Hashimoto’s Encephalopathy Presenting with Seizures in an Adolescent Boy

Background: Hashimoto`s encephalopathy is a rare and relapsing neurological disorder of unknown cause associated with thyroid autoimmunity. <sup>3</sup> All patients with unexplained acute or subacute encephalopathy, or atypical psychiatric manifestations, especially patients who have autoimmune thyroid disease, Hashimoto`s encephalopathy must be included in the differential diagnosis.

Case Report: An 11 year old boy presented to the emergency room with abnormal body movements.These movements were tonic clonic type and involved bilateral upper limbs with uprolloing of eye balls.It lasted for approximately 5 minutes and child became unresponsive with loss of consciousness. Deep tendon reflexes were present , tone was hypotonic.Airway was not maintainable so child was intubated and started on ventilator support.Child was manged initially as a case of acute encephalitis and started on IV acyclovir.Child is a known case of hypothyroidism .He was taking 75 micrograms of thyroxine daily. MRI head done was normal.EEG showed mild diffuse encephalopathy.Cerebrospinal fluid analysis showed a normal cell count with raised proteins (81.4 mg/dl) .Patient was extubated on 2nd day.Child continued to have unstable gait and posture.As child was on thyroxine for hypothyroididsm,anti thyroid peroxidise antibody levels were sent.Anti TPO levels high( 600 IU/ml).At this point of time hashimoto’s encephalopathy was considered and patient started on intravenous pulse methylpredinisolone for 3 days .Child showed a remarkable improvement and his gait started stabilising.Child was discharged on oral prednisolone.On follow up child is having a normal gait and sensorium.

Conclusion: Hashimoto encephalopathy is an extremely important, though rare, diagnosis. Hashimoto encephalopathy should be suspected and screened for in patients with encephalopathy due to unknown causes because responses to treatment are typically excellent.All patients with unexplained acute or subacute encephalopathy, or atypical psychiatric manifestations, especially patients who have autoimmune thyroid disease, Hashimoto`s encephalopathy must be included in the differential diagnosis