What is the management approach for a patient with Down syndrome presenting with abnormal gait, head tilt to the left, and decreased sensation in extremities without a history of trauma?

Urgent Neurological Evaluation for Atlantoaxial Instability

This patient with Down syndrome presenting with abnormal gait, head tilt, and decreased extremity sensation without trauma requires immediate cervical spine imaging to rule out atlantoaxial instability with spinal cord compression—a life-threatening complication that can occur spontaneously in Down syndrome patients.

Immediate Diagnostic Workup

Priority Imaging

• Obtain urgent cervical spine MRI with and without contrast to evaluate for:
  • Atlantoaxial instability (C1-C2 subluxation)
  • Spinal cord compression or myelopathy
  • Craniocervical junction abnormalities 1
• If MRI unavailable, obtain lateral cervical spine radiographs in neutral, flexion, and extension positions 2
• The combination of head tilt and sensory changes suggests possible upper cervical cord involvement 1

Critical Physical Examination Elements

• Assess for upper motor neuron signs: hyperreflexia, Babinski sign, clonus, and spasticity 2
• Evaluate cranial nerves systematically: eye movements, facial symmetry, tongue deviation, gag reflex 2
• Test sensory levels carefully: document dermatomal distribution of sensory loss 2
• Observe for Gower maneuver when rising from floor (indicates proximal muscle weakness) 2
• Measure deep tendon reflexes: diminished reflexes suggest lower motor neuron pathology, while increased reflexes indicate upper motor neuron dysfunction 2

Differential Diagnosis Considerations

Primary Concern: Atlantoaxial Instability

• Down syndrome patients have ligamentous laxity predisposing to C1-C2 instability 2, 1
• Can present insidiously without trauma 1
• Head tilt may represent torticollis from cervical pathology 2
• Progressive myelopathy causes gait abnormalities and sensory deficits 2

Alternative Neurological Etiologies

• Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): Down syndrome patients have increased autoimmune susceptibility 3

  • Presents with progressive weakness, sensory changes, and diminished reflexes 3
  • CSF shows elevated protein without pleocytosis 3
  • Nerve conduction studies demonstrate slowed velocities 3

• Concurrent neuromuscular disorders: spinal muscular atrophy can coexist with Down syndrome 4

  • Measure serum creatine kinase (CK) level 2
  • CK >1000 U/L suggests muscular dystrophy 2
  • Consider EMG/nerve conduction studies if CK elevated 2

Vestibular/Brainstem Pathology

• Head tilt with gait abnormality may indicate skew deviation from brainstem lesion 2
• Associated findings would include: nystagmus, internuclear ophthalmoplegia, diplopia, vertigo 2
• However, decreased extremity sensation makes peripheral vestibular cause less likely 2

Management Algorithm

If Atlantoaxial Instability Confirmed

1. Immediate neurosurgical consultation 2
2. Cervical spine immobilization until surgical evaluation complete 2
3. Avoid Dix-Hallpike maneuver and neck manipulation in Down syndrome patients due to atlantoaxial instability risk 2
4. Surgical stabilization indicated for progressive myelopathy or instability >5mm 2

If Inflammatory Neuropathy Suspected

1. Obtain lumbar puncture: CSF protein, glucose, cell count, cytology 2, 3
2. Serum testing: vitamin B12, TSH, HbA1c, vitamin B6, folate, serum protein electrophoresis 2
3. Consider autoimmune panel: ANA, ESR, CRP, ANCA, ganglioside antibodies 2
4. If CIDP confirmed: initiate methylprednisolone 1-2 mg/kg/day 2, 3
5. IVIG or plasmapheresis for severe cases 2

If Neuromuscular Disorder Suspected

1. Measure CK and TSH immediately 2
2. EMG and nerve conduction studies 2
3. Consider genetic testing if CK markedly elevated 2

Critical Safety Considerations

Contraindications in Down Syndrome

• Avoid cervical manipulation including Dix-Hallpike testing due to atlantoaxial instability risk 2
• Exercise extreme caution with procedures requiring neck extension 2
• Down syndrome specifically listed as contraindication for standard vestibular testing 2

Red Flags Requiring Emergency Intervention

• Progressive weakness or sensory loss (suggests evolving myelopathy) 2
• Bowel/bladder dysfunction (indicates spinal cord compression) 2
• Respiratory compromise (may occur with high cervical lesions or severe neuropathy) 3

Neurology Referral

Immediate neurology consultation is mandatory for:

• Coordination of diagnostic workup 2
• Interpretation of neuroimaging and electrodiagnostic studies 2
• Initiation of immunosuppressive therapy if inflammatory etiology confirmed 2, 3
• Coordination with neurosurgery if structural pathology identified 2

The combination of Down syndrome with new neurological deficits represents a high-risk scenario requiring urgent systematic evaluation to prevent permanent neurological injury 2, 1.