1GIT 3 Anatomy of the Intestine

Dr. Lakal Dissabandara

School of Medicine

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Presented on 03/02/2009

Lesions

Presented on 06/05/2014

CNS lesions Usually a large area is affected due to the involvement of long tracts

(white matter) or their cell bodies (Cortex). Long tracts signs may not

help accurately locating the level of the lesion.

Eg. In a patient presenting with right sided UMN type of weakness of both UL and LL, the lesion can be anywhere above

cervical cord ****.

Unilateral CNS lesions generally wont affect trunk muscles and muscles supplied by cranial nerves EXCEPT lower facial muscles

and tongue muscles.

Additionally CNS lesions (at & below midbrain) can involve central components of PNS

Eg in Spinal nerves

Ventral Horn LMN type paralysis of the muscles supplied by that spinal segment (Myotome)

Dorsal Horn - Complete sensory loss (all modalities) in the area of skin innervated by that spinal segment (Dermatome)

Eg. in Cranial nerves

Motor Nuclei - Ipsilateral*** LMN type cranial nerve palsy

Sensory nuclei - Ipsilateral Sensory loss in the area of distribution by the cranial nerve

Rostral lesions (larger cross sectional area/2 sides are separated) unilateral symptoms Eg. Cortical and internal capsular

Caudal lesions (smaller cross sectional area) may be bilateral symptoms (Specially spinal cord) Eg. Specially

spinal cord/brainstem

Pattern of motor deficit Contralateral Hemiparesis

Mostly the lesions are vascular in origin UL+Face >leg MCA territory

Leg>UL+face ACA territory

Smaller lesions may cause isolated deficits! Smaller cortical artery obstruction

Localized tumour

Localized injury

Pattern of sensory deficit Contralateral Hemisensory deficit (deficit rather than a loss. WHY?)

Follows the same pattern as above.

Localizing CNS Lesions - Cortex

Associated cortical signs Dominant hemisphere

Dysphasias

Expressive Frontal lobe

Receptive parietotemporal

Acalculia - Parietal

Nondominant hemisphere Visuospatial awareness defects

Constructional apraxia - Parietal

Sensory inattention/neglect - Parietal

Any hemisphere Frontal eye field eyes looking at the side of the lesion.

Posterior parietal lobe

Agraphaesthesia

Loss of 2 point discrimination

astereognosis

**Visual pathway Quadrantonopias or hemianopias

Can be examined

only if the 1ry

sensations are

reasonably intact

i.e presence of

cortical lesions

Pattern of motor deficit

Dense hemiplegia affecting face, arm, leg equally***.

Pattern of sensory deficit

Hemisensory deficit.

Associated signs Caudally extended capsular lesions cause

hemianopia

***Aware of the possibility of isolated motor or sensory deficit as a result of lacunar infarcts very small lenticulostriate artery

occlusion/rupture Lacunar syndromes. Pure motor hemiparesis

Ataxic hemiparesis

Localizing Lesions Internal Capsule

Internal Capsule

Case 1A 67-year-old man with history of DM and Hpt, when woke up in the morning

noticed weakness of left hand. Additionally, his wife is concerned that his speech

is not normal. He came to the emergency walking.

Based on this history what is your working hypothesis for further history taking

and examination?

Examination on admission

There was obvious slurring of speech. But he was able to communicate well during the examination.

He could raise the eye browses symmetrically, close his eyes tightly on both sides. When asked to blow his cheeks out there was weakness on left cheek

and his mouth deviated to right when he tried to show his teeth.

Moderate to severe weakness of left upper limb muscles compared to left lower limb. Left UL weakness is more marked on the hand compared to shoulder.

BJ and TJ were exaggerated on left side. The knee jerk on the left was only slightly increased with no change in left ankle jerk.

Although she could feel pinprick on both sides, it was less intense and localization was poor on left UL & left face compared to right side.

Proprioception/vibration also impaired on left UL.

There was a bruit heard over the left carotid area.

Locate the area of the lesion.

Which blood vessel is affected?

In this patient, WOF would you expect to find?

a. Down and out positioned right eyeball.

b. Deviation of tongue to left on protrusion.

c. Loss of corneal reflex on right side.

d. Sensory inattention

e. Receptive aphasia

f. Left gaze preference

A week later he suddenly appeared confused and readmitted.

On examination - Left lower face, arm and leg were densely paralyzed with spasticity. Left BJ, TJ, KJ, AJ were all exaggerated. Left Babinskis sign positive. Left gaze preference+.

He opens eyes in response speech. Withdraw limbs in response to painful stimuli. Utters inappropriately in response to questions.

Bilateral Papilloedema +. Sluggish right pupillary reaction to light.

CT scans on first and second admission are given below. Explain the main findings of the CT. Explain the new examination findings.

1st admission 2nd admission

Neurological Examination

On admission Left lower limb - Flaccid with compromised all sensory modalities.

Following day

left KJ & AJ has become exaggerated Positive Babinski sign in her left foot. Impaired touch, pain, temperature and proprioception in her left lowerlimb. Rest of the neurological examination was normal. She remained in low mood throughout. She had urinary incontinence in the first few days but improved later.

Which area of the CNS is likely to be affected? Explain your answer. If this is due to a vascular occlusion which part of the circulation is affected?

One morning, while attempting to stand from the

bed Mrs.Jones, 69 years, noticed that her left leg

was too weak and numb. You are going through

her notes 2 weeks after admission.

Case 2

Mrs. Jones CT scans.

Describe the findings.

Case 3State the motor and sensory signs of this patient.

Could this patient develop dysphasia?

Could he be having any CN palsies except

optic and facial?

Localizing Lesions Brain stem At subhemispheric level the most important feature is the lesions may

involve both long tracts and central components of peripheral cranial nerves

(motor/sensory nuclei of the cranial nerves).

An important thing to remember is the dual cortical innervation of all cranial motor nuclei except CN VII innervating lower facial muscles CN XII

innervating genioglossus muscles.

Involvement of extra ocular, upper facial, masticatory, pharyngeal and laryngeal muscles together with contralateral long tract signs below the

lesion usually** indicate brainstem lesion.

Levels

IIIrd and IVth midbrain

V-VII Pons

VIII XII Medulla

Additional localization (in transverse plain) is also possible.

Eg. Pyramidal tract involvement indicate a ventral lesion.

Sensory tracts/Cranial nerve involvement indicate a relatively posterior lesion

Both of the above signs usually indicate large lesion

This patient presented with weakness and numbness of

right side of the body.

On examination

Right sided hemiplegia and hemisensory loss. BJ/TJ/KJ/AJ exaggerated on right Babinski + ve Right side

What would you expect to see in CN VI, CN VII and CN XII examination in this

patient?

Case 4

I have weakness in the dark area indicated.Where is the lesion?

Case 5

Case 6A 54 year old man admitted with sudden onset numbness of the right side of

the body, double vision and slurring of speech.

Examination revealed:

Loss of pain temperature sensation on right side limbs and trunk. Loss of pain and temperature on left side of the face however tactile

sensation is intact.

Left facial muscles are paralysed. Absence of both abduction of left and adduction or right eye when

looking towards left

and

absence of right respectively. Normal convergence.

No weakness of the limbs. Tendon reflexes are normal and symterical.

What is the level of the lesion?

What is the horizontal extension of the lesion/what structures are affected?

CN VI Nu

CN VII Nu

Spinal trigeminal tract

Spinal lemniscus

VTT

DCML

MLF

In a patient with LEFT abducens nuclear lesion, WOF would

you expect during examination of the eye movements? T/F

a. Lack of abduction of left eye when looking to left

b. Lack of adduction of left eye when looking to right

c. Lack of adduction of right eye when looking to left

d. Normal abduction of right eye when looking to right

Spinal tract

of trigeminal

L/Spiniothalamic Tr.

Inferior cerebellar

peduncle

Vestibular Nu.

Nu. ambiguss

Case 7 - Lateral Medullary syndrome

State the physical signs of lateral medullary syndrome. Which blood vessel is implicated?

Medial lemniscus

Pyramid

Dorsal vagal Nu

Hypoglossal Nu

Descending

sympathetic

fibres

A 24-year-old medical student noticed while shaving one morning that he was unable to move the left side of his face. He had had influenza-like symptoms the week before this sudden incident.

Neurologic examination showed that the patient could not wrinkle his forehead on the left side or show his

teeth or purse his lips on that side. He had trouble closing his left eye.

Taste sensation was abnormal in the left anterior two- thirds of the tongue

On direct questioning he accepted there was some dryness of the left eye.

Loud noises caused discomfort. He was in good health otherwise, and there were no additional signs or symptoms.

Which of the following is/are the likely site/s of lesion?

a. Distal to geniculate ganglion

b. Within the parotid gland

c. Within stylomastoid foramen

d. Between Internal acoustic meatus and geniculate ganglion

e. Cerebelopontine angle

Case 8

Which of the following neural structure is unlikely to be

affected by this lesion?

a. Greater petrosal nerve

b. Chordatympani nerve

c. Deep petrosal nerve

d. Marginal mandibular nerve

e. Pterygopalatine ganglion

A patient presented with chronic headache and vertigo. Direct questioning

revealed impaired hearing and feeling increasingly unsteady while walking. On

examination there was,

Bilateral early papilloedema

Deviation of mouth to right with inability to close her left eyelid tightly.

No apparent weakness

Loss of all sensations over left side of the face.

Unable to stand feet close together, hands by the side with eyes open.

Finger nose and hell shin tests positive on left side.

Joint position sense/vibration Normal

What is the most likely cause for above findings?

a. Left cerebellar infarct

b. DCML lesion at cervical level

c. Anterior pontine lesion

d. Right cerebral peduncle lesion

e. Left CP angle Schwannoma

Case 9

Localizing Lesions Spinal cord Similar to brainstem, both long tracts and central components of

spinal nerves (ventral and dorsal grey horns) can be affected.

Long tract signs

Motor ipsilateral UMN

Sensory dissociated sensory loss (Pain temperature on one side and the DCML signs on the other).

A sensory level is demonstrable using pin prick test (contralaterally about 2-3 segments below the lesion important for locating the level of lesion)

Proprioception can only be tested accurately in hand and feet limited vaulein accurate localization of the level of the lesion. Vibration can only be tested

on bones.

Involvement of grey matter gives rise to segmental deficit at the level of lesion.

motor - myotome

Sensory - dermatome

Where is my Lesion?

T12 dermatome

Also I have difficulty walking in the dark. Explain.

Case 10

You are examining a 27-year-old electrician with stab injury to the back of the lower neck 6 weeks ago.

Brain 8

Rt upper limb - Wasting of intrinsic hand muscles and weakness of finger abduction & adduction, opposition of thumb and little finger. All upper limb reflexes are normal.

Rt lower limb - unable to move, spastic and KJ/AJ exaggerated, positive Babinski sign.

loss of pain and temperature sensibility below the T3 level on the left.

loss of position sense in right lower limb.

What is the location of lesion?

Would you expect complete sensory loss anywhere in the right upper limb?

Case 11

What muscles group would be flaccidly paralysed? Where would you expect complete sensory loss?

Case 12Write an exam question (Locate lesion type) based on a left side C5,C6

spinal cord hemisection.

There was loss of knee jerk on right side with exaggerated ankle jerk.

Which one of the above lesions is compatible with these findings?

Case 13

A patient was presented with the exacerbated chronic lower back pain

in the Sacral region radiating to the left buttock, back of the left leg,

producing a burning pain behind the knee. Pain was aggravated when

bending forward or in reaching out position.

He had an accident that resulted in fracture of one of lumbar vertebrae. He was on NSAID s for back pain as well as for his

osteoarthritic pain of both knees.

If you are an extremely busy but smart GP and want to carry out a

quick neurologic examination what tests would you perform which

would likely to give positive result?

Case 14

Motor Always LMN type

Sensory - all sensory modalities affected

In relation to spinal nerves

Most proximal lesion is at the root level

Sensory deficit - Dermatomal

Motor deficit - Myotomal

Peripheral nerves trunks of brachial pleus/nerves This is where you need knowledge of peripheral nerve anatomy.

Localizing Lesions Peripheral nerve lesions

Case 15

A patient was asked to make a circle using

the first 2 fingers. Which of the following

is/are true regarding this test?

a. Tests the median nerve

b. Tests anterior interosseous nerve

c. Tests both oponens polcis and first dorsal

interosseous

d. Inability to do this test may be associated

with weak pronation of the forearm

Case 16

A patient was complaining of radiating pain along the lateral

aspect of the upper limb down to the thumb and index finger.

He is likely to have:

a. extension weakness of the wrist

b. Extension weakness of the elbow

c. compression of the ulnar nerve in the cubital tunnel

d. suffered a axillary nerve injury with resulting neuroma

formation

Case 17

A patient presented with burning sensation over the lateral aspect of the right thigh.

On examination there was markedly reduced sensations over lateral aspect of

the upper thigh.

No other abnormalities.

Roots Vs Nerve Lesion Dermatomal vs Nerve distribution

Disc

Prolapse

Lateral cutaneous N

of Thigh LI

L2

L3

A 39 years old secretary working for a busy private company, came to a

general practitioner with right wrist pain for a duration of 2years initially

occurring periodically and later more frequently. In addition to the pain, she

had paraesthesia of the little finger and part of the ring finger.

Examination of right upper limb revealed:

- impaired sensation mostly in the little finger and medial aspect of the ring

finger.

- generalized mild to moderate wasting of palmer and dorsal aspect of right

hand except over the thenar area.

- finger and thumb adduction and abduction were weaker

- movements of wrist, elbow and shoulder were normal

A medical student on GP rotation told the general practitioner that the signs

and symptoms were probably due to a lesion of the lower trunk of the

brachial plexus. The GP disagreed.

Discuss, using the history and available examination findings, why the

medical students diagnosis is likely to be incorrect.

Case 18

A patient presents with inability to dorsiflex the left

foot and extension of toes. There is a notable

weakness of inversion of the left foot. No other

motor deficit.

Based on above findings which of the

following condition best describe his

physical signs?

a.Tarsal tunnel syndrome

b.Lateral compartment syndrome

c.Anterior compartment syndrome

d.Fibular head fracture

e.Posterior dislocation of hip

Case 19

76-year old man woke up this morning with

weakness in his left leg. He noted difficulty in lifting

up his left foot from the floor. Also there is

numbness on the lateral aspect of leg and foot.

The patient has bought a computer recently and

has been browsing the web, sitting with legs

crossed for prolonged periods. He has been

having calf pain on walking moderate distance.

when he walks more than He is a smoker and a

diabetic patient with poor control.

O/E - 3/5 left foot dorsiflexion; Area of sensory loss is shown in the diagram.

What is the diagnosis?

Likely pathophysiology?

Case 20

Complete sensory loss in areas indicated

Locate the lesions