Ultrasound Elastography in Neurosurgery: Current Applications and Future Perspectives.

BACKGROUND: Similar to clinical palpation, Ultrasound elastography (USE) helps distinguish between tissues by providing information on their elasticity. While it has been widely explored and has been applied to many body organs, USE has not been studied as extensively for application in neurosurgery. The current systematic review was performed to identify articles related to the use of interoperative USE in neurosurgery. METHODS: Search included MEDLINE(R) database. Only original peer-reviewed full-text articles were included. No language or publication year restrictions were imposed. Two independent reviewers assessed the search results for relevance. The identified articles were screened by title, abstract, and full-text review. RESULTS: Seventeen articles were included in the qualitative analysis and 13 articles were related to oncology, epilepsy (n = 3), and spine (n = 1). In oncology, USE was found useful in defining tumor stiffness, aiding surgical planning, detecting residual tumors, discriminating between tumor and brain tissue, and differentiating between different tumors. In epilepsy, USE could improve the detection of epileptogenic foci, thereby enhancing the prospect of complete and safe resection. The application in spinal surgery was limited to demonstrating that a compressed spinal cord is stiffer than the decompressed one. CONCLUSIONS: USE was found to be a safe, quick, portable, and economic tool that was a useful intraoperative adjunct to provide information corresponding to a variety of neurosurgical diseases, at different stages of surgery. This review describes the current intraoperative neurosurgical applications of USE, the concept of elasticity, and different USE modalities as well as the technical challenges, limitations, and possible future implications.

Conjunctival Lesions: A 5-Year Basic Demographic Data and Clinicopathological Review in a Tertiary Eye Care Hospital.

BACKGROUND: Conjunctival lesions are common with a wide spectrum of benign, premalignant, and malignant lesions. Few histopathological studies have been conducted on conjunctival lesions with variable designs and results. Our aim in this study is to provide information on common conjunctival lesions seen in an ophthalmology tertiary care center in Saudi Arabia. METHODS: A retrospective, observational study of all consecutive conjunctival tissue specimens sent for histopathological assessment to the pathology department from 2015 to 2019 were analyzed. Clinical data were collected from medical records, and the histopathological slides were reviewed by a single pathologist. RESULTS: A total of 110 conjunctival specimens from 108 patients were included (mean age: 53 years, 67 males and 43 females). Bilateral involvement was mostly found in inflammatory lesions (40%). Most lesions were benign (91%), with a significantly longer duration of symptoms in malignant lesions (p = 0.036*). The clinical diagnosis matched the final histopathological diagnosis in 75.5% of the total specimens. The most frequent category of benign lesions was fibrodegenerative and proliferative lesions (53.6%), with a significantly higher prevalence among adult males (p < 0.001). Melanocytic lesions were more common in children (33.3%) than adults (9.8%), and the mean age of children was significantly lower (p = 0.013). The most frequent malignant lesion was ocular surface squamous neoplasia (50%), with equal prevalence among males and females. The overall outcome was favorable in 89.4% and unfavorable in 10.6%, mostly due to surgical complications, further progression of the lesion, or recurrence. CONCLUSION: This study shows variability in the frequency of conjunctival lesions based on gender, age, geographical, racial, and environmental factors. There has been a shift in the gender-based prevalence of ocular squamous neoplasia over the last three decades, probably due to a change in lifestyle.

Effects of compressive lesions on intraoperative human spinal cord elasticity.

OBJECTIVE: Although evaluating tissue elasticity has various clinical applications, spinal cord elasticity (SCE) in humans has never been well documented. In this study, the authors aimed to evaluate the impact of compression on human SCE in vivo. METHODS: The authors prospectively assessed SCE using intraoperative shear wave elastography (SWE). All consecutive patients undergoing spinal cord (SC) decompression (laminectomy or corpectomy) between June 2018 and June 2019 were included. After intraoperative exposure of the patient's dura mater, at least three SWE measurements of the SC and its coverings were performed. Intraoperative neurological monitoring in the form of motor and somatosensory evoked potentials was utilized. Cases were divided into two groups based on the state of SC compression following bone removal (laminectomy or corpectomy): patients with adequate decompression (the decompressed SC group [DCG]) following bone removal and patients with remining compression, e.g., compressing tumor or instability (the compressed SC group [COG]). RESULTS: A total of 25 patients were included (8 females and 17 males) with a mean age of 48.28 ± 21.47 years. Most cases were degenerative diseases (10 cases) followed by tumors (6 cases), and the compression was observed at cervical (n = 14), thoracic (n = 9), and conus medullaris (n = 2) levels. The COG (6 cases) expressed significantly higher elasticity values, i.e., greater stiffness (median 93.84, IQR 75.27-121.75 kPa) than the decompressed SC in DCG (median 9.35, IQR 6.95-11.22 kPa, p < 0.001). Similarly, the compressed dura mater in the COG was significantly stiffer (mean ± SD 121.83 ± 70.63 kPa) than that in the DCG (29.78 ± 18.31 kPa, p = 0.042). Following SC decompression in COG, SCE values were significantly reduced (p = 0.006; adjusted for multiple comparisons). Intraoperative monitoring demonstrated no worsening from the baseline. CONCLUSIONS: The current study is to the authors' knowledge the first to quantitatively demonstrate increased stiffness (i.e., elasticity value) of the human SC and dura mater in response to external compression in vivo. It appears that SCE is a dynamic phenomenon and is reduced following decompression. Moreover, the evaluation of human SCE using the SWE technique is feasible and safe. Information from future studies aiming to further define SCE could be valuable in the early and accurate diagnosis of the compressed SC.

Shear wave elastography for intracranial epidermoid tumors.

BACKGROUND: Ultrasound elastography (USE) is a novel technique that assesses the mechanical properties of body tissues in real time. Based on elasticity measurements, USE enables the differentiation of tumor tissue from surrounding normal tissue. OBJECTIVES: We aimed to evaluate an intraoperative SWE technique for differentiating tumor tissue (epidermoid cyst) from the surrounding normal brain tissue based on elastic properties. METHODS: We prospectively report the intraoperative elasticity assessments of four patients diagnosed with epidermoid cysts. Along with standard ultrasonography, intraoperative shear wave elastography (SWE) was used to identify tumor tissue and assess the elasticity of each tumor and the surrounding normal brain. RESULTS: USE enabled the differentiation between epidermoid cysts and the surrounding normal brain tissue in real time intraoperatively; visual data (SWE elasticity map) and quantitative data (elasticity measurements in kilopascals) were utilized to identify the epidermoid cyst based on its elastic properties. The area representing the epidermoid cyst had an increased elasticity on SWE view and high mean elasticity values (193.7 ± 70.9 kPa in case 1, 168 ± 24.5 kPa in case 2, 205.1 ± 6.7 kPa in case 3, and 101.3 ± 12.6 kPa in case 4). The area representing the adjacent normal brain tissue on SWE view had lower mean elasticity values (14.9 ± 1.9 kPa in case 1, 22.6 ± 8.3 kPa in case 2, and 23.8 ± 1.4 kPa in case 4). CONCLUSION: This study demonstrates the feasibility and promising value of SWE as an intraoperative tool during epidermoid cyst resection. Epidermoid tissue remnants that are hidden from the microscopic view can be detected using SWE.

Pilomatrixoma in a child mimicking a ruptured epidermal cyst clinically and histopathologically: Case report.

INTRODUCTION AND IMPORTANCE: Pilomatrixoma is a superficial benign skin tumor that originates from the matrix cells of the hair follicles. It presents more frequently during the first two decades of life and usually involves the head and neck, most often in the eyelid or eyebrow area. CASE PRESENTATION: We present a case of pilomatrixoma, which appeared at the age of 14 years with history of recurrent inflammation and discharge mimicking a ruptured epidermal cyst. DISCUSSION: Pilomatrixomas are often confused clinically with other benign masses, encountered in the clinical practice more frequently like dermoid cysts and epidermal inclusion cysts. The rate of accurate preoperative diagnosis ranges between 0%-30% and the correct diagnosis can be established only after excision and histopathological examination. Our case demonstrates an atypical presentation of pilomatrixoma as an epidermal inclusion cyst. CONCLUSION: Ophthalmologists and ocular pathologists should be aware of the atypical presentation of pilomatrixomas to ensure early accurate diagnosis and curative treatment.

Association between craniovertebral junction abnormalities and syringomyelia in patients with chiari malformation type-1.

OBJECTIVE: To assess the correlation between craniovertebral junction (CVJ) abnormalities and syringomyelia in patients with Chiari malformation type-1 (CM1). METHODS: This was a retrospective study including patients with CM1. Identification of cases was done by searching a radiology database at a university hospital from 2012 to 2017. Patients were divided into 2 groups based on whether CVJ abnormalities were present (CVJ+) or absent (CVJ-). The patients` demographic and clinical data were reviewed. All magnetic resonance imaging studies were examined by a certified neuroradiologist. RESULTS: Sixty-four consecutive patients with CM1 were included. The mean age was 24+/-17 years; 59% were females. The CVJ+ group had more female patients (p=0.012). The most frequent CVJ abnormality was platybasia (71%), followed by short clivus (44%) and cervical kyphosis (33%). The CVJ abnormalities were more in Syringomyelia cases (p=0.045). However, the results were not significant when hydrocephalus cases were excluded. CONCLUSION: Among CM1 patients, CVJ abnormalities were found more in patients with syringomyelia. Future studies with larger sample size are required to further study the correlation between CVJ abnormalities and both syringomyelia and hydrocephalus in CM1 patients.

Pediatric intracranial hypertension. Experience from 2 Tertiary Centers.

OBJECTIVE: To review the experience of 2 tertiary centers in Saudi Arabia with intracranial hypertension (IH) in the pediatric population. METHODS: We retrospectively reviewed and analyzed pediatric patients diagnosed with IH from June 2002 to May 2017 in 2 institutes. RESULTS: We identified 53 patients (30 females and 23 males) with a mean age of 7 years at the time of presentation. Among them, 41 patients were younger than 12 years, and 12 were older. Obese and overweight patients constituted 27.00% (n = 14) of all cases, 8 (66.7%) of whom were older than 12 years. The most common presenting feature was papilledema followed by headache. Vitamin D deficiency, which constituted the most common associated condition, was identified in 12 (22.6%) patients. Acetazolamide was the treatment option in 98.11% of patients, and only 5.7% underwent surgical interventions. The length of follow-up ranged from 6 months to 8 years. CONCLUSION: Intracranial hypertension is rare in children and commonly seen in overweight females older than 12 years similar to adults. Patients younger than 12 years tend to develop secondary IH. More studies are needed to characterize the clinical presentation and guide the management plan.

Revision surgery for refractory cubital tunnel syndrome: A systematic review.

BACKGROUND: Indications for revision surgery are unclear in refractory cubital tunnel syndrome patients, and the optimal surgical method has not been determined. The systematic review evaluates the evidence of functional outcome for revision surgery in refractory cubital tunnel syndrome patients. HYPOTHESIS: We hypothesize that functional outcome of revision surgery in refractory cubital tunnel syndrome will be favorable. METHODS: We searched PubMed, Ovid/MEDLINE, Cochrane, Google Scholar, and EMBASE databases using the keywords "cubital tunnel syndrome" or "recurrent cubital tunnel syndrome" and "revision surgery" according to the MeSH index for English-language studies. We performed a systematic review using PRISMA guidelines. The review was registered in PROSPERO (CRD42018096622). RESULTS: Based on the Oxford Centre for Evidence-Based Medicine criteria, one level 3b study and nine level 4 studies were identified, including 195 elbows of 192 patients aged 15-75 years. The remission period for recurrent cubital tunnel syndrome was 6-21 months, and the follow-up period was 6-113 months. Transposition surgery was the primary surgery in 99 (51%) of 178 elbows. The most common intraoperative finding at revision surgery was perineural scarring (79%), with the most frequent entrapment site being the medial intermuscular septum (33%). The most common revision surgery was submuscular transposition of the ulnar nerve (75%). Most studies reported favorable outcomes, although outcomes varied widely among studies. CONCLUSION: This is the first study to summarize the functional outcomes of revision surgery for refractory cubital tunnel syndrome which showed to be favorable. Functional outcomes were averagely reported and varied widely. A consensus regarding the functional outcomes parameter after surgery for cubital tunnel syndrome is urgently needed. LEVEL OF EVIDENCE: III, systematic review.

Central Nervous System Lymphoma in a Patient with Chronic Lymphocytic Leukemia: A Case Report and Literature Review.

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia that affects older adults in the Western world. Symptomatic nervous system invasion in undiagnosed CLL is rare, poorly understood, challenging to treat, and associated with decreased survival. The average survival of CLL patients with central nervous system (CNS) involvement is 3.79 years as compared to six years in CLL patients without CNS involvement. Autopsy studies demonstrated a high incidence of undiagnosed CLL with CNS involvement, suggesting that CNS involvement is either underdiagnosed or subclinical. Although the most common site of CNS involvement is the leptomeninges, our case demonstrates an extremely rare form of CNS diffuse large B-cell parenchymal involvement in a patient with a concurrent diagnosis of systemic CLL.