing her hand lightly over the affected areas seemed normal, she was no longer able to perceive pain or temperature in those regions. She had burned her hands in the kitchen on several occasions and had not been aware of doing so.
Examination showed a loss of pain and temperature sensibility over the upper thorax, shoulders and both upper extremities. There was no disturbance of tactile sensibility, no ataxia or loss of the sense of posture or of passive movement. The deep tendon reflexes were normal and there was no disturbance of motor functions except that there was weakness and atrophy of the small muscles of both hands. Examination of the cranial nerves was normal.

Answer 21

S, M, M, N

Pain and temp = Spinothalamic tract
Atrophy = LMN
Hypothenar + Interosseus = Ulnar Nerve= C8+T1
Thenar = Median Nerve (C5, C6, C7) + (C8, T1)
(Recurrent Branch)
The cyst is expanding into the corticospinal tracts in the lateral horns.
Tactile, proprioception, vibration spared = Dorsal Column/Medial Lemniscus tract doesn’t cross through the anterior white commissure.

Disorder in which a cyst or cavity forms within the spinal cord. This cyst, called a syrinx, can expand and elongate over time, destroying the spinal cord.

1. Excess cerebrospinal fluid in the central canal of the spinal cord is called hydromyelia. This excess CSF is secreted by the ependymal cells.
2. When fluid dissects into the surrounding white matter forming a cystic cavity or syrinx, the term syringomyelia is applied
3. The cyst forms along the spinal canal and as it grows it eventually compresses the anterior white commissure. This is the location of crossing for the secondary neurons of the spinothalamic tract.
4. The diffuse nature of pain and temperature loss can be attributed to the primary neurons ascending and descending 1-2 spinal segments in lisseurs tract
5. Dx: MRI - Syrinx cavities (AKA the Cyst) characteristic appearance is well-defined areas of low signal (dark) on T1-weighted images and high signal intensity (white) on T2-weighted images.

Question 22

Medial medullary syndrome?

A 70-year-old woman had the sudden onset of weakness of her right upper and lower extremities, and difficulty moving her tongue. In the emergency room she was found to have weakness of right upper and lower extremities, increased muscle stretch reflexes on the right, a Babinski on the right, decreased ability to perceive proprioceptive stimuli on the right, and when her tongue was protruded it deviated to the left.

Answer 22

PF, L, N, V (medial medulla) - anterior spinal artery

Decr proprioception Rt = ML on the Lt
Rt UE/LEs weakness = Lt corticospinal tract
Incr reflexes = Lt corticospinal
Babinski = corticospinal
Tongue deviate Lt = Lt hypoglossal nucleus

Question 23

Neurosyphillis (Tabes dorsalis)

A 40-year-old woman had the gradual onset of a tingling sensation in her feet and later suffered from shooting pains in the legs. Six months ago she developed neck pain, and coughing and sneezing aggravated the pain. Three months ago, the pain became progressively worse and was associated with progressive difficulty walking around in the dark. When walking in the light it was necessary to watch the ground to keep from falling. Although her legs were as strong as ever, she would sway from side to side as she walked. One month ago she noted a decreased ability to perceive objects in her hands.
Examination disclosed no weakness or atrophy of the muscles, but when relaxed they did not exhibit the normal tone. The knee jerk was abolished. There was a complete loss of the sense of posture and passive movement and of the vibratory sense bilaterally in both upper and lower extremities, and decreased ability to recognize objects and written letters and numbers in her hands bilaterally. When the skin of the leg was touched with the two points of a compass she could not recognize the duality of the contact or accurately locate the area stimulated. Except for this loss of tactile localization and tactile discrimination there was not much disturbance of exteroceptive sensibility.

Answer 23

M, D, N, D (syphillitic myelopathy)
Dorsal Column & Dorsal root ganglia - Inflammatory reaction toward pseudounipolar neurons in DRG 
Tx: penicillin & opiates
D: dorsal column degeneration
O: orthopedic pain (charcot joints)
R: reflexes decreased (DTR)
S: shooting pain
A: Argyll-robertson pupils
L: locomotor ataxia
I: impaired proprioception
S: syphillis

-Proprioception LEs = dorsal spinocerebellar (cell bodies Clark’s)
-Proprioception UEs = cuneocerebellar (cell bodies cuneate nucleus)
-She is ataxic because no proprioceptive information is getting to Clark’s nucleus or the lateral cuneate nucleus due to the degeneration of her dorsal horn.
-Two of the following three are needed for walking:
Vision, vestibular system, and proprioception
Our patient has proprioception deficits, and she loses her vision in the dark. She cannot sense the location of her feet, and this is exacerbated when she cannot see her feet.
Atonia = Tone is maintained by neuromuscular spindle afferents to the dorsal horn. Without this input, hypotonia results.
No reflexes = Patellar reflex: L3/4. Reflex cannot be elicited because the 1a afferent pathway has been damaged. Degeneration of dorsal horn cells (have no sensory of muscle stretch) → no patellar reflex

Pain in legs neck = inflamm in DRG
Perception of objects in hands
Loss of vibration in UE/LEs
Location/duality of touch

Question 24

Wallenberg syndrome?

A 68-year-old woman, previously in good health, suddenly became extremely nauseated and dizzy, as if the room were spinning around her. She remained conscious and could describe her symptoms to a companion, who noted that her voice was hoarse.

Examination in the emergency room several hours later revealed the following abnormalities: The patient could not sit or stand because of vertigo. She was anxious and perspiring, except on the left side of her face. Her left pupil was small, and her left eyelid drooped slightly. There was horizontal and rotatory nystagmus. The left side of the palate was drooping, and the left gag reflex was absent. Muscle strength and stretch reflexes were normal in the extremities. There was moderate incoordination of her left upper and lower extremities. Sensory examination revealed loss of pain and temperature sensation in her right upper extremity, trunk, and lower extremity. Conscious proprioception, epicritic touch and vibration were intact on her body. There was loss of pain and temperature sensation on the left side of her face, but epicritic touch and vibration sense were intact.

Answer 24

PF, L, N, V (PICA stroke)

Vertigo = vestibular nuyclei
Nystagmus = vestibular nuclei
Loss of pain/temp Lt face = Spinal trigeminal tract
Loss of pain/temp Rt body = Rt spinothalamic tract
Lt anhidrosis = hypothalamo-reticulospinal tract
ptosis and miosis = hypothalamo-reticulospinal tract
Lt palate paralysis = nucleus ambiguous
Lt gag reflex absent = nucleus ambiguous
Lt extremity coordination = inferior cerebellar peduncle
Muscle strength normal b/c pyramids are intact
Touch, vibration face normal b/c main sensory nucleus of V intact
Touch, vibration body normal b/c ML intact

Question 25

Lateral pontine syndrome?

A 70-year-old man awoke one morning and found that the left side of his face was paralyzed, that the left side of his face and right side of his body felt numb, and that he had difficulty using his left hand. Neurologic exam revealed that he could not wrinkle his forehead or smile on the left side, that he had decreased sensation to pinprick over the left face and right side of the body, ptosis and miosis of the left eye, and decreased coordination of the left hand and leg. Muscle strength and reflexes were within normal limits.

Answer 25

PF, L, N, V (anterior inferior cerebellar artery)

Lt facial pain = Lt spinal tract of trigeminal
Rt body pain = Rt spinothalamic
Lt face paralysis = Lt VII
Lt ptosis and miosis= Lt hypothalamo-reticulospinal
Lt ataxia = Lt inferior cerebellar peduncle (spinocerebellar)

Question 26

Lateral pontine(AICA) vs Lateral medullary(PICA)?

Answer 26

Similar tracts, different CNs.
Lateral pontine: facial nerve/nuclei (can’t wrinkle forehead)
Lateral medullary: vagus ambiguous (palate drop, gag, hoarseness) CN VIII (vertigo nausea, dizzy, nsytagmus)

Both:

• Unilateral ptosis and miosis
• Loss of pain and temp in ipsilateral face
• Loss of pain and temp in contralateral body
• Ataxia

Question 27

Vitamin B12 deficiency

A 52-year-old woman is brought to the hospital by her husband because of ataxia. She says that three years ago she began complaining to her doctor of a “pins and needles” sensation in her feet and hands; this gradually spread to her knees and elbows. For the past 18 months she has had progressive gait incoordination and she has complained of weakness in her legs.

On examination her gait is ataxic. Although she stands alone quite well, she nearly falls when asked to close her eyes. Both legs are moderately weak, particularly flexor groups. Muscle stretch reflexes are decreased in the arms and absent in the legs. There are bilateral Babinski signs. Position sense is mildly impaired in the fingers and severely impaired in the feet. Vibration sense is absent to the iliac crest. Touch, pain and temperature sensation are not significantly impaired including the perianal region. The anal reflex and anal tone are normal. An EMG nerve conduction study showed absent sensory potentials in the lower extremities.

Answer 27

M, D, N, D

Bilat babinski = UMN corticospinal degeneration
+Romberg(proprioception) = dorsal comlumn/ML pathway

Dx: vit B12, CBC (megaloblastic anemia), LFTs, EMG

Question 28

Weber Syndrome?

A 58-year-old man suddenly developed double vision and weakness on the left side of his body. On examination his right eye showed ptosis, a dilated pupil, and the eye was positioned down and out. The man had a left hemiparesis with left-sided hyperreflexia and Babinski sign. The patient could wrinkle his forehead, but when asked to smile, the left lower side of his mouth drooped. When asked to protrude his tongue, it deviated to the left.

Answer 28

PF, R, N, V (ventromedian midbrain)
Superior alternating hemiplegia
Paramedian branch of the posterior cerebral artery (perforates tentorium to midbrain, also supplies occipital lobe superior)

Rt ptosis, Rt mydriasis, Rt down/out = CN III
Lt hemiparesis, hyper-reflexia, babinski = Rt corticospinal
Lt lower face paralysis, Lt tongue deviation=Rt corticobulbar

Corticospinal fibers: Contralateral hemiparesis and typical upper motor neuron findings; contralateral because it occurs before the decussation in the medulla

Corticobulbar tract: Difficulty with contralateral lower facial muscles and hypoglossal nerve functions (forehead bilaterally innervated by the cortex)

If lesion was more lateral would run into medial lemniscus and STT (CN III, VI, VII and more medial)

Question 29

Amyotrophic Lateral Sclerosis/ Lou Gehrig Disease?

A 66-year-old married, white male merchant, 9 months prior to evaluation had the insidious onset of progressive weakness and atrophy involving the lower extremities. The feet could not be lifted from the ground, but were dragged along, and the entire lower extremity moved as one piece from the hip. Subsequently, a similar but lesser involvement of the upper extremities occurred.

Neurological examination demonstrated widespread muscular atrophy and weakness in all four extremities. Twitching was seen under the skin in his triceps and hand muscles as well as in both anterior tibial compartments. The deep tendon stretch reflexes at the biceps, triceps, and patella were hyperactive (3 +). However, the right Achilles reflex was 2 +, while the left was decreased at 0 to 1. Clonus was evident at the knees and ankles bilaterally. The plantar responses were both extensor (bilateral Babinski sign). Sensory and cerebellar examinations were normal.

Answer 29

S, D, N, D
Extends the length of the spinal cord
Anterior Horn (LMN):
Fasciculations, hyporeactive reflexes, atrophy, decreased tone
Corticospinal Tract (UMN):
Clonus, bilateral muscle weakness, hyperreactive reflexes, babinski, weakness

Atrophy = LMN death
Weakness = UMN --> alpha motor neurons
Hyper-reflexive = decr cortical inhibition

Question 30

Spasticity vs rigidity

Answer 30

Spasticity -is a feature of altered skeletal muscle performance present only at the onset of passive movements with paralysis, increased tendon reflex activity and hypertonia; tightness, pulled muscle, or stiffness; rate dependent and elicited by high-speed movements

Rigidity is a feature of decreased bodily movement; characterized by an increase in muscle tone causing resistance to externally imposed joint movements

Leadpipe Rigidity - increased muscle tone with resistance throughout the duration of passive movement
Cogwheel Rigidity - leadpipe rigidity with tremor
Clasp-Knife Rigidity - a stretch reflex with a rapid decrease in resistance when attempting to flex a joint, upper motor neuron lesion.
Decorticate - Upper Extremeties in Flexion, Lower Extremeties in Extension. Due to lesion above the Red Nucleus
Decerebrate - All extremeties in Extension. Due to lesion below the Red nucleus. Medical Emergency.