Critical Care Physician Charleston Area Medical Center, United States
Introduction: Periodic hypothermia is a rare congenital or acquired phenomenon due to dysfunction or injury of the preoptic area of the hypothalamus. There are few cases that mention successful pharmacologic treatment.
Description: A 36-year-old male with a history of spinal ependymoma with resection 10 years ago, achalasia, and anxiety presented with headaches and blurry vision. A brain MRI showed a 3.4 x 2.0 x 3.5 cm enhancing lesion in the region of the third ventricle, with obstructive hydrocephalus due to the mass. He was admitted to the Neuroscience ICU following a bifrontal craniotomy with resection of the third ventricular tumor and external ventricular drain placement. Pathology results were consistent with myxopapillary ependymoma. In the following days, he developed hypernatremia with a peak serum sodium of 163 mmol/L. Diabetes insipidus was ruled out due to an absence of polyuria and a peak urine osmolarity of 1,276 mOsm/kg. Nurses reported that he was soaking his bed sheets due to severe hyperhidrosis. During this time, he exhibited lethargy and adipsia with episodes of hypothermia as low as 30 degrees Celsius and bradycardia as low as 35 beats per minute. Thyroid function was tested and showed normal levels of T4 and FT3. The patient was diagnosed with acquired periodic hypothermia secondary to hypothalamic dysfunction after his tumor removal. His free water deficits were replaced intravenously and with free water via a nasogastric tube. To prevent further episodes of hypothermia and hyperhidrosis, he was ordered clomipramine 100 mg daily. His temperature, bradycardia, and sodium levels gradually improved over the next several days, and he was eventually transferred to a rehabilitation facility.
Discussion: Clomipramine, clonidine, and cyproheptadine have been reported to prevent future episodes of periodic hypothermia. Given clomipramine’s mechanism of action as a serotonin-2A and histamine receptor antagonist, it is thought that neurotransmitter dysregulation plays a role in periodic hypothermia. Since this rare phenomenon can present like other endocrinologic diagnoses following neurosurgery, recognition in the postoperative course is important for informed treatment decisions and improved patient outcomes. This case adds to the small body of literature on this topic.
