First Lesion Localization Problem Solving Assignment

First Lesion Localization Problem Solving Assignment

February 14, 2008

Place completion date in this box

February 14, 2008

Place completion date in this box

Place names of team members in this box

Team name?

Create your own design?

Instructions for the First Lesion Localization Problem Solving Exercise

Instructions for the First Lesion Localization Problem Solving Exercise

Attempt to have between 4 & 6 members in your groups. Submit one PowerPoint presentation per group. Make sure that each member of your group understands the answers to the case problems.

Following the next slide, an example slide, five cases are presented. For each case use the most appropriate image from the 18 images on the last slide to diagram the smallest possible lesion that could account for the given symptoms. If one lesion can’t account for the symptoms, explain why not. Label the neuroanatomical structures that are involved in your lesions. Use the five slides labeled Lesion #1 through Lesion #5 for your diagrams.

Each person resolve the problems own your own at first, then meet with team. When finished evaluate team members.

When you have completed the exercise, e-mail your PowerPoint presentation to rclark2@med.miami.edu.

Keep the size of your presentation under 6 MBs.

Deadline = Friday, February 15, 2008 @ noon.

Example

Example

A 27-year-old woman has the following symptoms:1. Loss of pain sensation in her left upper & lower extremities2. Loss of pain sensation on the left side of her face (V1,V2, & V3)3. Loss of position sense in her left upper & lower extremities4. Loss of position sense on the left side of her face5. Loss of fine tactile sensation in her left upper & lower extremities6. Loss of fine tactile sensation on the left side of her face (V1,V2, & V3)7. Loss of vibratory sensation in her left upper & lower extremities8. Loss of fine vibratory sensation on the left side of her face9. The remainder of the neurological exam was normal

The lesion can’t be localized to a single level. It would involve the medial lemniscus, trigeminal lemniscus, & spinothalamic tract on the right side. It could be located in the rostral pons or midbrain, or even in the posterior thalamus (VPM + VPL). Ipsilateral symptoms of a cranial nerve would have permitted localization!

RIGHT LEFT ST

ML = medial lemniscus; ST = spinothalamic tract; TL = trigeminal lemniscus

ML

TL

Level of the Superior Colliculus of the Midbrain

Case #1Case #1HISTORY

Over a course of several months, a 66-year-old woman noticed progressive weakness (paresis) in her

right arm and leg. Her speech became slurred (dysarthria) and she had difficulty closing her right eye.

She began to have headaches.

EXAMINATION

On examination, her blood pressure and pulse are within normal limits and she has no history of

cardiovascular disease. Her mental status is normal, including language function, as are eye

movements. However, her visual fields examination revealed a right homonymous hemianopsia.

Sensation (including touch, conscious proprioception & stereognosis) is decreased from the right face,

arm and leg. She wrinkles her forehead and brow symmetrically but has difficulty closing her right eye.

She has weakness in her right lower face. Upon protrusion her tongue deviates to the right with no

atrophy. Her right upper and lower extremities are weak and she has difficulty writing with her right

hand. Both muscle tone (hypertonia) and tendon reflexes (hyperreflexia) are increased in her right arm

and leg. When the outer sole of her right foot is firmly stroked with the handle of a reflex hammer,

there is extension of the large toe accompanied by extension and separation (fanning) of the other

toes (Babinski Sign or Extensor Plantar Response).

Case #2Case #2

HISTORY

A 77-year-old man had a sudden onset of confusion and difficulty in talking.

EXAMINATION

On examination, his blood pressure and pulse are elevated. His eyes are deviated to the left. He

understands your command for him to squeeze your hands with both of his hands. But he has great

difficulty talking and expressing his thoughts. He cannot name the digits of your hand. Sensation

(including touch, conscious proprioception & stereognosis) is normal from the right and left face, arm

and leg. He responds to pinprick on both sides of the body and face. He wrinkles his forehead and

brow symmetrically but has difficulty closing his right eye. Upon protrusion his tongue deviates to the

right with no fasciculations. He has no weakness in his extremities and reflexes are normal.

Case #3Case #3

HISTORY

A 35-year-old man is starting to see double images, and has lost sensation in his right hand and foot.

EXAMINATION

On examination, his blood pressure and pulse are normal. Sensation (including touch, conscious

proprioception & vibratory sensation) is greatly decreased from his right face, arm and leg. He doesn’t

respond to pinprick on right side of his body and face. He wrinkles his forehead and brow

symmetrically and smiles symmetrically. He has no weakness in his extremities and reflexes are

normal.

EYE EXAM

He has a drooping left eyelid (ptosis), and his left pupil is deviated down and out. His left pupil is

dilated and neither responds to light nor accommodation.

Case #4Case #4HISTORY

Over a course of several months, a 23-year-old woman noticed progressive weakness (paresis) in her

left arm and leg. Her speech became slurred.

EXAMINATION

On examination, her blood pressure and pulse are within normal limits and she has no history of

cardiovascular disease. Her mental status is normal, including language function, as are eye

movements. Sensation (including touch, conscious proprioception & stereognosis) is normal from the

right & left face, arm and leg. She responds to pinprick on both sides of the body and face. She

wrinkles her forehead and brow symmetrically and smiles symmetrically. Upon protrusion her tongue

deviates to the right with atrophy & fasciculations. Her left upper and lower extremities are weak. Both

muscle tone (hypertonia) and tendon reflexes (hyperreflexia) are increased in her left arm and leg.

When the outer sole of her left foot is firmly stroked with the handle of a reflex hammer, there is

extension of the large toe accompanied by extension and separation (fanning) of the other toes.

Case #5Case #5

HISTORY

A 43-year-old woman gradually started to have difficulty closing her left eye.

EXAMINATION

On examination, her blood pressure and pulse are normal. Her mental status is normal, including

language function, as are eye movements. Sensation (including touch, conscious proprioception &

stereognosis) is normal from all extremities. She does not respond to pinprick anywhere on the left

side of her face, but does respond to touch and position sense on both sides of her face. She wrinkles

her forehead and brow on the right but not the left side. She has difficulty closing her left eye. She has

weakness in her left upper & lower face. Muscle fasciculations are present on the left side of her face.

She has normal sensation and muscle tone in all extremities.

• Rt homonymous hemianopsia (LEFT LAT GENICULATE)

• Decreased sensation (touch, conscious proprioception & stereognosis) from Rt face, arm & leg (*see below)

• Wrinkles forehead & brow symmetrically; difficulty closing Rt eye (CORTICOBULBAR CN7)

• Weakness Rt lower face (CORTICOBULBAR CN7)

• Upon protrusion tongue deviates to Rt with no atrophy (CORTICOBULBAR CN12)

• Rt upper & lower extremities weak; writing difficulty (CORTICOSPINAL)

• Increased muscle tone & DTRs Rt arm & leg; Rt Babinski Sign (CORTICOSPINAL)

Lesion #1Lesion #1

LeftLeft RightRight

ThalamusThalamus

PLICPLIC

Lat GeniculateLat Geniculate

* Thalamocortical from VPL & VPM which

receive Med Lemniscus & Trigeminal

Lemniscus: NOTE Pain & Temp would also

have to be decreased or absent from the

right side of the face & body!

VPMVPM

VPLVPL

• NOTE: Sudden onset indicative of stroke

• Eyes deviated to the left (LEFT LATERAL GAZE CENTER)

• Understands your command for him to squeeze your hands (NOT WERNICKE’S)

• Great difficulty talking & expressing his thoughts (BROCA’S APHASIA)

• Cannot name the digits of your hand (SYMPTOM OF BROCA’S & OTHER APHASIAS)

• Sensation normal (NO INVOLVEMENT OF POSTCENTRAL GYRUS)

• Wrinkles his forehead and brow symmetrically but has difficulty closing his Rt eye

(CORTICOBULBAR CN7; THEREFORE MUST ALSO HAVE WEAKNESS OF RT LOWER FACE)

• Upon protrusion tongue deviates to Rt with no fasciculations (CORTICOBULBAR CN12)

• No weakness in extremities & reflexes are normal (NO CORTICOSPINAL INVOLVEMENT)

Lesion #2Lesion #2

LEFT LAT GAZE

CENTER

LEFT LAT GAZE

CENTER

BROCA’S AREABROCA’S AREA

PRECENTRAL

GYRUS FACE

PRECENTRAL

GYRUS FACE

Lesion #3Lesion #3• No weakness in extremities, reflexes normal

• Wrinkles forehead & smiles symmetrically

• Decreased sensation of all types Rt face & body (Left: Spinothalamic, Medial Lemniscus, & Trigeminal

Lemniscus)

• Diplopia (CN3, 4, or 6

• LEFT EYE: ptosis; pupil down and out; dilated; no light or accmmodation (LT CN3)

CN3CN3

LeftLeft RightRight

Midbrain: Superior Colliculus LevelMidbrain: Superior Colliculus Level

Medial LemniscusMedial Lemniscus

Trigeminal LemniscusTrigeminal Lemniscus

Spinothalamic TractSpinothalamic Tract

Lesion #4Lesion #4• Normal sensation right & left face & body

• Wrinkles forehead & smiles symmetrically

• Weakness Lt arm & leg (RT CORTICOSPINAL TRACT)

• Increased muscle tone & DTRs Lt arm & leg (RT CORTICOSPINAL TRACT)

• Slurred speech (RT CN12)

• Upon protrusion tongue deviates to Rt with atrophy & fasciculations (RT CN12)

• Lt Babinski sign (RT CORTICOSPINAL TRACT)

Pyramid with

Corticospinal

Tract

Pyramid with

Corticospinal

Tract

Level of the Rostral MedullaLevel of the Rostral Medulla

LeftLeft RightRight

CN 12CN 12

Lesion #5Lesion #5• Normal sensation & muscle tone in all extremities

• Responds to fine tactile and position sense on both sides of her face

• No pinprick sensation Lt side of face (LT Spinal TractV)

• Wrinkles her forehead and brow on the right but not the left side (LT CN7)

• Difficulty closing her left eye (LT CN7)

• Weakness Lt upper & lower face with fasciculations (LT CN7)

Level of the Caudal PonsLevel of the Caudal Pons

CN7CN7

Note: the patient would

also lose taste in the ant

2/3 tongue on the left,

have a dry left eye, &

decreased salivation.Spinal TractVSpinal TractV

LeftLeft RightRight

ImagesImages