[Paroxysmic anarthria in multiple sclerosis]. / Anartria paroxística en la esclerosis múltiple.

INTRODUCTION: The paroxystic clinical features of multiple sclerosis (MS) include trigeminal neuralgia, itch, transient diplopia, Lhermitte's sign, akinesia, dystonia, Uhthoff's phenomenon and others which are very characteristic, such as paroxystic ataxia and dysarthria. CLINICAL CASE: We present the case of a 30 year old man who consulted for multiple episodes lasting only a few seconds, of complete inability to speak. This symptom recurred several times a day and in many different situations. It was often triggered off by external stimuli such as having to speak in front of several people. The disorder disappeared without treatment seven days after onset. Magnetic resonance using fast spin echo image sequences showed multiple hyperintense lesions in mid right cerebellar peduncle, right pons, left temporal lobe, white substance of both internal capsules, periventricular and semioval centres. Biochemical study of the cerebrospinal fluid showed that there were 9 cells/microliter (mainly lymphocytes), proteins 45 mg/dl and a normal glucose level. The Tibling-Link level was 0.73. Cortical somestesic evoked potentials showed slowed conduction after stimulation of the right median nerve and both peroneal nerves. Acoustic evoked potentials of the brain stem were conducted more slowly by the right acoustic pathway at intraxial level. The patient was diagnosed as having clinically defined MS. CONCLUSIONS: We consider that our patient's symptom was a kind of paroxystic dysarthria which we call paroxystic anarthria. Differential diagnosis of this symptom should be basically with phonatory or dysphasic simple partial seizures.

[Room tilt illusion: Report of two cases and terminological review]. / Ilusión de inclinación de la imagen visual. Descripción de dos casos y revisión de la terminología.

The room tilt illusion is a transient misperception of the visual image as tilted on its side or even upside down; in this case it has been termed acute upside down reversal of vision. We report on two cases of room tilt illusion as manifestation of VIII nerve neuritis (herpes-zoster infection) and cerebellar hemorrhage. Room tilt illusion has been reported in association with vertebrobasilar stroke, migraine, multiple sclerosis, epilepsy and labyrinthine disorders. The pathophysiology of this rare visual illusion has been related to a lesion of the visual or vestibulo-otolith pathways. In animals the neurones of the parieto-insular vestibular cortex areas are multisensory. So, they can respond to somatosensory, optokinetic and visual stimuli. In humans the knowledge about vestibular cortex function and localization is less precise than in animals. However, we propose a disorder of multisensorial vestibular cortex, resulting from a lession of vestibular pathways or association cortex, as mechanism of this phenomenon.