Localising the lesion: “where in the CNS” - PowerPoint Presentation

Slide1

Localising the lesion: “where in the CNS”

Kate HassanSlide2

Learning objectives

Definition of CNS and PNS

Definition of UMN and LMN

Function of each of the cerebral lobes

The homunculus

Circle of

willis

and blood supply to the cerebral hemispheres

Motor tracts – lateral

corticospinal

Sensory tracts – lateral

spinothalamic

and dorsal columns

Stroke syndromes

Clinical case scenariosSlide3

Definitions

CNS = Brain and spinal cord

PNS = anything outside brain and spinal cord

Also include autonomic nervous system and cranial nervesSlide4

Motor control systems

Corticospinal

(

pyradmial

)

S

killed, intricate, strong and organised movements

Defectiveness

 loss of skilled voluntary movement, spasticity and reflex changes

Extrapyradimal

system

F

ast, fluid movements that the

corticospinal

system has generated

Defectiveness 

bradykinesia

, rigidity, tremor, chorea

The cerebellum

Co-ordinating smooth and learned movement initiated by the

pyradimal

system and in posture and balance control

Defectiveness  ataxia, past pointing, action tremor and incoordinationSlide5
Slide6

Corticospinal (

pyradimal

) systemSlide7

The homunculusSlide8

Definition of UMN and LMNSlide9

UMN signs vs

LMN signs

UMN

LMN

wasting

fasciculation

tone

Power

reflexes

Plantars

UMN

LMN

wasting

no

fasciculation

tone

Power

reflexes

Plantars

UMNLMNwastingnoyesfasciculationtonePowerreflexesPlantars

UMNLMNwastingnoyesfasciculationnotonePowerreflexesPlantars

UMNLMNwastingnoyesfasciculationnoyestonePowerreflexesPlantars

UMNLMNwastingnoyesfasciculationnoyestoneincreasedPowerreflexesPlantars

UMNLMNwastingnoyesfasciculationnoyestoneincreaseddecreasedPowerreflexesPlantars

UMNLMNwastingnoyesfasciculationnoyestoneincreaseddecreasedPowerdecreasedreflexesPlantars

UMNLMNwastingnoyesfasciculationnoyestoneincreaseddecreasedPowerdecreasedincreasedreflexesPlantars

UMNLMNwastingnoyesfasciculationnoyestoneincreaseddecreasedPowerdecreasedincreasedreflexesincreasedPlantars

UMNLMNwastingnoyesfasciculationnoyestoneincreaseddecreasedPowerdecreasedincreasedreflexesincreaseddecreasedPlantars

UMNLMNwastingnoyesfasciculationnoyestoneincreaseddecreasedPowerdecreasedincreasedreflexesincreaseddecreasedPlantarsup going

UMN

LMN

wasting

no

yes

fasciculation

no

yes

tone

increased

decreased

Power

decreased

increased

reflexes

increased

decreased

Plantars

up

going

down

goingSlide10

Sensory pathways

Peripheral nerves carry sensation from dorsal roots to the cord

Posterior columns (dorsal columns)

Vibration, joint position, light touch and point discrimination

Cross in the brainstem passing to the thalamus

Spinothalamic

tracts

Pain and temperature

Cross within the cord and pass in the

spinothalamic

tracts to the thalamus and reticular formation

Sensory cortex

Fibres from the thalamus pass to the parietal region sensory cortex and motor cortexSlide11

Cerebral lobesSlide12

Cortical functions

Frontal lobe

Reasoning, planning, parts of speech, movement, emotions and problem solving

Left frontal =

broccas

area (aphasia)

Parietal lobe

Movement, orientation, recognition, perception of stimuli

Occipital lobe

Visual processing

Temporal lobe

Perception and recognition of auditory stimuli, memory and speech

Left temporal =

wernicke’s

area

Cerebellum

Balance and co-ordination

Basal gangliaInitiation and inhibition of movementSlide13

quiz

Patient has difficulty walking and slurred speech

Cerebellum

Patients

wife reported personality change and difficulty wording what they wanted to say

Frontal

lobe

Patient has difficulty recognising objects and often gets lost unable to find

their way home

Parietal and occipital

lobe

Patient has difficulty remembering significant past events and no longer enjoys listening to music

Temporal lobeSlide14
Slide15
Slide16
Slide17

Stroke syndromes

TACS = total anterior circulation syndrome

PACS = partial anterior circulation syndrome

POCS = posterior circulation

syndrome

LACS = lacunar syndromeSlide18

Stroke

TACS – All three of

Hemiplegia or hemi sensory loss

Visual field defect

Disturbance of higher function

Dysphasia

Dysphagia

PACS – 2 out of 3

LACS – blockage of small branch of big artery

No visual field defect

Pure motor stroke

Pure sensory

Sensory motor

Ataxia

POCS – brain stem, cerebellum, cranial nerves

Bilateral motor or sensory

Conjugate eye movement disorder

Cerebeller dysfunctionHemiplegia or cortical blindnessSlide19

Stroke

Acute occlusion of blood vessel leading to hypoxia and infarction

Risk factors

DM, hypertension, smoking, hypercholesterolemia,

FHx

, AF

Investigations

bloods, CT, MRI, carotid

dopplers

, Echo, ECG, 24 hour tape

Treatment in ischaemic stroke

Aspirin

Clopidogrel

Supportive managementSlide20

Cerebellar syndrome

Causes

Vascular lesion

Alcohol

Demyelination

Tumours

Hypothyroidism

Metabolic disorders

Signs “DANISH”

Dysdiadochokinesis

Ataxia

Nystagmus

Intention tremor

Slurred speech, dysarthria

Hpyotonia

,

hyporeflexiaSlide21

Multiple Sclerosis

Areas of demyelination and perivascular inflammation (white plaques)

Disseminated in time and occurring anywhere within CNS

Aetiology - ?autoimmune ?vitamin D deficiency

Classification

Benign

Relapse remitting

Secondary chronic progressive

Primary

progressive

Investigations

LP – increased protein, increased immunoglobulin,

oligoclonal

bands

Visual evoked potentials

MRISlide22

Multiple sclerosis

On examination

Unsteady gait

Reduced proprioception

Brisk reflexes

Brown-

sequard

syndrome

Loss of movement on same side as damage

Loss of pain and temp and sensation on opposite side

M

anagement

Symptoms control (tremors, pain, muscle spasms

)

steroids

Beta-

inferons

GlatiramerIV natalizumabSlide23

Motor neurone disease

Degeneration of upper and lower motor neurones of unknown cause

5-10% autosomal dominant

T

ypes

Spinal muscular atrophy – limb weakness due to involvement of spinal cord anterior horn cells

Primary later sclerosis – spastic limb weakness due to UMN involvement of the spinal cord

Progressive bulbar palsy – involvement of bulbar motor neurones, progressive disease

Amyotrophic lateral sclerosis – mixture of all the above

Investigations

Diagnosed clinically after other causes excluded

EMG confirms fasciculation's and fibrillations

Management – symptom control

Fatal within 3-5 yearsSlide24

Motor neurone disease

Cardiac

and smooth muscle

aren’t

involved and

ocular

muscle very rarely

Autonomic dysfunction occurs

late

Signs

Dysarthria, brisk jaw reflex

Fasciculation/wasting in deltoids, biceps, quadriceps and in tongue

Weakness in all4 limbs, brisk reflexes in arms, absent in legs

Combination of UMN and LMNSlide25

Clinical case 1

23, female presents to her GP with a 2 week history of bilateral leg weakness having started with pins and needles and numbness in her hands and feet. She has had a few days of urinary incontinence which has resolved. 2 years ago she had an episode of blurred vision and pain in the right eye which lasted a month and fully resolvedSlide26

Case 1

What is the most likely diagnosis?

What other signs or symptoms might you see in this condition?

What is the pathological basis of this disorder?

What further investigations would you do?

How would you manage this patient?Slide27

Clinical case 2

61 female

Becoming increasingly weak on her right side over a one week period. She is unable to walk and has slurred speech and right side of her face is drooping

Past history of breast cancer

o/e – right facial weakness, grade 4/5 weakness of the right arm and leg, right homonymous hemianopia and some difficulty naming objects and reflexes are brisk on the right side and her right plantar response is

upgoingSlide28

Case 2

What is the likely diagnosis?Slide29

Case 2

CT head shows extensive oedema surrounding the subtle impression of a ring enhanced lesion in the left frontal lobe, extending into the left parietal lobe. There is associated mass effect displacing the lateral ventricleSlide30

Case 2

What is the likely cause?

Other features that may be present?

What management options are available?Slide31

Case 3

76 male

Background of AF (on warfarin) has 2 hour history of severe global right sided weakness. He is eye-opening to painful stimuli and is moving his left side spontaneously. When questioned he seems confusedSlide32

Case 3

What is his GCS?

What is the diagnosis?

What investigations would you do?

What are the important risk factors?

How wound you manage this patient?Slide33

Case 4

56 male

6 month history of progressive weakness of his right hand. Also had problems with swallowing and has choked whilst eating on several occasions

o/e he has wasting of his upper and lower limbs and some fasciculation's were noted his right plantar was up going and his reflexes were generally briskSlide34

Case 4

Diagnosis?

What investigations would you perform?

How would you manage this patient?Slide35

Thank you for listening

Any questions?