Antibody prevalence in epilepsy and encephalopathy (APE2 score)
| Antibody prevalence in epilepsy and encephalopathy (APE2 score) | Value |
| New onset, rapidly progressive mental status changes that developed over 1–6 weeks or new onset seizure activity (within 1 year of evaluation) | (+1) |
| Neuropsychiatric changes; agitation, aggressiveness, emotional lability | (+1) |
| Autonomic dysfunction (sustained atrial tachycardia or bradycardia, orthostatic hypotension (≥20 mm Hg fall in systolic pressure or ≥ 10 mm Hg fall in diastolic pressure within 3 min of quiet standing), hyperhidrosis, persistently labile blood pressure, ventricular tachycardia, cardiac asystole or gastrointestinal dysmotility) | (+1) |
| Viral prodrome (rhinorrhoea, sore throat, low-grade fever) to be scored in the absence of underlying systemic malignancy within 5 years of neurological symptom onset | (+2) |
| Faciobrachial dystonic seizures | (+3) |
| Facial dyskinesias, to be scored in the absence of faciobrachial dystonic seizures | (+2) |
| Seizure refractory to at least to two antiseizure medications | (+2) |
| CSF findings consistent with inflammation (elevated CSF protein >50 mg/dL and/or lymphocytic pleocytosis >5 cells/µL, if the total number of CSF RBC is <1000 cells/µL) | (+2) |
| Brain MRI suggesting encephalitis (T2/FLAIR hyperintensity restricted to one or both medial temporal lobes, or multifocal in grey matter, white matter or both compatible with demyelination or inflammation) | (+2) |
| Systemic cancer diagnosed within 5 years of neurological symptom onset (excluding cutaneous squamous cell carcinoma, basal cell carcinoma, brain tumour, cancer with brain metastasis) | (+2) |
| Total (max: 18) |
Adapted with permission from Dubey et al.28
CSF, cerebrospinal fluid.