Lymphocytic Hypophysitis in a Patient With Suspected Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH).

Lymphocytic hypophysitis (LH) is a rare, autoimmune condition that presents with a range of symptoms that must garner the attention of medical practitioners. Clinically, it is characterized by symptoms of a compressive sellar mass with varying degrees of hypopituitarism due to chronic inflammatory infiltrate of the pituitary gland. It is often seen in women in their third trimester or postpartum and is associated with other autoimmune phenomena. Our case report describes a 73-year-old female with a past medical history of hypothyroidism and hypertension, who presented with continued intermittent dizziness, fatigue, and mild subjective hearing loss for the past several months. She was referred to the emergency department due to a sodium level of 119 and was initially diagnosed with syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient was treated accordingly; however, she failed to show signs of improvement. Due to her clinical presentation, imaging studies, and laboratory results, the patient was suspected to have LH, which was confirmed with the improvement of her symptoms after treatment with steroids. Because of the rare occurrence and possible atypical presentation of LH, this case illustrates the importance of maintaining a high index of clinical suspicion when diagnosing a patient with an unknown cause of hyponatremia, especially in patients with coexisting autoimmune disorders.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis (ANMDARE) in a Patient With Hashimoto's Thyroiditis.

Although encephalitis is more commonly caused by various infections, other etiologies that may rarely cause encephalitis must garner the attention of medical practitioners. In the realm of immune-mediated etiologies, anti-N-methyl-D-aspartate receptor encephalitis (ANMDARE) is the most common. It usually presents in a typical fashion with psychiatric symptoms followed by abnormal movements such as orofacial-lingual dyskinesia, tremor, dystonia, bradykinesia, ballism, or choreoathetosis occurring at or within the first month of onset, often affecting women and having a high correlation with ovarian teratomas. Our case report describes a 59-year-old Hispanic male with Hashimoto thyroiditis who presented with rapid cognitive decline. The diagnosis was confirmed with positive detection of NMDA receptor antibodies in the patient's cerebrospinal fluid following a lumbar puncture. The patient was treated with the first-line therapy of intravenous (IV) immunoglobulins and corticosteroids with temporary relief of symptoms. Due to the rare occurrence and possible atypical presentation of ANMDARE, this case illustrates the importance of maintaining a high index of clinical suspicion when diagnosing a patient with an unknown cause of cognitive dysfunction, especially when considering various differentials based on the patient's history.