Objective: Pelizaeus-Merzbacher disease (PMD) is a rare X-linked recessive disorder caused by mutations in the PLP1 gene. It causes severe demyelination in the central nervous system in infancy and early childhood. The typical symptoms of PMD are hypotonia, nystagmus, and delayed development of motor skills. As the child gets older, spasticity, ataxia, and choreiform movements develop. The prevalence of PMD is estimated to be approximately 1.45 in 100, 000 live births in Japan and 0.13 in 100, 000 live births in Germany. The average life span of PMD patients is approximately 30 years. No cure for PMD is known yet, nor does it have a standard course of treatment. We aimed to report functional improvement of a child with PMD after rehabilitation treatment.
Case description: A 12-month-old boy with PMD visited our children’s hospital rehabilitation center for comprehensive pediatric rehabilitation. His brain MRI (Figure 1) showed total demyelination in the bilateral white matter. He had nystagmus, decreased truncal tone with ataxia. His consciousness was clear and the muscle strength of all four limbs was measured grade 3 (normal grade 5). Muslce stretch reflex was increased in both lower limbs and Babinski reflex was positive in both sides. Spascity was not observed. Gross Motor Function Classification System (GMFCS) was checked level V and Gross Motor Function Measure (GMFM) was scored 19. On developmental assessment, gross motor was measured 5 months, fine motor 7 months, social 7 months, and language 10 months. Comprehensive rehabilitation was performed for 3 months. The first and the last one month of 3 months were through inpatient rehabilitation and he received inpatient rehabilitation at another hospital during the second month.
After 3 months of rehabilitation, there was no difference in physical examination such as consciousness, mucle strength, muscle stretch reflex, and Babinski reflex. However, GMFCS, developmental assessment and GMFM showed some improvement. GMFCS was checked level IV. Gross motor was measured 6 months, fine motor 10 months, social 9 months, and language 12 months. GMFM scored 51; the score improved 17 to 36 in lying & rolling, 2 to 12 in sitting, and 0 to 3 in crawling & kneeling probably because of the improvement of truncal tone and ataxia (Table 1).
Conclusion: We report an infant with PMD who underwent comprehensive rehabilitation for 3 months. After rehabilitation treatment, GMFCS, GMFM and developmental assessment improved. Comprehensive pediatric rehabilitation would help children with rare PMD achieve their maximal functional ability.
Key Words: Pelizaeus-Merzbacher disease, congenital disease, ataxia, rehabilitation |
