Imaging of trochlear nerve schwannomas: a case series and systematic review of the literature.

Purpose Trochlear nerve schwannomas are rare tumors. So far, only 121 cases have been published. We present four new cases, discuss the imaging characteristics and summarize all previously published cases through a systematic review.Methods Four cases, all treated in AZ Sint-Jan Hospital Brugge-Oostende (Belgium), were collected, including their demographic, clinical and radiological data. All MR imaging was performed with the three-dimensional fluid-attenuated inversion recovery (3D-FLAIR), turbo spin echo T1 high-resolution (TSE T1 HR), three-dimensional balanced fast-field echo (3D b-FFE) and three-dimensional T1 black blood (3D T1 black blood) sequence. We compared our findings with the present literature through a systematic literature review in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines.Results Screening with routine unenhanced 3D-FLAIR imaging could identify all schwannomas as hyperintense lesions on the course of the trochlear nerve. The use of 3D T1 black blood sequences was superior in depicting the lesions, while high-resolution 3D b-FFE images enabled us to visualize the anatomic boundaries of the lesions in detail. Most trochlear schwannomas are located in the ambient cistern, at or just below the free edge of the tentorium.Conclusion The majority of trochlear nerve schwannomas are located cisternal and display variable enhancement on contrast administration. 3D-FLAIR imaging is superior in detecting these lesions. Comparison with data collected from previous cases demonstrates the importance of early diagnosis and treatment. Generally, patients with trochlear nerve schwannomas have a good prognosis.

Trends in diagnosis, referral, red flag onset, patient profiles and natural outcome of de novo cardiac amyloidosis and their multidisciplinary implications.

BACKGROUND: Cardiac amyloidosis (CA) is often overlooked or misdiagnosed. Effects of growing disease awareness, diagnostic ameliorations and novel treatment options on CA diagnosis and management are scarcely reported. OBJECTIVE: To report trends in diagnosis, referral routes, clinical presentation, early onset diagnostic red flags and outcome in de novo CA subjects. METHODS: An unselected cohort of 139 de novo CA patients over an 8-year period in a tertiary referral hospital was recruited. RESULTS: Transthyretin (ATTR, 82%, n = 114) was the most common CA form; Light-chain (AL, 15%, n = 21) and secondary (AA, 3%, n = 4) are less prevalent. Increased awareness over time led to a marked ATTR diagnostic surge, steep non-invasive diagnostic approach increment and increased nuclear medicine and external cardiologist referrals (all p < 0.001). A total of 41% (n = 57/139) of patients were referred by non-cardiology specialist disciplines. Specific referral to rule out CA (24-36%) and diagnostic time lag from symptom onset (9 ± 12 to 8 ± 14 months), however, did not improve (all p > 0.050). Multiple early red flag events preceded CA diagnose several years in ATTR: Left ventricular hypertrophy (LVH, 60%, 4.9 ± 4.3 y), heart failure (54%, 2.5 ± 3.5 y), atrial fibrillation (47%, 5.9 ± 6.7 y), bilateral carpal tunnel syndrome (43%, 9.5 ± 5.7 y) and spinal stenosis (40%, 7.4 ± 6.5 y). LVH ≥ 12 mm was absent in 11% ATTR (n = 13/114) and 5% AL (n = 1/21) patients. Hypertension was common in both ATTR (n = 70/114, 62%) and AL (n = 10/21, 48%). 56% (n = 78/139) of CA presented with heart failure. Cumulative 1 and 5-year mortality of 10%/66%, 40%/52% and 75%/75% for ATTR, AL, and AA, respectively, remains high. CONCLUSIONS: Although CA diagnostic uptake and referral improve, specialist-specific disease and diagnostic red flag ignorance result in non-timely diagnosis and unfavourable outcome.

Intraoperative Use of Cone-Beam Computed Tomography in the Treatment of Atlantoaxial Rotatory Subluxation.

BACKGROUND: Atlantoaxial rotatory subluxation (AARS) is a rare pathological condition of the upper cervical spine. It can be caused by multiple mechanisms, including minor neck manipulations. Children are more prone owing to the weaker periarticular soft tissue and a steeper slant of the C1 facet plane against the vertical axis of the dens. If AARS does not resolve spontaneously, a normal position of the atlantoaxial joint must be achieved by reduction and stabilization. CASE DESCRIPTION: A 15-year-old girl had presented with a painful torticollis that had already been present for 4 weeks after trimaxillary jaw correction for skeletal class II malocclusion. A computed tomography (CT) scan of the cervical spine showed AARS Field and Hawkins classification type I. We first attempted 1 week of conservative treatment with a soft collar and the prescription of a muscular relaxant. However, because the AARS persisted, we performed transoral closed reduction with the patient under general anesthesia, as previously described. During the procedure, we used intraoperative cone-beam CT to evaluate the degree of reduction. After obtaining complete reduction, immobilization with a halo-vest was applied. CONCLUSIONS: Complete reduction of the AARS was achieved with closed intraoral reduction. We used intraoperative cone-beam CT to confirm complete reduction. We found cone-beam CT to be a very useful tool.

Intracanal Optic Nerve Cavernous Hemangioma: A Case Report and Review of the Literature.

BACKGROUND: Cerebral cavernous malformations of the intracanalicular optic nerve are extremely rare lesions. Only a few case reports and 1 case series have been published. We report an additional case with atypical imaging and review the existing literature with attention to time to surgery and imaging characteristics. CASE DESCRIPTION: In a 38-year-old man with progressive visual field deficit, a lesion compressing the left optic nerve in the optic canal was diagnosed. On magnetic resonance imaging, this lesion had a homogeneous signal and was tentatively diagnosed as a meningioma. A left frontolateral craniotomy with extradural skull base approach with neuronavigation was performed for resection and definitive diagnosis of the lesion. Pathologic examination showed a lesion most consistent with a cavernous hemangioma. Follow-up magnetic resonance imaging at 6 months showed no remaining tissue or recurrence. Clinically, there was subjective and objective improvement of sight. CONCLUSIONS: A cerebral cavernous malformation should always be in the differential diagnosis of a lesion causing an optic neuropathy with visual acuity loss and visual field defect. Clinical presentation of an optic neuropathy requires medical imaging; magnetic resonance imaging is the modality of choice in the diagnosis of these lesions. The treatment of cerebral cavernous malformation is gross total resection.

Delayed Intraventricular Pneumocephalus Following Shunting for Normal-Pressure Hydrocephalus.

BACKGROUND: Pneumocephalus is usually seen in trauma or cranial surgery. It is rarely reported as a delayed complication of ventriculoperitoneal shunt placement for hydrocephalus secondary to trauma, tumor, or aqueduct stenosis. We describe a case of intraventricular pneumocephalus manifesting 10 months after placement of a shunt for normal-pressure hydrocephalus. CASE DESCRIPTION: A pressure-regulated ventriculoperitoneal shunt was implanted in an 81-year-old patient after diagnosis of normal-pressure hydrocephalus. He showed postoperative clinical improvement. Routine computed tomography performed 2 months after the procedure showed no abnormalities. He presented 10 months after shunting with a subacute deterioration of gait. Imaging revealed major intraventricular pneumocephalus and a left-sided temporal porencephalic cyst with a small, bony defect in the left petrous bone. A middle fossa approach was performed, and the temporal defect was covered with fascia of the temporal muscle. This resulted in a gradual resolution of pneumocephalus. CONCLUSIONS: Pneumocephalus after shunting for NPH is rare and described as a complication only during the first 2 postoperative months. This case is unique, as the pneumocephalus developed 10 months after shunting. The combination of an occult, possibly congenital, skull base defect and the insertion of a shunt resulted in delayed intraventricular and intraparenchymal pneumocephalus.

Multiple nocardial abscesses of the brainstem and spinal cord diagnosed after an open biopsy through a cervical partial central corpectomy: case report.

Nocardiosis of the central nervous system is a challenging and difficult diagnosis for the clinician. The combination of infections of the brain and spinal cord is even more rare. The authors report on a patient with multiple lesions in the brainstem and cervical spinal cord. This 81-year-old immunocompetent woman presented with symptoms of progressive walking difficulty and ataxia. The results of an extensive workup with laboratory investigation, MRI, lumbar puncture, positron emission tomography (PET), and bone marrow biopsy remained inconclusive. Only after an open biopsy of a cervical lesion by an anterior approach through a partial central corpectomy of the cervical spine, was the diagnosis of nocardiosis made, allowing for specific antibiotic treatment.

Lhermitte-Duclos disease: 11C-methionine positron emission tomography data in 4 patients.

BACKGROUND: Lhermitte-Duclos disease is a cerebellar lesion, characterized by an overgrowth of cerebellar ganglion cells, which replace granular cells and Purkinje cells. Lhermitte-Duclos disease may be a manifestation of Cowden syndrome (multiple hamartoma-neoplasia syndrome). The nature of LDD, whether neoplastic, dysplastic, or hamartomatous, is still not exactly understood. Metabolic imaging of the amino acid metabolism using PET could be useful for noninvasive characterization of these lesions. METHODS: To define the Meth-PET imaging characteristics of these lesions, we undertook a Meth-PET study in 4 patients with LDD after obtaining informed consent. All 4 patients had clinical signs of Cowden syndrome. In 2, the diagnosis was made with MRI; in 2, it was confirmed histologically. RESULTS: Using Meth-PET, the cerebellar lesions had a high methionine uptake, except in the subtotally resected lesion. The uptake of the lesions was markedly higher than that of the contralateral normal regions. The mean L/C ratio was 2.07. CONCLUSION: 11C-methionine positron emission tomography visualizes the lesion of Lhermitte-Duclos disease as a high uptake area. This amino acid hypermetabolism may be related to the slow growth of the lesions, and is an argument to suggest that patients with LDD should be followed up carefully to detect progression of the cerebellar lesion.