Atypical Infantile neuroaxonal dystrophy: a case report

Case Report: Infantile neuroaxonal dystrophy (INAD) is a progressive neurodegenerative disease which involves central and peripheral nervous system. Onset of symptoms is in the first or second year of life. Mental and motor milestones are lost, seizures typically develop. In addition, a progressive motor sensory neuropathy begins. Further clinical signs include hypotonia, spasticity, and vision loss.

We report on a 3.5-year-old girl with genetically confirmed INAD and atypical clinical results. Typical clinical symptoms began at 9 months of age with arrest of speech development, muscular hypotonia, ataxic arm and hand movements and increased deep tendon reflexes at weak lower limbs. Lower limb weakness within several months developed into complete paraparesis, and dysphagia occurred. Serial cranial MRI revealed progressive cerebellar atrophy, but did not show the expected hyperintensity of the cerebellar cortex. Mental abilities further decreased from one to three years of age, however epilepsy and vision loss did not occur. During the diagnostic work-up muscle and nerve biopsy were done which did not show any of the typical axonal spheroids. Finally molecular testing confirmed the diagnosis of INAD. Diagnosis was finally confirmed with molecular genetic testing and the finding of PLA2G6 mutation.

This case report demonstrates that a lack of typical clinical signs should not hinder to investigate a plausible hypothesis.