Table 1 The clinical characteristics of 25 patients

1/M/6y

Movement disorders

Normal

Normal

Pimozide, tetrabenazine

CS, IVIG

Recovered

Erer Özbek S et al (2015) [7]

2/F/8y

Encephalopathy, seizures, psycho-behavioral changes

Epileptiform discharge

MRI: hyperintense lesions in the right hippocampal region

LEV

CS, IVIG

Recovered

Incecik F et al (2016) [9]

3/F/7y

Psycho-behavioral changes, encephalopathy, sleep disorders, movement disorders

Background slowing

Normal

-

CS, IVIG

Recovered

AlHakeem AS et al (2016) [8]

4/M/14y

Psycho-behavioral changes, amnesia, seizures

Normal

MRI: swelling of the left hippocampus

-

CS, PE, MMF

Improved

Schimmel M et al (2018) [10]

5/M/9y

Encephalopathy, seizures, dizzy, psycho-behavioral changes

Epileptiform discharge

MRI: Brainstem: T2 hyperintensity without enhancement

-

IVIG

Improved

López-Chiriboga AS et al (2018) [5]

6/F/17y

Encephalopathy, sleep disorders, pain, ANS

-

Normal

-

IVIG

Improved

López-Chiriboga AS et al (2018) [5]

7/F/17y

Encephalopathy, seizures

Epileptiform discharge

Normal

-

IVIG, Aza

Improved

López-Chiriboga AS et al (2018) [5]

8/F/5y

Encephalopathy, seizures, psycho-behavioral changes

Epileptiform discharge

Normal

VPA, LCM

-

Seizures cessation

López-Chiriboga AS et al (2018) [5]

9/M/13y

Encephalopathy, amnesia, seizures, pain, psycho-behavioral changes

Normal

MRI: Left limbic T2 hyperintensities

-

IVIG, CS

Improved

López-Chiriboga AS et al (2018) [5]

10/F/17y

Weight loss, pain, ANS

Normal

N/A

Symptomatic

-

N/A

López-Chiriboga AS et al (2018) [5]

11/F/14y

Dizzy, pain, psycho-behavioral changes

Normal

Normal

Symptomatic

-

Stable

López-Chiriboga AS et al (2018) [5]

12/F/7y

Seizures (including FBDS), encephalopathy, hyponatremia, amnesia

Epileptiform discharge

PET: subtle hypometabolism in the right temporal and bilateral parietal cortices

LEV, VPA, CBZ, midazolam, TP, PB, PHT, LCM; TPM

CS, IVIG, R-FC

Relapsed

Mir A et al (2019) [11]

Alotaibi W (2022) [15]

13/M/8y

Sleep disorder

Focal slow waves

MRI: left hippocampal lesions

-

IVIG

Improved

Zhang J et al (2019) [12]

14/M/15y

Seizures

Focal slow waves and epileptic form discharge

Normal

LEV,

IVIG

Recovered

Zhang J et al (2019) [12]

15/F/14y

Sleep disorders, movement disorders, psycho-behavioral changes

N/A

Normal

N/A

N/A

N/A

Giannoccaro MP et al (2021) [13]

16/F/4y

Seizures, encephalopathy, sleep disorders, psycho-behavioral changes

epileptiform discharge

normal

LEV, CZP, OXC;

IVIG, CS

Recovered

Luo J et al (2021) [14]

17/F/7y

Seizures

Background slowing and epileptiform discharge

normal

OXC

IVIG, CS

Recovered

Wang Y et al (2022) [16]

18/M/2y

Cerebellar ataxia

normal

normal

-

CS

Recovered

Weihua Z et al (2022) [17]

19/M/4y

Cerebellar ataxia, seizures (including FBDS), encephalopathy

Background slowing

PET: significantly increased metabolism in bilateral basal ganglia and mildly increased in the medial temporal lobes

LEV, CZP

IVIG, CS

Recovered

Weihua Z et al (2022) [17]

20/F/14y

Movement disorders, ataxia, dysarthria, psycho-behavioral changes, hyponatremia,

normal

MRI: hyperintensities in the left frontal cortex, right medial temporal lobe, left insula and corpus striatum, right inferior frontal region, and left temporal lobe

LEV

CS, IVIG

Improved

Özçifçi G et al (2022) [18]

21/F/11y

Seizures

Background slowing and epileptiform discharge

normal

OXC

IVIG

Recovered

Wang Y et al (2023) [19]

22/M/4y

Seizures, psycho-behavioral changes

Background slowing and epileptiform discharge

MRI: mild atrophy on the cortex of left hemisphere

VPA, OXC, LCM

IVIG, CS, RTX, CLB

Improved

Wang Y et al (2023) [19]

23/M/17y

Seizures

Background slowing and epileptiform discharge

normal

VPA, OXC

IVIG, CS

Recovered

Wang Y et al (2023) [19]

24/F/6y

Seizures (including FBDS), movement disorders, ataxia, psycho-behavioral changes, amnesia

Focal slow and sharp waves

MRI: T2 and FLAIR high signal intensity in the left anterior putamen and right caudate nucleus

PB, OXC, VPA, LTG

CS, IVIG, RTX, TCZ

Improved

Jang S et al (2023) [20]

25/F/6y

Seizures (including FBDS), hyponatremia

Epileptiform discharge

MRI: an increased signal in the left temporal pole on T2FLAIR

PER, LCM

IVIG, CS, MMF

Recovered

This study