Rituximab Was Effective in Relieving Symptoms of Isaacs Syndrome: A Case Report

Horiuchi, Kazuhiro; Kudo, Akihiko; Inoue, Takashi; Fujii, Shintaro; Oshima, Yuki

doi:10.7759/cureus.30100

Cited by 5 publications

(6 citation statements)

References 16 publications

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“…Both patients showed a satisfactory response, suggesting that rituximab remains an effective option for patients with resistant HPNDs. Other studies have found rituximab to be effective in HPNDs as well 17–19 …”

Section: Discussionmentioning

confidence: 98%

Acquired hyperexcitable peripheral nerve disorders: Clinical and laboratory features, therapeutic responses, and long‐term follow‐up

Khadilkar,

Pandya,

Dhonde

et al. 2023

Muscle and Nerve

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Introduction/AimsHyperexcitable peripheral nerve disorders (HPNDs) are rare. Although their clinical and laboratory features have been well studied, information on treatment and follow‐up is limited. The aim of this study is to explore the long‐term clinical, investigative, and therapeutic profile of patients with acquired HPNDs.MethodsThis study retrospectively analyzed patients from a single tertiary care center with HPND (January 2012 to January 2022). Patients were recruited according to published inclusion and exclusion criteria. Details of clinical features, diagnostic tests, therapeutic interventions, and follow‐up were recorded. This study included patients with follow‐up of 2 or more years.ResultsA total of 32 patients (M = 26, F = 6) were studied. The common clinical features included myokymia, neuropathic or shock‐like pain, cramps, sleep disturbances, encephalopathy, cerebellar ataxia, and seizures. A total of 81.25% of patients responded favorably to corticosteroids and membrane stabilizers. Among the nonresponders, five received intravenous immunoglobulin (IVIG), and one received plasma exchange (PLEX). Two patients required rituximab due to poor responses to the above treatments. The mean duration of response was 6 weeks (4–24 weeks) from the initiation of treatment. All patients had favorable outcomes, reaching clinical remission within 1–5 years from the initiation of treatment. Only two patients had relapses. Immunotherapy could be stopped in 78% of patients within 3 years and 100% by 5 years.DiscussionChronic immunosuppression starting with corticosteroids is required for satisfactory outcomes of HPNDs. These disorders usually run a monophasic course, and relapses are uncommon.

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Section: Discussionmentioning

confidence: 98%

Acquired hyperexcitable peripheral nerve disorders: Clinical and laboratory features, therapeutic responses, and long‐term follow‐up

Khadilkar,

Pandya,

Dhonde

et al. 2023

Muscle and Nerve

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“…It is also rational to begin oral steroid therapy with prednisolone, with eventual taper, and azathioprine or methotrexate to further boost immunosuppression. One case of IS reported in October 2022 demonstrated response to rituximab after initial treatment with many of the agents listed above was refractory [ 13 ].…”

Section: Discussionmentioning

confidence: 99%

A Rare Phenomenon of Isaacs Syndrome: A Case Report

Patel¹,

Patel²,

Desai³

et al. 2023

Cureus

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We illustrate the case of a 71-year-old male who initially presented with sudden onset muscle weakness and ambulation difficulty. Following medication discontinuation and additional clinical studies, he failed to improve and was admitted to the hospital 11 weeks later. He had an associated 20-pound weight loss, sudorrhea, and muscle stiffness only when weight-bearing. A complete connective tissue cascade and a paraneoplastic panel were obtained. Clinical diagnosis of acquired neuromyotonia, or Isaacs syndrome (IS), was made, and he began experiencing significant improvement after intravenous steroid infusion. IS is a rare disease that has been poorly documented in the literature. There have only been a limited number of cases which are globally documented. One of the difficulties is a lack of definite autoantibody with which to correlate the disease; however, there has been some correlation linking the disease to voltage-gated potassium channels. Ultimately, the diagnosis should be driven by history and clinical presentation. The aim of this case report is to highlight a rare disease process and increase awareness among clinicians. We also describe the associated evaluation and recommended treatment for an optimal patient outcome.

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“…and disagreement was resolved by consensus. This left us with a total of 61 case reports and 4 case series 14,16,30–91 (Fig. 1).…”

Section: Methodsmentioning

confidence: 99%

“…Testing for oligoclonal bands was reported in 17 cases and was positive in 3 cases. 16,31 Nine cases tested positive for antibodies against contactin-associated protein-like 2 (CASPR2) (Table 2). 36,46,75,88,89,94…”

Section: Clinical Characteristics and Management Of Ismentioning

confidence: 99%

Systematic Review of the Clinical Characteristics and Management of Isaac Syndrome

Al-Chalabi,

Hegde,

Moore

et al. 2023

Journal of Clinical Neuromuscular Disease

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Objectives: Isaac syndrome (IS) is a condition characterized by peripheral nerve hyperexcitability caused by voltage-gated potassium channel (VGKC)-complex antibodies. Muscle twitching, stiffness, hypertrophy, and dysautonomic characteristics, such as hyperhidrosis, are common manifestations. The syndrome can be autoimmune or paraneoplastic, with thymoma being a common cause of paraneoplastic IS. Furthermore, this condition could be handed down from one generation to another. However, there is limited information regarding outcomes, relapses, associated syndromes, associated malignancies (other than thymoma), and treatment options. Despite its rarity, there remains a need for effective management strategies for patients with IS. To address this gap, we conducted a systematic review to summarize the most common and effective treatments of IS in immunomodulatory agents and symptomatic medications, as well as to describe outcomes, relapses, and associated malignancies. Altogether, this review serves to guide clinical practice recommendations for IS and highlight areas for further research. Methods: We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol to conduct a systematic review of cases reposted through the PubMed and Google Scholar databases. The terms “Isaac Syndrome” and “Acquired Neuromyotonia” were used. The Joanna Briggs Institute's critical appraisal tool was used to evaluate the quality of the included studies. Results: We identified 61 case reports and 4 case series, comprising a total of 70 patients with IS (mean age at onset: 42.5 ± 18 years, and 69% were males). Fourteen cases reported relapses. Thymoma was the most common malignancy associated with IS, followed by lymphoma. Among various serum antibodies, voltage-gated potassium channel-complex antibodies were the most reported antibodies elevated in IS (reported in 38 patients and elevated in 21 patients [55.2%]), followed by acetylcholine ganglionic receptor antibodies, which were reported in 30% of patients (n = 21) and were elevated in 5 cases. The most common electromyography findings were myokymic discharges (n = 22), followed by fasciculations (n = 21) and neuromyotonia (n = 19). For treatment, combining anticonvulsants such as carbamazepine with immunotherapy therapy showed the best results in controlling the symptoms. Among immunotherapy therapies, the combination of plasma exchange plus intravenous high-dose steroids achieved the best results in the acute treatment of IS ([n = 6], with improvement noted in 83.3% [n = 5] of cases). Among the symptomatic treatments with anticonvulsants, carbamazepine was the most efficacious anticonvulsant in treatment of IS, with an average effective dosing of 480 mg/day (carbamazepine was used in 32.3% of acute treatment strategies [n = 23], with improvement noted in 73.9% [n = 17] of cases). Conclusions: IS a rare neuromuscular syndrome that tends to affect middle-aged men. These patients should be screened for thymoma and other malignancies such as lymphomas. The management of IS symptoms can be challenging, but based on our review, the combination of multiple immunosuppressives such as IV steroids and plasmapheresis with anticonvulsants such as carbamazepine seems to achieve the best results.

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Rituximab Was Effective in Relieving Symptoms of Isaacs Syndrome: A Case Report

Cited by 5 publications

References 16 publications

Acquired hyperexcitable peripheral nerve disorders: Clinical and laboratory features, therapeutic responses, and long‐term follow‐up

Acquired hyperexcitable peripheral nerve disorders: Clinical and laboratory features, therapeutic responses, and long‐term follow‐up

A Rare Phenomenon of Isaacs Syndrome: A Case Report

Systematic Review of the Clinical Characteristics and Management of Isaac Syndrome

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