0363-X215 :X I IO-0267SO2 00 0
COMPUTERIZED
TOMOGRAPHY
OF FRONTAL
SINUS
PNEUMATOCELE ALI SHIRKHODA Imaging
Division,
(Receioed
Department Chapel
and EDWARD
V. STAAB
of Radiology, University Hill, NC 27514, U.S.A.
2 Ma!: 1978; receit,edfbr
publication
of North
13 June
Carolina.
197X)
Abstract-The radiographic feature and computerized tomography (CT) findings in a case of frontal sinus osteoma associated with pneumatocele are described along with the clinical history and surgical findings. CT gives useful information regarding the extent of air dissection and its relation with the ventricular ,ystem. Computerized
tomography.
cranial
Meninges
CASE
cysts
Pneumatocele
REPORT
A 44 year old white male struck his head on a cabinet six weeks prior to admission. Five weeks before admission, some personality changes were observed by his wife. Previously he was very loquacious but recently he became disinterested in his family and had very little to say. Four weeks ago he began to have severe headaches and two weeks later he had speech difficulty. On physical examination, the patient was shown to be disoriented as to the time or place, and having difficulty in speech. He also complained of severe headaches. The pupils were equal, reacting to light, and there was no evidence of popilledema or visual field deficit. The reflexes were relatively equal bilaterally and there was no evidence of sensory deficit. The remainder of the examination was unremarkable. The laboratory data, including CBC, urinalysis, VDRL, SMAC-20, EKG, and chest X-ray, were all reported as normal. Skull radiograph (Fig. 1) shows a large air filled cystic structure in the left anterior hemisphere occupying almost the entire left frontal region. Computerized tomography clearly demonstrates that the lesion is filled with gaseous substance and is connected to the left frontal sinus (Fig. 2A). The posterior and superior extension of this pneumatocele can be evaluated by CT. There is no communication with the ventricles and absence of significant shift of the midline structures is probably due to chronicity of the disease (Fig. 2B). On the skull radiograph, immediately inferior to this air bubble, there is a sharply demarcated dense bony outgrowth within the left frontal sinus characteristic for an osteoma. On CT, one can demonstrate the neck of this osteoma and appreciate the rising point of this bony tumor. Four days following discovery of this pneumatocele. a left frontal craniotomy was performed and the cystic area was capped and collapsed. The osteoma was excised and a dural graft with temporal facia was placed where it had arisen from the posterior wall of the left frontal sinus. After surgery there was rapid improvement. Follow-up skull radiograph was essentially normal.
DISCUSSION Since 1844 when Chiari first described the cranial aerocele, there have been several articles regarding the causes, complications, and management of the problem. Markham, in 1967, made a followup investigation and listed the various causes of pneumatocele. He described trauma to be the most common cause followed by neoplasm, infection, surgical intervention and idiopathic. The recognition of the presence of gas within the cranial vault may be of great clinical significance. latrogenic causes such as diagnostic procedures should be excluded. Osteoma of the paranasal sinuses are not common; however. if present, about 80”; of them are in the frontal sinuses. They can erode through the dura and cause communication between the air filled sinuses and dura or arachnoid spaces. 267
Fig. 1. Frontal view of skull radiograph showing a large air tilled cystic slructurc tn the left side. Inferior to this air bubble. there is a sharply demarcated dense bony outgrowth rn the left frontal sinus (osteoma).
Fig. 2(A). CT clearly demonstrates the air filled lesion to be connected to the left frontal sinus. Also the neck of the osteoma is well delineated. (B) Superior and posterior extension of the pneumatocele IS seen on the htgher cut. There is no ventricular connection.
Computerized
tomography
of frontal
sinus pneumatocele
‘69
Computerized tomography is useful in evaluation of pneumatocele regardless of its etiology. The extent and location of the air collection, plus the possible bony lesion, may be demonstrated by conventional radiography and tomography; however, these findings can be strikingly confirmed and more precisely localized by CT scan. Also the possibility of ventricular connection of aerocele can be better evaluated by CT. The discovery of an intracranial gas shadow during routine radiographic examination of the skull presents a condition that requires a thorough investigation and urgent treatment. Most commonly the gas shadow is due to air which has entered the cranial cavity through a fracture with dural laceration. Any communication between the subarachnoid space and the air sinuses is potentially lethal. Our patient did have a history of trauma six weeks prior to evaluation. It is possible that the patient’s bony tumor has caused adherence to the dura and subsequent tear took place at the time of the minor trauma. The anatomy of this region is favorable to the production of an intracerebral pneumatocele. The dura is applied so closely to the frontal bone that an erosion of the bone results in defect in the dura and subsequently dissection of air. The close apposition of the tip of the frontal lobe to the dura makes it more vulnerable.
REFERENCES I. M. R. Sage and V. L. McAllister, Spontaneous intracranial “aerocoele” with chromophobe adenoma. Br. J. Rtrtliol. 47, 727-729, October (1974). neurological complications of frontal and ethmoidal esteomas. Br. J. Sury. 58, 607-613. 2. J. R. Bartlett. Intracranial August (1971). 3. R. D’Addario, J. Greenberg, T. J. E. O’Neil and P. Spagna, Pneumocephalus: an unusual cause. J. Neural. Nuurosur~q. Psych&. 37, 27 l-274, (1974). 4. L. H. Pitts, C. B. Wilson, H. H. Dedo and R. Weyand, Pneumocephalus following ventriculoperitoneal shunt, .J. Nrurmy. 43, 631-633, November (1975). .5 T. BanerJee, J. N. Meagher and C. Donley, Osteoid osteoma of the ethmoid and pneumocephalus. S. Mr~tl. J. 68, 90-93. January (1975). 6. J. L. Pool, J. N. Potanos and E. G. Krueger, Osteomas and mucoceles of the paranasal sinuses. J. Nrurosurq. 19, 130 135 (1962). 7. C. D. Soucek. Pneumocephalus with osteoma, J. Krrnsus Med. SM. 75, 123.-124 (1974). x. L. H. Pell and D. Carroll, Pneumocephalus in association with fronto-ethmoidal osteoma. C/in. Rntliol. 14, I IO I12 C1963). 9. B. Azar-Kia. M. Sarwar, S. Batnitzky and M. M. Schechter, Radiology of intracranial gas. Am. J. Rtrcliol. 124, 315-323, June (1975). The clinical features of pneumocephalus based upon a surtey of 284 cases with report of I I additional 10. J. W. Markham, 16, l-78 (1967). cases, Acra Neurochirurgica Rndioloq~ 122, 727-728, March (1977). I I. J. T. Madeira and G. W. Summers, Epidural mastoid pneumatocele, SHIRKHODA was born in Yazd, Iran on 7 June, 1945. He attended Isfahan University About the Author-AL1 Medical School from 1963 to 1970 and received his M.D. in July 1970. Following two years of military service and one year of private practice, he started his Internship at Kingsbrook Jewish Medical Center in Brooklyn, New York in July 1973. Dr. Shirkhoda was a resident in Radiology from 1974 to 1977 at the George Washington University in Washington, D.C. Later he got an appointment as a fellow and then as an instructor at the University of North Carolina at Chapel Hill where he is serving presently. He is Board Certified in diagnostic radiology (1977).
About the Author-EDWARD V. STAAB received his B.S., M.D.. and MS. degrees from the University of Minnesota. He is Board Certified in radiology (1966) and nuclear medicine (1972). After spending two years in the Army at Walter Reed’s Medical Unit in Frederick, Maryland, he was on the staff at Vanderbilt University from 1968 through 1973. In 1973 he went to the University of North Carolina to head the Imaging Division which includes ultrasound, computed tomography and nuclear medicine.
COMPUTERIZED
TOMOGRAPHY
OF FRONTAL
SINUS
PNEUMATOCELE ALI SHIRKHODA Imaging
Division,
(Receioed
Department Chapel
and EDWARD
V. STAAB
of Radiology, University Hill, NC 27514, U.S.A.
2 Ma!: 1978; receit,edfbr
publication
of North
13 June
Carolina.
197X)
Abstract-The radiographic feature and computerized tomography (CT) findings in a case of frontal sinus osteoma associated with pneumatocele are described along with the clinical history and surgical findings. CT gives useful information regarding the extent of air dissection and its relation with the ventricular ,ystem. Computerized
tomography.
cranial
Meninges
CASE
cysts
Pneumatocele
REPORT
A 44 year old white male struck his head on a cabinet six weeks prior to admission. Five weeks before admission, some personality changes were observed by his wife. Previously he was very loquacious but recently he became disinterested in his family and had very little to say. Four weeks ago he began to have severe headaches and two weeks later he had speech difficulty. On physical examination, the patient was shown to be disoriented as to the time or place, and having difficulty in speech. He also complained of severe headaches. The pupils were equal, reacting to light, and there was no evidence of popilledema or visual field deficit. The reflexes were relatively equal bilaterally and there was no evidence of sensory deficit. The remainder of the examination was unremarkable. The laboratory data, including CBC, urinalysis, VDRL, SMAC-20, EKG, and chest X-ray, were all reported as normal. Skull radiograph (Fig. 1) shows a large air filled cystic structure in the left anterior hemisphere occupying almost the entire left frontal region. Computerized tomography clearly demonstrates that the lesion is filled with gaseous substance and is connected to the left frontal sinus (Fig. 2A). The posterior and superior extension of this pneumatocele can be evaluated by CT. There is no communication with the ventricles and absence of significant shift of the midline structures is probably due to chronicity of the disease (Fig. 2B). On the skull radiograph, immediately inferior to this air bubble, there is a sharply demarcated dense bony outgrowth within the left frontal sinus characteristic for an osteoma. On CT, one can demonstrate the neck of this osteoma and appreciate the rising point of this bony tumor. Four days following discovery of this pneumatocele. a left frontal craniotomy was performed and the cystic area was capped and collapsed. The osteoma was excised and a dural graft with temporal facia was placed where it had arisen from the posterior wall of the left frontal sinus. After surgery there was rapid improvement. Follow-up skull radiograph was essentially normal.
DISCUSSION Since 1844 when Chiari first described the cranial aerocele, there have been several articles regarding the causes, complications, and management of the problem. Markham, in 1967, made a followup investigation and listed the various causes of pneumatocele. He described trauma to be the most common cause followed by neoplasm, infection, surgical intervention and idiopathic. The recognition of the presence of gas within the cranial vault may be of great clinical significance. latrogenic causes such as diagnostic procedures should be excluded. Osteoma of the paranasal sinuses are not common; however. if present, about 80”; of them are in the frontal sinuses. They can erode through the dura and cause communication between the air filled sinuses and dura or arachnoid spaces. 267
Fig. 1. Frontal view of skull radiograph showing a large air tilled cystic slructurc tn the left side. Inferior to this air bubble. there is a sharply demarcated dense bony outgrowth rn the left frontal sinus (osteoma).
Fig. 2(A). CT clearly demonstrates the air filled lesion to be connected to the left frontal sinus. Also the neck of the osteoma is well delineated. (B) Superior and posterior extension of the pneumatocele IS seen on the htgher cut. There is no ventricular connection.
Computerized
tomography
of frontal
sinus pneumatocele
‘69
Computerized tomography is useful in evaluation of pneumatocele regardless of its etiology. The extent and location of the air collection, plus the possible bony lesion, may be demonstrated by conventional radiography and tomography; however, these findings can be strikingly confirmed and more precisely localized by CT scan. Also the possibility of ventricular connection of aerocele can be better evaluated by CT. The discovery of an intracranial gas shadow during routine radiographic examination of the skull presents a condition that requires a thorough investigation and urgent treatment. Most commonly the gas shadow is due to air which has entered the cranial cavity through a fracture with dural laceration. Any communication between the subarachnoid space and the air sinuses is potentially lethal. Our patient did have a history of trauma six weeks prior to evaluation. It is possible that the patient’s bony tumor has caused adherence to the dura and subsequent tear took place at the time of the minor trauma. The anatomy of this region is favorable to the production of an intracerebral pneumatocele. The dura is applied so closely to the frontal bone that an erosion of the bone results in defect in the dura and subsequently dissection of air. The close apposition of the tip of the frontal lobe to the dura makes it more vulnerable.
REFERENCES I. M. R. Sage and V. L. McAllister, Spontaneous intracranial “aerocoele” with chromophobe adenoma. Br. J. Rtrtliol. 47, 727-729, October (1974). neurological complications of frontal and ethmoidal esteomas. Br. J. Sury. 58, 607-613. 2. J. R. Bartlett. Intracranial August (1971). 3. R. D’Addario, J. Greenberg, T. J. E. O’Neil and P. Spagna, Pneumocephalus: an unusual cause. J. Neural. Nuurosur~q. Psych&. 37, 27 l-274, (1974). 4. L. H. Pitts, C. B. Wilson, H. H. Dedo and R. Weyand, Pneumocephalus following ventriculoperitoneal shunt, .J. Nrurmy. 43, 631-633, November (1975). .5 T. BanerJee, J. N. Meagher and C. Donley, Osteoid osteoma of the ethmoid and pneumocephalus. S. Mr~tl. J. 68, 90-93. January (1975). 6. J. L. Pool, J. N. Potanos and E. G. Krueger, Osteomas and mucoceles of the paranasal sinuses. J. Nrurosurq. 19, 130 135 (1962). 7. C. D. Soucek. Pneumocephalus with osteoma, J. Krrnsus Med. SM. 75, 123.-124 (1974). x. L. H. Pell and D. Carroll, Pneumocephalus in association with fronto-ethmoidal osteoma. C/in. Rntliol. 14, I IO I12 C1963). 9. B. Azar-Kia. M. Sarwar, S. Batnitzky and M. M. Schechter, Radiology of intracranial gas. Am. J. Rtrcliol. 124, 315-323, June (1975). The clinical features of pneumocephalus based upon a surtey of 284 cases with report of I I additional 10. J. W. Markham, 16, l-78 (1967). cases, Acra Neurochirurgica Rndioloq~ 122, 727-728, March (1977). I I. J. T. Madeira and G. W. Summers, Epidural mastoid pneumatocele, SHIRKHODA was born in Yazd, Iran on 7 June, 1945. He attended Isfahan University About the Author-AL1 Medical School from 1963 to 1970 and received his M.D. in July 1970. Following two years of military service and one year of private practice, he started his Internship at Kingsbrook Jewish Medical Center in Brooklyn, New York in July 1973. Dr. Shirkhoda was a resident in Radiology from 1974 to 1977 at the George Washington University in Washington, D.C. Later he got an appointment as a fellow and then as an instructor at the University of North Carolina at Chapel Hill where he is serving presently. He is Board Certified in diagnostic radiology (1977).
About the Author-EDWARD V. STAAB received his B.S., M.D.. and MS. degrees from the University of Minnesota. He is Board Certified in radiology (1966) and nuclear medicine (1972). After spending two years in the Army at Walter Reed’s Medical Unit in Frederick, Maryland, he was on the staff at Vanderbilt University from 1968 through 1973. In 1973 he went to the University of North Carolina to head the Imaging Division which includes ultrasound, computed tomography and nuclear medicine.
