Intracranial posterior fossa proliferating trichilemmal tumor: first case report.

Proliferating trichilemmal tumors (PTT) are rare benign lesions that predominantly occur in elderly women and usually affect the scalp. They originate from the outer root sheath of hair shafts and have trichilemmal differentiation on histopathological examination. Compared to trichilemmal cysts, PTTs show increased cell proliferation and variable cytological atypia. We report the first case of a patient with an intracranial PTT in the posterior fossa. The clinicoradiological presentation and surgical management of the patient as well as the possible pathogenesis of this tumor are discussed.

Surgical strategies in the management of atlantoaxial dislocation in Down syndrome.

Aims: To study the clinicoradiological features and treatment outcomes of atlantoaxial dislocation (AAD) in Down syndrome. Settings and Design: Retrospective case series. Subjects and Methods: A retrospective chart and radiology review of 9 Down syndrome patients with AAD managed at our center from 2007 to 2018. Statistical Analysis Used: Chi-squared/Fisher's exact test. Results: There were 4 males and 5 females (n = 9). The median age was 14 years (interquartile range [IQR]: 7-15.5). 77.7% (7/9) of patients had severe spasticity (Nurick Grades 4 and 5). The median duration of symptoms was 9 months (IQR: 5-39). The AAD was reducible in all (n = 9) cases. Eight (88.8%) patients had os odontoideum. The mean atlantodental interval (ADI) was 8.5 mm (±2.9). T2W cord hyperintensity was seen in 66.6% (6/9). Posterior C1-2 transarticular fixation was done in 8 and occipitocervical fusion in 1 patient. Follow-up of more than 6 months (7-57 months) was available in 8/9 (88.9%) patients. There was a significant improvement in spasticity (n = 8, mean Nurick Grade 1.7 (±1.1), P = 0.003). Follow-up radiographs (n = 8) showed good reduction and fusion. A preoperative bedbound patient with poor respiratory reserve expired at 10 months following surgery. There were no other complications. Conclusions: Posterior surgical approach for AAD in Down syndrome resulted in good alignment and fusion, with excellent clinical improvement. Patients with elevated PCO2 are poor surgical candidates and require home ventilation facility.

Morphometric Analysis of the Neural Arch of C2 Vertebra in Indian Population.

BACKGROUND AND OBJECTIVE: The most common injuries to upper cervical spine are fractures of the second cervical vertebrae. The study aims to evaluate the morphometry of the neural arch of the second cervical vertebrae in the South Indian population. MATERIALS AND METHODS: Sixty-three second cervical vertebrae of undetermined gender and age without any gross defect were used for the study. The dimensions of neural arch, including superior articular facet, inferior articular facet, pediculoisthmic component, lamina, spinous process, foramen transversarium, and vertebral foramen, were measured by two independent observers using digital vernier caliper accurate to 0.1 mm and the data was analyzed. Descriptive statistics were obtained for the variables. Paired t-test was done to compare the measurements between right and left sides. RESULTS: There was no statistical difference between the right and left sides of the dimensions of superior articular facets, foramen transversarium, and the transverse diameter of inferior articular facet. The anteroposterior diameter of the inferior articular facets was more on the right side (P = 0.009). The width of the pediculoisthmic component in both the superior and inferior aspects was found to be less on the right side than that of the left (P = 0.006 and P = 0.031, respectively). The thickness in the middle one-third of laminae was optimum for bilateral safe screw insertion (≥4.0 mm) in 77% specimens. CONCLUSION: In summary, measurements of the transverse diameter of superior articular facet and thickness of lamina differed significantly from those reported in literature. This should be kept in mind while doing neurosurgery procedures in the Indian population.

Aerodynamic Evaluation of Flapping Wings with Leading-Edge Twisting.

The purpose of the current study is to emphasize the characteristics and phenomena of leading-edge twisting in flapping wing vehicles. A fused deposition modeling (FDM) 3D printing method is applied to develop the flapping mechanisms with bevel gears to achieve the leading-edge twisting. Three flapping mechanisms were developed, including simple flapping only (type-A1: normal servo mechanism), flapping with continuous leading-edge twisting (type-B: servo-bevel gear mechanism), and flapping with restricted leading-edge twisting via mechanical stoppers (type-B1: servo-bevel gear mechanism with adjustable mechanical stoppers). Utilizing a low-speed wind tunnel, the aerodynamic performances of these mechanisms are examined by extracting their lift and net thrust forces. The wind tunnel testing data showed that the flapping with restricted leading-edge twisting via mechanical stoppers (type-B1) showed better performance than the simple flapping (type-A1) by 32.9%, and also better performance than the flapping with continuous leading-edge twisting (type-B) by 64%. Next, MATLAB software was used to create the 3D wing surfaces from the instantaneous stereophotography Kwon3D trajectories to fully sketch the leading-edge twisting features. The 2D airfoil cut sections at the mean aerodynamic chord at different stroke moments depict the instantaneous angles of attack to justify the aforementioned wind tunnel testing data and it was verified using a theoretical trajectory model. This comprehensive study using the 3D-printed mechanisms is well suited for the quantitative evaluation of the lift contribution from leading-edge twisting.

Temporal progression and spatial distribution of "normal" prevertebral soft tissue swelling following central corpectomy for cervical spondylotic myelopathy.

OBJECTIVE: To document the temporal progression and spatial distribution of prevertebral soft tissue swelling (PSTS) after central corpectomy (CC) and to determine the variables affecting its severity. BACKGROUND: The natural attributes of PSTS following CC for cervical spondylotic myelopathy (CSM) have not been characterized in literature. MATERIALS AND METHODS: PSTS was measured at the C2 level and midpoint of the operated segment on lateral radiographs of the cervical spine taken pre-operatively and post-operatively (day 0, day 3/4, day 5 and day 6/7) in 93 patients with CSM undergoing one to three level uninstrumented CC. Patient's age, weight, Nurick's grade, number of corpectomy levels and intubation time were correlated with the PSTS. RESULTS: Proportionately, the swelling was maximal at the C2 level rather than at the level of CC, on all days, irrespective of the level of surgery. At the C2 level, the increase in PSTS was maximum by day 3/4 (P = 0.0001), whereas at the CC level, the PSTS continued to increase till day 5 (P = 0.0001). PSTS was higher in patients undergoing a three-level CC and in those with inclusion of C4 in the CC (P = 0.002). CONCLUSION: Patients undergoing CC are at risk for upper airway obstruction mainly at the C2 level in the first 3 days after surgery due to the PSTS. Those undergoing three-level CC, or having inclusion of C4 in the CC, have a greater degree of PSTS and have a higher risk of post-operative airway obstruction.

Turner Syndrome and Craniopharyngioma.

Turner syndrome (TS) affects nearly 1 in 2000 live births (1) and craniopharyngioma, a benign brain tumor, has been reported to occur at an incidence of 1.3 per million (2). These rare disorders are not known to coexist. The authors report a patient with incidental suprasellar mass who was diagnosed with both craniopharyngioma and TS, a rare association.

Treatment Outcomes and Follow-Up Compliance after Less than Total and Total Resection of Vestibular Schwannomas in 294 Patients.

BACKGROUND: To document the outcomes and quality of follow-up compliance after planned subtotal, near-total and gross-total resection (STR, NTR, and GTR) of vestibular schwannomas (VSs). METHODS: This is a retrospective study of 294 consecutive patients, who underwent excision of a previously untreated VS, between 2005 and 2015. Outcomes including long-term tumor control, facial nerve outcomes, and compliance with follow-up advice were studied. RESULTS: The mean diameter of the tumors was 4.2 cm (±0.8 cm; range: 2.2-7.5 cm). Less than total excision was performed in 55 cases (18.7%), of which NTR was performed in 65% of the cases (n = 36) and STR in the remaining 35%. In the GTR group, 29.3% of patients had a good facial outcome (House and Brackmann [HB] grades 1-3) whereas 81.8% of patients undergoing NTR/STR had a good facial outcome. Follow-up was available in 94.5% of patients undergoing NTR/STR whereas only 69.5% of patients undergoing GTR could be followed up. Only 61.8% of the patients who had NTR/STR were compliant with our follow-up advice and were on either regular radiological surveillance or underwent stereotactic radiosurgery (SRS) as advised. In this group of patients, those with larger tumors and those who underwent a more extensive resection of their tumor were less likely to be compliant with follow-up advice (P = 0.043 and 0.007, respectively). Among patients who had GTR, nine patients (3.7%) were detected to have tumor recurrence at a mean interval of 5.5 years after surgery. CONCLUSION: "Incomplete" microsurgical excision followed by SRS is an effective strategy that fulfills the twin objectives of preservation of function and long-term tumor control. Considering follow-up attrition due to various causes, upfront SRS at the first follow-up visit-even for a small residue-may be a prudent strategy in selected patients.

The 'rosette-forming glioneuronal tumor' of the fourth ventricle.

Tumors containing both neuronal and glial components are a rare heterogeneous group with unique features that require further subclassification. The rosette-forming glioneuronal tumor of the fourth ventricle is one of a number of recently described glioneuronal tumors, which has been accorded official WHO nosologic status only in 2007. We describe the clinical and pathologic features of two patients with rare rosette-forming glioneuronal tumors of the fourth ventricle, one of which was associated with dysgenetic tricho-rhinopharyngeal type I syndrome.

Mediastinal migration of distal occipito-thoracic instrumentation.

We present the occurrence and management of mediastinal migration of the distal aspect of a posterior occipito-thoracic screw-rod construct. No similar occurrence was found in the literature. This event occurred following an emergency tracheotomy (requiring neck hyperextension) in a patient with severe rheumatoid arthritis, who had previously undergone decompression and an Occiput-T2 instrumented fusion for cranio-cervical and sub-axial cervical spine instability. Imaging showed fracture-subluxation of T1/2 and T2/3 with the bilateral C7, T1 and T2 screws in the mediastinum causing tracheal and esophageal compression. Removal of the instrumentation, decompression (T2 corpectomy) and construct revision down to T10 was safely performed from a posterior approach. Severe osteoporosis, some pre-existing screw loosening and hyperextension of the neck were the predisposing factors of this near catastrophic event. By staying directly posterior to the rod and following the fibrous tract already created, the instrumentation was safely removed from the mediastinum.

Neuropsychiatric Systemic Lupus Erythematosus: A Diagnostic Conundrum.

A 70-year-old man presented with complaints of rapid cognitive decline and new onset leukopenia. The patient had a 17-year history of refractory seizures. Detailed review of symptoms and investigations revealed the patient met American College of Rheumatology (ACR) diagnostic criteria for systemic lupus erythematosus (SLE). The patient had high titer ANA with a strongly positive dsDNA. Immunosuppressive therapy with hydroxychloroquine and mycophenolate mofetil led to significant improvement in cognition and seizures. Neuropsychiatric SLE should be considered a potential differential diagnosis for patients presenting with seizures or cognitive decline. Moreover, neuropsychiatric manifestations especially seizures are an early event in the disease course of SLE. Hence, we believe that early diagnosis of SLE by neuropsychiatric manifestations will not only lead to better control of CNS symptoms but early immunosuppressive therapy could control the progression of the underlying autoimmune disease.

Cervical intramedullary schwannoma mimicking a glioma.

We present a case of a cervical intramedullary schwannoma (IS), which resembled a glioma on radiology. Somatic and root pain, the most common presenting complaints of IS, were lacking in our patient, and the characteristic magnetic resonance finding of an enhancing thickened nerve root in IS, was absent in our case. Preoperative diagnosis of a cervical IS is not always possible. Complete tumor resection is the ideal treatment for IS. Intraoperative frozen section can be a useful for decision making though the tumor-cord plane will ultimately decide if the tumor can be radically excised.

MR ventriculography for the study of CSF flow.

BACKGROUND AND PURPOSE: Various MR techniques have been used to assess CSF flow and to image the subarachnoid spaces and ventricles. Anecdotal reports describe the use of intrathecal and intraventricular gadolinium-based contrast agents in humans and animals. We sought to determine the clinical usefulness of gadolinium-enhanced MR ventriculography for assessing CSF flow in patients with various neurologic conditions. METHODS: Five patients (three female and two male patients aged 6 months to 65 years) were included in the study. After performing sagittal, coronal, and axial T1-weighted MR imaging of the brain, 0.02-0.04 mmol of gadodiamide was injected into the lateral ventricle. Sagittal, coronal, and axial T1-weighted imaging was repeated soon after the injection. We were specifically looking for the site of obstruction to CSF flow in those patients with hydrocephalus, communication between cysts and ventricles, elucidation of suspicious intraventricular lesions, and patency of third ventriculostomies. RESULTS: MR ventriculography showed good delineation of the ventricular system in all patients. In one patient with carcinomatosis and hydrocephalus, a block to contrast material flow was detected at the right foramen of Luschka. In another patient with hydrocephalus, partial block to the flow of contrast material was demonstrated at the right foramen of Monro. In a patient with hydrocephalus and a posterior fossa cyst, flow of contrast material was blocked between the third ventricle and the cyst, with a thin streak of contrast material in the aqueduct. As an assessment of the patency of a third ventriculostomy, MR ventriculography showed flow of contrast material into the suprasellar cisterns from the third ventricle in one patient and absence of flow in another. CONCLUSION: MR ventriculography is a safe technique for assessing CSF flow, with application in determining the site of obstruction in hydrocephalus, in assessing communication between cysts and the ventricle, and in determining the functioning status of endoscopic third ventriculostomies.

Benign metastasizing leiomyoma causing spinal cord compression.

BACKGROUND: Leiomyoma as a cause of cord compression is extremely rare. To our knowledge this is the first report of a dural-based leiomyoma and second report of a leiomyoma causing cord compression. CASE DESCRIPTION: A 38-year-old female renal transplant recipient presented with features of cervical cord compression. On imaging and at surgery, the tumor was mistaken for a neurofibroma. A cervical laminectomy and near total excision of the tumor was done. She did well in the postoperative period but presented 5 months later with thoracic empyema leading to septicemia and her demise. Ultrasound examination and autopsy showed leiomyomas in many other sites including the uterus. CONCLUSIONS: The presence of extrauterine and uterine leiomyomas is a curious condition termed as "benign metastasizing leiomyoma." As our patient was on immunosuppressant therapy following a renal transplant, it might have predisposed her to this rare condition with multifocal tumors.

An unusually long survival of a patient with glioblastoma of spinal cord: a case report.

Primary glioblastoma of spinal cord are rare and are associated with poor survival especially in adults. We report a case of glioblastoma of thoracic spinal cord (D3 to D6) in an adult treated with partial resection surgery and radiation therapy with a survival of six years with good quality of life. The patient had paraplegia at presentation but improved after surgery and radiation therapy to grade 4 in both lower limbs. After 5 years, he developed new lesion in a different location of the spine (L1, L2 & L5) along with multiple lesions over entire spine and was treated with radiation therapy and a year later developed a new lesion intracranially in the posterior fossa involving cerebellopontine angle region infiltrating brainstem. He was treated with palliative radiotherapy and is on chemotherapy with Temozolomide and is still alive with ability to do activities of daily living at the time of this report. Radiation therapy provided prolonged local control with effective palliation of symptoms and good quality of life in this patient enabling to do activities of daily living.