Coexistence of Lambert–Eaton myasthenic syndrome and autoimmune encephalitis with anti-CRMP5/CV2 and anti-GABAB receptor antibodies in small cell lung cancer: A case report

Rationale: Autoimmune encephalitis and Lambert–Eaton myasthenic syndrome are classic paraneoplastic neurological conditions common in patients with small cell lung cancer. Patient concerns: The patient complained of tiredness, fluctuating recent memory loss, and inability to find his home. His family members reported a change in character, irritability, and paranoia. One month later, the patient had 1 grand mal seizure lasting 5 minutes. Diagnosis: The patient was diagnosed with limbic encephalitis combined with Lambert–Eaton myasthenic syndrome. The gamma-aminobutyric acid B (GABAB) receptor and collapsin response mediator protein 5 (CRMP5, also called CV2) antibody test results were positive. Nine months after the onset of symptoms, the patient was diagnosed with small cell lung cancer. Interventions: The patient was administered intravenous immunoglobulin for 5 days. He was then treated with 60 mg prednisone once per day. The prednisone dose was gradually reduced by 1 tablet every 2 weeks. After the diagnosis, the patient underwent 6 courses of chemotherapy with cisplatin combined with sequential chemoradiation therapy. Outcomes: The patient was able to take care of himself. Neurological examination revealed a lower limb proximal muscle strength level of 4 and a reduced limb tendon reflex. The patient had deficits in short-term memory, a Mini-Mental State Examination score of 26, Montreal Cognitive Assessment score of 24, Self-rating Depression Scale ...
Source: Medicine - Category: Internal Medicine Tags: Research Article: Clinical Case Report Source Type: research