Childhood Ataxia with Central Nervous System Hypomyelination/Vanishing White Matter Disease (CACH-VWM) is a progressive disorder that mainly affects the brain and spinal cord (central nervous system). This leukodystrophy disorder causes deterioration of the CNS white matter, which consists of nerve fibers covered by myelin. Myelin is the fatty substance that insulates and protects nerves. In most cases, children with CACH show no signs or symptoms of the disorder at birth. Affected children may have slightly delayed development of motor skills such as crawling or walking. During early childhood, previously healthy children begin to develop motor impairments, including abnormal muscle stiffness (spasticity) and difficulty with coordinating movements (ataxia). There may also be some deterioration of mental functioning, but this is not usually as pronounced as the motor impairments. Specific changes in the brain are seen using magnetic resonance imaging (MRI) are characteristic of CACH-VWM and may be visible before the onset of symptoms.
DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM CODING
Diagnostic testing: The diagnosis of CACH-VWM is made by physical examination; MRI demonstrating bilateral cerebral destruction of white matter; Genetic testing documenting mutations in one of the five causative gene mutations (EIF2B1, EIF2B2, EIF2B3, EIF2B4, and EIF2B5).
Physical findings: Children with CACH-VWM have cerebellar ataxia, hypotonia or spasticity, difficulty swallowing (bulbar symptoms), optic atrophy, and lethargy.
ONSET AND PROGRESSION
With CACH-VWM, generally the earlier onset of symptoms and signs correlates with faster progression and worse prognosis. In congenital or antenatal form, onset is in utero and newborns present with hypotonia, feeding difficulties, and microcephaly; progression is rapid with systemic involvement, development of intractable seizures, coma, and death before age 1. The infantile form has onset in the first months of life, similar rapid progression, motor dysfunction, and death usually by age 2 years. The early childhood onset form is the most common with onset between 1 and 5 years, with less spasticity and usually no cognitive decline. Most children with the early childhood form die within a few years of onset. In older children, adolescents, and adults, the clinical course is usually more slowly progressive than earlier onset forms, with spastic diplegia and ataxia, relative sparing of cognition, and typically longer survival.