- Email: [email protected]
Neglected Recurrent Scalp Sinus: Calvarial Tuberculosis with Intracranial and Extracranial Extension
Case Report
Neglected Recurrent Scalp Sinus: Calvarial Tuberculosis with Intracranial and Extracranial Extension Krishnamurthy B. Holeppagol, Biswaranjan N. Nayak, Ram Kumar K. Goyal, Arunkumar K. Kumar, Prafulla K. Sahoo, Debabrat Biswal
Key words Anaplastic meningiomas - Calvarial tuberculosis - Intracranial abscess - Sinus -
Abbreviations and Acronyms TB: Tuberculosis Department of Neurosurgery, Apollo Hospitals, Bhubaneswar, Odisha, India To whom correspondence should be addressed: Krishnamurthy B. Holeppagol, M.B.B.S., M.S. [E-mail: [email protected]] Citation: World Neurosurg. (2016). http://dx.doi.org/10.1016/j.wneu.2016.11.065 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
- BACKGROUND:
Calvarial tuberculosis (TB) with intracranial tuberculoma and skin involvement is rare condition even in endemic regions.
- CASE
PRESENTATION: A 43-year-old man presented with a generalized seizure, altered mental state, scalp swelling, and pus-discharging sinus over the scalp. Magnetic resonance imaging of the brain indicated a conflicting diagnosis of anaplastic meningiomas and chronic osteomyelitis with intracranial extension. Débridement and drainage of intracranial pus was performed. Histopathologic examination revealed TB. After surgery, the patient’s general condition improved, and he was started on antitubercular drugs.
- CONCLUSIONS:
Calvarial TB manifests with various clinical features, and strong clinical suspicion is needed to diagnose and treat it. Only a few cases of calvarial TB with either skin involvement or intracranial extension have been reported in the literature. The present case was challenging to diagnose with a rare presentation involving both intracranial and extracranial extension.
1878-8750/$ - see front matter ª 2016 Elsevier Inc. All rights reserved.
INTRODUCTION Tuberculosis (TB) of the bone most commonly occurs through the hematogenous route but can also through adjacent structures and lymphatics. TB of the bone most commonly involves metaphyses of long bones, cancellous bones, or articular cartilages and less commonly affects flat bones such as ribs, scapula, pubis, and calvaria. Calvarial TB constitutes approximately 0.2%e1.3% of all types of skeletal TB.1 The reasons for delayed presentation of such grossly visible and apparent lesions could be attributed to a painless initial presentation, low clinical suspicion, and absence of classic symptoms. We report a case of calvarial TB with both intracranial and extracranial extension.
CASE PRESENTATION History and Examination A 43-year-old man was admitted to the neurosurgery ward with complaints of sudden onset of irregular and jerky movements of the body with loss of consciousness for 2e3 minutes for the past 7 months, intermittent frontal headache for 7 months,
and history of swelling over the left side of the frontal region for 5 months. He reported an altered sensorium and loss of interest in surroundings for the past 15 days. The patient reported a history of recurrent swelling in the same region for 5 years, for which he underwent multiple incision and drainage procedures at various institutions. He also underwent noncontrast computed tomography of the brain, the results of which were normal. He is diabetic and takes regular oral hypoglycemic medications. He reported no history of fever, chronic cough, night sweats, bodily weakness, nausea, or vomiting. On physical examination, the patient’s vital signs were stable. Central nervous system examination showed the patient to be apathetic with a Glasgow Coma Scale score of 9 (eye response, 2; verbal response, 2; motor response, 5). Pupils on both sides were briskly reactive to light diameter of 3 mm. Cranial nerve examination was normal. Examination of the motor and sensory system was normal. There was no evidence of meningism. Bowel and bladder function was normal. Examinations of the respiratory, cardiovascular, and gastrointestinal systems all
WORLD NEUROSURGERY -: ---, MONTH 2016
were normal. On local examination, an inflammatory swelling of 3 3 2 cm with pus discharge at the upper border was noted over the left side of the frontal region, 8 cm above the left eyebrow. A sinus of 0.5 0.5 cm was noted higher above the swelling reaching to the frontal bone. The skin surrounding the sinus was fibrotic and adhered to underlying bone. Blood Tests and Imaging Routine blood tests were normal. Magnetic resonance imaging of the brain with 10 mL of the intravenous contrast agent gadoterate meglumine was suggestive of a malignant lesion (anaplastic meningioma) over the left frontal region, chronic osteomyelitis with intracranial extension, and a left frontal lobe abscess (Figure 1). Surgery We planned for cranial exploration. The patient underwent a left frontal craniectomy and débridement through a bicoronal incision. A 2 2 mm sinus over the left frontal bone 5 cm anterior to the coronal suture and 4 cm lateral to midline was noted. Other intraoperative findings included thick white-colored epidural pus, epidural
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CASE REPORT KRISHNAMURTHY B. HOLEPPAGOL ET AL.
NEGLECTED RECURRENT SCALP SINUS
Figure 1. (A) Irregular enhancing extra-axial plaque-like lesion noted in the left frontal region, overlying calvarial sclerosis. (B) Hyperostosis noted with diffuse periosteal reaction. (C) Lesion is
granulations, thickened underlying dura mater, pus between 2 tables of frontal bone, a pus pocket within the left middle frontal lobe along falx, and edema of surrounding brain (Figure 2). After thorough washing with warm normal saline, the involved brain, dura mater, and calvaria were débrided. Duroplasty was not done. Scalp closed in two layers without drain. Microbiology and Histopathology Microbiologic examination of pus was negative for bacteria, fungi, and acid-fast bacilli. Polymerase chain reaction for TB from dura mater was negative. Histopathology showed granuloma with large necrotic areas being infiltrated by acute
and chronic inflammatory cells in addition to lymphocytes and plasma cells, epithelioid cells, and Langerhans giant cells suggestive of tuberculous granuloma with abscess formation (Figure 3).
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patient was shown to have recovered well, and the wound was healthy. Sutures were removed after 10 days.
DISCUSSION Postoperative Period The postoperative period was uneventful. The patient’s Glasgow Coma Scale score improved to 15. He became ambulatory and was discharged on the third postoperative day and antitubercular regime of 2 months intensive course of 4 drugs started: INH of 10 mg/kg body weight, RIFAMPICIN of 15 mg/kg body weight, pyrazinamide of 35 mg/ kg body weight, ethambutol of 20 mg/kg body weight. At 1-week follow-up, the
Figure 2. (A and B) Frontal craniectomy specimen showing sinus on outer table and multiple granulations with abscess on inner
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crossing midline up to the falx and right side of the frontal dura mater.
In developing countries, TB still poses a major health problem. Skeletal TB accounts for 1% of tuberculous infection, but only 0.2%e1.3% of these cases are estimated to be calvarial TB.1,2 Extrapulmonary TB in patients with human immunodeficiency virus infection is 70% compared with 15% in patients without human immunodeficiency virus infection.3 In 1842, Reid from Germany reported the first case of calvarial TB. Tubercular
table. (C) Thickened dura mater with tubercular granuloma.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2016.11.065
CASE REPORT KRISHNAMURTHY B. HOLEPPAGOL ET AL.
NEGLECTED RECURRENT SCALP SINUS
CONCLUSIONS
Figure 3. (A) Low-power image showing central caseous necrosis. (B) High-power image showing Langerhans giant cells. (Hematoxylin-eosin staining.)
Calvarial TB is rare even in endemic areas, and having both intracranial and extracranial extension is still rarer. Our patient presented initially with recurrent scalp sinus and later progressed to generalized seizures. Calvarial TB with involvement of adjacent structures was seen in our patient mimicking anaplastic meningioma. Strong clinical suspicion is needed in patients especially from endemic areas. Surgery is the treatment of choice in such scenarios along with antitubercular drug treatment. REFERENCES
osteomyelitis occurs through the hematogenous route from a primary focus, usually the lungs with other sources being lymph nodes.4,5 Direct spread from the face, paranasal sinuses, orbit, and nasal mucosa has also been reported in the literature. Tubercular bacilli deposit in the diploic space during hematogenous spread. Proliferation of bacteria with granulation tissue and abscess formation and subsequent destruction of the bone is seen in a highly virulent bacterium in the presence of altered host immunity. Involvement and destruction of the outer table is followed by relatively resistant inner table and dura mater.6 Trauma has also been implicated as an associative or causative factor for calvarial TB. Clinical Presentations Calvarial TB is most commonly seen in young patients with 50% of patients being <10 years old. It most commonly manifests as painless, soft, fluctuant swelling over the scalp with or without a discharging sinus. Initial presentation with seizures, neurologic deficit, or other manifestations of meningitis is uncommon. Diyora et al.7 in their report of 11 cases of calvarial TB described a clinical presentation similar to our case. Two types of lesions are generally recognized: the circumscribed perforating type and the progressive infiltrating type. The perforating type, which was seen in our patient, is more common.8 Occasionally patients may also present with focal headache. Common sites are frontal parietal bones with large cancellous diploic spaces compared with temporal and sphenoid bones.9 Dura mater generally acts as a strong barrier. There are
3 radiologic types of calvarial TB reported in the literature: 1) perforating TB of the skull involving both inner and outer tables with granulation tissue covering either side, 2) diffuse TB of the skull characterized by widespread involvement in diploë with destruction of the inner table of the skull and epidural granulations in the form of pachymeningitis externa, and 3) circumscribed sclerotic type characterized by marked thinning of bone because of lack of blood supply to diseased bone. The present case was a perforating type of calvarial TB. Management A positive Mantoux test and increased erythrocyte sedimentation rate are important diagnostic clues for TB, but these may not be present in 10% of patients. Demonstration of acid-fast bacilli on a smear by Ziehl-Neelsen staining or the isolation of mycobacteria by culture is diagnostic but rarely seen. Histopathology gives a definitive diagnosis. Treatment for calvarial TB includes surgery and antituberculous therapy. Although there are reports that favor antituberculous therapy alone, studies have indicated that combined treatment is better, as extensive areas of diseased bone may become foci of tuberculous bacilli unless surgically removed.7,10 Surgery is indicated to establish the diagnosis, to remove thick extradural granulation tissue and necrotic bone, and to relieve mass effect. Antituberculous therapy must be continued for 9 months to 1 year, and the response to drugs should be monitored by clinical examinations, erythrocyte sedimentation rate, and noncontrast computed tomography of the brain.
WORLD NEUROSURGERY -: ---, MONTH 2016
1. LeRoux PD, Griffin GE, Marsh HT, Winn HR. Tuberculosis of the skull—a rare condition: case report and review of the literature. Neurosurgery. 1990;26:851-855. 2. Agarwal N, Jain SK. Tuberculous osteitis of skull: a case report. Indian J Tuberc. 2002;49:105-106. 3. Mukherjee KK, Kaushik R, Nada R, Khosla VK, Khandelwal N. Calvarial tuberculosis. Surg Neurol. 2002;57:195-203. 4. Mohanty S, Rao CJ, Mukherjee KC. Tuberculosis of the skull. Int Surg. 1981;66:81-83. 5. Mishra SK, Nigam P. Tuberculosis of flat bones. Indian J Chest Dis Allied Sci. 1984;26:174-176. 6. Malhotra R, Dinda AK, Bhan S. Tuberculous osteitis of the skull. Indian Pediatr. 1993;30:1119-1123. 7. Diyora B, Kumar R, Modgi R, Sharma A. Calvarial tuberculosis: a report of eleven patients. Neurol India. 2009;57:607-612. 8. Tripathi AK, Gupta N, Khanna M, Ahmad R, Tripathi P. Tuberculosis presenting as osteolytic soft tissue swellings of skull in HIV positive patient: a case report. Indian J Tuberc. 2007;54: 193-195. 9. Meng CM, Wu YK. Tuberculosis of the flat bones of the vault of the skull. J Bone Joint Surg. 1942;34:341-353. 10. Nergizoglu G, Duman N, Ertürk ¸ S, Keven K, Ates K, Akar H, et al. Tuberculosis of the skull in a patient on maintenance haemodialysis. Nephrol Dial Transpl. 1999;14:2019-2021.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 13 August 2016; accepted 12 November 2016 Citation: World Neurosurg. (2016). http://dx.doi.org/10.1016/j.wneu.2016.11.065 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2016 Elsevier Inc. All rights reserved.
www.WORLDNEUROSURGERY.org
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Neglected Recurrent Scalp Sinus: Calvarial Tuberculosis with Intracranial and Extracranial Extension Krishnamurthy B. Holeppagol, Biswaranjan N. Nayak, Ram Kumar K. Goyal, Arunkumar K. Kumar, Prafulla K. Sahoo, Debabrat Biswal
Key words Anaplastic meningiomas - Calvarial tuberculosis - Intracranial abscess - Sinus -
Abbreviations and Acronyms TB: Tuberculosis Department of Neurosurgery, Apollo Hospitals, Bhubaneswar, Odisha, India To whom correspondence should be addressed: Krishnamurthy B. Holeppagol, M.B.B.S., M.S. [E-mail: [email protected]] Citation: World Neurosurg. (2016). http://dx.doi.org/10.1016/j.wneu.2016.11.065 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
- BACKGROUND:
Calvarial tuberculosis (TB) with intracranial tuberculoma and skin involvement is rare condition even in endemic regions.
- CASE
PRESENTATION: A 43-year-old man presented with a generalized seizure, altered mental state, scalp swelling, and pus-discharging sinus over the scalp. Magnetic resonance imaging of the brain indicated a conflicting diagnosis of anaplastic meningiomas and chronic osteomyelitis with intracranial extension. Débridement and drainage of intracranial pus was performed. Histopathologic examination revealed TB. After surgery, the patient’s general condition improved, and he was started on antitubercular drugs.
- CONCLUSIONS:
Calvarial TB manifests with various clinical features, and strong clinical suspicion is needed to diagnose and treat it. Only a few cases of calvarial TB with either skin involvement or intracranial extension have been reported in the literature. The present case was challenging to diagnose with a rare presentation involving both intracranial and extracranial extension.
1878-8750/$ - see front matter ª 2016 Elsevier Inc. All rights reserved.
INTRODUCTION Tuberculosis (TB) of the bone most commonly occurs through the hematogenous route but can also through adjacent structures and lymphatics. TB of the bone most commonly involves metaphyses of long bones, cancellous bones, or articular cartilages and less commonly affects flat bones such as ribs, scapula, pubis, and calvaria. Calvarial TB constitutes approximately 0.2%e1.3% of all types of skeletal TB.1 The reasons for delayed presentation of such grossly visible and apparent lesions could be attributed to a painless initial presentation, low clinical suspicion, and absence of classic symptoms. We report a case of calvarial TB with both intracranial and extracranial extension.
CASE PRESENTATION History and Examination A 43-year-old man was admitted to the neurosurgery ward with complaints of sudden onset of irregular and jerky movements of the body with loss of consciousness for 2e3 minutes for the past 7 months, intermittent frontal headache for 7 months,
and history of swelling over the left side of the frontal region for 5 months. He reported an altered sensorium and loss of interest in surroundings for the past 15 days. The patient reported a history of recurrent swelling in the same region for 5 years, for which he underwent multiple incision and drainage procedures at various institutions. He also underwent noncontrast computed tomography of the brain, the results of which were normal. He is diabetic and takes regular oral hypoglycemic medications. He reported no history of fever, chronic cough, night sweats, bodily weakness, nausea, or vomiting. On physical examination, the patient’s vital signs were stable. Central nervous system examination showed the patient to be apathetic with a Glasgow Coma Scale score of 9 (eye response, 2; verbal response, 2; motor response, 5). Pupils on both sides were briskly reactive to light diameter of 3 mm. Cranial nerve examination was normal. Examination of the motor and sensory system was normal. There was no evidence of meningism. Bowel and bladder function was normal. Examinations of the respiratory, cardiovascular, and gastrointestinal systems all
WORLD NEUROSURGERY -: ---, MONTH 2016
were normal. On local examination, an inflammatory swelling of 3 3 2 cm with pus discharge at the upper border was noted over the left side of the frontal region, 8 cm above the left eyebrow. A sinus of 0.5 0.5 cm was noted higher above the swelling reaching to the frontal bone. The skin surrounding the sinus was fibrotic and adhered to underlying bone. Blood Tests and Imaging Routine blood tests were normal. Magnetic resonance imaging of the brain with 10 mL of the intravenous contrast agent gadoterate meglumine was suggestive of a malignant lesion (anaplastic meningioma) over the left frontal region, chronic osteomyelitis with intracranial extension, and a left frontal lobe abscess (Figure 1). Surgery We planned for cranial exploration. The patient underwent a left frontal craniectomy and débridement through a bicoronal incision. A 2 2 mm sinus over the left frontal bone 5 cm anterior to the coronal suture and 4 cm lateral to midline was noted. Other intraoperative findings included thick white-colored epidural pus, epidural
www.WORLDNEUROSURGERY.org
1.E1
CASE REPORT KRISHNAMURTHY B. HOLEPPAGOL ET AL.
NEGLECTED RECURRENT SCALP SINUS
Figure 1. (A) Irregular enhancing extra-axial plaque-like lesion noted in the left frontal region, overlying calvarial sclerosis. (B) Hyperostosis noted with diffuse periosteal reaction. (C) Lesion is
granulations, thickened underlying dura mater, pus between 2 tables of frontal bone, a pus pocket within the left middle frontal lobe along falx, and edema of surrounding brain (Figure 2). After thorough washing with warm normal saline, the involved brain, dura mater, and calvaria were débrided. Duroplasty was not done. Scalp closed in two layers without drain. Microbiology and Histopathology Microbiologic examination of pus was negative for bacteria, fungi, and acid-fast bacilli. Polymerase chain reaction for TB from dura mater was negative. Histopathology showed granuloma with large necrotic areas being infiltrated by acute
and chronic inflammatory cells in addition to lymphocytes and plasma cells, epithelioid cells, and Langerhans giant cells suggestive of tuberculous granuloma with abscess formation (Figure 3).
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patient was shown to have recovered well, and the wound was healthy. Sutures were removed after 10 days.
DISCUSSION Postoperative Period The postoperative period was uneventful. The patient’s Glasgow Coma Scale score improved to 15. He became ambulatory and was discharged on the third postoperative day and antitubercular regime of 2 months intensive course of 4 drugs started: INH of 10 mg/kg body weight, RIFAMPICIN of 15 mg/kg body weight, pyrazinamide of 35 mg/ kg body weight, ethambutol of 20 mg/kg body weight. At 1-week follow-up, the
Figure 2. (A and B) Frontal craniectomy specimen showing sinus on outer table and multiple granulations with abscess on inner
1.E2
crossing midline up to the falx and right side of the frontal dura mater.
In developing countries, TB still poses a major health problem. Skeletal TB accounts for 1% of tuberculous infection, but only 0.2%e1.3% of these cases are estimated to be calvarial TB.1,2 Extrapulmonary TB in patients with human immunodeficiency virus infection is 70% compared with 15% in patients without human immunodeficiency virus infection.3 In 1842, Reid from Germany reported the first case of calvarial TB. Tubercular
table. (C) Thickened dura mater with tubercular granuloma.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2016.11.065
CASE REPORT KRISHNAMURTHY B. HOLEPPAGOL ET AL.
NEGLECTED RECURRENT SCALP SINUS
CONCLUSIONS
Figure 3. (A) Low-power image showing central caseous necrosis. (B) High-power image showing Langerhans giant cells. (Hematoxylin-eosin staining.)
Calvarial TB is rare even in endemic areas, and having both intracranial and extracranial extension is still rarer. Our patient presented initially with recurrent scalp sinus and later progressed to generalized seizures. Calvarial TB with involvement of adjacent structures was seen in our patient mimicking anaplastic meningioma. Strong clinical suspicion is needed in patients especially from endemic areas. Surgery is the treatment of choice in such scenarios along with antitubercular drug treatment. REFERENCES
osteomyelitis occurs through the hematogenous route from a primary focus, usually the lungs with other sources being lymph nodes.4,5 Direct spread from the face, paranasal sinuses, orbit, and nasal mucosa has also been reported in the literature. Tubercular bacilli deposit in the diploic space during hematogenous spread. Proliferation of bacteria with granulation tissue and abscess formation and subsequent destruction of the bone is seen in a highly virulent bacterium in the presence of altered host immunity. Involvement and destruction of the outer table is followed by relatively resistant inner table and dura mater.6 Trauma has also been implicated as an associative or causative factor for calvarial TB. Clinical Presentations Calvarial TB is most commonly seen in young patients with 50% of patients being <10 years old. It most commonly manifests as painless, soft, fluctuant swelling over the scalp with or without a discharging sinus. Initial presentation with seizures, neurologic deficit, or other manifestations of meningitis is uncommon. Diyora et al.7 in their report of 11 cases of calvarial TB described a clinical presentation similar to our case. Two types of lesions are generally recognized: the circumscribed perforating type and the progressive infiltrating type. The perforating type, which was seen in our patient, is more common.8 Occasionally patients may also present with focal headache. Common sites are frontal parietal bones with large cancellous diploic spaces compared with temporal and sphenoid bones.9 Dura mater generally acts as a strong barrier. There are
3 radiologic types of calvarial TB reported in the literature: 1) perforating TB of the skull involving both inner and outer tables with granulation tissue covering either side, 2) diffuse TB of the skull characterized by widespread involvement in diploë with destruction of the inner table of the skull and epidural granulations in the form of pachymeningitis externa, and 3) circumscribed sclerotic type characterized by marked thinning of bone because of lack of blood supply to diseased bone. The present case was a perforating type of calvarial TB. Management A positive Mantoux test and increased erythrocyte sedimentation rate are important diagnostic clues for TB, but these may not be present in 10% of patients. Demonstration of acid-fast bacilli on a smear by Ziehl-Neelsen staining or the isolation of mycobacteria by culture is diagnostic but rarely seen. Histopathology gives a definitive diagnosis. Treatment for calvarial TB includes surgery and antituberculous therapy. Although there are reports that favor antituberculous therapy alone, studies have indicated that combined treatment is better, as extensive areas of diseased bone may become foci of tuberculous bacilli unless surgically removed.7,10 Surgery is indicated to establish the diagnosis, to remove thick extradural granulation tissue and necrotic bone, and to relieve mass effect. Antituberculous therapy must be continued for 9 months to 1 year, and the response to drugs should be monitored by clinical examinations, erythrocyte sedimentation rate, and noncontrast computed tomography of the brain.
WORLD NEUROSURGERY -: ---, MONTH 2016
1. LeRoux PD, Griffin GE, Marsh HT, Winn HR. Tuberculosis of the skull—a rare condition: case report and review of the literature. Neurosurgery. 1990;26:851-855. 2. Agarwal N, Jain SK. Tuberculous osteitis of skull: a case report. Indian J Tuberc. 2002;49:105-106. 3. Mukherjee KK, Kaushik R, Nada R, Khosla VK, Khandelwal N. Calvarial tuberculosis. Surg Neurol. 2002;57:195-203. 4. Mohanty S, Rao CJ, Mukherjee KC. Tuberculosis of the skull. Int Surg. 1981;66:81-83. 5. Mishra SK, Nigam P. Tuberculosis of flat bones. Indian J Chest Dis Allied Sci. 1984;26:174-176. 6. Malhotra R, Dinda AK, Bhan S. Tuberculous osteitis of the skull. Indian Pediatr. 1993;30:1119-1123. 7. Diyora B, Kumar R, Modgi R, Sharma A. Calvarial tuberculosis: a report of eleven patients. Neurol India. 2009;57:607-612. 8. Tripathi AK, Gupta N, Khanna M, Ahmad R, Tripathi P. Tuberculosis presenting as osteolytic soft tissue swellings of skull in HIV positive patient: a case report. Indian J Tuberc. 2007;54: 193-195. 9. Meng CM, Wu YK. Tuberculosis of the flat bones of the vault of the skull. J Bone Joint Surg. 1942;34:341-353. 10. Nergizoglu G, Duman N, Ertürk ¸ S, Keven K, Ates K, Akar H, et al. Tuberculosis of the skull in a patient on maintenance haemodialysis. Nephrol Dial Transpl. 1999;14:2019-2021.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 13 August 2016; accepted 12 November 2016 Citation: World Neurosurg. (2016). http://dx.doi.org/10.1016/j.wneu.2016.11.065 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2016 Elsevier Inc. All rights reserved.
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