Hashimoto's encephalopathy

Clinic

• Hashimoto's encephalopathy, also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT)
• It is a neurological condition characterized by encephalopathy, Hashimoto's thyroiditis and good clinical response to corticosteroids.

Encephalopathy with cognitive impairment and at least one of the following features:

1. Neuropsychiatric symptoms (e.g. hallucination, delusion or paranoia)
2. Myoclonus, generalised tonic-clonic or partial seizures
3. Focal-neurological deficits

Signs / Symptoms

• Psychosis: Personality changes, Aggression, Delusional behavior
• Concentration and memory problems
• Coma, Disorientation
• Headaches
• Myoclonus (65%)
• Ataxia (65%)
• Partial paralysis on the right side
• Seizures (60%), Status epilepticus (20%)
• Sleep abnormalities (55%)
• Transient aphasia (80%)
• Tremors (80%)

Pathogenesis

• The mechanism of pathogenesis is not known, but is thought to be an autoimmune disorder, similar to Hashimoto's thyroiditis, as its name suggests.
• Consistent with this hypothesis, autoantibodies to alpha-enolase have been found to be associated with Hashimoto's encephalopathy.

Laboratory and radiological finding

• Increased liver enzyme levels (55% cases)
• Increased TSH (55% cases)
• Increased ESR (25% cases)
• MRI abnormalities consistent with encephalopathy (26%)

• Thyroid hormone abnormalities are common (>80%)
• Anti-TPO is elevated

• Electroencephalogram studies almost always abnormal (98% of cases)