. 2020 Oct 1;9:100154. doi: 10.1016/j.bbih.2020.100154

Table 2.

Definitions of autoimmune based psychiatric syndrome.

A. POSSIBLE AUTOIMMUNE PSYCHIATRIC SYNDROME

a) a/cAPS:

o
with one or more of the following diagnosis:
Psychotic and schizophrenia spectrum disorders, mood disorders, minor and major neurocognitive impairment, anxiety disorders, obsessive compulsive disorder, attention deficit hyperactivity disorder, autism spectrum disorders, addiction, and eating disorders.
o
or with one or more symptoms of the following symptom or syndrome domains:
Altered conciousness, disorientation, cognitive dysfunction, obsessive-compulsive, psychosis, catatonia, mood dysfunction, anxiety, behavioral abnormalities (autism, hyperkinetic) and sleep dysfunction.

b) a/cPS with one of the following items:

1
Actual or recent diagnosis of a tumor
2
Movement disorder (catatonia, hypo- or hyperkinetic movements)
3
Adverse response to antipsychotics or antidepressants, DD neuroleptic malignant syndrome
4
Severe cognitive dysfunction
5
Altered consciousness
6
Seizures
7
Optic hallucinations
8
Infectious prodrome with fever
9
Aphasia, dysathria, mutism

B. PROBABLE AUTOIMMUNE PSYCHIATRIC SYNDROME

a) a/cPS with one the following nine items:

1
Actual or recent diagnosis of a tumor
2
Movement disorder (catatonia, hypo- or hyperkinetic movements)
3
Adverse response to antipsychotics or antidepressants, DD neuroleptic malignant syndrome
4
Severe cognitive dysfunction
5
Altered consciousness
6
Seizures
7
Optic hallucinations
8
Infectious prodrome with fever
9
Aphasia, dysathria, mutism

b) a/cPS with one of the following items:

o
CSF pleocytosis of >5 μl white blood cells per μL or ntrathecal IgG synthesis
o
Uni- or bilateral brain abnormalities/unilateral brain abnormalities on T2-weighted fluid-attenuated inversion recovery MRI highly restricted to temporal lobe/hyperintense lesions outside the limbic system
Or a/cPS with two of the following items:
o
EEG changes [spike, spike wave, rhythmic slowing changes, extreme delta brush, FIRDA or TIRDA (frontal or temporal irregular delta activity)]
o
Presence of serum auto-antibodies
o
High Tau/or Nfl changes related to acute phase

C. DEFINITIVE AUTOIMMUNE PSYCHIATRIC SYNDROME

a)
Probable a/cAPS with IgG class auto-antibodies in CSF
b)
These criteria do not exclude an episode if a previous psychiatric episode that has already terminated

Abbreviations:a/cAPS = subacute or subchronic autoimmune based psychiatric syndrome, a/cPS = subacute or subchronic psychiatric syndrome, DD = differential diagnosis, EEG = electroencephalography, IgG = immunoglobulin G, MRI = magnetic resonance imaging, Nfl = neurofilament light chain.

The proposed definitions have been developed in consideration of the criteria for autoimmune psychosis from Pollak (2020) and autoimmune encephalitis from Graus (2016).