Background. Hypertrophic olivary degeneration (HOD) is a rare degenerative disorder that is thought to occur subsequent to a disruption of the dentate-rubro-olivary pathway. Case. We report a pediatric case of unilateral HOD presented with persistent hiccups and palatal tremor. Radiological examination of diaphragm was normal considering ultrasound and chest x-ray. On T2WI (weighted images) and Fluid Attenuated Inversion Recovery (FLAIR) images, hyperintense enlargement of the right inferior olivary nucleus was seen. No abnormal enhancement was detected on post-contrast scans and no evidence of restricted diffusion was seen. Susceptibility weighted imaging (SWI) sequences revealed a chronic hemorrhage involving the medulla oblongata and cerebellum. Cranial magnetic resonance imaging (MRI) findings were consistent with unilateral HOD. Palatal tremor and dentate-rubral tremor are frequent presentation of HOD, however to our knowledge persistent hiccups had not yet been reported in children with HOD. Conclusion. We highlight a pediatric case of unilateral HOD, which presented with persistent hiccups. Awareness of clinical and radiological findings of HOD is important to avoid misinterpretation as a mass lesion, an ischemic event, or a demyelinating disease and provide adequate management.
___
1. Gautier JG, Blackwood W. Enlargement of the inferior olivary nucleus in association with lesions of the central tegmental tract or dentate nucleus. Brain 1961; 84: 341-361.
2. Goyal M, Versnick E, Tuite P, et al. Hypertrophic olivary degeneration: metaanalysis of the temporal evolution of MR findings, AJNR Am J Neuroradiol 2000; 21: 1073-1077.
3. Ballestero MFM, Viana DC, Teixeira TL, Santos MV, de Oliveira RS. Hypertrophic olivary degeneration in children after posterior fossa surgery. An underdiagnosed condition. Childs Nerv Syst 2018; 34: 409-415.
4. Tartaglione T, Izzo G, Alexandre A, et al. MRI findings of olivary degeneration after surgery for posterior fossa tumours in children: incidence, time course and correlation with tumour grading. Radiol Med 2015; 120: 474-482.
5. Tilikete C, Desestret V. Hypertrophic olivary degeneration and palatal or oculopalatal tremor. Front Neurol 2017; 8: 302.
6. Walker G, Limaye K, Jankowitz BT, Jadhav AP. Hypertrophic olivary degeneration after cerebellar hemorrhage. J Clin Neurosci 2017; 43: 162-164.
7. Nishie M, Yoshida Y, Hirata Y, Matsunaga M. Generation of symptomatic palatal tremor is not correlated with inferior olivary hypertrophy. Brain 2002; 125(Pt 6): 1348-1357.
8. Sanverdi SE, Oguz KK, Haliloglu G. Hypertrophic olivary degeneration in children: four new cases and a review of the literature with an emphasis on the MRI findings. Br J Radiol 2012; 85: 511-516.
9. Konno T, Broderick DF, Tacik P, Caviness JN, Wszolek ZK. Hypertrophic olivary degeneration: A clinico-radiologic study. Parkinsonism Relat Disord 2016; 28: 36-40.
10. Kinghorn KJ, Kaliakatsos M, Blakely EL, et al. Hypertrophic olivary degeneration on magnetic resonance imaging in mitochondrial syndromes associated with POLG and SURF1 mutations. J Neurol 2013; 260: 3-9.
11. Oh SI. Hypertrophic olivary degeneration following listerial rhombencephalitis. Can J Neurol Sci 2018; 45: 593-595.
12. JI Seok, Yi H, Song YM, Lee WY. Metronidazoleinduced encephalopathy and inferior olivary hypertrophy: lesion analysis with diffusionweighted imaging and apparent diffusion coefficient maps. Arch Neurol 2003; 60: 1796-1800.
13. Eisenächer A, Spiske J. Persistent hiccups (singultus) as the presenting symptom of medullary cavernoma. Dtsch Arztebl Int 2011; 108: 822-826.
14. Sweeney J, Bodman A, Hall WA. Brain abscess of basal ganglia presenting with persistent hiccups. World Neurosurg 2018; 112: 182-185.
15. Franco-Macías E, Roldán-Lora F, Martínez-Agregado P, Cerdá-Fuertes N, Moniche F. Neuro-Behçet: pons involvement with longitudinal extension to midbrain and hypertrophic olivary degeneration. Case Rep Neurol 2015; 7: 148-151.