Case Presentation: 67 years old lady presented with confusion, poor oral intake, subjective fevers and generalized weakness for 4 weeks. Physical examination revealed a lady oriented only to person, who was experiencing visual hallucinations and had tangential speech. She had no focal motor or sensory deficits. Initial laboratory workup was unremarkable other than a toxicology screen positive for cannabinoids. Serum and CSF workup had no evidence of an active infection. Her TSH was 2.6. Patient had multiple episodes of generalized tonic clonic (GTC) movements following which she became agitated, disoriented and aggressive. Her brain MRI was normal and there was no epileptiform activity on EEG. Given the sudden deterioration in her mental status she was started on empiric therapy for bacterial and viral meningitis, which was later held after her HSV PCR and CSF cultures came back negative. Attributing her symptoms to polypharmacy, all her medications were held. She was started on levetiracetam and discharged with only partial improvement in her mental status to follow up with Neurology. A week later she presented with worsening mental status and GTC movements. EEG showed Left lateralized epileptiform discharges. Lumbar puncture showed elevated proteins. Repeat TSH came back as 13.8 and Anti-TPO was elevated to 49. A diagnosis of Hashimoto’s encephalitis was made and she was promptly started on therapy with IV solumedrol and synthyroid.
Discussion: Hashimoto’s encephalopathy (HE) described first in 1966; is a rare disease with an estimated prevalence of 2.1/100,000 and only around 300 reported cases. The diagnosis is often missed because of nonspecific clinical presentation and laboratory findings. The mean age of onset is 40-45 years with a female to male ratio of 4:1. There are two distinct clinical presentations of HE. Vasculitic type has an acute presentation with seizures, stroke-like episodes and sudden onset neuropsychiatric symptoms. Progressive type presents with gradual decline in cognition, agitation and hallucinations. Most common symptom for HE is seizures (seen in 66% of patients), followed by psychosis and stroke-like symptoms. Initial finding on Imaging, CSF and EEG are non-specific but are useful in ruling out differentials. Anti-thyroid antibodies are frequently present but most patients are euthyroid at the time of diagnosis. CSF findings of elevated protein and pleocytosis are common. Diffuse slowing of the background is the most common EEG abnormality seen in patients with HE, followed by epileptiform activity. Pathophysiology of HE continues to be unclear. Treatment of HE is centered on immunomodulation with steroids, which results in significant improvement in a majority of patients.
Conclusions: Altered mental status and seizures can be clinical manifestations of the rare Hashimto’s Encephalopathy. It is imperative that hospitalists recognize this as initiation of steroid therapy results in a prompt clinical response.
To cite this abstract:Mushtaq U, Fiazuddin F, Mushtaq Z, Mahmood Z. When in Doubt, Check the Thyroid. Abstract published at Hospital Medicine 2016, March 6-9, San Diego, Calif. Abstract 703. Journal of Hospital Medicine. 2016; 11 (suppl 1). https://www.shmabstracts.com/abstract/when-in-doubt-check-the-thyroid/. Accessed March 30, 2020.