Tran TM, Lee MS, McClelland CM. Downbeat nystagmus: a clinical review of diagnosis and management.
Curr Opin Ophthalmol 2021;
32:504-514. [PMID:
34456290 DOI:
10.1097/icu.0000000000000802]
[Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW
This review will extensively cover the clinical manifestations, causes, diagnostic evaluation, and management strategies of downbeat nystagmus (DBN).
RECENT FINDINGS
Historically, MRI to assess for structural lesions at the cervicomedullary junction has been the primary diagnostic test in the evaluation of DBN since the 1980s. In recent years, there is increasing awareness of nonstructural causes of DBN including gluten ataxia, nutritional deficiencies, and paraneoplastic syndromes, among others. Medical management with aminopyridines has become first-line therapy in addition to disease-specific therapies.
SUMMARY
DBN is a common form of acquired nystagmus and the differential diagnosis remains broad, including both benign and potentially fatal causes. For practical purposes, the causes can be categorized as structural vs. nonstructural with MRI as the ideal, initial diagnostic study to differentiate the two. General therapeutic options include pharmacotherapy to enhance Purkinje cell function, strabismus surgery or prisms to shift null points, and behavioural changes. Disease-specific treatment is necessarily broad, though a significant proportion of patients will be idiopathic.
Collapse