MRI-based morphometry in children with multiple complex developmental disorder, a phenotypically defined subtype of...

Area of Science:

• Neuroscience
• Developmental Psychology
• Radiology

Background:

• Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) is a broad category within autism spectrum disorders.
• Multiple Complex Developmental Disorder (MCDD) may represent a distinct subtype requiring further neurobiological investigation.
• Understanding subtypes of autism spectrum disorders is crucial for addressing heterogeneity.

Purpose of the Study:

• To investigate the neurobiological specificity of MCDD by comparing brain morphology with autism and typically developing controls.
• To identify potential subtypes within the broader autism spectrum disorders.

Main Methods:

• Structural Magnetic Resonance Imaging (MRI) was used to assess brain morphology.
• Compared brain volumes in high-functioning children with MCDD (n=22), autism (n=21), and matched controls (n=21).

Main Results:

• MCDD subjects exhibited an enlarged cerebellum and a trend towards increased grey-matter volume compared to controls.
• MCDD subjects had smaller intracranial volume compared to subjects with autism.
• Brain volumetric changes in MCDD show both overlap with and divergence from autism.

Conclusions:

• MCDD displays a unique pattern of brain volumetric changes, partially overlapping with autism spectrum disorders.
• The absence of enlarged head size in MCDD differentiates it from some autism presentations.
• These findings suggest distinct developmental trajectories for MCDD compared to autism.