An unusual presentation of subdural empyema caused by Porphyromonas gingivalis
A 34-year-old male was admitted to Thammasat University Hospital, Thailand with 1 day of high fever, severe headache, photophobia, left hemiparesis, and repeated vomiting. He had had rhinorrhea, sore throat, facial pain, and low grade fever 2 weeks earlier and was treated with a short course of oral antibiotics.\nOn admission, he was alert and oriented. The patient had a temperature of 39°C, heart rate of 120 beats/min, and blood pressure of 130/90 mmHg. Neurological examination revealed nuchal rigidity and left hemiparesis grade 3 (medical research council scale). He had left facial weakness, upper motor neuron type with purulent nasal discharge, nasal turbinate swelling, and frontal sinus tenderness. His blood profile showed leukocytosis of 23,700 cells/mm3 with 95% neutrophils. His basic metabolic panel showed normal electrolytes, glucose, liver, and renal function. Computed tomography (CT) of the brain revealed crescent-shaped hypodense to isodense lesion at right frontal convexity and along right falx cerebri with 0.6 cm in maximal thickness at right frontal lobe suggestive of subdural effusion. The CT additionally revealed opacification at both frontal sinuses, both ethmoid sinuses and left maxillary sinus suggestive of sinusitis. A magnetic resonance imaging (MRI) was obtained and showed thin subdural collection over right hemispheric convexity and right interhemispheric fissure causing subfalcian brain herniation to the left for about 8 mm with bilateral frontal, ethmoid, and left maxillary sinusitis [].\nHe was diagnosed with subdural empyema and started on intravenous ceftriaxone 4 g daily divided every 12 h and metronidazole 1.5 g daily divided every 8 h and were continued for 6 weeks without dose adjustment. He received supportive care with neurosurgical consultation. On the 2nd day of admission he developed increased left hemiparesis (from grade 3 to grade 0) and his consciousness level deteriorated. Right frontoparietal craniectomy was performed. Antiepileptic drugs were started. Seizure prophylaxis was started as intravenous dilantin 300 mg daily divided every 8 h. Yellowish purulent material with a total volume of 100 ml was drained and sent for microbiological examination. No organisms were isolated in aerobic pus culture. Polymerase chain reaction (PCR) molecular identification for bacteria isolated Porphyromonas gingivalis. The 16S rRNA sequences of the genus Porphyromonas were selected from the taxonomy database of the National Center for Biotechnology Information (). The sequence of the forward primer, was 5’-GCGCTCAACGTTCAGCC-3’ (base pairs 612-628); the sequence of the reverse primer was 5’-CACGAATTCCGCCTGC-3’ (base pairs 664-679); and the sequence of the Taqman probe, was 5’-CACTGAACTCAAGCCCGGCAGTTTCAA-3’ (base pairs 634-660).[] Patient regained full consciousness 2 days after the surgery. Bilateral anterior ethmoidectomy and bilateral frontal sinectomy were also performed. On 15th day of admission, his consciousness deteriorated. MRI showed subdural empyema along bilateral falx cerebri and right parieto-temporo-occipital region. A second craniotomy was done and drainage tubes were placed at posterior midline parietal and occipital area, a total of 100 ml of yellow purulent material was drained. Patient gradually improved and was discharged after 6 weeks of the intravenous antibiotics. Dental consultations revealed no dental or root canal abscesses, no further work up for periodontal disease were carried out. At the time of discharge, his motor power was 5/5 with normal mental status. No signs of recurrent infection were detected on the follow-up 1 month after discharge [].