From the Guidelines
Autoimmune encephalitis is characterized by a diverse range of clinical features, including cognitive dysfunction, seizures, psychiatric manifestations, movement disorders, and autonomic instability, which can develop subacutely over days to weeks 1. The clinical presentation of autoimmune encephalitis can vary greatly depending on the specific antibody involved and the brain regions affected. Patients may experience:
- Cognitive dysfunction, including memory deficits, confusion, and behavioral changes
- Seizures, which can be difficult to control with standard antiepileptic medications
- Psychiatric manifestations, such as psychosis, hallucinations, agitation, and personality changes
- Movement disorders, including dystonia, chorea, myoclonus, and catatonia
- Autonomic instability, manifesting as fluctuations in blood pressure, heart rate, temperature, and urinary retention
- Sleep disturbances, particularly insomnia and hypersomnia
- Decreased level of consciousness, ranging from drowsiness to coma
- Focal neurological deficits, depending on the brain regions affected Specific syndromes, such as LGI1 antibody encephalitis and NMDAR encephalitis, have characteristic features, including orofacial dyskinesias and faciobrachial dystonic seizures, and prominent ovarian teratomas, respectively 1. The clinical presentation can be classified anatomically, serologically, and aetiologically, with different antibodies associated with distinct clinical features and outcomes 1. Early recognition of these clinical features is crucial, as prompt immunotherapy can improve outcomes in patients with autoimmune encephalitis 1.
From the Research
Clinical Features of Autoimmune Encephalitis
The clinical features of autoimmune encephalitis are diverse and can vary depending on the specific antibody involved. Some common features include:
- Altered mental status
- Behavioral changes
- Irritability
- Insomnia
- Developmental regression
- Seizures
- Dyskinetic movements
- Autonomic instability
- Cognitive impairment
- Psychiatric disturbances
- Movement disorders
- Peripheral features 2, 3, 4, 5
Antibody-Associated Autoimmune Encephalitis
Different antibodies are associated with distinct clinical features, including:
- Leucine-rich glioma inactivated protein 1 (LGI1)
- N-methyl-d-aspartate (NMDA) receptors
- Contactin-associated proteinlike 2 (CASPR2)
- Glutamic acid decarboxylase 65 (GAD65) 2 Each antibody-associated autoimmune encephalitis typically presents with a recognizable blend of clinical and investigation features, which help differentiate each from alternative diagnoses.
Diagnostic Approach
The diagnostic approach for autoimmune encephalitis involves a combination of clinical evaluation, electroencephalography, magnetic resonance imaging, and lumbar puncture. Once infectious and other causes are reasonably ruled out, treatment should be started empirically without waiting for antibody confirmation 3, 5.
Treatment
Treatment for autoimmune encephalitis typically involves immunotherapy, including corticosteroids, intravenous immunoglobulin, and/or plasmapheresis. Severe or refractory cases may require other treatments, such as rituximab, cyclophosphamide, or other immunotherapies using novel monoclonal antibodies 6, 3, 4.