Yes, tethered cord, syringomyelia, and Chiari malformation are definitely possible in this patient and warrant urgent evaluation with MRI of the entire spine and brain.
This 15-year-old boy with left-sided lumbar scoliosis and new-onset secondary enuresis has multiple red flags that strongly suggest an underlying neural axis abnormality requiring comprehensive MRI evaluation of the entire neuraxis (brain and complete spine). 1
Why These Conditions Are Likely
The combination of features in this patient raises significant concern:
- Left thoracic/lumbar curve pattern - This is one of the most consistent risk factors for neural axis abnormalities 1, 2
- Secondary enuresis - This represents a new neurological symptom suggesting possible cord dysfunction from tethering, syrinx, or Chiari-related compression
- Male sex - Males have significantly higher rates of intraspinal anomalies with scoliosis 2
Studies show that 18.7% of juvenile scoliosis patients have neural axis abnormalities, with Chiari malformation (with or without syringomyelia) accounting for 64.8% of these cases 2. In presumed idiopathic scoliosis, tethered cord, syringomyelia, and Chiari I malformation are the most common intraspinal abnormalities detected 1, 3.
Required MRI Protocol
Order MRI of the entire spine (cervical through sacral) AND brain without contrast 1, 4.
Specific imaging requirements:
Complete spine coverage - Cervical, thoracic, lumbar, and sacral regions must all be included to evaluate for:
- Tethered cord (low-lying conus, thickened filum terminale)
- Syringomyelia throughout the cord
- Other intraspinal abnormalities
Brain imaging - Essential to evaluate for Chiari I malformation (cerebellar tonsillar descent >5mm below foramen magnum) and associated hydrocephalus 4
No contrast needed - IV gadolinium is not routinely required unless tumor or infection is suspected 1
The ACR Appropriateness Criteria specifically state that MRI with superior soft-tissue contrast is selectively used to detect and characterize suspected intraspinal abnormalities in scoliosis 1. The Congress of Neurological Surgeons guidelines recommend that in patients with Chiari I diagnosed on limited imaging, complete brain and spine imaging may be helpful to evaluate for clinically relevant pathology such as hydrocephalus or spine syrinx 4.
Critical Clinical Reasoning
Do not delay this imaging. The presence of secondary enuresis represents a change in neurological function that could indicate:
- Tethered cord causing bladder dysfunction
- Expanding syrinx affecting autonomic pathways
- Chiari malformation with brainstem compression
Left-sided curves, particularly left thoracic patterns, have been consistently identified as atypical and associated with higher rates of neural axis abnormalities 1, 2, 5. One study found that left thoracic curves and right lumbar curves were significantly associated with neural axis abnormalities 2.
Common Pitfalls to Avoid
Don't order only cervical spine MRI - You need complete spine coverage to assess for tethered cord (which would be missed on cervical-only imaging) and the full extent of any syrinx 4
Don't assume "idiopathic" scoliosis - Idiopathic scoliosis is a diagnosis of exclusion. This patient has red flags (left curve, male, new neurological symptoms) that make neural axis pathology likely 1
Don't wait for more obvious neurological signs - Secondary enuresis IS a neurological finding. Studies show that 10.3% of presumed idiopathic scoliosis patients have positive MRI findings, with 2.1% requiring neurosurgical intervention before spinal surgery 3
What Happens If Abnormalities Are Found
If neural axis abnormalities are detected, neurosurgical consultation is mandatory before any scoliosis surgery 3. Some patients (approximately 2-3%) will require neurosurgical intervention (such as posterior fossa decompression for Chiari, detethering surgery, or syrinx shunting) before orthopedic correction can proceed safely 3.