Hypothyroid Crisis limiting neurologic recovery after Traumatic Brain Injury: A Case Report

Case Diagnosis: 62 year old male with traumatic brain injury (TBI) found to be in hypothyroid crisis

Case Description or Program Description: 62 year old male who sustained a TBI resulting in left frontal and temporoparietal subarachnoid hemorrhages and a right subdural hematoma. Following medical stabilization, his mental status declined from a minimally conscious state to an unresponsive wakefulness syndrome. Upon admission to acute rehabilitation, he was found to have an elevated thyroid stimulating hormone (TSH) level of 86.95 and a low thyroxine level of < 0.23, qualifying a hypothyroid crisis. Intravenous levothyroxine sodium and hydrocortisone were prescribed. Within 10 days, TSH improved to 12.43, thyroxine improved to 0.88, and his Coma Recovery Scale (CRS) improved from 8 to 11.

Setting: Acute Rehabilitation Hospital

Assessment/Results: Within days following the initiation of IV thyroid hormone replacement, not only did TSH improve, but also his response to environmental triggers. He began opening his eyes spontaneously and exhibiting localized withdrawal to noxious stimuli, two things not seen prior to the initiation of levothyroxine and steroids.

Discussion (relevance): Hypothyroid crisis is a life-threatening condition where thyroid hormone levels drop with a compensatory decline in the hypothalamic pituitary adrenal axis, together resulting in lethargy, cognitive impairment, and even coma. This patient's neurologic recovery appeared to have rapidly accelerated with thyroid replacement therapy. Screening for hormonal abnormalities on a regular basis is warranted in the setting of neurological decline. Guidelines focus on the use of steroids to address potential concurrent adrenal insufficiency and the use of intravenous thyroid replacement therapy as data lacks on oral therapy.

Conclusions: In severe TBI, hypothalamic pituitary axis dysregulation can manifest itself through hormonal abnormalities. In this case, the severe hypothyroidism went undiagnosed simply because the patient was unable to express typical symptoms. This treatable condition may slow neurologic recovery and worsen neurological outcomes.