Prematurity is Most Strongly Associated with Periventricular Leukomalacia
Prematurity (Option C) is the most strongly associated factor with periventricular leukomalacia, representing the primary risk factor and underlying pathophysiological mechanism for developing this condition. 1
Understanding the Question's Context
The clinical scenario describes a child with:
- Scissoring gait (indicating bilateral lower limb spasticity)
- MRI-confirmed periventricular leukomalacia (PVL)
- The question asks what is "most strongly associated" with this diagnosis
While all four options have relationships to PVL, the question is asking about the strongest association—meaning the primary risk factor or cause, not the consequences or diagnostic findings.
Why Prematurity is the Answer
Prematurity is the fundamental risk factor that creates the conditions for PVL to develop. 1 The evidence demonstrates a clear dose-response relationship:
- Infants born at 22 weeks gestational age have a 30% incidence of severe periventricular hemorrhagic infarction 1
- This decreases to only 3% at 28 weeks gestational age 1
- PVL is very rare in term infants 2
The pathophysiology centers on the vulnerability of the premature brain during mid-to-late gestation, when the relatively immature cerebrovasculature combined with perfusion failure creates the greatest period of vulnerability. 3
Why the Other Options Are Incorrect
Option A: Static Motor Delay
This is an outcome of PVL, not an association with the diagnosis itself. 1 Static motor delay is a broad category that could result from many conditions and represents a consequence rather than a causative or associated factor. 1
Option B: Bilateral Lower Limb Spasticity
This is a characteristic clinical manifestation of PVL, but it is a consequence of the condition, not the underlying cause or primary association. 1 The scissoring gait described in the vignette reflects this spasticity, which develops as a result of the white matter injury. 4
Option D: Periventricular White Matter Changes on MRI
This is the diagnostic finding itself—it's what PVL literally is, not what is "associated with" it. 1 This would be circular reasoning, as the question states the patient already has PVL diagnosed on MRI.
Clinical Context and Prognosis
The dramatic reduction in cerebral palsy incidence (3-fold decrease from early 1990s to early 2000s) was largely due to a 93% reduction in cystic PVL, underscoring that preventing prematurity and its complications is the key intervention. 5, 1
Important prognostic considerations:
- 43% of infants with cystic PVL also have intraventricular hemorrhage, requiring monitoring for both conditions 1, 6
- Bilateral cystic PVL specifically predicts nonambulant cerebral palsy with more severe motor impairment 1
- Cerebellar hemorrhage co-occurs in 10% of preterm infants with PVL and increases the risk of abnormal neurological outcomes 5-fold 1, 6