Olivopontocerebellar atrophy with velopharyngolaryngeal paralysis: a contribution to the somatotopy of the nucleus ambiguus.

The authors report a case of olivopontocerebellar atrophy (OPCA) with velopharyngolaryngeal paralysis. The cerebellar syndrome appeared in a 66 year-old woman and ran its course until her death at 75. The velopharyngolaryngeal paralysis occured two years after the beginning of the cerebellar symtomatology and was limited for 6 months to a Gerhardt syndrome. Postmortem examination showed typical lesions of OPCA, and on serial sections of the medulla a massive loss of neurons in the lower two thirds of the nucleus ambiguus, bilaterally. The association of OPCA with velopharyngolaryngeal paralysis is exceptional. The anatomical findings in this case contribute to the somatotopy of the nucleus ambiguus in man by demonstrating the location of the velopharyngolaryngeal centers in this formation. The upper third plays only an accessory role in the velopharyngolaryngeal functions, and in the two lower thirds one finds, from the oral to the caudal extremity, first the velopharyngeal, then the laryngeal centers.