Peripheral neuropathy as the sole initial finding in three children with infantile metachromatic leukodystrophy

Area of Science:

• Neurology
• Biochemistry
• Genetics

Background:

• Metachromatic leukodystrophy (MLD) is a lysosomal storage disorder caused by arylsulfatase A (ARSA) deficiency.
• This deficiency leads to the accumulation of sulfatides, causing progressive demyelination in the central and peripheral nervous systems.
• Early diagnosis is critical for managing the neurodegenerative progression of MLD.

Observation:

• Three children presented with infantile MLD, exhibiting difficulties in standing and walking with absent reflexes.
• Cerebrospinal fluid (CSF) analysis revealed elevated protein levels, and nerve conduction studies showed slowed motor nerve conduction velocity.
• Initial cerebral MRI scans did not reveal white matter changes, delaying diagnosis.

Findings:

• Follow-up MRI and ARSA testing confirmed MLD in all three children after the onset of neurodegenerative symptoms.
• The study highlights that MLD can present with initially normal MRI findings in young children.
• Delayed diagnosis underscores the importance of considering MLD in the differential diagnosis of acute/subacute demyelinating polyneuropathy.

Implications:

• MLD should be considered in the differential diagnosis of young children presenting with acute/subacute demyelinating polyneuropathy, even with initially normal brain MRI.
• This case series emphasizes the need for comprehensive diagnostic approaches, including biochemical and genetic testing for ARSA deficiency.
• Timely diagnosis and potential therapeutic interventions can significantly impact the management and outcomes for patients with MLD.