Comparison of the clinical features and association with infections in paediatric patients with antibody positive and antibody negative encephalopathy
| Antibody positive (n=21) | Antibody negative (n=27) | |
|---|---|---|
| Cognitive dysfunction | 18 (86%) | 19 (70%) |
| Behavioural change | 16 | 14 |
| Confusion | 11 | 13 |
| Aphasia | 7 | 7 |
| Amnesia | 1 | 2 |
| Psychiatric disturbances | 13 (62%) | 14 (52%) |
| Hallucinations | 9 | 3 |
| Agitation | 7 | 11 |
| Mood disorders | 2 | 1 |
| Obsessive behaviour | 0 | 1 |
| Seizures | 18 (86%) | 22 (81%) |
| Generalised | 14 | 20 |
| Focal | 15 | 12 |
| Movement disorders | 7 (33%) | 11 (41%) |
| Choreoathetosis | 7 (limb 7, face 4) | 7 (limb 6, face 2) |
| Myoclonus | 0 | 1 |
| Startle | 0 | 2 |
| Tremor | 0 | 2 |
| Sleep disorders with disturbed sleep wake cycle | 7 (33%) | 11 (41%) |
| Dysautonomia | 2 (1%) | 4 (7%) |
| Blood pressure instability | 2 | 1 |
| Tachycardia/bradycardia | 2 | 3 |
| Fever at presentation | 8 (38%) | 9 (33%) |
| Associated infection | 10 (47%) | 17 (63%) |
| Mycoplasma | 2 | 2 |
| ASOT | 3 | 3 |
| HSV | 2 (PCR positive in CSF)* | 0 |
| EBV | 1 | 0 |
| HHV6 | 0 | 1 |
| Influenza | 0 | 3 (2 H1N1, 1 influenza A) |
| Adenovirus | 0 | 1 (positive in CSF) |
| Neoplasm | 1 (5%) | 0 (0%) |
| Screening for neoplasm | 18 (86%) | 9 (33%) |
No significant difference was seen in cognitive dysfunction, seizures, movement disorder, dysautonomia, sleep disorders, psychiatric features and associated infections, immunotherapy response and outcome. The presence of co-existing or preceding known infective pathogens was identified in both groups. Screening for neoplasms was done less frequently in the antibody negative group and might reflect clinicians’ views on the link between autoimmune encephalopathies and malignancies in patients without a known antigen.
*Both positive for NMDAR-Ab.
ASOT, anti-streptococcal antibody titre; CSF, cerebrospinal fluid; EBV, Epstein–Barr virus; HHV-6, human herpes virus 6; HSV, herpes simplex virus; NMDAR, N-methyl-D-aspartate receptor.