Table 1.
Specific autoantibodies against surface neuronal proteins associated with seizure disorders.
| Antibodies | LGI1 > CASPR2 | GlyR | NMDAR | GABABR | AMPAR |
|---|---|---|---|---|---|
| Syndrome | LE, epilepsy, and a subacute encephalopathy | Stiff-person syndrom, PERM, limbic encephalitis, cerebellar degeneration, or optic neuritis | Encephalitis | LE | LE and encephalitis |
| Main known target | LGI1 and CASPR2 | GlyRα1 | Mainly NR1 and NR2b subunits | GABABR1 | GluA1/2 |
| Gender/number of cases | M ˃ F, more than 500 cases | M > F, dozens of patients | F ˃ M, ˃ 1000 patients | M > F, only dozens of patients | F > M, only dozens of cases |
| Clinical features and characteristic seizures | Cognitive impairments, seizures, psychiatric and behavioral conditions, sleep abnormalities and autonomic disturbances, three types of epileptic seizures: FBDS, CPS, GTC | Stiffness, rigidity, brainstem disturbance, cognitive involvement, rare but occasional seizures: GTC, CPS | Subacute psychiatric disturbance, consciousness decline, autonomic dysfunction, movement disorders, and hypoventilation, seizures: GTC, SE, CPS | LE with prominent seizures: CPS, GTC, SE | Early or prominent epileptic seizures: GTC, CPS |
| EEG: focal or generalized slowing; CSF: ↑ cell count or unmatched oligoclonal bands, except LGI1; encephalitic lesions on MRI | Focal epileptic activity on EEG; encephalitic lesions on MRI and ↑ cell count | A pathognomonic EEG pattern, extreme delta brush; encephalitic lesions on MRI and ↑ cell count | EEG with focal/generalized epileptic activity; encephalitic lesions on MRI and ↑ cell count | EEG with focal epileptic activity; encephalitic lesions on MRI and ↑ cell count or unmatched oligoclonal bands | |
| Favorable immune therapy response | Yes | Yes | Yes | Yes | Yes, relapses are common |
| Antibody screening | iIHC, RIA, CBA | CBA | iIHC, ELISA, CBA | iIHC, CBA | iIHC, CBA |
| References | [3,8,12,36,37,39,40,41,60,77] | [2,16,69,74,75,78] | [18,19,20,27,45,66,67,68,79,80,81,82] | [21,83,84,85,86] | [5,85,87,88,89,90] |
Ab, antibody; AMPAR, a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor; CASPR2, contactin-associated protein 2; GABABR, gamma-aminobutyric acid B receptors; GlyR, glycine receptor; LE, limbic encephalitis; LGI1, leucine-rich glioma-inactivated 1 protein; NMDAR, N-methyl-D-aspartate receptors; SE, status epilepticus; EEG, electroencephalogram; FBDS, facio-brachial dystonic seizure; GTC, generalized tonic-clonic; CPS, complex partial seizure; M, male; F, female; CSF, cerebrospinal fluid; MRI, magnetic resonance imaging; iIHC, indirect immunohistochemistry (immunofluorescence); RIA, radioimmunoprecipitation assay; CBA, cell-based assay; PERM, progressive encephalomyelitis with rigidity and myoclonus; ↑ cell count, an increased cell count