Abstract 4- 1055-1010
Category: Clinical

At the end of the session, participants will be able to:

  1. To review the pathological features of polymicrogyria, particularly in the setting of congenital CMV encephalitis (CMVE)
  2. To consider how the injuries in congenital CMVE can influence the balance of tensegrity within the developing brain

COI Disclosure:

I have a relationship with a for-profit and/or a not-for-profit organization to disclose. Indicate the organization(s) with which you
have/had a relationship over the previous two years and briefly describe the nature of that relationship.

Name of for-profit or not-for-profit organization(s) : MedCBL
Description of relationship(s) : President


The University of Western Ontario was home to my MD (1987) and NP training (1992) under John Kaufmann, Joseph Gilbert, David Ramsay, David Munoz, George Davidson, Sam Ludwin and Ian MacKenzie with memorable electives at UBC under Marg Norman and Ken Berry. Research fellowships followed under Fred Gage (UC SanDiego/Salk) and Clayton Wiley (University of Pittsburgh). I have practiced Neuropathology at the London Health Sciences Centre since 1995.

A common thread to my interests in science, medicine, and life is the analysis of visual data.  Funded research has included intrauterine hypoxia/ischemia, HIV-1 associated neurotoxicity, cerebrovascular disease and epilepsy; all connected by image analysis/AI.  In medical education I am interested in bias and asynchronous learning.

My presentation has its roots with one of my mentors, Marg Norman, who nurtured an interest in developmental anomalies of the nervous system and their frequently stunning morphology.


Robert Hammond1, Christopher Dunham2

1Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada

2Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada

    Target Audience:

    Pathologists, Residents, Medical students, Graduate students


    Medical expert, Communicator, Collaborator, Leader, Scholar

    Polymicrogyria through a tensegrity lens

    Polymicrogyria is an anomaly of cortical development. It may be pure or associated with other lesions. Polymicrogyria is etiologically diverse and associated with a spectrum of neurological consequences proportional to its extent and associated abnormalities.  The literature has mediated a debate on the timing and significance of particular etiologies, inviting a variety of theories to account for its stereotypic architecture.

     Congenital cytomegalovirus (CMV) infection is a common cause of polymicrogyria. In a collection of such cases, ranging from 16 to 39 weeks gestational age, several findings were almost invariable: subventricular zone necrosis, subventricular germinal cell infection, radial glial disruption and injuries to the pial-glial border.  Subcortical neuronal heterotopias and leptomeningeal heterotopias were also common.  Clinical details and pathological findings indicate that the responsible insults occurred before neuronal migration was complete, lasted several weeks and led to a variety of structural perturbations to the developing brain. 

     These cases add to the evidence that polymicrogyria is not solely post-migrational and that a variety of injuries (and timings) can replicate its relatively stereotyped morphology.  A reductionist focus on timing and etiology has distracted from a more fundamental and versatile construct built on the principles of tensegrity, whereby the brain’s unique morphology (and disruptions of the same) can be explained on the basis of forces that exist at the tissue, cellular and subcellular levels.  The natural experiment of polymicrogyria in congenital CMV infection lends support for tensegrity as a basis for normal and abnormal morphologies while embracing the variables of timing and etiology.