Merchant, Shabbir HussainVial Undurraga, FelipeLeodori, GiorgioFahn, StanleyPullman, SethHallett, Mark2019-08-132019-08-132019Parkinsonism and Related Disorders. 2019 Apr.http://hdl.handle.net/11447/2579http://dx.doi.org/10.1016/j.parkreldis.2018.10.007Background: Many different oligosynaptic reflexes are known to originate in the lower brainstem which share phenomenological and neurophysiological similarities. Objective: To evaluate and discuss the differences and aberrancies among these reflexes, which are hard to discern clinically using neurophysiological investigations with the help of a case report. Methods: We describe the clinical and neurophysiological assessment of a young man who had a childhood history of opsoclonus-myoclonus syndrome with residual mild ataxia and myoclonic jerks in the distal extremities presenting with subacute onset total body jerks sensitive to sound and touch (in a limited dermatomal distribution), refractory to medications. Results: Based on clinical characteristics and insights gained from neurophysiological testing we could identify a novel reflex of caudal brainstem origin. Conclusions: The reflex described is likely an exaggerated normal reflex, likely triggered by a dolichoectatic vertebral arterial compression and shares characteristics of different reflexes known to originate in caudal brainstem, which subserve distinctive roles in human postural control38 p.enJerk-like movementsMyoclonusPhysiologyReflexStartleArticle