Intermittent Maple Syrup Urine Disease Presenting With Chronic Demyelinating Polyneuropathy: A Genetically Confirmed DBT-Related Case.
Gustavo Rodrigues Ferreira Gomes, Antonio Edvan Camelo Filho, Ellen Mourão Soares Lopes et al.
✦ AI-curated · Sources linked
Case in brief
A female patient with intermittent maple syrup urine disease (MSUD), genetically confirmed by compound heterozygous pathogenic DBT variants, had recurrent ataxic episodes from early childhood. At age 12, acute ascending weakness during metabolic decompensation was initially suspected to be Guillain-Barré syndrome; biochemical and molecular testing established MSUD. Five years later, despite good metabolic control and substantial functional recovery, nerve conduction studies and electromyography showed chronic demyelinating sensorimotor polyneuropathy. Examination also found bilateral pes cavus and persistent mild distal lower-limb weakness.
What made this case unusual
The case documents chronic peripheral neuropathy in intermittent MSUD, with electrophysiological evidence of demyelinating sensorimotor involvement despite good metabolic control and substantial functional recovery.
Diagnostic / clinical pearl
In a patient with MSUD and weakness, peripheral nerve involvement may persist beyond metabolic decompensation; longitudinal neurological assessment and electrophysiological testing can help identify it.
Why it matters
The case adds a longitudinal description of peripheral neuropathy to the reported neurological spectrum of intermittent MSUD, while the mechanism of nerve injury remains uncertain.