A case series: Three cases of Morvan's syndrome as a rare autoimmune disorder with anti-Caspr2 antibody

Rationale: Morvan syndrome (MoS) is an uncommon male-dominant autoimmune disorder marked by peripherally innervated hyperexcitability, autonomic disturbances, and encephalopathic encephalopathy, frequently with mass complaints manifesting as neuromyotonia (involuntary jerking, twitching, and stiffening of muscles), myotonia, neuropathic pain, hyperhidrosis, severe constipation, and severe sleep disturbances accompanied by dream reenactments, agrypnia agitation, and delusions, associated with autoantibodies to voltage-gated and potassium channel complexes such as anti-contactin-associated protein-like 2 (Caspr2) antibody. All this misery can be very disabling and even life-threatening. Reported cases show an unforeseeable outcome, with fatalities occurring even in those who initially responded. It has been reported that patients have reacted to immunologic therapies-corticosteroids, intravenous immunoglobulins, plasma exchanges, azathioprine, cyclophosphamide, rituximab, or carbamazepine, gabapentin, and clonazepam. However, no long-term effective cure has yet been found for this condition. Clinicians and researchers increasingly emphasize alternative and complementary medicine, with a growing trend toward traditional Chinese medicine (TCM).

Patient concerns: Following glucocorticoid therapy, all 3 patients experienced a recurrence of the disease. Patients 1 and 2 observed symptomatic relief after intravenous immunoglobulin administration; however, upon discontinuation of the treatment, their conditions relapsed and worsened compared with the previous state.

Diagnoses: The 3 patients were definitively diagnosed with serum Caspr2-positive MoS, accompanied by a constellation of neurological manifestations.

Interventions: The 3 patients were treated under the guidance of TCM theory. According to the principles of TCM, the patients were characterized by the deficiency of Yin, so the prescriptions were as follows: Shaoyao-Gancao decoction combined with Sanjia-Fumai decoction.

Outcomes: After the application of TCM, there was a reversal of neuropsychiatric manifestations such as unintentional rippling, jerking, muscle stiffness, myokymia, hyperhidrosis, and extreme constipation. Patients' quality of life improved significantly; to date, they have achieved Karnofsky Performance Status scores of 100, and the anti-Caspr2 antibody result in case 2 dropped from 1:32 to normal.

Lessons: We first report the effective treatment of the MoS case series with TCM as complementary and alternative medicine.