Biallelic KITLG variants lead to a distinct spectrum of hypomelanosis and sensorineural hearing loss.

BACKGROUND: Pathogenic variants in KITLG, a crucial protein involved in pigmentation and neural crest cell migration, cause non-syndromic hearing loss, Waardenburg syndrome type 2, familial progressive hyperpigmentation and familial progressive hyper- and hypopigmentation, all of which are inherited in an autosomal dominant manner. OBJECTIVES: To describe the genotypic and clinical spectrum of biallelic KITLG-variants. METHODS: We used a genotype-first approach through the GeneMatcher data sharing platform to collect individuals with biallelic KITLG variants and reviewed the literature for overlapping reports. RESULTS: We describe the first case series with biallelic KITLG variants; we expand the known hypomelanosis spectrum to include a 'sock-and-glove-like', symmetric distribution, progressive repigmentation and generalized hypomelanosis. We speculate that KITLG biallelic loss-of-function variants cause generalized hypomelanosis, whilst variants with residual function lead to a variable auditory-pigmentary disorder mostly reminiscent of Waardenburg syndrome type 2 or piebaldism. CONCLUSIONS: We provide consolidating evidence that biallelic KITLG variants cause a distinct auditory-pigmentary disorder. We evidence a significant clinical variability, similar to the one previously observed in KIT-related piebaldism.

Variants in CIB2 cause DFNB48 and not USH1J.

The genetic, mutational and phenotypic spectrum of deafness-causing genes shows great diversity and pleiotropy. The best examples are the group of genes, which when mutated can either cause non-syndromic hearing loss (NSHL) or the most common dual sensory impairment, Usher syndrome (USH). Variants in the CIB2 gene have been previously reported to cause hearing loss at the DFNB48 locus and deaf-blindness at the USH1J locus. In this study, we characterize the phenotypic spectrum in a multiethnic cohort with autosomal recessive non-syndromic hearing loss (ARNSHL) due to variants in the CIB2 gene. Of the 6 families we ascertained, 3 segregated novel loss-of-function (LOF) variants, 2 families segregated missense variants (1 novel) and 1 family segregated a previously reported pathogenic variant in trans with a frameshift variant. This report is the first to show that biallelic LOF variants in CIB2 cause ARNSHL and not USH. In the era of precision medicine, providing the correct diagnosis (NSHL vs USH) is essential for patient care as it impacts potential intervention and prevention options for patients. Here, we provide evidence disqualifying CIB2 as an USH-causing gene.

A Mayan founder mutation is a common cause of deafness in Guatemala.

Over 5% of the world's population has varying degrees of hearing loss. Mutations in GJB2 are the most common cause of autosomal recessive non-syndromic hearing loss (ARNHL) in many populations. The frequency and type of mutations are influenced by ethnicity. Guatemala is a multi-ethnic country with four major populations: Maya, Ladino, Xinca, and Garifuna. To determine the mutation profile of GJB2 in a ARNHL population from Guatemala, we sequenced both exons of GJB2 in 133 unrelated families. A total of six pathogenic variants were detected. The most frequent pathogenic variant is c.131G>A (p.Trp44*) detected in 21 of 266 alleles. We show that c.131G>A is associated with a conserved haplotype in Guatemala suggesting a single founder. The majority of Mayan population lives in the west region of the country from where all c.131G>A carriers originated. Further analysis of genome-wide variation of individuals carrying the c.131G>A mutation compared with those of Native American, European, and African populations shows a close match with the Mayan population.

Exploring the relationship between the severity of oligozoospermia and the frequencies of sperm chromosome aneuploidies.

The study was aimed to investigate the association between the degree of oligozoospermia and sperm chromosome aneuploidy frequencies in male infertility and to determine whether chromosomal profiles of sperm nuclei would be used for a supportive test before additive reproduction technics. The meiotic segregation profiles of chromosomes X, Y, 13, 18 and 21 were compared by fluorescent in-situ hybridisation (FISH) on the spermatozoa of 30 normally karyotyped oligozoospermic (10 mild, 11 moderate, nine severe) cases without Y-microdeletions, and 10 normozoospermic cases. The results showed significantly higher frequencies of chromosomes 13, 18, 21 disomies (P < 0.001) in the group of patients with moderate and severe oligozoospermia compared with the disomy frequencies of normozoospermic group. The statistically significant differences were also determined in disomy frequencies of sex chromosomes (XY, XX and YY) in between oligozoospermic and normozoospermic groups (P < 0.001, P < 0.001, P < 0.040, respectively). Because oligozoospermic patients are the ones consulted the most for assisted reproductive techniques, identification of sperm aneuploidy rates in men could be considered as an appropriate supportive test before the reproductive implementations. Furthermore, the patients should be counselled with respect to genetic screening results for the potential risk of aneuploid embryo and pre-implantation genetic diagnosis or prenatal diagnosis.

Extremely delayed renal cell carcinoma metastasis mimicking convexity meningioma.

Cerebral extra-axial metastasis mimicking meningioma which satisfy several criteria for a diagnosis of meningioma, but which have proved instead to be metastatic carcinoma and extremely delayed cerebral metastasis from renal cell carcinoma, form the focus of the presentation. 68-year-old-woman who had been operated for renal cell carcinoma 20 years previously is presented with new symptoms of intracranial mass. A large extra-axial mass of the convexity which destroyed calvarium and dura was excised with Simpson Grade I removal, revealed metastatic carcinoma. Imaging characteristics can not always discern between meningioma and metastatic tumours. A meticulous clinical evaluation and histopathological diagnosis is essential in patients with intracranial mass even when they resemble both primary and metastatic tumours.

Can facet joint infiltrative analgesia reduce postoperative pain in degenerative lumbar disc surgery?

OBJECTIVE: Perioperative analgesia effects the postoperative course of pain. The purpose of this study was to evaluate its possible relation with the consumption of dolantine and analgesics and the facet-induced pain and postoperative pain score in degenerative disc surgery. METHODS: We employed perioperative intra- and perifacet bupivacaine infiltration technique to reduce the postoperative pain after lumbar disc surgery. The study was randomized and observer blinded enrolling 40 American Society of Anesthesiologists physical status class I-II patients scheduled for elective degenerative lumbar disc surgery. The patients were divided into two groups of 20 of which Group 1 underwent injection of bupivacaine into the subcutaneous and muscular layers around the incision site, while Group 2 underwent additional intra- and perifacetal joint infiltration. Postoperatively, the patients were provided with a programmed patient-controlled pump which was only activated on demand to infuse dolantine for the next 24 hours. In the postanesthesia care unit the delay for analgesia and the dose of dolantine used were recorded. RESULTS: There was no statistical significance between these two groups regarding postoperative visual analoque scale scores. The time before the first analgesic request was significantly longer in facet group (p= 0,006). The cumulative dolantine dose was also significantly lower in the facet group (p= 0,001). CONCLUSION: The results indicate that facet joint infiltrative analgesia may have an effect on the postoperative analgesic requirement and reduce the dolantine consumption.

VACTERL-H associated with central hypothyroidism: a case report.

The VACTERL-H syndrome is a rare combination of vertebral anomalies, anal atresia, congenital heart defects, tracheo-esophageal fistula, abnormalities of kidneys and limb anomalies together with hydrocephalus. This condition is recognized as a hereditary entity with poor prognosis. We present a newborn weighing 3400 g, born by cesarean section to a 27 years old mother who had had an irregular antenatal follow-up. The patient had severe hydrocephalus, proximal esophageal atresia and distal tracheoesophageal fistula, gastric outlet obstruction, imperforated anus and recto-urethral fistula, patent ductus arterious, a bifid scrotum, a vertebral defect, sacral dimple and central hypothyroidism. The patient had no limb defects. The association of central hypothyroidism and VACTERL-H has previously not been reported.

Persistent metopic suture can mimic the skull fractures in the emergency setting?

Metopism is partially or totally persisting suture extending from the nasion to the anterior angle of the bregma. The time of physiological closure of the metopic suture varies from birth to 8 years of age. Widely accepted closuring time is approximated at 2 years of age. Although formerly reported skull studies mentioned the persistent metopic suture, it is extremely rare in clinical practice. We presented a trauma case of 43 years of age who was demonstrated radiologically to have a persisting suture. Persistent metopic suture may be misdiagnosed as a vertical traumatic skull fracture extending in the mid-line in head trauma patients. Therefore the surgeon should be aware of this anatomical condition in the primary and secondary surveillance of the traumatized patient and during surgical intervention including especially frontal craniotomy. Reconstructed tomography scan demonstrating sutural closuring status may provide additional informative value in the diagnostic sequence superior to plain X-ray in the emergency setting.

Late dissemination of ependymoma: case report.

Spinal cord dissemination over 10 years after surgical removal of the fourth ventricle ependymoma without local recurrence is extremely rare. A 49-year-old male underwent a macroscopically gross total removal of the fourth ventricle ependymoma and postoperative radiotherapy to the posterior fossa. Twelve years after the initial operation, the patient complained from uncontrolled fever attacks, low back pain and numbness of the legs. Spinal Magnetic Resonance Imaging revealed intradural extramedullary mass lesions located at the thoracic 2-3 and lumbar 5 vertebrae levels. Cerebrospinal fluid examination showed no tumour cells. He underwent total excision of these spinal lesions. Although the majority of the recurrences take place within a few years after surgery, we experienced a case with multiple spinal disseminations 12 years after the resection of the fourth ventricle ependymoma and administration of the radiation therapy to the posterior fossa. Up to our knowledge, this case represents the second unusual late recurrence reported in the literature. We conclude that low grade ependymomas should be followed neurologically and radiologically for more than 10 years after the initial treatment.

First illustrations of female "Neurosurgeons" in the fifteenth century by Serefeddin Sabuncuoglu.

Males have dominated medicine for many centuries. Females could not appear in the medical history equally till the end of the 18th century; although they always have been in medicine as healers. It is worth mentioning that first illustrations indicating female surgeons were found in the book written in Turkish by Serefeddin Sabuncuoglu in the 15th century; while Europe was newly waking up from its dark ages and Middle East was under the influence of strict rules of Arabic and Islamic culture. Serefeddin Sabuncuoglu (1385-1470) was the author of the first illustrated surgical textbook Cerrahiyyetu'l-Haniyye (Imperial surgery) in Turkish Literature. Inside miniatures drawn by Serefeddin Sabuncuoglu indicated that the female surgeons, acknowledged "Tabibe", had been allowed to practice alone in Anatolia. Tabibes are illustrated in the miniatures practicing on the management of dead foetus with foetal hydrocephalus and macrocephalus which were the first clues by means of Turkish women in Neurosurgery.

Variations in Multiple Syndromic Deafness Genes Mimic Non-syndromic Hearing Loss.

The genetics of both syndromic (SHL) and non-syndromic hearing loss (NSHL) is characterized by a high degree of genetic heterogeneity. We analyzed whole exome sequencing data of 102 unrelated probands with apparently NSHL without a causative variant in known NSHL genes. We detected five causative variants in different SHL genes (SOX10, MITF, PTPN11, CHD7, and KMT2D) in five (4.9%) probands. Clinical re-evaluation of these probands shows that some of them have subtle syndromic findings, while none of them meets clinical criteria for the diagnosis of the associated syndrome (Waardenburg (SOX10 and MITF), Kallmann (CHD7 and SOX10), Noonan/LEOPARD (PTPN11), CHARGE (CHD7), or Kabuki (KMT2D). This study demonstrates that individuals who are evaluated for NSHL can have pathogenic variants in SHL genes that are not usually considered for etiologic studies.

Pott's puffy tumor of the vertex years after trauma in a diabetic patient: case report.

Pott's puffy tumor is a rare clinical entity characterized by subperiosteal abscess associated with osteomyelitis. It is usually seen as a complication of frontal sinusitis or trauma. This is the unique report of a Pott's puffy tumor located over the vertex of a type 1 diabetic patient with an unusual latency of 14 years following injury. A 27-year old man presented with pain and a soft swelling on his vertex. Magnetic resonance imaging demonstrated subperiosteal abscess in the vertex region associated with dural thickening and perisinusal irregularities of epidural space. Further history revealed that he had a trauma to the same location when he was 13 years old. Considering possible complications due to proximity of the lesion to the sagittal sinus, we retrained from aggressive surgical interventions. We treated our patient with a simple surgical abscess drainage followed by prolonged use of antibiotics and achieved complete therapy. The cellular and humoral elements of the immune system may be disrupted in diabetic patients resulting in such atypical courses and complications of infections. We want to emphasize both importance of the prompt diagnosis of Pott's puffy tumor as intracranial invasion may cause severe neurologic problems, and importance of a surgical intervention tailored for the individual lesion.

The morphometric and cephalometric study of anterior cranial landmarks for surgery.

OBJECTIVE: The aim of this work was to determine reliable bony landmarks for the anterior skull base and to standardize some specific dimensions among the frontal sinus and neighboring structures for safe anterior cranial surgery. METHODS: The study consisted of a topographical anatomic examination and cephalometric analysis of the skull. Thirty adult skulls (60 sides) were studied regarding the localization and dimensions of the supraorbital foramen (SOF), frontal sinus (FS), frontozygomatic fissure, infraorbital foramen, anterior nasal spine, and nasion. Differences between the measurement of skulls and cephalograms were analyzed by Student's t test. The Pearson correlation test was used for statistical analysis of the cephalogram. RESULTS: Examination of the 60 sides of the bony heads revealed that the shape of the SOF was a foramen in 25 sides (41%), a notch in 29 sides (49%), and a groove in 6 sides (10%). A total of 20 (33%) SOFs were inside the FS and the mean distance was 6.3+1.34 mm from the lateral border of the sinus, 27 (45%) of SOFs were outside of the FS and the mean distance was 8.8+2.01 mm, and 13 (22%) of SOFs were at the border of the FS. According to our measurements the medial border of the craniotomy should be placed approximately 43 mm lateral to the nasion to avoid entering into the frontal sinus. CONCLUSION: To plan and to decide the convenient and safe anterior midline skull base approach and to avoid postoperative complications, bony landmarks and anatomic measurements around the SOF and FS will be helpful for the surgeon to constitute a simplification of topographic anatomy.

Critically located cavernous malformations.

INTRODUCTION: The aim of this study was to evaluate the clinical results of patients who underwent resection with the aid of microsurgical techniques and stereotactic and image-guided surgery for critically located cavernous malformations which still represent a considerable surgical challenge due to the close proximity of vital and eloquent structures. METHODS: Between 1997 and 2003, 12 patients with critically located cavernous malformations (CMs) underwent surgical resections at Ankara University Hospital. CMs of the pons (n=3), medulla oblongata (n=1), cavernous sinus (n=3), motor cortex (n=4) and the newly defined superior cerebellar peduncle (n=1) were treated using image-guidance and advanced microsurgical principles. Preoperative assessment was done with CT, MRI and angiography. Lesion locations, clinical presentations and outcome were analyzed. The surgical approach was chosen as lateral suboccipital (n=4), parietal (n=4), cranio-orbitozygomatic (n=3) and retrosigmoid (n=1). RESULTS: All CMs were readily identified and completely removed with no permanent morbidity and mortality. The immediate outcome after surgery was improved for 8 patients (66.6%). Long-term outcome was unchanged for one patient and a proved good surgical outcome for three patients, during the mean follow-up period. DISCUSSION: Stereotactic methods together with image-guidance and microsurgical techniques allow the creation of most effective and safe corridors to access the CMs in eloquent regions with a minimization of tissue manipulation and low risk of permanent neurological deficit.

"Triple cross" of the hypoglossal nerve and its microsurgical impact to entrapment disorders.

OBJECTIVE: Cadaveric dissections were performed to review the intracranial and extracranial course of the hypoglossal nerve. The neurological significance of a newly defined "triple cross" of the hypoglossal nerve is discussed. MATERIALS AND METHODS: 10 cadaveric heads (left and right; 20 sides) were dissected using microsurgical techniques. RESULTS: In the cisternal segment of hypoglossal nerve, the diameter of the rostral trunk amounted to 155-680 microm (mean 435 microm), and the caudal trunk to 210-820 microm (mean 482 microm). The roots formed three trunks in 20% of the hypoglossal nerves and two trunks in the rest. As a first cross, the anterior medullary segment of the vertebral artery crossed the hypoglossal nerve roots in 14 of 20 sides (70%). As a rare variation, the vertebral artery extended medial to the nerve (25%) or between its roots (5%). The second cross was found between the descendens hypoglossus and the occipital artery (75%), sternocleidomastoid artery and vein complex (15%) and external carotid artery (10%). The third cross was shown in the submandibular triangle between the lingual hypoglossus and its drainage vein; vena committans nervus hypoglossus. CONCLUSION: Throughout its way, the hypoglossal nerve passes over vascular structures in three crossing points which may serve as a probable cause of hypoglossal nerve entrapment disorders.

Tracing the dural tail with image-guided surgery.

OBJECTIVE: The extent of dural resection is important for preventing recurrence in meningioma management. An image-guidance assisted technique is described to perform adequate dural resection. METHODS: A universal instrument adapter system for image-guidance was used to track the dural extension of the meningioma accurately. RESULTS: The universal instrument adapter offers the surgeon the possibility to image-guide nearly any rigid instrument via the computed calibration method. In this way a surgical marking pen was used to chase and adequately mark the "dural tail". DISCUSSION: Image-guidance systems can be used to avoid incomplete resection of the affected dura that may be responsible for tumour recurrence.

Posterior communicating artery: from microsurgical, endoscopic and radiological perspective.

OBJECTIVE: The main objective of this study was to display the morphological characteristics of the posterior communicating artery and its perforating branches in various configurations of the circle of Willis and their relationship with neighbouring anatomic structures by microscopic examination of the brain hemispheres and endoscopic examination of cadaver specimens. A secondary aim was to investigate the possibility of detecting the posterior communicating artery and its variations in cerebral MR angiographies performed for various reasons. METHODS: The posterior communicating artery was examined under the microscope in 24 cerebral hemisphere specimens, by endoscopy in 5 cadavers and by 3D TOF MRI in 62 patients. RESULTS: The posterior communicating artery had a hypoplastic configuration in 28 %, whereas it was transitional in 14 %, fetal in 28 % and adult in 30 % of cerebral hemisphere specimens. While no posterior communicating artery and transitional configuration could be detected in 11 % of the MR angiography examinations, 34 % had a hypoplastic configuration, 10 % a fetal configuration and 45 % an adult configuration. The percentage of infundibular dilatation was 22 % and the pre-mamillary artery was the thickest perforating branch. The diameter of the posterior communicating artery varied between 0.5 and 3.03 mm. DISCUSSION: A detailed knowledge on the variations of the posterior communicating artery and the morphological characteristics of the perforators arising from this artery in various configurations of the circle of Willis is an important factor affecting the results of surgical interventions.

Microsurgical landmarks for safe removal of anterior clinoid process.

OBJECTIVE: The microsurgical and radiological anatomy of the clinoid process were studied to give surgeons more details about the anterior clinoid process and its relations to the vascular and nervous neighbourhood during intradural and extradural clinoidectomy, thus making the operative procedures safer. METHODS: Seven formalin-fixed (14 sides) and two fresh cadavers (four sides) were studied to reveal the surgical anatomy of the anterior clinoid process and related landmarks during intradural and extradural drilling techniques of clinoid process. Furthermore, aeration of the anterior clinoid process was investigated in 100 paranasal tomography (200 sides) scans. RESULTS: Careful drilling of the anterior clinoid process is mandatory to avoid damage to the extremely important adjacent structures. The anterior clinoid process must not be removed in one piece. Clinoid folds and the frontotemporal fold should be exposed adequately. The falciform ligament must be cut to visualize the optic nerve and ophthalmic artery clearly. Preoperative radiological assessment of clinoid process variations should be done. In computerized tomography scans, pneumatization of the right anterior clinoid process was found in 12%, of the left anterior clinoid process in 7% and bilaterally pneumatization was present in 9%. CONCLUSIONS: Removal of the ACP is one of the most critical procedures to the successful and safe management of ophthalmic segment aneurysms and tumors located in the paraclinoid region and cavernous sinus. Special attention should be paid to the anatomic landmarks indicating the relationship between the anterior clinoid process and adjacent structures. Beside that, pneumatization of the anterior clinoid process should be evaluated preoperatively with computed tomography to avoid complications such as rhinorrhea and pneumocephalus.

Non-traumatic elevation techniques of the hypoglossal nerve during carotid endarterectomy: a cadaveric study.

OBJECTIVE: Ligation and dissection techniques of sternocleidomastoid artery, vein, ansa cervicalis and posterior belly of digastric muscle were developed in a cadaveric study for achieving minimally invasive elevation of the hypoglossal nerve during carotid endarterectomy and were subsequently used in patient treatment. METHODS: Carotid bifurcations, the extracranial part of the hypoglossal nerve, the sternocleidomastoid artery and vein and neighboring neurovascular structures were studied on 10 formalin-fixed adult cadaver heads (20 sides) under the surgical microscope. Landmarks and measurements for identification of the sternocleidomastoid artery and vein are described. RESULTS: The distance between the hypoglossal loop and the carotid bifurcation was measured as 14.5 - 25.2 mm (mean: 19.24 mm). 30 % of 20 sides were determined to have a Zone II-type carotid bifurcation. In 33 % of the Zone-II-type bifurcations, a low-lying hypoglossal loop was demonstrated. The sternocleidomastoid artery begins 2.2 - 3.5 mm (mean: 2.94 mm) supero-posterior from the occipital artery after the crossing point between the occipital artery and the hypoglossal nerve. The sternocleidomastoid artery and vein complex was 17.1 - 21.5 mm (mean 18.47 mm) away from the carotid bifurcation and forms a right angle with the descending hypoglossal nerve. The contribution of the sternocleidomastoid branch of the occipital artery always reaches the middle parts of the sternocleidomastoid muscle. CONCLUSION: Carotid endarterectomy through having knowledge of the normal and variable trajectories of the structures can almost always be accomplished as a safe procedure when appropriate maneuvers are applied. Dissection and ligation of the sternocleidomastoid artery, vein, ansa cervicalis and posterior belly of digastric muscle are very simple but effective techniques to obtain adequate exposure either for safe arterial reconstruction or to diminish the necessity for more complicated technical procedures.

Ceftriaxone-induced symptomatic pseudolithiasis mimicking ICP elevation.

In neurosurgery, ceftriaxone is a widely used, third generation cephalosporin for the treatment of CNS infections and perioperational prophylaxis. Recent studies have demonstrated that ceftriaxone induces reversible precipitates in the gallbladder. This complication is referred to as "biliary pseudolithiasis", and it has symptoms similar to the raised intracranial pressure (ICP) symptoms of the perioperative period. Symptomatic biliary pseudolithiasis should be kept in mind in all pediatric neurosurgery cases under ceftriaxone therapy in order to prevent unnecessary postoperative investigations and surgery.