Subclinical Hypothyroidism With Overt Symptoms in Patient With Well-Controlled Epilepsy on Valproate Therapy: A Case...

Valproate is known to have various adverse effects including hormonal dysfunction. There is debate in literature regarding the association between valproate therapy and subclinical hypothyroidism, with some studies suggesting a potential link. However, none of the studies on our review have noted overt hypothyroid symptoms with subclinical hypothyroidism. We present a pediatric patient with generalized epilepsy on long-term valproate therapy who developed subclinical hypothyroidism with overt hypothyroid symptoms. Our patient initially presented as a 3-year-old with absence epilepsy and was well-controlled with valproate monotherapy. After more than 2 years of seizure freedom, the patient developed symptoms of hypothyroidism, leading to a diagnosis of grade 2 subclinical hypothyroidism. Symptom resolution occurred with discontinuation of valproate and with initiation of levothyroxine. Ultimately, thyroid studies normalized, and levothyroxine was also discontinued. Although subclinical hypothyroidism is a known potential side effect of valproate therapy, this case demonstrates that overt hypothyroid symptoms are rare, but possible.