The lateral medullary syndrome Jane Luker, BDS, FDS, PhD,a and Crispian Scully, BSc, BDS, MD, FDS, PhD, MRCPath,h CENTRE FOR SURGERY, AND THE STUDY OF PATHOLOGY, ORAL DISEASE, BRISTOL UNIVERSITY DENTAL Bristol, England DEPARTMENT HOSPITAL AND OF ORAL MEDICINE, SCHOOL The lateral medullary syndrome is a rare syndrome resulting from a cerebrovascular accident involving part of the medulla oblongata with consequent loss of pain and temperature sensation in the orofacial region, loss of taste, and palatal palsy and loss of gag reflex, together with Horner’s syndrome and ataxia. A case is presented and the literature reviewed. (ORAL SURC ORAL MED ORAL PATHOL 1990;69:322-4) C erebrovascular accidents (CVAs) are a common cause of upper motor neuron lesions, particularly in later life. The common pattern is hemiplegia consequent on a CVA in the internal capsule.’ An example of a less common lesion is produced by infarction in the lateral medulla (Fig. 1) lying posteriorly to the inferior olivary nucleus, which produces a clinical syndrome referred to variously as the lateral medullary syndrome, posterior inferior cerebellar artery (PICA) syndrome, or Wallenberg’s Table syndrome.2, 3 The infarction may be caused by occlusion of the vertebral artery or posterior cerebellar Sympathetic fibers artery supplying the medulla and the inferior bellum,‘, 4 and may affect structures Though the signs and symptoms cere- as in Table 1. of the lateral medullary syndrome are some of the most striking in neurology and of particular interest to the dental surgeon because of the involvement of the V, IX, and X cranial nerves, the syndrome appears not to have been recorded in the dental literature. I. Structures within the medulla affected in lateral medullary syndrome Structure affected Symptoms/sign Dorsal nuclei of cranial nerves IX and X Spinothalamic and quintothalamic tracts Inferior cerebellar peduncle Nucleus ambiguus Nucleus and tract of cranial nerve V Tractus solitarius Inferior vestibular nucleus Reticular formation Hoarseness. Dysphagia. Dysarthria. lpsilateral palatal and vocal chord paralysis. Diminished gag reflex. Loss of pain/thermal sensation in contralateral limbs and trunk -t/- face. Ipsilateral Horner’s syndrome (constricted pupil, ptosis, decreased sweating). Ataxia-falling to affected side. Vomiting. Impaired sensation of ipsilateral side of face. Loss of taste. Nystagmus. Oscillopsia. Diplopia. Vertigo. Nausea. Hiccup. CASEREPORT A 63-year-old, previously fit retired laborer was admitted to the hospital with complaints of the sudden onset of dysphagia, hoarseness, ataxia, and hiccups. On examination, a left-sided Horner’s syndrome was present together with nystagmus of both eyes to lateral gaze and diplopia to the right. The left side of the face exhibited loss of sensationto pain and temperature,as did the right arm and leg. The coordination of the left leg and trunk was poor, and the right arm exhibited an increasein muscle tone and weakness. On standing, the patient tended to fall to the left side. Oral features Intraorally, there was loss of pain and temperature sensation in the distribution of the left maxillary and mandibular branches of the trigeminal nerve, the gag reflex was absent and the left side of the palate paralyzed, as evident by deviation of the uvula to the right (Fig. 2), andthere waslossof tastesensationon the left. From these signsand symptoms, it was clear that a lesion affected cranial nervesV, IX, and X, the sympathetic,vestibular nucleus, and cerebellum, and a diagnosisof left-sided lateral ‘Senior Dental Officer. bProfessor. 7/13/11378 322 medullary syndrome was made and confirmed by nuclear magnetic resonanceimaging (Fig. 3), which showeda degreeof cerebral atrophy together with asymmetry of the brain stem,mostlikely due to an infarct. Volume Number 69 3 Lateral medullary syndrome D?RSAL NUCLEUS INFERIOR 323 X VESTIBULAR NUCLEUS NUCLEUS ,RESTIFORM BODY LESIC ,N - ./SPINAL TRACT V “‘SPINOCEREBELLAR TRACT \,‘NUCLEUS OF SPINAL TRAC TV \,‘SYMPATHETIC FIBRES \,‘NUCLElJS AMBIGUUS ‘SPINOTHALAMIC TRACT Fig. 1. Diagram of medulla oblongata Fig. 2. Intraoral view showing showing deviation site of lesion producing lateral medullary of soft palate to right as result of left-sided syndrome. palatal paralysis. Management A nasogastric tube was inserted to permit adequate nutrition. After 3 weeks, the palatal paralysis improved and the gag reflex had returned, and there was also a marked improvement in coordination. After 4 months, the patient had made an almost complete recovery, apart from mild loss of coordination requiring the patient to walk with a stick. and loss of sensation of the left side of the face, right leg. and arm. DISCUSSION Lateral medullary syndrome, although uncommon, is of particular interest, because it is a cause of unilateral palatal paralysis, impaired facial and oral sensation, and loss of sense of taste. The dental surgeon can aid the restoration of speech and swallowing by the provision of intraoral appliances.5 REFERENCES 1. Patten Oxford J, ed. Neurological differential University Press, 1977:105-35. diagnosis. Oxford: Fig. 3. Nuclear magnetic resonance (MRI) scan showing assymetry of brain stem (as shown by arrows). 324 Luker and Scully ORAL SURG ORAL MED ORAL March 2. Sumi SM, Ruff RL, Swanson PD. Motor disturbances. In: Swanson PB, ed. Signs and symptoms in neurology. Philadelphia: JB Lippincott Company, I984:132-205. 3. Scuily C, Cawson RA. Medical problems in dentistry. 2nd ed. Bristol: Wright, 1987:359. 4. Fisher CM, Karnes WE, Kubik CS. Lateral medullary infarction-the pattern of vascular occlusion. J Neuropathol Exp Neural 1961;20:323-70. 5. Enderby P, Hathorn IS, Servant S. The use of intraoral appliances in the management of acquired velopharyngeal disorders. Br Dent J 1984;157:157-9. Reprint Dr. requests to. J. Luker Centre for the Study of Oral Disease University Department of Oral Medicine, Pathology Bristol Dental Hospital and School Lower Maudlin Street Bristol BSl 2LY Engiand Surgery, and PATHOL 1990