Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor encephalitis: A case report
Introduction:
: Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) is a subtype of glutamate receptor that mediates most of the fast excitatory neurotransmission in the brain. Anti-AMPAR encephalitis is an autoimmune-mediated neurological disorder, frequently accompanied by the presence of neoplasms, comprising a spectrum of paraneoplastic syndrome.
Patient Concerns:
A 56-year-old man was admitted for deterioration in memory and aberrant psychological behaviors, which lasted for at least 20 days.
Diagnosis:
The patient was diagnosed as anti-AMPAR encephalitis and 4 months later, he was diagnosed with small cell lung cancer.
Interventions:
Once diagnosis for anti-AMPAR encephalitis was confirmed, methylprednisolone was prescribed with initial dose 500 mg/d for 14 days until the patient returned to pre-illness state. Then he was discharged with oral treatment with corticosteroids. Following the diagnosis of small cell lung cancer, he received 5 rounds of chemotherapy, including carboplatin and etoposide.
Outcomes:
After taken the prescription of Methylprednisolone for anti-AMPAR encephalitis, he returned to pre-illness state and was discharged. In April 21, 2017, after symptoms of respiratory system showed up, he was diagnosed with small cell lung cancer and he eventually died of respiratory failure.
Conclusion:
Though progress has been made in recent years in diagnosis and treatment for autoimmune encephalitis, it is challenging to diagnose due to the similarity in clinical findings with other autoimmune or infectious encephalitis. In addition, it is necessary for these patients to regularly have tumor screening, considering AMPAR antibody encephalitis is closely associated with neoplasm, and the incidence of paraneoplastic syndrome is 63% to 70%.
Insights
Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis is a challenging autoimmune disorder. Early diagnosis and tumor screening are crucial, as it is frequently linked to neoplasms and paraneoplastic syndromes.
Area of Science:
- Neuroimmunology
- Oncology
Background:
- Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis is an autoimmune neurological disorder targeting glutamate receptors.
- It is often associated with neoplasms, presenting as a paraneoplastic syndrome.
Observation:
- A 56-year-old man presented with memory decline and behavioral changes.
- He was diagnosed with anti-AMPAR encephalitis and subsequently with small cell lung cancer four months later.
Findings:
- Treatment with methylprednisolone led to the patient's recovery from encephalitis.
- The patient later succumbed to respiratory failure following chemotherapy for small cell lung cancer.
Implications:
- Diagnosing anti-AMPAR encephalitis can be difficult due to overlapping symptoms with other encephalitides.
- Regular tumor screening is essential for patients with anti-AMPAR antibody encephalitis due to its high association with neoplasms (63-70% incidence of paraneoplastic syndrome).
