Antibody Prevalence in Epilepsy and Encephalopathy (APE2 ) score

A guide to predict the likelihood of neural antibody positivity in patients with encephalopathy and/or seizures1-2

SCORE
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 minutes of quiet standing), hyperhidrosis, persistently labile blood pressure, ventricular tachycardia, cardiac asystole, or gastrointestinal dysmotility]
+1
Viral prodrome
(rhinorrhea, 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 from at least two anti-seizure medications
+2
CSF findings consistent with inflammation
(elevated CSF protein >50 mg/dL and/or lymphocytic pleocytosis >5 cells/mcL, if the total number of CSF red blood cell count is <1,000 cells/mcL)
+2
Brain MRI suggesting encephalitis (T2/FLAIR hypersensitivity 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 tumor, cancer with brain metastasis)
+2

Calculate Score

APE2 SCORE:

≥4: Presence of neural specific antibodies clinically validated to have an association with autoimmune encephalopathy or epilepsy is likely. Order Tests: Encephalopathy, Autoimmune Evaluation, Spinal Fluid (Mayo ID: ENC2); and Encephalopathy, Autoimmune Evaluation, Serum (Mayo ID: ENS2)

APE2 SCORE:

<4: Presence of neural specific antibodies clinically validated to have an association with autoimmune encephalopathy or epilepsy is unlikely.

CLINICAL REFERENCES

1. Dubey D, Kothapalli N, McKeon A, et al. Predictors of neural-specific autoantibodies and immunotherapy response in patients with cognitive dysfunction. Journal of Neuroimmunology. 2018;323:62-72.

2. Dubey D, Singh J, Britton JW, et al. Predictive models in the diagnosis and treatment of autoimmune epilepsy. Epilepsia. 2017;58(7):1181-1189. doi: 10.1111/epi.13797.