Possible malignant neuroleptic syndrome that associated with hypothyroidism

A 54-year-old woman with schizophrenia presented to hospital with unconsciousness, fever and marked muscle rigidity. She had been given fluphenazine decanoete 20 mg intramuscularly 15 days before the admission and she had continued taking haloperidol 20 mg daily and oral biperiden 2-4 mg. She was extremely rigid and unresponsive. On laboratory investigations revealed: serum sodium 120 mEq/l, creatinine phosphokinase 12,980 IU/l (normal up to 170), lactate dehydrogenase 1544 IU/l (150-500), free trioidothyronine < 1.00 pg/ml (1.5-4.5), free throxyine 0.76 ng/dl (0.8-1.9), thyroid stimulating hormone 1.14 μU/ml (0.4-4), cortisol (at 8.00 a.m.) 9 μg/dl (5-25). Antipsychotic drugs were withdrawn after admission. A diagnosis of secondary adrenal insufficiency and secondary hypothyroidism was made. Hormonal substitution with hydrocortisone and levothyroxine and correction of hyponatremia with intravenous hypertonic saline solution resulted in rapid improvement of symptoms and signs. It seems that the symptoms and signs of hypothyroidism and hyponatremia were attributed to acute psychosis in this patient. As a conclusion failure to recognize the endocrinopathy may not only produce recovery difficulties but also psychiatric and endocrine repercussions if psychotropic medications are given in such masked cases.