Antiphospholipid antibodies and cerebellar ataxia: A clinical analysis and literature review

Background: Although it has been established that antiphospholipid antibodies (APAbs) bind to and modulate the signaling of cerebellar neurons in vitro, the clinical correlation between increased APAbs and cerebellar ataxia has rarely been investigated. Methods: We reviewed 10 patients presenting with cerebellar ataxia with increased blood APAbs from our database along with 3 APAb-associated cerebellar ataxia patients in the literature. Results: Of these 10 patients, 4 exhibited a subacute onset of progressive ataxia, and there were no significant structural changes in their brains that appeared to be responsible for the symptoms. Another 6 showed a chronic course of ataxia, and shared similar morphological changes that included symmetrical lesions in bilateral hemispheres, periventricular lucency and central and temporal atrophy of varying severity; the cerebellum was spared. The predominant APAbs for subacute and chronic ataxia were the anti-beta₂-glycoprotein I antibody and anticardiolipin antibody, respectively. Cancer was found in 1 patient with subacute ataxia and in 4 with chronic ataxia. The removal of the cancer, the plasmapheresis and immunosuppressive therapy successfully abolished the ataxia and increased APAb levels in all 5 patients. Conclusions: The relation between APAbs and nonvascular neurological disorders, such as cerebellar ataxia, should be further studied. APAbs may mediate neurological deficits via different mechanisms such as structural damage or functional neurotoxicity. Clinically, the examination of blood APAb levels is recommended for patients with cerebellar ataxia without a determined cause, and the further survey of systemic cancers in the case of APAb positivity is also recommended. Finally, plasmapheresis is a reasonable and effective treatment for APAb-associated cerebellar ataxia.