[A case of Isaacs' syndrome causing various central nervous symptoms successfully treated with high-dose intravenous methylprednisolone therapy].

Abstract

A 44-year-old man with a bilateral hand tremor suffered from a decline in concentration and abnormal vision for several months. He also complained of easily falling down because of muscle stiffness and cramps in his lower limbs. On admission, he demonstrated lower limb stiffness, muscle cramps, diplopia, hyperhidrosis, left upper limb ataxia and dysesthesia in all limbs. Laboratory examination showed a marked elevation in his serum creatine kinase level (26,890 U/l), and needle electromyography demonstrated myokymic discharges in the muscles of his lower extremities. Isaacs' syndrome was diagnosed based on a positive voltage-gated potassium channel antibody titer of 1,007 pM. Administration of an anticonvulsant (phenytoin, 200 mg/day) did not resolve his symptoms; however, high-dose intravenous methylprednisolone therapy (1 g/day for 3 days) resulted in marked clinical improvement. This case suggests that high-dose intravenous methylprednisolone therapy for Isaacs' syndrome might be as effective as other immunosuppressive therapies such as plasma exchange or intravenous immunoglobulin.

• Authors: Mitsunori Shimmura, Norihisa Maeda, Shuji Kanetou, Nobuyoshi Takashima, Kei-ichiro Takase
• Journal: Rinsho shinkeigaku = Clinical neurology (Rinsho Shinkeigaku) Vol. 55 Issue 1 Pg. 37-40 ( 2015) ISSN: 1882-0654 [Electronic] Japan
• PMID: 25672864 (Publication Type: Case Reports, English Abstract, Journal Article)

Chemical References

• Autoantibodies
• Biomarkers
• Glucocorticoids
• Potassium Channels, Voltage-Gated
• Creatine Kinase
• Methylprednisolone

Topics

• Adult
• Autoantibodies (blood)
• Biomarkers (blood)
• Creatine Kinase (blood)
• Electromyography
• Glucocorticoids (administration & dosage)
• Humans
• Infusions, Intravenous
• Isaacs Syndrome (diagnosis, drug therapy, immunology, pathology)
• Magnetic Resonance Imaging
• Male
• Methylprednisolone (administration & dosage)
• Muscle, Skeletal (pathology)
• Potassium Channels, Voltage-Gated (immunology)
• Pulse Therapy, Drug
• Treatment Outcome