Downloaded from http://jnnp.bmj.com/ on April 15, 2015 - Published by group.bmj.com Neurological picture A case of bilateral stroke of the medulla oblongata CASE REPORT A 64-year-old woman with a history of hypertension and diabetes was admitted to the emergency room with tetraparesis which had slowly progressed over the previous week. On examination the patient presented a right-sided dominant tetraparesis, no inferior limb deep tendon jerks and upper limb paraesthesia. No sensory loss, cranial nerve impairment, or weakness of the face or tongue was noted on admission. MRI of the medulla was performed with T1 and T2 weighted sequences because of the possibility of cervical compression myelopathy. This MRI showed no medullary abnormalities except for a narrow spinal canal. Within the next 24 h the patient developed severe dysphagia. Teraparesis progressed to a right-sided hemiplegia, and bilateral Babinsky signs appeared. MRI of the brain and medulla was then performed showing bilateral hyperintense signal of the medullary pyramids in the diffusion weighted imaging (figure 1) and T2 weighted (figure 2) sequences. The lesion was later confirmed by axial T1 weighted sequences which showed a Y shaped hypointense signal in favour of ischaemic sequelae (figure 3). In our case no respiratory failure was noted and dysphagia rapidly disappeared in the following week. Tetraparesis progressively improved throughout the following months. DISCUSSION According to previous studies,1e4 medial medullary infarction accounts for approximately 1% of vertebrobasilar strokes and less than 0.5% of all acute brain infarctions. Bilateral medial medullary infarction is a very rare event as it accounts for less than 1% of medial medullary infarctions, and less than 20 cases have been reported in the literature. Previous studies have Figure 1 Diffusion weighted MRI showing bilateral hyperintense signal in the medullary pyramids in favour of an acute stroke. 1322 Figure 2 T2 weighted sequences in the acute stage showing bilateral medullary hyperintensity. showed that the prognosis of this injury is linked with respiratory failure which did not occur in our case.5 It has been reported6 that an anatomical variant of the anterior spinal artery which originates from one vertebral artery Figure 3 Axial T1 MRI showing the Y shaped stroke sequelae. J Neurol Neurosurg Psychiatry December 2010 Vol 81 No 12 Downloaded from http://jnnp.bmj.com/ on April 15, 2015 - Published by group.bmj.com Neurological picture Figure 4 Occlusion of the V4 segment of the right vertebral artery in MR angiography. occurs in approximately 10% of patients. In the presence of this anatomical variant, atherosclerosis and atheromatous disease of the vertebral artery, anterior spinal artery or branches of the anterior spinal artery are very likely to explain bilateral medullary pyramid infarction. In our case, occlusion of the right vertebral artery, discovered on MR angiography (figure 4), along with a probable anatomical variant of the anterior spinal artery possibly accounted for the occurrence of this infarction. Moreover, tractography images showed bilateral lesions of the main pyramidal tract, with a left dominant impairment, agreeing with the clinical presentation of right hemiplegia and left hemiparesis (figure 5). The most frequent aetiologies for tetraparesis include myelitis, cervical compression myelopathy and neuropathy. Most of these causes can be diagnosed by either lumbar puncture or MRI. Our case illustrates a rare cause of tetraparesis which should not be forgotten when all previous aetiologies have been discarded. Moreover, diffusion weighted imaging should be part of all MRIs probing a tetraparesis as it is the most sensitive sequence in acute brain infarction. Figure 5 Diffusion tensor MR tractography showing left dominant impairment of the corticospinal tracts. Correspondence to Mr A Kastler, Department of Neurology, Hôpital Gabriel Montpied, CHU Clermont-Ferrand, 58 Rue Montalembert, F-63000 Clermont-Ferrand, France; a_kastler@chu-clermontferrand.fr Competing interests None. Patient consent Obtained. Provenance and peer review Not commissioned; not externally peer reviewed. Accepted 23 December 2009 Published Online First 14 June 2010 J Neurol Neurosurg Psychiatry 2010;81:1322e1323. doi:10.1136/jnnp.2009.201467 REFERENCES 1. 2. 3. 4. Adrian Kastler,1 Miguel Ulla,1 Beatrice Claise,2 Frank Durif1 5. 1 6. 2 Department of Neurology, Gabriel Montpied Hospital, Clermont-Ferrand, France; Department of Radiology, Gabriel Montpied Hospital, Clermont-Ferrand, France J Neurol Neurosurg Psychiatry December 2010 Vol 81 No 12 Kumral E, Afsar N, Kirbas D, et al. Spectrum of medial medullary infarction: clinical and magnetic resonance imaging findings. J Neurol 2002;249:85e93. Thijs RD, Wijman CA, van Dijk GW, et al. A case of bilateral medial medullary infarction demonstrated by magnetic resonance imaging with diffusion-weighted imaging. J Neurol 2001;248:339e40. Katoh M, Kawamoto T. Bilateral medial medullary infarction. J Clin Neurosci 2000;7:543e5. Paliwal VK, Kalita J, Misra UK. Dysphagia in a patient with bilateral medial medullary infarcts. Dysphagia 2009;24:349e53. Takano K, Takasugi K. [A case of bilateral lower pons-medial medullary infarction presenting quadriparesis] [in Japanese]. No To Shinkei 2003;55:879e83. Lang J, Wachsmuth W, Lanz von T, eds. Praktische Anatomie, ein Lehr- und Hilfsbuch der anatomischen Grundlagen ärztlichen Handelns. Berlin: Springer, 1979:429. 1323 Downloaded from http://jnnp.bmj.com/ on April 15, 2015 - Published by group.bmj.com A case of bilateral stroke of the medulla oblongata Adrian Kastler, Miguel Ulla, Beatrice Claise and Frank Durif J Neurol Neurosurg Psychiatry 2010 81: 1322-1323 originally published online June 14, 2010 doi: 10.1136/jnnp.2009.201467 Updated information and services can be found at: http://jnnp.bmj.com/content/81/12/1322 These include: References Email alerting service Topic Collections This article cites 5 articles, 0 of which you can access for free at: http://jnnp.bmj.com/content/81/12/1322#BIBL Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article. 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