Clinical and Radiologic Findings in Children with Anomalous Pontine Cranial Nerves

Area of Science:

• Neurology
• Radiology
• Pediatrics

Background:

• Aberrant cranial nerve 7 (CN7) is a rare condition.
• Associated anomalies of other pontine cranial nerves are not well-characterized.

Purpose of the Study:

• To describe the spectrum of imaging findings in children with aberrant cisternal CN7.
• To identify associated anomalies of other pontine cranial nerves and potential risk factors.

Main Methods:

• Retrospective review of clinical and radiologic findings in 17 children with aberrant cisternal CN7.
• Detailed analysis of magnetic resonance imaging (MRI) to assess cranial nerves (CNs) 5, 6, 7, and 8, and related structures.

Main Results:

• Hallmark finding: aberrant, enlarged cisternal CN7 coursing towards the Gasserian ganglion.
• Commonly associated anomalies: small, laterally bowed CN5; widened Meckel cave; CN8 deficiency; variable CN6 deficiency.
• Most patients had preserved facial nerve function; no pathogenic variants found on genetic testing. Maternal/gestational diabetes noted in 69% of cases with available history.

Conclusions:

• Aberrant cisternal CN7 is part of a broader spectrum of pontine CN anomalies in children.
• These findings suggest a possible early intrauterine insult, potentially related to maternal diabetes, affecting developing cranial nerves.
• Further research is needed to elucidate the etiology and long-term implications.