Paraneoplastic cerebellar degeneration associated with thymic germinoma

We present a 69 year-old man with hypertension who developed the sudden onset of horizontal binocular diplopia and stuttering of speech. On examination, bilateral exotropia (i.e. 'wall-eyed') was observed in the primary position. Attempted horizontal saccades revealed bilateral internuclear ophthalmoplegia; all consistent with the wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) syndrome. Convergence, vertical saccades and vestibular ocular reflexes were likewise impaired. Pupillary and levator palpebrae superioris functions were intact. Mild left-sided dysmetria, intention tremor and dysdiadochokinesia were elicited. Conspicuously, further characterization of the patient's history revealed that he had stuttered as a child, but it had resolved in adolescence. Brain MRI revealed an acute infarction of the mesencephalic and upper pontine tegmentum involving the periaqueductal gray region and the medial longitudinal fasciculus bilaterally with greater involvement of the left. Like the WEBINO syndrome, re-emergent developmental stuttering is a rare neurologic phenomenon. To our knowledge, this is the first case report of a mesencephalic and upper pontine infarction causing both syndromes. We discuss the pathobiological underpinnings of the WEBINO syndrome and neurogenic stuttering and in relationship to this unusual case.