Otology & Neurotology 00:00Y00 Ó 2015, Otology & Neurotology, Inc.
Imaging Case of the Month
Spontaneous Otogenic Temporal Lobe Pneumatocele Presenting With Acute Aphasia *Meaghan Noud, *Alex D. Sweeney, †Matthew L. Carlson, and *Marc L. Bennett *Department of OtolaryngologyYHead and Neck Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and ÞDepartment of OtolaryngologyYHead and Neck Surgery, The Mayo Clinic, Rochester, Minnesota, U.S.A.
Repeat CT imaging showed an interval decrease in the size of the pneumatocele.
CASE PRESENTATION A 78-year-old right-handed female patient with a medical history significant for Alzheimer dementia presented with a 6-week history of sudden-onset aphasia. At the time of her presentation, the patient had no clear otologic symptoms, denying otorrhea, otalgia, tinnitus, hearing loss, or rhinorrhea. There was no reported history of head trauma or frequent Valsalva maneuvers. Otomicroscopy revealed intact tympanic membranes bilaterally without retraction, middle ear effusion, or perforation. Tuning fork testing revealed air conduction greater than bone conduction bilaterally, and Weber testing localized in the midline. Her neurologic examination revealed confusion to time and place, as well as an expressive and receptive aphasia. The remainder of the neurologic examination was normal. A symmetric, severe sensorineural hearing loss with type A tympanograms was seen bilaterally. Contrast-enhanced magnetic resonance imaging (MRI) revealed intraparenchymal air in the left temporal lobe (Fig. 1), and computed tomography (CT) of the temporal bone revealed a clear communication with the left mastoid cavity through a tegmen defect (Fig. 2). Neurosurgical consultation was sought, and the patient and her family were counseled regarding the diagnosis and treatment options. Ultimately, a tegmen repair via a transmastoid approach was offered, with neurosurgery available should conversion to an intracranial operation be required. However, after considering the risks, benefits, alternatives, and limitations of surgery, the patient’s family elected to proceed with close clinical observation given the patient’s age, health status, and wishes. At a 6-week follow-up visit, the patient was found to have stable symptoms and physical examination.
DISCUSSION Spontaneous otogenic pneumocephalus is rare. When pneumocephalus is seen, it is primarily associated with head and facial trauma, otomastoiditis, or surgery. The first description of spontaneous pneumocephalus was in 1954 by Jelsma et al. (1), and there have been only 23 cases reported to date with just five having intraparenchymal extension (2). The clinical presentation varies depending on the size, intracranial location, and mass effect of the pneumatocele. Previous reports have found that headache is the most common presenting symptom, followed by otorrhea, meningeal signs, tinnitus, vertigo, facial paralysis, visual changes, vomiting, and fainting (2,3). Symptoms that are related to the temporal lobe, such as seizure, aphasia, and memory loss, can also be observed. In the present case, the patient’s pneumatocele was in the left temporal lobe resulting in local mass effect, explaining the patient’s sudden aphasia. Specifically, the left posterior inferior frontal gyrus, also described as Broca’s area, the posterior section of the superior temporal gyrus (Wernicke’s area), and/or other adjacent accessory language pathways were likely disrupted from compression and local cerebritis. Diagnosis is usually achieved with high-resolution CT and MRI, where intracranial air and an associated skull base defect can be identified. In the present case, the large amount of intracranial air with a connection to the tegmen mastoideum made the otogenic source clear on either modality. The occurrence of spontaneous otogenic pneumocephalus generally requires two prerequisite conditions. First, defects in the middle fossa floor and dura must be present. The pathogenesis of this finding can be variable, ranging from a congenital dehiscence to one caused by chronic intracranial hypertension or chronic inflammation. Second,
Address correspondence and reprint requests to Marc L. Bennett, M.D., Department of OtolaryngologyYHead and Neck Surgery, The Bill Wilkerson Center for Otolaryngology & Communication Sciences, 7209 Medical Center East, South Tower 1215 21st Avenue South, Nashville, TN 37232-8605, U.S.A.; E-mail: [email protected] The authors report no conflicts of interest.
1
Copyright © 2015, Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
2
M. NOUD ET AL.
FIG. 1. Multiplanar and multisequence MR imaging of the brain with contrast. A, Sagittal T1 image post-gadolinium demonstrates a 2.6 2.6 4.6 cm air and fluid collection in the left temporal lobe (white arrow) resulting in mass effect. B, Axial T2 image post-gadolinium redemonstrates the air-fluid level (white arrowhead) and reveals a 4-mm surrounding rim of bright signal intensity, which can represent mild edema or gliosis (white arrow). C, Coronal T1 image post-gadolinium depicts another view of the lesion originating from the temporal bone (white arrow).
FIG. 2. High-resolution temporal bone CT imaging. A, Coronal view shows a large collection of air in the left temporal parietal region (white arrow) that extends from the roof of the left mastoid cavity, which appears to be focally dehiscent. It measures up to 4.6 cm in craniocaudal dimension, 2.7 cm in AP dimension, and 2.8 cm in transverse dimension. B, Coronal view with tegmen defect under high magnification (white arrow). C, Axial cuts re-demonstrate the pneumatocele with an air-fluid level and communication with the mastoid roof (white arrow). There are multifocal benign-appearing lucencies (white arrowheads) throughout the occipital calvarium, representing intraosseous arachnoid granulations. Otology & Neurotology, Vol. 00, No. 00, 2015
Copyright © 2015, Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
SPONTANEOUS OTOGENIC PNEUMATOCELE a pressure difference between the temporal bone and the intracranial space is required to encourage air to enter the cranium (4). The sequential accumulation and equalization of pressure creates a ‘‘ball valve’’ mechanism that allows air to become trapped in the intracranial space. This could be caused by elevated pressure from coughing, nose blowing, sneezing, or continuous positive airway pressure therapy for treatment of obstructive sleep apnea. Once intracranial air is recognized, the preferred management is generally surgical. Treatment goals include normalizing intracranial pressure, and preventing infection and recurrence. Defects are most commonly found over the ossicles in the tegmen tympani, where identification and repair can be achieved transmastoid, via a middle fossa craniotomy or through a combined approach. A variety of autologous and synthetic materials have been described to seal fistulas (2), with or center favoring composite grafts of fascia, bone, and an artificial dural substitute. More radical
3
approaches have also been described for refractory cases (5). Postoperatively, patient education to avoid Valsalva maneuvers may help prevent recurrence.
REFERENCES 1. Jelsma F, Moore DF. Cranial aerocele. Am J Surg 1954;87:437Y51. 2. Abbati SG, Torino RR. Spontaneous intraparenchymal otogenic pneumocephalus: A case report and review of literature. Surg Neurol Int 2012;3:32. 3. Rabello FA1, Massuda ET, Oliveira JA, et al. Otogenic spontaneous pneumocephalus: Case report. In: Braz J Otorhinolaryngol 2013; 79:643. 4. Krayenbu¨hl N, Alkadhi H, Jung HH, et al. Spontaneous otogenic intracerebral pneumocephalus case report and review of the literature. Eur Arch Otorhinolaryngol 2005;262:135Y8. 5. Dowd GC, Molony TB, Voorhies RM. Spontaneous otogenic pneumocephalus: Case report and review of the literature. J Neurosurg 1998;89:1036Y9.
Otology & Neurotology, Vol. 00, No. 00, 2015
Copyright © 2015, Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
Imaging Case of the Month
Spontaneous Otogenic Temporal Lobe Pneumatocele Presenting With Acute Aphasia *Meaghan Noud, *Alex D. Sweeney, †Matthew L. Carlson, and *Marc L. Bennett *Department of OtolaryngologyYHead and Neck Surgery, Vanderbilt University Medical Center, Nashville, Tennessee; and ÞDepartment of OtolaryngologyYHead and Neck Surgery, The Mayo Clinic, Rochester, Minnesota, U.S.A.
Repeat CT imaging showed an interval decrease in the size of the pneumatocele.
CASE PRESENTATION A 78-year-old right-handed female patient with a medical history significant for Alzheimer dementia presented with a 6-week history of sudden-onset aphasia. At the time of her presentation, the patient had no clear otologic symptoms, denying otorrhea, otalgia, tinnitus, hearing loss, or rhinorrhea. There was no reported history of head trauma or frequent Valsalva maneuvers. Otomicroscopy revealed intact tympanic membranes bilaterally without retraction, middle ear effusion, or perforation. Tuning fork testing revealed air conduction greater than bone conduction bilaterally, and Weber testing localized in the midline. Her neurologic examination revealed confusion to time and place, as well as an expressive and receptive aphasia. The remainder of the neurologic examination was normal. A symmetric, severe sensorineural hearing loss with type A tympanograms was seen bilaterally. Contrast-enhanced magnetic resonance imaging (MRI) revealed intraparenchymal air in the left temporal lobe (Fig. 1), and computed tomography (CT) of the temporal bone revealed a clear communication with the left mastoid cavity through a tegmen defect (Fig. 2). Neurosurgical consultation was sought, and the patient and her family were counseled regarding the diagnosis and treatment options. Ultimately, a tegmen repair via a transmastoid approach was offered, with neurosurgery available should conversion to an intracranial operation be required. However, after considering the risks, benefits, alternatives, and limitations of surgery, the patient’s family elected to proceed with close clinical observation given the patient’s age, health status, and wishes. At a 6-week follow-up visit, the patient was found to have stable symptoms and physical examination.
DISCUSSION Spontaneous otogenic pneumocephalus is rare. When pneumocephalus is seen, it is primarily associated with head and facial trauma, otomastoiditis, or surgery. The first description of spontaneous pneumocephalus was in 1954 by Jelsma et al. (1), and there have been only 23 cases reported to date with just five having intraparenchymal extension (2). The clinical presentation varies depending on the size, intracranial location, and mass effect of the pneumatocele. Previous reports have found that headache is the most common presenting symptom, followed by otorrhea, meningeal signs, tinnitus, vertigo, facial paralysis, visual changes, vomiting, and fainting (2,3). Symptoms that are related to the temporal lobe, such as seizure, aphasia, and memory loss, can also be observed. In the present case, the patient’s pneumatocele was in the left temporal lobe resulting in local mass effect, explaining the patient’s sudden aphasia. Specifically, the left posterior inferior frontal gyrus, also described as Broca’s area, the posterior section of the superior temporal gyrus (Wernicke’s area), and/or other adjacent accessory language pathways were likely disrupted from compression and local cerebritis. Diagnosis is usually achieved with high-resolution CT and MRI, where intracranial air and an associated skull base defect can be identified. In the present case, the large amount of intracranial air with a connection to the tegmen mastoideum made the otogenic source clear on either modality. The occurrence of spontaneous otogenic pneumocephalus generally requires two prerequisite conditions. First, defects in the middle fossa floor and dura must be present. The pathogenesis of this finding can be variable, ranging from a congenital dehiscence to one caused by chronic intracranial hypertension or chronic inflammation. Second,
Address correspondence and reprint requests to Marc L. Bennett, M.D., Department of OtolaryngologyYHead and Neck Surgery, The Bill Wilkerson Center for Otolaryngology & Communication Sciences, 7209 Medical Center East, South Tower 1215 21st Avenue South, Nashville, TN 37232-8605, U.S.A.; E-mail: [email protected] The authors report no conflicts of interest.
1
Copyright © 2015, Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
2
M. NOUD ET AL.
FIG. 1. Multiplanar and multisequence MR imaging of the brain with contrast. A, Sagittal T1 image post-gadolinium demonstrates a 2.6 2.6 4.6 cm air and fluid collection in the left temporal lobe (white arrow) resulting in mass effect. B, Axial T2 image post-gadolinium redemonstrates the air-fluid level (white arrowhead) and reveals a 4-mm surrounding rim of bright signal intensity, which can represent mild edema or gliosis (white arrow). C, Coronal T1 image post-gadolinium depicts another view of the lesion originating from the temporal bone (white arrow).
FIG. 2. High-resolution temporal bone CT imaging. A, Coronal view shows a large collection of air in the left temporal parietal region (white arrow) that extends from the roof of the left mastoid cavity, which appears to be focally dehiscent. It measures up to 4.6 cm in craniocaudal dimension, 2.7 cm in AP dimension, and 2.8 cm in transverse dimension. B, Coronal view with tegmen defect under high magnification (white arrow). C, Axial cuts re-demonstrate the pneumatocele with an air-fluid level and communication with the mastoid roof (white arrow). There are multifocal benign-appearing lucencies (white arrowheads) throughout the occipital calvarium, representing intraosseous arachnoid granulations. Otology & Neurotology, Vol. 00, No. 00, 2015
Copyright © 2015, Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
SPONTANEOUS OTOGENIC PNEUMATOCELE a pressure difference between the temporal bone and the intracranial space is required to encourage air to enter the cranium (4). The sequential accumulation and equalization of pressure creates a ‘‘ball valve’’ mechanism that allows air to become trapped in the intracranial space. This could be caused by elevated pressure from coughing, nose blowing, sneezing, or continuous positive airway pressure therapy for treatment of obstructive sleep apnea. Once intracranial air is recognized, the preferred management is generally surgical. Treatment goals include normalizing intracranial pressure, and preventing infection and recurrence. Defects are most commonly found over the ossicles in the tegmen tympani, where identification and repair can be achieved transmastoid, via a middle fossa craniotomy or through a combined approach. A variety of autologous and synthetic materials have been described to seal fistulas (2), with or center favoring composite grafts of fascia, bone, and an artificial dural substitute. More radical
3
approaches have also been described for refractory cases (5). Postoperatively, patient education to avoid Valsalva maneuvers may help prevent recurrence.
REFERENCES 1. Jelsma F, Moore DF. Cranial aerocele. Am J Surg 1954;87:437Y51. 2. Abbati SG, Torino RR. Spontaneous intraparenchymal otogenic pneumocephalus: A case report and review of literature. Surg Neurol Int 2012;3:32. 3. Rabello FA1, Massuda ET, Oliveira JA, et al. Otogenic spontaneous pneumocephalus: Case report. In: Braz J Otorhinolaryngol 2013; 79:643. 4. Krayenbu¨hl N, Alkadhi H, Jung HH, et al. Spontaneous otogenic intracerebral pneumocephalus case report and review of the literature. Eur Arch Otorhinolaryngol 2005;262:135Y8. 5. Dowd GC, Molony TB, Voorhies RM. Spontaneous otogenic pneumocephalus: Case report and review of the literature. J Neurosurg 1998;89:1036Y9.
Otology & Neurotology, Vol. 00, No. 00, 2015
Copyright © 2015, Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
