This document discusses several types of autoimmune encephalitis, including Hashimoto's encephalopathy, NMDA encephalitis, and limbic encephalitis. Hashimoto's encephalopathy is defined by the presence of thyroid peroxidase antibodies in patients with encephalitis that responds to steroids. It can cause non-specific neurological symptoms. NMDA encephalitis commonly affects young women and can cause psychiatric issues, decreased consciousness, and movement disorders. Diagnosis involves detecting NMDA receptor antibodies in CSF or serum. Limbic encephalitis involves inflammation of limbic structures and is associated with antibodies against proteins like LGI1; it typically causes memory loss, behavioral changes and seizures in older patients.

1. AUTOIMMUNE ENCEPHALITIS
Rusudan Genebashvili

2. Definition
 The term autoimmune encephalitis is used to
describe a group of disorders:
- Characterized by symptoms of the CNS
(limbic, extra-limbic, basal ganglia,
autonomic structures or more wide-spread)
due to autoantibodies against neuronal
surface or synaptic proteins, which are likely
to mediate the disease.

3. HASHIMOTO ENCEPHALOPATHY
 Defined by the detection of thyroid
peroxidase (TPO) antibodies in patients with
acute or subacute encephalitis that responds
to steroids.
 “Encephalopathy associated with
autoimmune thyroid disease” is considered
more accurate- due to normal thyroid
function.
 Very vague symptoms- unclear course

4.  Clinical features : non specific
- Stroke-like symptoms
-Tremor, myoclonus
-Transient aphasia
- Sleep and behaviour abnormalities
- Hallucinations, seizures and ataxia.

5. Diagnosis:
 Clinical triad of neuropsychiatric symptoms,
detection of antimicrosomal or
antithyroglobulin antibodies, and exclusion of
other causes.
 Antithyroid peroxidase, antithyroglobulin,
 lesser extent thyroid-stimulating hormone
receptor
 blocking antibodies.
 α-enolase

6. Diagnosis:
 Autoimmune cerebral vasculitis perhaps
related to immune complex deposition.
 CSF show moderately elevated protein, may
be positive for anti thyroid Ab, OCB seen
 EEG: slowing, triphasic waves, epileptiform
discharges.
 MRI usually normal, occasionally non-specific
sub cortical white matterT2 signal changes.
 Thyroid status may be normal.

7. HASHIMOTO ENCEPHALOPATHY

10.  •Treatment: short course high dose steroids
(55% full recovery)
- Initial treatment is usually with oral prednisone (50–
150 mg/day) or high-dose IV methylprednisolone (1 g/day) for
3–7 days.Thyroid hormone treatment is also included if
required.
- Failure of some patients to respond to this first line
treatment has produced a variety of alternative treatments
including azathioprine, cyclophosphamide, chloroquine, met
hotrexate, periodic intravenous immunoglobulin and plasma
exchange.
-Seizures, if present, are controlled with typical antiepileptic
agents.
 Recurrence – continued steroids, IVIG, other
immunomodulatory drugs.

11. NMDA ENCEPHALOPATHY
 Leading cause of autoimmune encephalitis in
children and adolescents.
 Age- frequently 2– 40 years, 80% Female
 Stages :
1. Stage1 – prodromal phase
2. Stage 2 – psychiatric and behavioral problems
3. Stage 3 – Decreased level of consciousness
 Behavioral changes included new-onset
temper tantrums, agitation, aggression, and
changes in mood or personality

12. NMDA ENCEPHALOPATHY
Clinical features
 Behavioural disturbance,Psychosis
 Catatonia
 Seizures
 Movement disorders including orolingual
dyskinesias and stereotypic movement.
 Dysautonomia.
 Ovarian teratoma is associated in up to 50%
of the cases

15. diagnosis
 CSF : -lymphocytic pleocytosis,
-elevated protein levels
-oligoclonal bands
 EEG – extreme delta brush
 MRI demonstrate medial temporal lobe
attenuated inversion recovery high signal or
focal areas of hyperintensity in the frontal or
parietal cortex
 fluorodeoxyglucose positron emission
tomography (FDG-PET) scan show cortical
hypermetabolism in acute stages, and
hypometabolism in more subacute stages of the
illness.

16. NMDA ENCEPHALOPATHY

17. 19 year old with NMDA encephalitis
Delta Brush

19. treatment
 first line of immunotherapies including
corticosteroids, intravenous immunoglobulin,
or plasma exchange
 Rituximab and cyclophosphamide, alone or
combined, are often effective in adults
 Approximately 80% of patients have
substantial or full recovery.

20. LIMBIC ENCEPHALITIS
 Definition: characterised by subacute
development of short term memory loss,
behavioural change and seizures involving the
temporomedial lobes , the amygdalae, and
cingulate gyrus with variable evidence of CSF
inflammation and neuronal antibodies
 Antibodies against the neuronal secreted protein
called leucine-rich gliomainactivated 1 (LGI1)
 LGI1 - secreted neuronal protein that interacts
with the presynaptic and postsynaptic proteins
ADAM23 and ADAM22 -modulate synaptic
transmission

21.  In 1968 , as Para neoplastic syndrome
 median age of patients is 60 years
 Severe short term memory loss
 hyponatremia and myoclonic-like
movements, described as faciobrachial
dystonic seizures
 Other antibodies associated- antibodies
against intracellular antigens (eg, Hu, CRMP5,
Ma2) or against cell surface or synaptic
proteins (eg (AMPA) [GABA(B)] [mGluR5])
 Ophelia syndrome (- association with
Hodgkin’s lymphoma)

22. Diagnosis:
 CSF - mild-to-moderate lymphocytic pleocytosis (usually less than 100
WBCs / mm³) in 60–80% of patients
 CSF – elevated IgG index or oligoclonal bands ( 50% cases)
 Among all immunological subtypes of limbic encephalitis, patients with LGI1
antibodies present with a lower frequency of CSF pleocytosis (41%) or
elevated CSF protein concentrations (47%) and rarely have intrathecal IgG
synthesis.
 MRI – often shows increased signal onT2w FLAIR in the medial aspect of the
temporal lobes.
 Antibodies against the intracellular antigen Glutamic acid decarboxylase
(GAD) occur in a subgroup of patients with limbic encephalitis.
 Mainly young women (median age 23 years) with predominant seizures and
no evidence of cancer.
 The risk of cancer, usually SCLC or thymoma, is higher, however, among
patients with GAD antibodies and limbic encephalitis who are older than 50
years or have concomitant GABA B receptor antibodies.

25. Treatment:
 Treatments that have been tried
include intravenous immunoglobulin,
plasmapheresis, corticosteroids, cyclophosph
amide and rituximab
 If an associated tumour is found, then
recovery is not possible until the tumour is
removed

26. Thank you 
Rusudan Genebashvili