Dysautonomia is common and associated with disease disability or activity in multiple sclerosis. However, in neuromyelitis optica spectrum disorder (NMOSD), the clinical and MRI correlates of autonomic dysfunction are unknown.
The aim of this study was to investigate the relationship of autonomic dysfunction and clinical findings in patients with NMOSD.
A total of 27 patients (mean age, 44.4±12.26 years; female: male=22:5) were enrolled in this study. For the assessment of autonomic dysfunction, hear rate variability (HRV) and blood pressure (BP) measurement to deep breathing, Valsalva maneuver or head tilt-table test, with quantitative sudomotor axon reflex test (QSART) were used and interpreted in the form of the composite autonomic scoring scale (CASS). Clinical and radiological correlates with autonomic profiles were analyzed.
Among the 27 patients, 74.1% (N=20) showed autonomic dysfunction, involving the adrenergic, cardiovagal, and sudomotor domains. Demographics and MRI findings were associated with each index of CASS. The number of attacks showed the association with cardiovagal index (B=0.197, S.E. 0.070, 95% CI 0.051-0.342, p=0.010), corticospinal tract lesion with adrenergic index (B=2.780, S.E. 0.970, 95% CI 0.783-4.777, p=0.008), the involvement of brain and/or spinal cord with total CASS score (B=1.258, S.E. 0.566, 95% CI 0.081-2.434, p=0.037) and male gender with sudomotor index (B=1.317, S.E. 0.425, 95% CI 0.376-2.259, p=0.008). In multivariable analysis, delayed pressure recovery time in the Valsalva maneuver, onset age, and disease activity showed a significant positive association with EDSS score (B=2.177, S.E. 0.758, 95% CI 0.553-3.802, p=0.011; B=0.061, S.E. 0.023, 95% CI 0.014-0.107, p=0.013; B=1.369, S.E. 0.593, 95% CI 0.142-2.596, p=0.030, respectively).
Cardiovascular and sudomotor autonomic dysfunction are common in NMOSD. Several clinical and MRI characteristics of patients may warrant the investigation of autonomic dysfunction and its proper management.