Hashimoto’s Encephalopathy

Overview

Hashimoto’s encephalopathy—also called steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT)—is a rare, treatable autoimmune condition affecting the brain. People may have raised anti-thyroid antibodies (often anti-TPO/anti-TG) with normal or only mildly abnormal thyroid function. Symptoms can develop over days to weeks and often improve with steroid treatment once other causes are excluded.

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Common Symptoms

Symptoms can fluctuate and vary between people. You may notice:

• Confusion, “brain fog”, trouble concentrating or memory problems
• New seizures, jerks (myoclonus), tremor, or unsteady gait/ataxia
• Headache, sleep disturbance, fatigue
• Mood or behavioural change: anxiety, low mood, irritability, psychosis
• Word-finding difficulty, slowed thinking, or reduced alertness

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When to seek urgent help

Call 999 or go to A&E if you develop:

• New or rapidly worsening confusion, severe headache, or collapse
• A first seizure or repeated seizures
• Sudden weakness, speech difficulty, or vision loss

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Causes & risk factors

• Autoimmune mechanism associated with raised anti-thyroid antibodies
• May occur with normal thyroid hormone levels
• More common in women and in people with other autoimmune conditions
• Exact cause is unknown; it is a diagnosis of exclusion

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Diagnosis

Your clinician may recommend:

• Blood tests: thyroid function (TSH, free T4/T3) and anti-thyroid antibodies (anti-TPO/anti-TG); other autoimmune and inflammatory tests where indicated
• Brain MRI: often normal or non-specific
• EEG: may show diffuse slowing
• Lumbar puncture (CSF): sometimes raised protein

Diagnosis is made after ruling out infection, metabolic, structural, toxic, prion, and other autoimmune or paraneoplastic causes.

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Treatment

• First-line: high-dose corticosteroids (e.g. IV methylprednisolone then taper)
• If partial/refractory: IVIG, plasma exchange, or steroid-sparing immunotherapy (e.g. azathioprine, mycophenolate, rituximab) guided by your consultant

Many people improve significantly with timely treatment, though relapses can occur and are managed by your medical team

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Rehabilitation at The Royal Buckinghamshire Hospital

If symptoms persist after the acute phase, our neurology-led rehabilitation can help you regain function.

What we focus on

• Cognition: attention, memory, executive skills, word-finding
• Mobility & balance: gait re-training, coordination, tremor/ataxia strategies
• Fatigue & sleep: pacing, energy conservation, sleep hygiene
• Mood & adjustment: coping skills, anxiety/low mood support
• Daily activities & work/education: graded return plans and reasonable adjustments

Your team

Neurology, Neuropsychology, Physiotherapy, Occupational Therapy, Speech & Language Therapy, and Specialist Nursing.

Format

Individualised day-rehab or inpatient blocks, typically 3–5 sessions per week, with clear goals and outcome measures.

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Who we help

• Mood or anxiety changes related to encephalopathy recovery
• Ongoing cognitive or functional difficulties after suspected/confirmed SREAT
• Unsteadiness, tremor, or coordination problems limiting daily life
• Significant fatigue, sleep disturbance, or reduced exercise tolerance