Scuba Diving-Induced Inner-Ear Pathology: Imaging Findings of Superior Semicircular Canal and Tegmen Tympani Dehiscence.

BACKGROUND Superior semicircular canal dehiscence is an inner-ear pathology which presents with vertigo, disequilibrium, and hearing loss. Although the exact etiology of superior semicircular canal dehiscence is unknown, it is thought that an increase in middle-ear pressure disrupts a thin overlying temporal bone. Superior semicircular canal dehiscence is frequently seen in association with dehiscence of the tegmen tympani, which overlies the middle ear. Here, we present a case report of a 52-year-old Puerto Rican man with vertigo, dizziness, vomiting, and mild hearing loss associated with superior semicircular canal and tegmen tympani dehiscence after performing improper scuba diving techniques. CASE REPORT A 52-year-old Puerto Rican man presented to the emergency department with vertigo, dizziness, vomiting, and mild hearing loss in the right ear. The symptoms began shortly after scuba diving with inadequate decompression techniques on ascent. He was treated with recompression therapy with mild but incomplete improvement in symptoms. Bilateral temporal magnetic resonance imaging was suggestive of segmental dehiscence of the right superior semicircular canal and tegmen tympani. High-resolution computed tomography of the temporal bone confirmed right superior semicircular canal and tegmen tympani dehiscence with an intact left inner ear. CONCLUSIONS The increased inner-ear pressure that occurs during scuba diving can lead to dehiscence of the superior semicircular canal and tegmen tympani, causing vertigo and hearing loss. Performance of improper diving techniques can further increase the risk of dehiscence. Therefore, appropriate radiologic evaluation of the inner ear should be performed in such patients.

Tolosa Hunt Syndrome: MRI Findings.

Tolosa-Hunt syndrome (THS) is an idiopathic inflammatory condition involving the cavernous sinus and orbital apex with an incidence of 1 case per million per year. We report on a case of a 70-year-old male with atypical MRI findings, vision loss, and painless ophthalmoplegia.  Ophthalmic evaluation revealed his best-corrected visual acuity was 20/40 in the right eye and counting fingers at a 0.5-foot distance in the left eye. External examination of the left eye revealed limited ocular movement, proptosis, and a positive relative afferent pupillary defect. Complete blood count, inflammatory markers, and full biochemistry tests, including thyroid and liver function tests, were within the normal range. A magnetic resonance imaging of the orbits with and without contrast demonstrated a homogenously enhancing lesion at the posterior intraconal compartment of the left orbit, extending to the orbital apex with the involvement of the adjacent extraocular muscles. The patient was started on intravenous methylprednisolone 60 mg daily and later discharged on prednisone 5 mg daily with partial symptom improvement on follow-up. Resection and biopsy revealed a soft tissue lesion with mixed inflammatory infiltrate. The clinical, pathological, and imaging findings favored the diagnosis of THS.

Lemierre syndrome leading to an ischaemic stroke and malignant cerebral oedema.

Lemierre syndrome is an often misdiagnosed disease caused by an anaerobic bacterial infection that produces thrombophlebitis of the internal jugular vein and septic metastasis to distal organs, especially the lungs. Carotid stenosis or thrombosis is a rare complication. We present a patient with Lemierre syndrome who developed malignant cerebral oedema secondary to an ischaemic stroke which required a decompressive craniectomy.

Primary Brain Melanoma in a Pediatric Patient: A Case Report.

BACKGROUND Primary malignant melanoma of the brain is a challenging radiological diagnosis and a high index of suspicion is required about patients with the condition. In the pediatric population, only a few cases have been reported in the literature. The purpose of this report was to describe the expected imaging characteristics and the importance of a multidisciplinary approach in the diagnosis of this rare entity. CASE REPORT A 17-year-old Hispanic male who presented with new-onset tonic-clonic seizures had no focal neurologic deficits on physical examination. An initial computed tomography scan showed a hyperdense, right frontal, parafalcine mass. Brain magnetic resonance imaging was performed and revealed a T1 hyperintense and T2 hypointense, right-frontal-lobe, extra-axial mass with foci of susceptibility. Resection of the mass revealed a lesion that had a dark, pigmented macroscopic appearance. Histopathologic analysis confirmed that it was a primary intracranial malignant melanoma after no primary site was identified on dermatologic and ophthalmologic evaluations. CONCLUSIONS Diagnosing a primary intracranial melanoma with imaging alone is virtually impossible if clinical data and findings from a thorough physical examination are unavailable. Intracranial primary malignant melanoma remains a complex radiological diagnosis that relies on the exclusion of other potentially more common entities and an optimal multidisciplinary approach.

Delayed Spontaneous Resolution of a Traumatic Middle Meningeal Artery Pseudoaneurysm.

BACKGROUND Middle meningeal artery (MMA) aneurysms are a very rare entity, comprising less than 1% of all intracranial aneurysms. In particular, traumatic MMA pseudoaneurysms (MMAP) are reported in the literature to have a poor outcome in about 20% of cases. Moreover, in extremely rare cases, MMAPs can spontaneously thrombose. CASE REPORT We present the case of a 42-year-old Hispanic man with multiple craniofacial hemangiomas and history of chronic migraines that increased in frequency after blunt head trauma 1 month prior to initial evaluation. CTA and brain MRI showed a right-sided MMAP adjacent to the foramen spinosum with a pan-hemispheric subdural hematoma and no associated skull fractures. The MMAP was not visualized 2 days later on digital subtraction angiography (DSA) and was therefore presumed to be thrombosed. CTA at 3 months showed interval progression of the MMAP with subsequent spontaneous resolution on CTA at 10 months. CONCLUSIONS Knowledge regarding MMAPs is limited since it is based on a small number of cases and literature reviews. Additional studies are needed to elucidate the true incidence and natural course of this entity and produce adequate treatment guidelines.

Alveolar rhabdomyosarcoma metastatic to the brain.

Alveolar rhabdomyosarcoma (ARMS) has a predilection for the peripheral extremities, and brain metastases are rare, with only a few cases reported after the initial diagnosis. We present a 22-year-old male patient with a right orbital-ethmoidal ARMS who presented with a recurrence to the brain 1 year after the initial diagnosis. He was referred to our institution due to acute neurological deterioration. A brain MRI was performed, showing an enhancing bilateral parafalcine lesion centred about the bilateral cingulate gyri with extension into the corpus callosum. The patient was taken to the operating room for a stereotactic biopsy under general anaesthesia, which was compatible with metastatic ARMS. Our case is exceedingly rare, considering the initial diagnosis of an orbital/ethmoidal ARMS, its subsequent metastasis to the brain and its clinical sequelae after a biopsy. Prognosis after cerebral metastatic ARMS is dismal, with most patients expiring due to central nervous system metastatic disease.

Temporal Evolution of Hypertrophic Olivary Degeneration in a Pediatric Patient: A Case Report and Review of Literature.

Hypertrophic olivary degeneration (HOD) is a rare type of neuronal degeneration seen after interruption of the dentato-rubro-olivary tract also known as the Guillain-Mollaret triangle (GMT). It is associated with hypertrophic changes of the inferior olive. Commonly reported in adults, this lesion presents with ataxia and oculopalatal myoclonus. Up to date, few cases have been published in the literature that refer to pediatric cases. This diagnosis is particularly important in the setting of brainstem tumor surgery as it should not be confused for tumor recurrence or metastasis, in turn avoiding unwarranted surgical intervention. We present the case of a 15-year-old male who underwent resection of a left superior cerebellar peduncle (SCP) pilocytic astrocytoma. On follow-up, magnetic resonance imaging (MRI) demonstrated evidence of mild residual tumor as well as progressive engorgement of the inferior olivary nucleus (ION). The patient was clinically asymptomatic and has since been observed expectantly without any issues. We were able to pinpoint the most probable location of injury in our patient's GMT. HOD remains a somewhat obscure entity. Its presentation may be early and not accompanied by significant neurologic findings, in contrast to what has been previously reported. Particularly in neoplastic cases, it may represent a diagnostic challenge and could be easily confused for tumor recurrence. A multidisciplinary approach for this entity, as with other pathologies, is of particular importance. Its proper recognition will result in the best outcomes for the patient.

A Rare Case of a Primary Spinal Solitary Fibrous Tumor/Hemangiopericytoma in a 9-Month-Old Patient.

BACKGROUND Solitary fibrous tumors (SFTs)/hemangiopericytomas (HPCs) are mesenchymal tumors commonly found in middle-aged patients, usually localized to thoracic pleurae. Spinal tumor involvement is rarely seen, and its imaging findings are largely inconsistent because of the rarity of these cases. We present a case report of a 9-month-old girl with a rare intraspinal tumor with histologic evidence of SFT/HPC, but no STAT6 nuclear immunoreactivity. CASE REPORT A 9-month-old girl, born at term with good prenatal care, presented to the emergency room with regression of developmental milestones. The patient was in good health until 2 months, when she developed decreased spontaneous leg movements. Physical exam revealed diffuse muscular atrophy, with no deep tendon reflexes, sensation, or spontaneous movements of the lower extremities. Computed tomography and magnetic resonance imaging showed a heterogeneous irregular mass filling the lumbosacral spinal canal, extending through the neural foramina to the prevertebral/perivertebral and presacral regions. The tumor was biopsied and referred to the National Institutes of Health for consultation and the diagnosis of SFT/HPC was confirmed on the basis of its histologic features, despite the fact that the tumor was negative for STAT6 immunoreactivity. CONCLUSIONS Although the tumor histology was consistent with SFT/HPC, it was negative for STAT6 nuclear immunoreactivity, which is unusual and may exclude the diagnosis. To our knowledge, this is the youngest patient to present with a spinal SFT with these features.

Obstructive Hydrocephalus and Chemical Meningitis Secondary to a Ruptured Spinal Epidermoid Cyst.

BACKGROUND: Epidermoid cysts of the spinal cord may rupture, resulting in keratin dissemination in the subarachnoid space, in the ventricles, and along the central canal of the spinal cord causing meningitis, myelopathic changes, or hydrocephalus. CASE DESCRIPTION: A 53-year-old woman with no past medical history presented with a 2-week history of headache located in the occipital region associated with neck pain. Brain magnetic resonance imaging demonstrated multiple fat droplets scattered throughout the subarachnoid and intraventricular spaces with significant edema of the right posterior temporoparietal lobes with trapping of the right temporal horn of the lateral ventricle and atrium. An intracranial lesion could not be observed in the study. The spinal region was suspected as the possible culprit, and spinal imaging showed a large cystic lesion at the level of the conus medullaris. The patient underwent neuronavigation endoscopic exploration of the right lateral ventricle with flushing of the keratin particles followed by a posterior lumbar decompression with resection of the epidermoid cyst. Pathology was consistent with an epidermoid cyst. Successful recovery with improvement in symptoms was quickly observed. CONCLUSIONS: When an epidermoid cyst is suspected but no intracranial lesion is found, the intraspinal area should be studied. Rupture of a spinal epidermoid cyst may cause meningitis and inflammation producing obstructive hydrocephalus. We present this rare entity and describe the diagnostic and surgical techniques used.

Radiographic diagnosis and endovascular treatment of an unruptured superior hypophyseal aneurysm.

A 37-year-old female with a large unruptured superior hypophyseal aneurysm underwent a guglielmi detachable-coil embolization after proper diagnostic three-dimensional digital subtraction angiography (DSA) of the internal carotid artery. Only a few case reports exist in the scientific literature about this uncommon entity that accounts for 1% of all intracranial aneurysms. We discuss the etiology, prevalence, and incidence of saccular intracranial aneurysms as well as their risk factors, prognosis, and differential diagnosis. We also review the literature on intracranial aneurysm and evaluate its current diagnostic management and therapeutic treatment.