A 54-year-old male with history of cocaine and marijuana abuse presented to the emergency room (ER) with a few-hour history of dizziness and abdominal pain. He also reported a two-month history of intermittent right upper jaw pain that he was treated for presumed gingivitis with analgesics and antibiotics. In the emergency department, vital signs included blood pressure of 68/48, heart rate of 55, and oxygen saturation of 85%, all of which improved after supplemental oxygen, atropine, and intravenous fluids. Physical examination was notable for a mass pushing through the right side of the hard palate and a new right-sided trigeminal nerve palsy. Laboratory testing revealed leukocytosis (12ˆ3/uL) with unremarkable comprehensive metabolic panel, lipase, troponin, thyroid-stimulating hormone, and blood cultures. EKG showed sinus bradycardia with unrevealing echocardiography and chest imaging. Facial bones CT was concerning for osteomyelitis of right maxilla for which vancomycin and ampicillin-sulbactam were started. MRI of the brain and orbit revealed a 2.8 cm x 2.0 cm x 3.0 cm solidly enhancing mass centered in the posterior aspect of the right maxilla with retrograde extension along the right trigeminal nerve up to the surface of the midbrain (Figure 1). Transoral biopsy of the mass revealed adenocarcinoma, not otherwise specified, without evidence of nodal or distant metastasis on positron emission tomography. Patient then underwent right paletectomy, maxillectomy, and right selective neck dissection and reconstruction with right anterior left thigh flap.
Discussion:
Trigeminocardiac reflex (TCR) is a brainstem reflex that manifests as sudden onset of hemodynamic dysfunction including vagally-mediated bradycardia, hypotension, hypopnea and gastric hypermotility due to stimulation of the trigeminal nerve or any of its branches. It has been mostly described in the surgical literature as the surgeon manipulates the trigeminal nerve intraoperatively. The mechanism of the TCR starts with stimulation of any portion of the trigeminal nerve branches or the trigeminal ganglion itself (Figure 2). This stimulus then sends afferent neuronal signals to the trigeminal nerve sensory nucleus in the medulla. From here, short internuncial nerve fibers of the reticular formation connect with efferent parasympathetic neurons in the motor nucleus of the vagus nerve. Stimulation of the vagus nerve is responsible for the cardiac bradyarrhythmia, hypotension, and gastric hypermotility.
This reflex is primarily observed in the operating room when surgical tools cause mechanical stimulation of the reflex. To our knowledge, this is the first case recorded in which the trigeminocardiac reflex-induced hemodynamic derangements are responsible for the initial presentation in a patient with a sinonasal malignancy.
Conclusions:
This case emphasizes the importance of considering brainstem reflexes such as TCR in the differential diagnosis of hemodynamic derangements in the setting of recurrent sinus pathology and new-onset neurologic deficits.