Neuropsychiatry Of Encephalitis

Question 1

What are the main groups of encephalitis by cause?

Answer 1

Infectious encephalitis
Immune-mediated encephalitis (post infectious and autoimmune)
Unknown

Question 2

What cells produce antibodies?

Answer 2

B-lymphocytes

Question 3

What are examples of immune mediated encephalitis?

Answer 3

Rasmussen encephalitis
Connective tissue diseases/vasculitis
ADEM
Basal ganglia encephalitis (lethargica)
Hashimoto encephalopathy
Antibody-associated encephalitis

Question 4

When might encephalitis be T-cell mediated?

Answer 4

In paraneoplastic encephalitis

Question 5

Which antibody associated encephalitides are less responsive to treatment?

Answer 5

Associated with cancer
Intracellular antigens

Question 6

What are examples of bacterial causes of encephalitis?

Answer 6

Syphilis
Lyme
Tuberculosis

Question 7

What are examples of viral causes of encephalitis?

Answer 7

Heroes
HIV
Measles
Influenza
Polio
Dengue
West Nile
JC Virus
CMV
Rabies

Question 8

What are examples of protozoal causes of encephalitis?

Answer 8

Malaria
Toxoplasma
Sleeping sickness

Question 9

What are examples of autoimmune causes of encephalitis?

Answer 9

Paraneoplastic
Non-paraneoplastic (NMDAR, LGI1, CASPR2, IgLON5)
Lupus
ADEM

Question 10

Where does herpes encephalitis start?

Answer 10

Limbic system

Question 11

What are the symptoms of acute HSV encephalitis?

Answer 11

Headache, fever, seizures
+
Agitation
Confusion
Psychosis
Mania
Delirium
Confabulation
Catatonia

Question 12

What are the neuropsychiatric sequelae of HSV encephalitis (chronic)?

Answer 12

Cognitive impairment
Anterograde amnesia 25-75%
Retrograde amnesia
Executive dysfunction 40%
Disinhibition
Aggression
Kluver-Bucy

Question 13

What are more likely causes of antibody encephalitis than targeting of VGKC?

Answer 13

Targeting of CASPR2
Targeting of LGI1
Both complex with VGKC

Question 14

What is the characteristic progression of Anti NMDA receptor encephalitis?

Answer 14

Prodromal malaise/flu like symptoms
Psychiatric symptoms
Movement disorder
Seizures
Autonomic dysfunction

Question 15

What are the psychiatric symptoms associated with Anti NMDAR encephalitis?

Answer 15

Agitation
Anxiety
Psychosis
Catatonia
Echolalia
Sleep disturbance

Question 16

What are the investigations in Anti NMDAR encephalitis?

Answer 16

MRI - 33% abnormal
CSF - 80% abnormal
EEG - 80-90% abnormal (delta blush)
Malignancy found in 39%

Question 17

What is a typical investigation that is unhelpful in Anti NMDAR encephalitis?

Answer 17

Serum inflammatory markers

Question 18

What is likely to be seen in CSF with anti nmdar encephalitis?

Answer 18

Lymphophytic pleocytosis (over abundance of white blood cells) 75%

Oligoclonal bands (indicating immunoglobulins) 50%

Question 19

What are the mechanisms of Anti NMDAR encephalitis?

Answer 19

Antibodies target receptor causing internalisation
Resultant NMDAR hypofunction

Question 20

Which type of encephalitis are people with type 1 diabetes at increased risk for and why?

Answer 20

GAD65
They already have antibodies for it.

Question 21

What disorders is CASPR2 implicated in?

Answer 21

Autism and other neurodevelopmental disorders

Question 22

What are the intrinsic risk factors for LGI1 encephalitis?

Answer 22

HLA
Male gender

Question 23

When does LGI1 encephalitis typically present?

Answer 23

Early 60s

Question 24

What does LGI1 encephalitis typically get misdiagnosed as?

Answer 24

Alzheimer’s
Other dementias

Question 25

What does LGI1 encephalitis typically affect?qq

Answer 25

Medial temporal lobe Particularly hippocampus (atrophy)

Question 26

What might you test for in a patient mimicking Anti NMDAR encephalitis but who has testing negative for NMDAR antibodies?

Answer 26

Neurexin

Question 27

What does IgLON5 encephalitis present as?

Answer 27

Chronic cognitive decline Frank dementia (IgLON5 typically seen on older people)

Question 28

What are the Graus criteria for anti NMDAR encephalitis?

Answer 28

1. Less than three months onset of (4/6) - psychiatric abnormality or cognitive dysfunction -speech dysfunction -seizures -movement disorder -decreased consciousness -autonomic dysfunction or hypoventilation 2. One of the below results - abnormal EEG -CSF with pleocytosis or oligoclonal bands 3. Reasonable exclusion of other disorders

Question 29

What are the criteria for autoimmune encephalitis? (Barcelona)

Answer 29

1. Less than 3 months onset of -working memory deficits -altered mental status -psychiatric symptoms 2. At least one of -new focal CNS findings -seizures not explained by previous disorder -CSF pleocytosis -MRI suggestive of encephalitis 3. Reasonable exclusion of other causes

Question 30

What is abnormal lymphocyte count?

Answer 30

More than 5

Question 31

At what point should it no longer be assumed that a patient has viral encephalitis?

Answer 31

After two negative viral PCRs (acyclovir should be given until then)

Question 32

How do the autoimmune psychosis diagnosis guidelines (Pollak et al) differ from Graus criteria?

Answer 32

Reduced emphasis on serum tests More emphasis on CSF Fewer factors needed to test for autoimmune encephalitis

Question 33

How is relapse likely to present in AE?

Answer 33

Isolated psychiatric or cognitive symptoms

Question 34

What impairments are people with Anti NMDAR encephalitis often left with?

Answer 34

Episodic memory Processing speed Executive function

Question 35

What impairments are people with Anti LGI1 encephalitis often left with?

Answer 35

Memory deficits (NTL atrophy) Executive function Attention Semantic/phonemic fluency

Question 36

How long does recovery from AE typically take?

Answer 36

Months May need to be in rehab