PEER-REVIEW REPORTS
Posttraumatic Human Cerebral Myiasis Sergei Terterov, Alexander Taghva, Matthew MacDougall, Steven Giannotta
䡲 OBJECTIVE: Only eight cases of cerebral myiasis in humans have been reported worldwide and only one in the United States. Presented here is a case of cerebral myiasis in the setting of head trauma in suburban Los Angeles. 䡲 METHODS: The article includes chart review and description of a clinical case presentation. 䡲 RESULTS: A 42-year-old HIV-positive man was found in a ditch after 2 weeks, the victim of apparent assault. He had multiple facial fractures along with open depressed bifrontal sinus fractures with necrotic bone, eroded dura, exposed cortex, and extensive maggot infestation of the left frontal lobe. The patient was taken urgently to the operating room, where the maggots where evacuated by irrigation and suction. Debridement of necrotic bone, dura, and brain was performed, the frontal sinuses were exenterated, and skull defects plated with titanium mesh. Intraoperative cultures revealed a polymicrobial meningitis/encephalitis, which was treated postoperatively with antibiotics. The patient’s neurologic exam stabilized and the patient was transferred to a rehabilitation facility for further care, ultimately achieving functionality and holding a job. 䡲 CONCLUSION: This is the first published case of cerebral myiasis secondary to trauma, and to our knowledge, the first documented long-term survivor of extensive cerebral myiasis. Wide debridement to normal brain followed by 6 weeks of broad-spectrum antibiotic treatment is effective in managing this condition. A well-functioning outcome can be expected with prompt recognition and treatment of the disease. Larval infestation may have a protective effect against bacterial infection and may allow for greater tolerance of treatment delay.
Key words 䡲 Cerebral 䡲 Diptera 䡲 Infection 䡲 Myiasis 䡲 Parasites 䡲 Trauma Abbreviations and Acronyms CT: Computed tomography HIV: Human immunodeficiency virus From the Department of Neurosurgery, Keck School of Medicine, University of Southern California Los Angeles, California, USA To whom correspondence should be addressed: Sergei Terterov, M.D. [E-mail:
[email protected]] Citation: World Neurosurg. (2010) 73, 5:557-559. DOI: 10.1016/j.wneu.2010.01.004 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter © 2010 Elsevier Inc. All rights reserved.
INTRODUCTION Myiasis is a parasitic infection of tissues caused by the larvae of Diptera insects. In primary myiasis, the Diptera species is an obligate parasite, which completes its life cycle inside the host as follows. The female lays its eggs on the abdomens of hemophagous insects. When the carrier insect feeds, the surrounding warmth stimulates the eggs to hatch, and the first-stage larvae penetrate the skin or the puncture site left by the insect. Once inside the host, the first-stage larvae mature into end-stage larvae during the course of 7 to 15 weeks, after which they extricate from the host and pupate in the soil, giving rise to flies. In secondary myiasis, female flies are attracted to lay their eggs on the edges of open ulcers or wounds. From there, end-stage larvae penetrate the tissues and feed on necrotic flesh. Calli-
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phora, Musca, and Lucilia species are common in secondary myiasis. Myiasis is more prevalent in humid tropical and subtropical regions, which are natural habitats to many species of flies. The main reservoirs for this infection are rodents and large mammals, but cattle, horses, and pigs are the most common hosts in rural areas, perpetuating the infestation, whereas humans are accidental hosts. Poor hygiene, diabetes, and immune depression predispose to myiasis in humans (15). Cutaneous myiasis is the most common presentation, often seen in travelers from endemic areas. However, visceral involvement has been described in various organ systems (5, 7, 12). Cerebral myiasis is exceptionally rare, with fewer than 10 confirmed cases reported worldwide, and only one case reported in North America. Cerebral myiasis is almost uniformly fatal, especially if a large area of the brain is affected (1). We present a second case of intracerebral myiasis in North America, and to our knowledge, the first survivor of extensive cerebral myiasis, who ultimately had a functional outcome.
CASE REPORT History A 42-year-old HIV-positive Caucasian man was found in a ditch after having been missing for 2 weeks. The patient was brought to the emergency room with evidence of head and face trauma notable for a 5- ⫻ 10-cm forehead defect with an open depressed skull fracture, exposed cortex, and maggot infestation of the area (Figure 1).
Examination and Laboratory Findings On exam, the patient was somnolent, but oriented to name, was following simple commands, and moving all extremities equally. Notable lab values at that time included a serum sodium of 159 and a CD4 count of 400.
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ures of the medial, lateral, and anterior walls of the maxillary sinus; fracture of the pterygoid plate; fracture of the orbital floor and lateral wall, with adjacent fracture of the sphenoid bone; and a fracture of the superior alveolar ridge. These fractures represented a right sphenozygomatic complex fracture in a LeFort-I pattern.
Figure 1. Photograph demonstrating penetrating frontal skull wound with visible maggot infestation.
Imaging Computed tomography (CT) of the head at the time of admission revealed a depressed, comminuted bifrontal fracture involving the frontal sinuses with underlying bifrontal hemorrhagic contusions, left frontal lobe edema suspicious for abscess, right frontal subdural hematoma, and pneumocephalus (Figure 2). CT of the cervical spine was significant for a nondisplaced fracture of the anterior–superior portion of the C6 vertebral body. Facial CT demonstrated a comminuted fracture of the anterior and posterior tables of the left frontal sinus with comminution into the roof of the orbit. There were multiple right-sided facial fractures, including a comminuted fracture of the zygoma; fract-
Figure 2. Computed tomography (CT) axial cut image demonstrating comminuted depressed left frontal skull fracture with underlying hemorrhagic contusion and pneumocephaly.
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Operation Once the patient was medically stabilized, he was taken to the operating room for washout and repair of the wounds. The patient was put in the supine position with the head slightly flexed in a Mayfield head clamp as for a standard bicoronal craniotomy. A Betadine paintand-wash prep was applied to the face and scalp, avoiding exposed areas of brain. Gentle suction and irrigation with normal saline were used to remove maggots from the cranial wound. After all visible larvae were removed, the absence of dura over the left frontal lobe was noted, along with necrotic brain parenchyma. This was minimally debrided because of concerns about the proximity of this area to the frontal horn of the left lateral ventricle. The area was copiously irrigated and the oral maxillofacial surgeons performed a flap advancement procedure, consisting of the pericranium and part of the left temporalis muscle. This flap was mobilized and positioned over the area of denuded dura over the left frontal lobe. The LeFort fracture complex was then reduced and fixed with screws and plates. The neurosurgery team then cranialized both frontal sinuses and covered the anterior cranial defect with a flexible titanium Lorenz mesh (Figure 3).
Postoperative Course Postoperatively, the patient was maintained on broad-spectrum antibiotic coverage empirically. Intraoperative post-wash cultures revealed a polymicrobial infection. Aerobic cultures revealed Proteus penneri, Streptococcus faecalis, Acinetobacter calcoaceticus-baumannii complex, Enterococcus faecalis. Anaerobic cultures revealed Peptostreptococcus anaerobius and Prevotella/Porphyromonas species. Mycology revealed non-albicans species candida. Antibiotic coverage was converted to vancomycin, ceftazidime, metronidazole, and fluconazole following sensitivity testing and was continued for a period of 6 weeks postoperatively.
Figure 3. Postoperative computed tomography (CT) axial cut image demonstrating evidence of bone fragment extraction, debridement, and cranioplasty. Also, left frontal lobe geographic area of hypodensity consistent with edema, infection, and/or infarction.
The postoperative course was uncomplicated, significant only for placement of a gastrostomy tube because of the initial inability to pass the swallow study. Immediately postoperatively, the patient was moving all extremities and localizing well. He was extubated on Postoperative Day 3, and over the next 20 days his neurologic state gradually improved. On discharge, he was oriented to self and situation, following commands, moving all extremities, and intermittently engaging in conversations. However, he was oblivious to the events preceding his hospitalization. He was discharged to a subacute rehabilitation facility. He remained there for 3 weeks, and now the patient is living independently, able to drive a car, and maintain employment.
DISCUSSION Human cerebral myiasis is an exceedingly rare condition. The first case was described in 1939 by Froomin and Kaznelson (4). Since then, only eight confirmed cases have been described in the literature worldwide to date (1, 4, 6, 8, 11, 13, 14, 16). Two additional cases of clinically or radiologically suspected, but unconfirmed, cases of cerebral myiasis have been reported (2, 3). The age of the reported patients ranged from 5 months to 75 years. Six were male and two were female. The offending species were Hypoderma bovis in three of the cases, Phaenicia sericata in one case, Hypoderma lineatum in
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one case, Hypoderma unspecified in one case, Dermatobia hominis in one case, and undetermined in one case. The location of the infestation seems to have a predilection for the frontal lobes, as seen in six of the nine cases. All but one case had a fatal outcome, with one case having an unspecified outcome. The one surviving case was a 6-year-old child with limited disease, intraoperatively found to have a single worm abutting the head of the caudate nucleus. Most of the described cases occurred in Europe, with only one occurring in the United States. In our case, the exact species of the larvae was not identified; however, based on the geographic location, time of year, and description of the maggots, a forensic entomologist presumed it to be a blue bottle fly, Calliphora vomitoria. Our patient had some of the risk factors predisposing to larval infestation, including a depressed immune system and an open cranial wound. Nonetheless, after surgical debridement and antibiotic treatment, he had a surprisingly nonfatal and functional outcome. Another surprising aspect of this case was the absence of a rampant and fatal meningitis and encephalitis in the setting of an open skull fracture with prolonged cortical exposure. Although cultures were indicative of polymicrobial overgrowth, the patient did not have signs or symptoms of systemic infection. The latter scenario would have resulted in a rapid deterioration and death. These findings could possibly be explained by the presence of the larvae on the surface of the open wound. Beneficial effects of wound infestation with maggots have been known for many centuries and were first used medically during the American Civil War, and thereafter until the emer-
gence of antibiotics (9, 10). It is possible that while causing structural damage to our patient’s brain, the fly larvae were protecting it from bacterial invasion.
6. Gilly R, Lapras C, Mamelle JC, Challamel MJ, Ghilot JH, Nicholas A, Ravussin JJ, Spiler: Hypodermic migrant myiasis with intracerebral hematoma. Apropos of a case in a 7-year-old child [in French]. Pediatrie 31:67-75, 1976.
CONCLUSION
7. Kahn DG: Myiasis secondary to Dermatobia hominis (human botfly) presenting as a long-standing breast mass. Arch Pathol Lab Med 123:829-831, 1999.
Cerebral myiasis is an exceedingly rare neurosurgical problem, with less than 10 cases described worldwide. Wide debridement to normal brain followed by 6 weeks of broadspectrum antibiotic treatment is effective in managing this condition. A well-functioning outcome can be expected with prompt recognition and treatment of the disease. Larval infestation may have a protective effect against bacterial infection and may allow for greater tolerance of treatment delay.
8. Kalelioglu M, Akturk G, Akturk F, Komsuoglu SS, Kuzeyli K, Tigin Y, Karaer Z, Bingol R: Intracerebral myiasis from Hypoderma bovis larva in a child. Case report. J Neurosurg 71:929-931, 1989. 9. Mumcuoglu KY: Clinical applications for maggots in wound care. J Clin Dermatol 2:219-227, 2001. 10. Orkiszewski M: Maggots of Lucilia sericata in treatment of intractable wounds [in Polish]. Wiad Lek 60:381-385, 2007. 11. Pouillaude JM, Dupont J, Gilly R, Lapras C: Intracerebral myiasis in a child. Pediatr Radiol 10:121-123, 1980. 12. Rodriguez G, Raschid M: Human scrotal myiasis (bot fly): a case of self-diagnosis. J Urol 166:13971398, 2001.
REFERENCES: 1. Cheshier SH, Bababeygy SR, Higgins D, Parsonnet J, Huhn SL: Cerebral myiasis associated with angiosarcoma of the scalp: case report. Neurosurgery 61: E167, 2007. 2. De Lucas EM, Diez C, Gutierrez A, Montiaga F, Arnaiz J, Mandly AG, Sanchez E, Valle N: Unusual MRI findings in a patient with history of frontal fracture and skin infestation by fly larvae, as a possible sign of intracerebral myiasis. Clin Neurol Neurosurg 110:725-728, 2008. 3. Francois P, Martin G, Goullier A, Plasse M, Beaudoing A: Neuromeningeal hypodermiasis complicated by hydrocephaly. Value of nuclear magnetic resonance imaging [in French]. Presse Med 16:12311233, 1987. 4. Froomin LL, Kaznelson AB: Intradural cyst of parasitic origin (myiasis clinic) [in Russian]. Zh Ushn Nos Gorl Bolezn 16:427-433, 1939. 5. Garrison RD: Human tracheopulmonary myiasis. J Clin Microbiol 42:3378, 2004.
13. Rossi MA, Zucoloto S: Fatal cerebral myiasis caused by the tropical warble fly, Dermatobia hominis. Am J Trop Med Hyg 22:267-269, 1973. 14. Semenov PV: A case of penetration of Hypoderma lineatum de Villers larva into the human brain [in Russian]. Med Parazitol (Mosk) 38:612-613, 1969. 15. Tania FC, Pessato S, Ramos-e-Silva M: Tungiasis and myiasis. Clin Dermatol 25:158-164, 2007. 16. Zucoloto S, Rossi MA: Facial myiasis with spreading to the cranial vault [in Portuguese]. Rev Bras Med 28:13-16, 1971.
received 15 October 2009; accepted 14 January 2010 Citation: World Neurosurg. (2010) 73, 5:557-559. DOI: 10.1016/j.wneu.2010.01.004 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter © 2010 Elsevier Inc. All rights reserved.
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