Contralateral body half hypalgesia in a patient with lateral medullary infarction: atypical Wallenberg syndrome.

On admission she was normotensive, and her general examination was normal. Neurological examination showed left Horner’s syndrome, with the left eye mildly ptotic ( fig. 1 a). There was no nystagmus in both eyes. The left pupil was about 3 mm and the right one 4 mm in diameter; both pupils were alert to light. The left palate was paraparetic, and the left throat reflex was decreased. The tongue moved well and there was no facial weakness. Sensation to pain and heat was decreased substantially in the right trunk and limbs, but decreased mildly in the right face, and normal in the left face and the left body. Bilateral vibratory and postural sensation was preserved. The left finger-nose test and the heel-knee-shin test were minimally incoordinated, compared with those of the right. When standing upright and closing the eyes, she felt mild lateropulsion to the left. There was no weakness of the limbs. Cerebral MRI detected a small bandlike ischemic lesion in the left retro-olivary midlateral tegmentum, with preservation of the far dorsal vestibular nucleus and inferior cerebellar peduncle ( fig. 1 c). Angiographic sequences disclosed congenital dysplasia of the left vertebral artery and segmental stenosis at the origin of the posterior inferior cerebellar artery ( fig. 1 b). Dear Sir, Lateral medullary infarction is one of the most frequently encountered cerebral infarctions involving the brainstem and often manifests as Wallenberg syndrome. Typically, it presents with vertigo, hoarseness and dysphagia, Horner’s syndrome and cerebellar ataxia on the same side of the lesion, and hypalgesia [1] , which usually involves the ipsilateral face and the opposite trunk and limbs (crossed sensory symptoms). Hypalgesia that involves the contralateral face, trunk, arm and leg without affecting the ipsilateral side of the face has seldom been reported [2] . Recently, we have encountered a female patient, who suddenly experienced hypesthesia in the entire contralateral body half with the ipsilateral side of the face unaffected.