Auditory Perception and Language Development in Nine Children with Classical Pelizaeus-Merzbacher Disease

Abstract

Auditory perception and language development in nine male infants and children clinically suspected as having classical Pelizaeus-Merzbacher disease (PMD), were studied. PMD is an X-linked recessive, leukodystrophy in which myelination of the central nervous system fails to mature. The patients exhibited only wave I, or waves I and II when tested for auditory brain stem response, congenital pendular nystagmus, hypotonia, and tremors of head, trunk, and upper limbs in the early infantile period, and later developed progressive spasticity of the lower extremities. MRI demonstrated high-signal areas over the entire cerebral white matter on T2-weighted images, with inversion of the usual contrast in all cases. Three cases proved to have normal hearing, and six showed mild hearing impairment by pure tone or conditioned orientation reflex (COR) audiometry. The infants and children responded well to voices and sounds. Language development was evaluated in the patients, ranging from four years to twenty-two years of age, and it was noted that the comprehension of daily conversation was extremely good, while eight cases suffered from severe dysarthria, and one had ataxic speech. It is important to consider augmentative or alternative communication systems for such children, with neurogenic articulation problems.