Expanding spectrum of contactin-associated protein 2 (CASPR2) autoimmunity—syndrome of parkinsonism and ataxia

Abstract

Contactin-associated protein 2 (CASPR2) antibodies are originally associated with Morvan's syndrome and peripheral nerve hyper excitability. Our objective was to study retrospectively the clinical spectrum of CASPR2 antibody-positive patients in our hospital. This is a retrospective observational study. Patients treated at the Amrita Institute of Medical Sciences from May 2013 to April 2016, who were tested positive for CASPR2 antibodies, were included. A total of 1584 samples were tested in the neuroimmunology laboratory during the study period for voltage-gated potassium channel (VGKC) complex antibodies-leucine-rich glioma-inactivated protein 1 (LGI1) and CASPR2 antibodies. Thirty-four were positive for LGI1, 13 were positive for CASPR2, and 7 were for both (total 54-3.4% positivity). Of these 54 cases, 11 were treated in our hospital. Seven were positive for LGI1, three for CASPR2, and one for both. The patient who had both CASPR2 and LGI1 antibody positive had Morvan's syndrome. One patient with CASPR2 had neuromyotonia. The other patient was admitted with status epilepticus with a syndrome of parkinsonism and ataxia. The third patient had encephalopathy and myoclonus with a syndrome of parkinsonism and ataxia. Two of them underwent siddha treatment for other ailments prior to the onset of the disease for other ailments. Our short series shows the expanding spectrum of CASPR2 autoimmunity. Syndrome of parkinsonism and ataxia is an important manifestation of CASPR2 autoimmunity where we can offer a definitive treatment.

Anti‐LGI1, anti‐GABABR, and Anti‐CASPR2 encephalitides in Asia: A systematic review

“…146 papers were read fully. Finally, 24 papers that fulfilled our inclusion criteria were included in the study (Bing‐Lei et al., 2019; Chen et al., 2017; Cui et al., 2018; Gao et al., 2016; Guan et al., 2015; Kannoth et al., 2018; Kim et al., 2014; Li, Ma, Zhang, & Lian, 2018; Li, Wu, et al, 2018; Li, Song, Liu, & Wang, 2020; Li, Cui, Shi, & Wang, 2016; Lin et al., 2019; Qiao et al., 2017; Shin et al., 2013; Si, Wang, Liu, Zhang, & Hu, 2019; Sunwoo et al., 2015; Wang, Hao, He, He, & Wang, 2018; Yang, Li, Zhao, Liu, & Wang, 2019; Yeo et al., 2018; Yu, Yu, Fang, Zhang, & Lin, 2016; Zeng, Cao, Zheng, & Yu, 2020; Zhang et al., 2020; Zhao, Zhang, Gao, & Sun, 2016; Zhu et al., 2020) (Figure 1).…”

“…A patient treated with azathioprine and corticosteroid relapsed, whereas a patient treated with azathioprine combined with both the first and second lines did not relapse (Shin et al., 2013). Among the two patients given corticosteroids combined with cyclophosphamide, one patient relapsed (Kannoth et al., 2018).…”

Frontotemporal Dementia with Parkinsonism and Epilepsy Associated with VGKC Antibodies: Case Report and Literature Review

“…It would be atypical to develop a parkinsonian disorder at a later stage of immune-related disease, especially after aggressive treatment with steroids and immunotherapy [7][8][9]. The extrapyramidal signs are always observed around the time of initial presentation [10][11][12]. There are some cases with CASPAR2 antibodies in a parkinsonian presentation in the context of a more florid encephalopathy or concomitant neuromyotonia [9,11].…”

Antibody-related movement disorders – a comprehensive review of phenotype-autoantibody correlations and a guide to testing

“…Further autoimmune parkinsonism mimicking PD, MSA or PSP was reported in patients with LGI1-, CASPR2-, and DPPX-antibodies [ 52 , 61 – 63 ]. Patients with stiff-person-spectrum-disorders (SPSD, see below) with glycine-receptor-alpha-1 (GlyRα1) or GAD antibodies may appear parkinsonian.…”