A 29-year-old man presented in our clinic due to repetitive head jerks since his first year of life, which were previously diagnosed as tics. Examination revealed difficulties initiating voluntary saccades in the horizontal plane and disturbed hand–eye coordination with compensatory head thrusts (video and figure, A). The diagnosis of congenital oculomotor apraxia was made. Brain MRI revealed cerebellar vermis hypoplasia with elongated superior peduncles (“molar tooth sign”; figure, B) characteristic for Joubert syndrome, a rare autosomal-recessive ciliopathy with genetic heterogeneity.1 Joubert syndrome is a common etiology of congenital oculomotor apraxia, a condition first described by Cogan,2 who considered compensatory head jerks diagnostic.
Video 1
Irregular, repetitive head-jerking movements during A) history-taking and (B) reading. (C) Oculomotor examination reveals broken smooth pursuit with intermittent saccadic intrusions, difficulties initiating visually guided and volitional saccades with prolonged latencies, as well as saccadic hypometria in horizontal plane. Eye movements in the vertical plane were unaffected. (D) There were no cerebellar signs in limb examination, but impaired hand–eye coordination with compensatory head thrusts was noted.Download Supplementary Video 1 via http://dx.doi.org/10.1212/008109_Video_1
(A) Video-oculographic recording of exemplary saccades to a visual target, jumping rightward from initial fixation to a peripheral position (9/12 degrees of visual angle [dva]) at time “0,” demonstrating prolonged latencies and hypometria of horizontal visually guided saccades. (B) T1-weighted transversal and sagittal brain MRI show hypoplasia of the cerebellar vermis with elongated superior cerebellar peduncles (molar tooth sign) (star) as well as enlargement of the fourth ventricle (arrow).
Author contributions
F. Borngräber: drafting/revising the manuscript, data acquisition, analysis or interpretation of data, accepts responsibility for conduct of research and final approval, acquisition of data. Y. Peng: drafting/revising the manuscript, data acquisition, analysis or interpretation of data, accepts responsibility for conduct of research and final approval. F. Ostendorf: drafting/revising the manuscript, analysis or interpretation of data, accepts responsibility for conduct of research and final approval, acquisition of data. A.A. Kühn: drafting/revising the manuscript, accepts responsibility for conduct of research and final approval, study supervision. C. Ganos: drafting/revising the manuscript, data acquisition, study concept or design, analysis or interpretation of data, accepts responsibility for conduct of research and final approval, study supervision.
Study funding
F. Borngräber is supported by the BIH-Charité Clinician Scientist Program of the Charité-Universitätsmedizin Berlin and the Berlin Institute of Health. Y. Peng and F. Ostendorf report no funding. A.A. Kühn is a consultant to Boston Scientific and has received honoraria for speaking from Medtronic, Boston Scientific, and Abbott, as well as grants from Medtronic, all outside the submitted work. C. Ganos holds research grants from the VolkswagenStiftung (Freigeist Fellowship) and the German Parkinson Society and was also supported by the Deutsche Forschungsgemeinschaft (DFG; GA2031/1-1 and GA2031/1-2).
Disclosure
The authors report no disclosures relevant to the manuscript. Go to Neurology.org/N for full disclosures.
Acknowledgment
The authors thank the patient for participation and support.
Footnotes
Go to Neurology.org/N for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
Teaching slides: links.lww.com/WNL/A951
- © 2019 American Academy of Neurology
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