Infections

Question 1

What is prion disease

Answer 1

Group of neurodegenerative diseases caused by prions which accumulate and damage nerve cells

Question 2

What is the most common prion disease

Answer 2

CJD

Question 3

What causes CJD

Answer 3

Sporadic - protein -> prion
New variant - consuming meat from cow with bovine spongiform encephalopathy
Familial - genetic
Acquired - infection

Question 4

How does sporadic present

Answer 4

Rapidly progressive dementia
Myoclonic jerks
>60
Behaviour abnormality
Cerebellar ataxia
Parkinsonism - Tremor / rigid / bradykinesia
Weakness
Hyperreflexia / UMN sign 
Seizure
Blidness

Question 5

What is prognosis

Answer 5

Death in 6 months

13 if new variant

Question 6

How does new variant present

Answer 6

Younger onset
Early behaviour change
Anxiety / withdrawal / dysphonia
Better prognosis

Question 7

How do you Dx

Answer 7

MRI = hyperextense
EEG
CSF = usually normal
Immunoassay for brain protein

Question 8

How do you Rx

Answer 8

No treatment currently

Question 9

What are differentials

Answer 9

Viral encephalitis
PML
HIV dementia
Lyme's / neurosyphillis
Whipple's
Alzheimer's
Lewybody
Tumour

Question 10

What is Reye’s

Answer 10

Fatty infiltration of liver, pancreas, kidney and brain

Question 11

What causes Reye’s

Answer 11

Post viral infection
Aspirin use
Common in children

Question 12

What are the symptoms

Answer 12

Severe progressive encephalopathy
Confusion
Seizures
N+V
Cerebral oedema
Coma
Abnormal LFT
Hypoglycaemia

Question 13

How do you treat

Answer 13

Supportive

Question 14

What are other rare infections in brain / affect nerves

Answer 14

Poliomyelitis
Lyme's
Neurosyphillis
Rabies
Tetanus
Botulism

Question 15

What does poliovirus 1,2,3 (enterovirus) cause and where does it affect

Answer 15

Poliomyelitis

Affects anterior horn cell to affect LMN

Question 16

How do you prevent

Answer 16

Vaccine

Question 17

What happens in rabies

Answer 17

Humans bitten by infected animal
Virus enters PNS
Migrates to CNS

Question 18

What does it cause

Answer 18

Ascending paralysis
Paraesthesia
Encephalitis

Question 19

How do you Dx

Answer 19

Nerve conduction
Culture of wound
Serology

Question 20

How do you Rx

Answer 20

Immunisation killed vaccine if high risk area before travel

If bitten
Clean and disinfect wound 
Immunisation active vaccine to boost 
Human rabies Ig
Consider Ax

Question 21

What causes tetanus

Answer 21

Clostridium tetani
Anaerobic gram +ve
Toxin acts at TMJ and blocks inhibition of motor neurones
Prevents release of GABA
Present in soil and can enter body

Question 22

How does it present

Answer 22

Fever
Lethargy
Hedache 
Trismus - locked jaw
Spasms
Rigidity 
Arched back and hyperextended neck
Dysphagia due to spasm

Question 23

How do you prevent

Answer 23

Immunisation x5

Penicillin and Ig if high risk wounds

Question 24

How do you treat

Answer 24

Ventilatory support
Muscle relaxant
IM Ig for high risk wounds
Metronidazole

Question 25

What causes botulism

Answer 25

Clostrodium botulinum Anaerobic gram +Ve Binds to pre-synaptic membranes of peripheral NMJ Block Ach release

Question 26

What are symptoms

Answer 26

``` Flaccid paralysis Resp failure Autonomic dysfunction - Urinary retention - Dry mouth - Dilated fixed pupils Diplopia Ataxia Bulbar palsy - Dysphagia - Dysphonia ```

Question 27

How do you Dx botulism / tetanus

Answer 27

Nerve conduction Wound culture Mouse neutralisation bioassay

Question 28

How do you treat

Answer 28

Anti-toxin ABE Prolonged penicillin Wound debridement

Question 29

What are considered high risk tetanus wound requiring prophylaxis with IM Ig + muscle relxant

Answer 29

``` Burns requiring surgery >6 hour wait Soil containation FB Compound fracture Systemic sepsis ```

Question 30

Meningitis and encephalitis

Answer 30

See infection

Question 31

What is most common cause of encephalitis

Answer 31

Viral | - HSV / VZV

Question 32

What is another cause

Answer 32

Autoimmune

Question 33

What are general encephalitis features

Answer 33

``` Fever Altered mental status Seizure Flu like prodrome Meningitis can become ```

Question 34

How do you Dx and Rx

Answer 34

CT head MRI LP if no focal Rx - Aciclovir - Anticonvulsant

Question 35

What does HSV cause

Answer 35

Temporal lobe change and multi-focal haemorrhage

Question 36

How does autoimmune present

Answer 36

``` Confusion Siezure Movement disorder Psychosis Cognitive change Low GCS Often fluctuating ``` Increasingly recognised as acute / subacute mental status change in the young

Question 37

How do you Dx

Answer 37

Ab - NMDA receptor Ab - Voltage gated K channel (low Na) - Anti-Hu MRI head EEG PET CT

Question 38

What is important to do in autoimmune

Answer 38

Cancer screen as can be parenoplatic - PET CT Ovarian = NMDA SCLC = anti-Hu

Question 39

How do you Rx

Answer 39

Steroid | IV Ig if required