What is the recommended treatment for pediatric patients with steroid-responsive encephalopathy associated with thyroiditis?

Steroid-Responsive Encephalopathy Associated with Thyroiditis in Pediatrics

Recommended Treatment

High-dose intravenous corticosteroids should be initiated immediately upon diagnosis, with dexamethasone 4 mg every 6 hours for one week, followed by a tapering course of oral prednisolone over 6 months. 1

Clinical Recognition and Diagnosis

SREAT is a diagnosis of exclusion requiring high clinical suspicion in pediatric patients presenting with:

• Acute encephalopathy (altered consciousness, seizures, cognitive dysfunction) 2, 1
• Elevated anti-thyroid peroxidase (Anti-TPO) antibodies as the hallmark diagnostic marker 1, 3
• Variable thyroid function (patients may be euthyroid, hypothyroid, or have subclinical thyroid dysfunction) 1
• Neuropsychiatric manifestations including behavioral changes, motor tics, myoclonus, tremors, and seizures 2, 1, 4

Diagnostic Workup

Essential investigations include:

• Anti-TPO antibody levels (markedly elevated in SREAT) 1, 3
• EEG (typically shows diffuse slowing) 1
• MRI brain (often normal, but helps exclude other pathology) 1
• CSF analysis (may show oligoclonal bands without pleocytosis) 1
• Exclusion of infectious, metabolic, and other autoimmune causes 1

Treatment Protocol

Acute Phase Management

Intravenous dexamethasone 4 mg every 6 hours for 7 days represents the evidence-based initial approach, with dramatic clinical response typically occurring within 24-48 hours (often after the second dose). 1

Maintenance and Tapering

Following the acute phase:

• Transition to oral prednisolone with a gradual taper over 6 months 1
• Monitor for relapse during steroid taper, as recurrence can occur 2, 1
• Continue thyroid function monitoring throughout treatment 1

Clinical Pitfalls and Important Considerations

Common Diagnostic Challenges

SREAT can present with isolated neuropsychiatric symptoms before overt encephalopathy develops. The condition has been reported with:

• Recurrent seizures of unknown etiology as the sole presenting feature 2
• Subtle neurocognitive decline preceding acute presentation 5
• Isolated tic disorders without other neurological signs 4
• Behavioral alterations weeks to months before acute decompensation 1

Critical Recognition Points

Do not wait for abnormal thyroid function tests to consider SREAT - patients can be completely euthyroid with normal TSH and free hormone levels while having markedly elevated anti-thyroid antibodies. 1

The diagnosis can occur even in patients with prior thyroid surgery (including partial thyroidectomy), as elevated anti-TPO antibodies can persist. 3

Brain biopsy, when performed, may show CNS vasculitis, but this is not required for diagnosis and treatment should not be delayed for biopsy. 5

Prognosis and Follow-up

Early recognition and prompt steroid therapy lead to favorable outcomes in pediatric SREAT. 1

• Rapid clinical improvement (within 24-48 hours of IV steroids) confirms the diagnosis 1
• Complete recovery is achievable with appropriate treatment duration 1
• Long-term follow-up (minimum 18 months) is necessary to monitor for relapse and ensure sustained remission 1

Response to Treatment

Therapeutic response to corticosteroids is the sine qua non for diagnosis - significant improvement in neurological symptoms with glucocorticoid administration is the defining feature that distinguishes SREAT from other encephalopathies. 3

Refractory Cases

For patients not responding adequately to corticosteroids alone or experiencing frequent relapses:

• Consider immunosuppressive agents as steroid-sparing therapy 3
• Total thyroidectomy has been reported as definitive treatment in refractory adult cases, though this is rarely necessary in pediatrics 3
• Additional immunomodulatory therapies may be required, though evidence in pediatrics is limited 3