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Subcutaneous cysticercosis
The Journal of Emergency Medicine, Vol. 16, No. 4, pp. 583–586, 1998 Copyright © 1998 Elsevier Science Inc. Printed in the USA. All rights reserved 0736-4679/98 $19.00 1 .00
PII S0736-4679(98)00039-0
Clinical Communications
SUBCUTANEOUS CYSTICERCOSIS Peter Yamashita,
MD,*
John Kelsey,
MD,*
and Sean O. Henderson,
MD†
*Department of Emergency Medicine, LAC1USC Medical Center and †Department of Emergency Medicine, University of Southern California School of Medicine, Los Angeles, California Correspondence Address: John Kelsey, MD, Department of Emergency Medicine, LAC1USC Medical Center, Unit #1, Room 1011, 1200 N. State St., Los Angeles, CA 90033
e Abstract—With the increasing numbers of immigrants coming to the United States from areas where Taeniasis and cysticercosis are endemic, it is important to be familiar with some of these more common entities. We present a patient with both neurologic and soft tissue cysticercosis as well as a review of the available literature. © 1998 Elsevier Science Inc.
extremity pain and swelling and decreased range of motion of the elbow and shoulder. The patient had been seen at an outside hospital 5 days previously for an alleged seizure. A head computed tomography (CT) scan at that time showed “worms in the brain” and the patient was loaded on phenytoin. The following day the patient began to develop the symptoms described above. Concomitantly, he noticed the development of lesions on his left hand. The patient stated that he had similar lesions on his elbows, forearms, and bilateral lower extremities that had gradually increased in size over the past 2 years. However, the lesions on his left hand were new. Review of systems was significant for right-sided temporal headaches for the past 4 days. He also had fever and chills but denied visual changes, nausea, or vomiting. His past medical history was significant for one other seizure 2 years previously for which he had never sought medical attention. Medications included phenytoin 200 mg p.o. twice daily. He had no known drug allergies. He did have a history of alcohol use, he smoked occasionally, but he denied any intravenous drug use. Clinical examination revealed a pleasant male who was in moderate distress due to left arm pain. The vital signs were blood pressure of 132/84 mm Hg, a pulse rate of 119 beats/min., a respiratory rate of 18 breaths/min. and a temperature of 37°C (98.6°F). The head, neck, lung, cardiovascular, and abdominal examinations were normal. The extremity examination was significant for swelling, erythema, and warmth of the left arm and wrist.
e Keywords—infection; human; Taenia-solium; cysticercosis
INTRODUCTION Taenia solium, the pork tapeworm, is a well known parasite of humans. Infection with the larval form, known as cysticercosis, has been documented in virtually every organ system of the body. Most reports deal mainly with the neurological manifestations of the disease as central nervous system (CNS) involvement results in the most significant pathology. We present the case of a patient with neurocysticercosis who also had involvement of the subcutaneous (s.c.) tissue. In a review of the literature, numerous case series suggest that the s.c. tissue is the most common site of involvement in cysticercosis, yet there are very few reported cases of this manifestation. CASE REPORT A 48-year-old Guatemalan male presented to the emergency department with a 4-day history of left upper
RECEIVED: 30 May 1997; FINAL ACCEPTED: 15 September 1997.
SUBMISSION RECEIVED:
5 September 1997; 583
584
P. Yamashita, J. Kelsey, and S. O. Henderson
soft tissue calcifications on X-ray and the findings of neurocysticercosis on head CT scan, it was felt that the nodules were most consistent with s.c. cysticercosis. The patient was admitted to the hospital, and his acute cellulitis was treated successfully. Doppler flow studies showed no evidence of deep venous thrombosis and the swelling and pain resolved with i.v. antibiotics. The Neurology service followed the patient and felt that the CT findings were consistent with inactive neurocysticercosis and that anti-parasitic therapy would be of no benefit. Cysticercosis titers were not performed during the admission. The patient had no further seizure activity and at a 6 month follow-up had the phenytoin tapered and stopped. DISCUSSION
Figure 1. Head CT scan. Arrows indicate cystic structures with central calcifications consistent with old neurocysticercosis.
There was tenderness to palpation over the entire extremity with decreased range of motion. The skin showed multiple firm, pale, non-tender nodules that varied in size from 1 mm to 9 mm scattered throughout the body including the hands, forearms, elbows, flank areas, lower legs, and feet. Neurologically, he was alert and fully oriented. The cranial nerves were grossly intact. Motor strength was 5/5 throughout except for the left upper extremity, which was difficult to assess due to his pain. Deep tendon reflexes were 21 and symmetrical. The Romberg test was negative and gait examination was normal. Laboratory values were unremarkable except for a C Reactive Protein (CRP) of 55.9 mg/dL (normal , 1.2 mg/dL) and a phenytoin level of 6.5 mg/ml (therapeutic range 10 –20 mg/ml). Additionally, the WBC count was 10,600 with 86% neutrophils and 0.5% eosinophils. Radiological studies included a head computed tomography (CT) scan that revealed multiple scattered cysticercal lesions of differing ages in the right frontal horn, left temporal lobe, bilateral convexities, and the right Sylvian fissure. There was no evidence of mass effect, hemorrhage, or hydrocephalus (Figure 1). Plain radiograph of the left upper extremity revealed diffuse crescent shaped calcifications within the soft tissues and no gas or bony abnormalities (Figure 2). In the presence of the diffuse
Taenia solium (T. solium) is a parasite of humans that causes two distinct diseases in man: Taeniasis, which is the infestation of the small intestine with the adult tapeworm, and cysticercosis, which is the infection of the organs and tissues with its larvae. T. solium is endemic in Mexico, Central and South America, Africa, Southeast Asia, India, Pakistan, and China (1,2). In some rural areas of central America, the prevalence of Taeniasis is up to 9.8% of the total population and autopsy data suggest that up to 3.6% of the population of Mexico has neurocysticercosis (1). Immigrants from these endemic areas account for the vast majority of cases in the US. T. solium propagates in areas where poor sanitary conditions and free range pig farming coexist (2). Man is the definitive host for T. solium and acquires the infestation from eating cured or undercooked pork meat that has been infected with the larvae (cysticerci) of T. solium. The life cycle of T. solium requires the pig as the intermediate host. The pig ingests human feces that
Figure 2. Plain radiograph with elliptiform soft tissue calcifications (arrow).
Subcutaneous Cysticercosis
contain the eggs released from the tapeworm. The eggs hatch in the porcine duodenum or jejunum after exposure to gastric juices. The released oncospheres penetrate the intestinal wall reaching the bloodstream of the pig, and are deposited throughout the body. The encystment usually occurs in striated muscles and within 10 to 11 weeks the larvae or cysticerci are infectious. Once the human ingests improperly prepared pork, digestive enzymes in the stomach destroy the outer shell, leaving behind the “head” of the parasite termed the scolex. The scolex is composed of four cup-shaped suckers and a double crown of prominent hooks (the rostellum) that is used to anchor itself to the mucosa of the small intestine (3). Once attached, the scolex begins to proliferate, becoming a mature tapeworm in 5–12 weeks. It can attain lengths of several meters by producing a proliferating chain of segments (termed proglottids) in the area just posterior to the scolex. This is a continuous process that is maintained throughout the life of the tapeworm, which can last for up to 25 years. (1) The midsection of the tapeworm contains the mature proglottids, which consist of one complete set each of male and female reproductive organs. The terminal portion or gravid segment contains the uterus that surrounds the ripe eggs. The terminal proglottids then become detached and are passed out in the stool. The eggs released from the proglottids into the soil remain viable for several weeks. Once the pigs eat the infected soil, the life cycle repeats. Neurocysticercosis occurs when the bloodstream transports the oncospheres to the central nervous system. Encystment occurs and the larvae remain viable for up to 10 years. T. solium is the most common parasitosis of the human central nervous system and is symptomatic in only 50% of these patients. The symptom complex includes seizures, focal neurologic deficits, increased intracranial pressures, obstructive hydrocephalus, and stroke. In most of Central America, neurocysticercosis accounts for up to 70% of all patients with a history of convulsions (4). The diagnosis of neurocysticercosis is based on the distinctive appearance on CT scan, namely, the presence of cystic structures with centralized calcifications (Figure 1). Although 60% of reported cases of cysticercosis involve the brain, it is believed that muscular and s.c. encystment is more common (5). Cysticerci have also been reported in the oral cavity, eye, and internal organs (6). In one case, a s.c. cyst mimicked metastatic breast carcinoma until diagnosed by excisional biopsy (7). Though the majority of s.c. infections are asymptomatic, there are reported cases of invasion of the muscle by the larvae giving rise to myositis, with accompanying fever and eosinophilia. In rare instances, there is muscular pseudohypertrophy, where initial muscle swelling is followed by muscle atrophy and fibrosis (3). Most fre-
585
quently, soft tissue cysticerci die and become calcified without giving rise to any symptoms. The definitive diagnosis of s.c. cysticercosis is made by biopsy and histologic examination of the nodule. The gross specimen is a fluid filled opaque bladder measuring 1 to 70 mm in diameter that contains a single solid, white sphere, the scolex. A wet mount viewed microscopically will reveal the four suckers and the double row of hooks. The hallmark of s.c. cysticercosis revealed by plain radiography is multiple elliptiform calcifications. Pathognomonic features are the central calcified scolex and the surrounding cyst wall. Calcification in soft tissue is estimated to occur approximately 5 years after infection. The differential diagnosis of soft tissue calcification is fairly narrow. However, the diffuse “millet seed” appearance of the calcification seen with cysticercosis is fairly pathognomonic for the disorder. The differential diagnosis of a patient presenting with calcifications in the CNS include tuberous sclerosis, scarring from TORCH infections, other infectious processes such as fungal or tuberculous infections, and neoplasms. (8) Cysticercosis is distinct in that it presents with a circular hypodense area and a central calcification, usually in a specific at-risk population. The treatment of soft tissue cysticercosis may be medical, surgical, or a combination of the two. Subcutaneous nodules, when asymptomatic, require no treatment. Surgical excision is reserved for cosmetic purposes if only a few nodules are present. Multiple lesions are best treated medically. Drugs used in this case are praziquantel or albendazole, but one must exercise caution in patients who have simultaneous neurocysticercosis due to the potentially serious side effects. These side effects include fever, cerebral edema, raised intracranial pressure, and convulsions, and are caused as the parasites die. If the decision to treat s.c. lesions is made, steroids also should be given to control any subsequent intracerebral edema (5). Following treatment, the neurocysticercosis cyst will appear on CT scan as an area of calcification (1). Concomitant taeniasis, which occurs in 25% of patients with cysticercosis, also can be treated with praziquantel or albendazole (5). With the constant influx of people to the US from areas where T. solium is endemic, the diagnosis of cysticercosis must be considered in the differential diagnosis of a growing number of disease processes. Subcutaneous cysticercosis is often overlooked as part of the medical workup. This is of little consequence as most patients are generally asymptomatic. However, these lesions can herald the presence of encystment of other vital tissues and organs. Therefore, knowledge of its characteristics on physical examination and on radiography can lead to earlier diagnosis and treatment.
586
P. Yamashita, J. Kelsey, and S. O. Henderson
REFERENCES 1. McGreery PB, Nelson GS. Larval cestode infections. In: Hunter GT, ed. Hunter’s tropical medicine. Philadelphia: WB Saunders; 1991:846 –9. 2. Garcia HH, Gilman R, Martinez M, et al. Cysticercosis as a major cause of epilepsy in Peru. Lancet. 1993;341:197–200. 3. Tantowitz HB, Wittner M. Tape worm infections. In: Hunter GT, ed. Hunter’s tropical medicine. Philadelphia: WB Saunders; 1991: 836 –9. 4. Schontz PM, Santi E, Plancarte A, et al. Community-based epidemiologic investigations of cysticercosis due to Taenia solium:
5. 6.
7. 8.
comparison of serological screening tests and clinical findings in two populations in Mexico. Clin Inf Dis. 1994;18:879 – 85. Schmidt DKT, Jordaan HF, Schneider JW. Cerebral and s.c. cysticercosis treated with albendazole. Int J Derm. 1995;34:574 –9. Garcia HH, Gilman RH, Tovar MA, et al. Factors associated with Taenia solium cysticercosis: analysis of nine hundred forty-six Peruvian neurologic patients. Am J Trop Med Hyg. 1995;52:145– 8. O’Grady TC, Robbins BA, Barrett TZ. Subcutaneous cysticercosis simulating metastatic breast carcinoma. Int J Derm. 1993;32:62– 4. Osborne AG, Tong KA. Calcifications (appendix). In: Handbook of neuroradiology: Brain and skull. St. Louis: C.V. Mosby; 1996: 656 –9.
PII S0736-4679(98)00039-0
Clinical Communications
SUBCUTANEOUS CYSTICERCOSIS Peter Yamashita,
MD,*
John Kelsey,
MD,*
and Sean O. Henderson,
MD†
*Department of Emergency Medicine, LAC1USC Medical Center and †Department of Emergency Medicine, University of Southern California School of Medicine, Los Angeles, California Correspondence Address: John Kelsey, MD, Department of Emergency Medicine, LAC1USC Medical Center, Unit #1, Room 1011, 1200 N. State St., Los Angeles, CA 90033
e Abstract—With the increasing numbers of immigrants coming to the United States from areas where Taeniasis and cysticercosis are endemic, it is important to be familiar with some of these more common entities. We present a patient with both neurologic and soft tissue cysticercosis as well as a review of the available literature. © 1998 Elsevier Science Inc.
extremity pain and swelling and decreased range of motion of the elbow and shoulder. The patient had been seen at an outside hospital 5 days previously for an alleged seizure. A head computed tomography (CT) scan at that time showed “worms in the brain” and the patient was loaded on phenytoin. The following day the patient began to develop the symptoms described above. Concomitantly, he noticed the development of lesions on his left hand. The patient stated that he had similar lesions on his elbows, forearms, and bilateral lower extremities that had gradually increased in size over the past 2 years. However, the lesions on his left hand were new. Review of systems was significant for right-sided temporal headaches for the past 4 days. He also had fever and chills but denied visual changes, nausea, or vomiting. His past medical history was significant for one other seizure 2 years previously for which he had never sought medical attention. Medications included phenytoin 200 mg p.o. twice daily. He had no known drug allergies. He did have a history of alcohol use, he smoked occasionally, but he denied any intravenous drug use. Clinical examination revealed a pleasant male who was in moderate distress due to left arm pain. The vital signs were blood pressure of 132/84 mm Hg, a pulse rate of 119 beats/min., a respiratory rate of 18 breaths/min. and a temperature of 37°C (98.6°F). The head, neck, lung, cardiovascular, and abdominal examinations were normal. The extremity examination was significant for swelling, erythema, and warmth of the left arm and wrist.
e Keywords—infection; human; Taenia-solium; cysticercosis
INTRODUCTION Taenia solium, the pork tapeworm, is a well known parasite of humans. Infection with the larval form, known as cysticercosis, has been documented in virtually every organ system of the body. Most reports deal mainly with the neurological manifestations of the disease as central nervous system (CNS) involvement results in the most significant pathology. We present the case of a patient with neurocysticercosis who also had involvement of the subcutaneous (s.c.) tissue. In a review of the literature, numerous case series suggest that the s.c. tissue is the most common site of involvement in cysticercosis, yet there are very few reported cases of this manifestation. CASE REPORT A 48-year-old Guatemalan male presented to the emergency department with a 4-day history of left upper
RECEIVED: 30 May 1997; FINAL ACCEPTED: 15 September 1997.
SUBMISSION RECEIVED:
5 September 1997; 583
584
P. Yamashita, J. Kelsey, and S. O. Henderson
soft tissue calcifications on X-ray and the findings of neurocysticercosis on head CT scan, it was felt that the nodules were most consistent with s.c. cysticercosis. The patient was admitted to the hospital, and his acute cellulitis was treated successfully. Doppler flow studies showed no evidence of deep venous thrombosis and the swelling and pain resolved with i.v. antibiotics. The Neurology service followed the patient and felt that the CT findings were consistent with inactive neurocysticercosis and that anti-parasitic therapy would be of no benefit. Cysticercosis titers were not performed during the admission. The patient had no further seizure activity and at a 6 month follow-up had the phenytoin tapered and stopped. DISCUSSION
Figure 1. Head CT scan. Arrows indicate cystic structures with central calcifications consistent with old neurocysticercosis.
There was tenderness to palpation over the entire extremity with decreased range of motion. The skin showed multiple firm, pale, non-tender nodules that varied in size from 1 mm to 9 mm scattered throughout the body including the hands, forearms, elbows, flank areas, lower legs, and feet. Neurologically, he was alert and fully oriented. The cranial nerves were grossly intact. Motor strength was 5/5 throughout except for the left upper extremity, which was difficult to assess due to his pain. Deep tendon reflexes were 21 and symmetrical. The Romberg test was negative and gait examination was normal. Laboratory values were unremarkable except for a C Reactive Protein (CRP) of 55.9 mg/dL (normal , 1.2 mg/dL) and a phenytoin level of 6.5 mg/ml (therapeutic range 10 –20 mg/ml). Additionally, the WBC count was 10,600 with 86% neutrophils and 0.5% eosinophils. Radiological studies included a head computed tomography (CT) scan that revealed multiple scattered cysticercal lesions of differing ages in the right frontal horn, left temporal lobe, bilateral convexities, and the right Sylvian fissure. There was no evidence of mass effect, hemorrhage, or hydrocephalus (Figure 1). Plain radiograph of the left upper extremity revealed diffuse crescent shaped calcifications within the soft tissues and no gas or bony abnormalities (Figure 2). In the presence of the diffuse
Taenia solium (T. solium) is a parasite of humans that causes two distinct diseases in man: Taeniasis, which is the infestation of the small intestine with the adult tapeworm, and cysticercosis, which is the infection of the organs and tissues with its larvae. T. solium is endemic in Mexico, Central and South America, Africa, Southeast Asia, India, Pakistan, and China (1,2). In some rural areas of central America, the prevalence of Taeniasis is up to 9.8% of the total population and autopsy data suggest that up to 3.6% of the population of Mexico has neurocysticercosis (1). Immigrants from these endemic areas account for the vast majority of cases in the US. T. solium propagates in areas where poor sanitary conditions and free range pig farming coexist (2). Man is the definitive host for T. solium and acquires the infestation from eating cured or undercooked pork meat that has been infected with the larvae (cysticerci) of T. solium. The life cycle of T. solium requires the pig as the intermediate host. The pig ingests human feces that
Figure 2. Plain radiograph with elliptiform soft tissue calcifications (arrow).
Subcutaneous Cysticercosis
contain the eggs released from the tapeworm. The eggs hatch in the porcine duodenum or jejunum after exposure to gastric juices. The released oncospheres penetrate the intestinal wall reaching the bloodstream of the pig, and are deposited throughout the body. The encystment usually occurs in striated muscles and within 10 to 11 weeks the larvae or cysticerci are infectious. Once the human ingests improperly prepared pork, digestive enzymes in the stomach destroy the outer shell, leaving behind the “head” of the parasite termed the scolex. The scolex is composed of four cup-shaped suckers and a double crown of prominent hooks (the rostellum) that is used to anchor itself to the mucosa of the small intestine (3). Once attached, the scolex begins to proliferate, becoming a mature tapeworm in 5–12 weeks. It can attain lengths of several meters by producing a proliferating chain of segments (termed proglottids) in the area just posterior to the scolex. This is a continuous process that is maintained throughout the life of the tapeworm, which can last for up to 25 years. (1) The midsection of the tapeworm contains the mature proglottids, which consist of one complete set each of male and female reproductive organs. The terminal portion or gravid segment contains the uterus that surrounds the ripe eggs. The terminal proglottids then become detached and are passed out in the stool. The eggs released from the proglottids into the soil remain viable for several weeks. Once the pigs eat the infected soil, the life cycle repeats. Neurocysticercosis occurs when the bloodstream transports the oncospheres to the central nervous system. Encystment occurs and the larvae remain viable for up to 10 years. T. solium is the most common parasitosis of the human central nervous system and is symptomatic in only 50% of these patients. The symptom complex includes seizures, focal neurologic deficits, increased intracranial pressures, obstructive hydrocephalus, and stroke. In most of Central America, neurocysticercosis accounts for up to 70% of all patients with a history of convulsions (4). The diagnosis of neurocysticercosis is based on the distinctive appearance on CT scan, namely, the presence of cystic structures with centralized calcifications (Figure 1). Although 60% of reported cases of cysticercosis involve the brain, it is believed that muscular and s.c. encystment is more common (5). Cysticerci have also been reported in the oral cavity, eye, and internal organs (6). In one case, a s.c. cyst mimicked metastatic breast carcinoma until diagnosed by excisional biopsy (7). Though the majority of s.c. infections are asymptomatic, there are reported cases of invasion of the muscle by the larvae giving rise to myositis, with accompanying fever and eosinophilia. In rare instances, there is muscular pseudohypertrophy, where initial muscle swelling is followed by muscle atrophy and fibrosis (3). Most fre-
585
quently, soft tissue cysticerci die and become calcified without giving rise to any symptoms. The definitive diagnosis of s.c. cysticercosis is made by biopsy and histologic examination of the nodule. The gross specimen is a fluid filled opaque bladder measuring 1 to 70 mm in diameter that contains a single solid, white sphere, the scolex. A wet mount viewed microscopically will reveal the four suckers and the double row of hooks. The hallmark of s.c. cysticercosis revealed by plain radiography is multiple elliptiform calcifications. Pathognomonic features are the central calcified scolex and the surrounding cyst wall. Calcification in soft tissue is estimated to occur approximately 5 years after infection. The differential diagnosis of soft tissue calcification is fairly narrow. However, the diffuse “millet seed” appearance of the calcification seen with cysticercosis is fairly pathognomonic for the disorder. The differential diagnosis of a patient presenting with calcifications in the CNS include tuberous sclerosis, scarring from TORCH infections, other infectious processes such as fungal or tuberculous infections, and neoplasms. (8) Cysticercosis is distinct in that it presents with a circular hypodense area and a central calcification, usually in a specific at-risk population. The treatment of soft tissue cysticercosis may be medical, surgical, or a combination of the two. Subcutaneous nodules, when asymptomatic, require no treatment. Surgical excision is reserved for cosmetic purposes if only a few nodules are present. Multiple lesions are best treated medically. Drugs used in this case are praziquantel or albendazole, but one must exercise caution in patients who have simultaneous neurocysticercosis due to the potentially serious side effects. These side effects include fever, cerebral edema, raised intracranial pressure, and convulsions, and are caused as the parasites die. If the decision to treat s.c. lesions is made, steroids also should be given to control any subsequent intracerebral edema (5). Following treatment, the neurocysticercosis cyst will appear on CT scan as an area of calcification (1). Concomitant taeniasis, which occurs in 25% of patients with cysticercosis, also can be treated with praziquantel or albendazole (5). With the constant influx of people to the US from areas where T. solium is endemic, the diagnosis of cysticercosis must be considered in the differential diagnosis of a growing number of disease processes. Subcutaneous cysticercosis is often overlooked as part of the medical workup. This is of little consequence as most patients are generally asymptomatic. However, these lesions can herald the presence of encystment of other vital tissues and organs. Therefore, knowledge of its characteristics on physical examination and on radiography can lead to earlier diagnosis and treatment.
586
P. Yamashita, J. Kelsey, and S. O. Henderson
REFERENCES 1. McGreery PB, Nelson GS. Larval cestode infections. In: Hunter GT, ed. Hunter’s tropical medicine. Philadelphia: WB Saunders; 1991:846 –9. 2. Garcia HH, Gilman R, Martinez M, et al. Cysticercosis as a major cause of epilepsy in Peru. Lancet. 1993;341:197–200. 3. Tantowitz HB, Wittner M. Tape worm infections. In: Hunter GT, ed. Hunter’s tropical medicine. Philadelphia: WB Saunders; 1991: 836 –9. 4. Schontz PM, Santi E, Plancarte A, et al. Community-based epidemiologic investigations of cysticercosis due to Taenia solium:
5. 6.
7. 8.
comparison of serological screening tests and clinical findings in two populations in Mexico. Clin Inf Dis. 1994;18:879 – 85. Schmidt DKT, Jordaan HF, Schneider JW. Cerebral and s.c. cysticercosis treated with albendazole. Int J Derm. 1995;34:574 –9. Garcia HH, Gilman RH, Tovar MA, et al. Factors associated with Taenia solium cysticercosis: analysis of nine hundred forty-six Peruvian neurologic patients. Am J Trop Med Hyg. 1995;52:145– 8. O’Grady TC, Robbins BA, Barrett TZ. Subcutaneous cysticercosis simulating metastatic breast carcinoma. Int J Derm. 1993;32:62– 4. Osborne AG, Tong KA. Calcifications (appendix). In: Handbook of neuroradiology: Brain and skull. St. Louis: C.V. Mosby; 1996: 656 –9.