A rare case of submandibular abscess complicated by stroke

A 33-year-old male presented to our institution with a left submandibular abscess secondary to dental infection. He had a three-day history of left jaw pain, lethargy, fever and decreased PO intake. He had no significant medical history. Examination findings included moderate to severe trismus and marked left submandibular swelling, and his 38th tooth was tender on palpation. His initial WCC was 18.7 with a neutrophilia and CRP was 153. Contrast CT demonstrated localized abscess in the left submandibular space. Ultrasound reported a small hypoechoic mass on the medial aspect of the left submandibular gland. He was admitted and commenced on IV ceftriaxone, metronidazole and dexamethasone. His symptoms and biochemical markers improved over the following three days and he was discharged home on oral cephalexin and metronidazole. Drainage was initially considered unnecessary due to the small size of the collection and excellent clinical response. Forty-eight hours after discharge, the patient re-presented to the same institution with right-sided weakness, confusion and sudden expressive aphasia. On examination, he was afebrile, had a BP of 159/92 and PR of 70. His GCS was 11, and he had a right upper motor neuron seventh nerve palsy and had decreased power in his right arm with hemi-sensory loss. His WCC was 14, CRP 45 and ESR 61. A noncontrast head CT scan was normal. A CT angiogram of the head and neck was performed which demonstrated a tight stenosis (greater than 90%) involving the mid-left internal carotid artery over a distance of approximately 2 to 3mm (Figure 1). A 1 cm-segment of thrombus was noted in the superior branch of the left MCA at the level of the anterior end of the Sylvian fissure and an abscess was seen involving the floor of mouth and submandibular space (Figure 2). MRI showed acute left inferior frontal cortical infarct in the distribution of the left MCA (Figure 1). It also showed further enlargement of the left submandibular space fluid collection, consistent with abscess formation with a focus of gas. The patient was taken to theatre for a left transcervical incision and drainage of abscess and removal of the left submandibular gland. The findings at operation included a large left submandibular gland, adherent to the surrounding fascia. There was a large quantity of necrotic tissue surrounding the gland with fistula extending to the gingival mucosa adjacent to the 38th tooth. The tooth was removed. Subsequent MRA of the neck performed one week postoperation demonstrated a stable stenosis of the distal left ICA at the level of C1 and, to a lesser extent, the right ICA. There was resolution of the left-sided submandibular fluid collection and the associated inflammatory change. ECHO/Holter monitor screen, thrombophilia screen and cholesterol studies were unremarkable. Two months later, the patient was admitted for an elective left carotid endarterectomy via a combined transcervical and mandibular osteotomy approach. The findings at operation were a small internal carotid artery with an obvious stenosis, with intimal hyperplasia, 1 cm away from the base of the skull. His postoperative progress was complicated by a 10th, 11th and 12th cranial nerve paresis secondary to postoperative oedema. This improved throughout his postoperative stay with some mild deficit remaining at discharge.