From the Guidelines
CASPR2 and LGI1 antibodies are significant autoantibodies associated with autoimmune encephalitis, and their presence requires prompt immunotherapy to improve outcomes, as recommended by the most recent guidelines 1. The presence of these antibodies can lead to a range of symptoms, including limbic encephalitis, seizures, memory problems, confusion, and hyponatremia in the case of LGI1 antibodies, and peripheral nerve hyperexcitability, neuropathic pain, and encephalitis with cognitive impairment in the case of CASPR2 antibodies. Some key points to consider in the management of these conditions include:
- The use of first-line immunotherapies such as high-dose corticosteroids (methylprednisolone 1g IV daily for 3-5 days, followed by oral prednisone taper), intravenous immunoglobulin (IVIG at 2g/kg divided over 2-5 days), or plasma exchange 1.
- The importance of early treatment to improve outcomes, as these conditions are potentially reversible with prompt immunotherapy 1.
- The need for screening for malignancy, particularly thymoma with CASPR2, as part of the diagnostic workup, although these antibodies are rarely associated with underlying tumors 1.
- The potential for intensive care unit admission in cases of refractory status epilepticus, severe dysautonomia, and respiratory compromise, and the need for careful monitoring and management of blood pressure and heart rate fluctuations in patients with severe dysautonomia 1. It is essential to note that the diagnosis and management of autoimmune encephalitis require a multidisciplinary approach, and the guidelines provided by recent studies 1 should be followed to ensure the best possible outcomes for patients.
From the Research
CASPR and LGI1 Significance
- CASPR2 and LGI1 antibodies are associated with autoimmune encephalitis, a rare immune-mediated disorder characterized by non-infectious neuroinflammatory disease processes 2.
- Patients with CASPR2 and LGI1 antibodies can present with a broad spectrum of neurological symptoms, including seizures, psychological abnormalities, limb weakness, and hyperhidrosis 3.
- The combination of both CASPR2 and LGI1 antibodies can contribute to a wide range of neurological symptoms in the central, peripheral, and autonomic nervous systems 3.
- Seizure underreporting is a recognized issue in patients with LGI1 and CASPR2 antibody encephalitis, and prolonged video-electroencephalography (EEG) telemetry is important for accurate diagnosis and treatment 4.
- Intravenous immunoglobulin (IVIG) can be used as a first-line acute treatment in adults with autoimmune encephalitis caused by antibodies to LGI1 and CASPR2, with significant improvements observed at the time of discharge and after 12 months compared to disease onset 5.
Clinical Characteristics
- Patients with CASPR2 and LGI1 antibodies can display different clinical syndromes, including isolated epilepsy, Morvan syndrome, and limbic encephalitis 3.
- White blood cell and glucose in cerebrospinal fluid (CSF) are typically normal, while CSF protein may be slightly elevated 3.
- Electromyography (EMG) may show abnormal spontaneous firing, and brain magnetic resonance imaging (MRI) may reveal bilateral hyper-intensity of the temporal lobe on T2 and FLAIR sequence 3.
- Cancer screening is important, as some patients with CASPR2 and LGI1 antibodies may have underlying tumors, such as thymoma 3.
Treatment and Outcome
- Early tumor screening and immunotherapy can improve the prognosis of patients with CASPR2 and LGI1 antibodies 3.
- IVIG therapy can be effective in treating autoimmune encephalitis caused by LGI1 and CASPR2 antibodies, with significant improvements observed in clinical outcomes 5.
- The choice of IVIG or plasma exchange (PE) as an additional treatment to corticosteroids does not affect the primary outcome in patients with LGI1 or CASPR2 encephalitis 5.
- Prompt diagnosis and management are necessary for patients with autoimmune encephalitis to decrease mortality and improve quality of life 6.