Bilateral Lower Limb Spasticity (Option B)
The most strongly supported diagnosis in a patient with scissoring gait and periventricular leukomalacia on MRI is bilateral lower limb spasticity, which defines the clinical syndrome of spastic diplegia cerebral palsy. 1, 2
Why Bilateral Lower Limb Spasticity is the Answer
The American Academy of Pediatrics explicitly states that bilateral lower limb spasticity is the hallmark clinical manifestation of spastic diplegia cerebral palsy, which is most strongly supported by the combination of scissoring gait and periventricular leukomalacia on MRI. 1 The scissoring gait pattern is pathognomonic for bilateral lower limb spasticity, specifically indicating spastic diplegia. 2
The clinical syndrome of spastic diplegia cerebral palsy is defined by the functional outcome of bilateral lower limb spasticity, making it the most strongly supported diagnosis. 1
Why the Other Options Are Incorrect
Static Motor Delay (Option A)
- While cerebral palsy is by definition a static encephalopathy with motor dysfunction, "static motor delay" is too vague and non-specific to capture the specific pattern of bilateral lower limb spasticity. 1
- This term does not describe the characteristic clinical presentation seen with scissoring gait. 1
Prematurity (Option C)
- Prematurity is a risk factor, not a diagnosis, and while strongly associated with bilateral spastic CP, it is not universally present. 1, 3
- The American Academy of Neurology recognizes prematurity as the primary risk factor and underlying pathophysiological mechanism for developing periventricular leukomalacia, but it represents the etiology rather than the clinical diagnosis. 3
- Prematurity is associated with periventricular leukomalacia (intracerebral hemorrhage and PVL are the main pathologic findings in preterm infants who develop CP), but the question asks what is most strongly supported by the diagnosis, not what caused it. 4, 5
Periventricular White Matter Changes on MRI (Option D)
- The American Academy of Pediatrics notes that the imaging finding of periventricular leukomalacia should not be confused with the clinical diagnosis of bilateral lower limb spasticity, which is defined by the motor manifestation. 1
- This option simply restates what is already given in the question stem (periventricular leukomalacia is periventricular white matter changes). 1
- The imaging finding is a radiologic observation, not the clinical syndrome that results from it. 2
Clinical Context
The presence of bilateral cystic PVL on MRI predicts nonambulant cerebral palsy with more severe motor impairment, while noncystic PVL is more likely to result in ambulant cerebral palsy. 2, 3 Early intervention with CP-specific therapies should be initiated immediately. 2