Anatomical variations of Koerner's septum: a computed tomography-based, single-centered study.

BACKGROUND: Koerner's septum (KS) is a bony plate located at the junction of the petrous and squamous parts of the temporal bone. The reported prevalence of KS varied between studies. KS variations are associated with various pathologies and pose difficulties during surgeries. The study aims to determine the KS frequency in Omani patients and analyze its association with sex and side. METHODS: The present study investigated the KS topography in 344 computed tomography (CT) scans of normal temporal bones of adult Omani patients at Sultan Qaboos University Hospital. The presence of KS and its parts (complete or incomplete), as well as its thickness at three anatomical landmarks were recorded. Additionally, sex and laterality differences in KS parameters were analyzed using a Chi-square test. RESULTS: The overall frequency of KS among Omani subjects was 39.5%. The complete KS was observed only in 14% of cases. The thickness of KS was 0.78 ± 0.21 mm, 0.93 ± 0.28 mm and 0.78 ± 0.21 mm at the head of the malleus (HM), the superior semicircular canal (SSC) and the tympanic sinus (TS), respectively (p < 0.01). KS was present most constantly at the level of HM (64.7%), followed by SSC (57.4%), and less constantly at the level of TS (49.3%). KS frequency was similar in both males than females (41.9% vs 37.3%), with statistically insignificant difference (p = 0.38). No side differences were observed concerning KS frequency (p = 0.955). CONCLUSION: The KS frequency in Omani subjects within the range of previously reported studies. It is incomplete in most of the cases and constantly present at the level of HM. Its thickness is more at the level of SSC.

Computed-tomography evaluation of parietal foramen topography in adults: a retrospective analysis.

BACKGROUND: The parietal foramen (PF) of the skull is a variable anatomic feature with important implications for venous drainage, infection, and injury. Its topography is clinically relevant for neurosurgeons for intracranial navigation and preoperative planning. METHODS: PF topography was investigated in a series of 440 head computed-tomography scans of Omani subjects at Sultan Qaboos University Hospital. The mean age of the patients was 52 ± 17 years and there were 160 males and 280 females. The topography features of the PF, including frequency, diameter, patency, and relative position in relation to the superior sagittal sinus (SSS), were recorded. Additionally, sex and laterality differences in PF parameters were analyzed using a Chi-square test. RESULTS: The overall prevalence of PF was 72.3% (318/440). The bilateral presence of PF was identified in 34% of skulls. Unilateral right-side prevalence was 18.2%, while left prevalence was 13.2% (p = 0.62). The prevalence of unilateral accessory PF on the right side was 1.8%, while it was 1.1% on the left (p = 0.69). PF within the sagittal suture/or intra-sutural PF was observed in 6.8% of skulls, with a frequency of 9.4% in men and 5.4% in women (p = 0.29). The diameter of the PF was 1.45 ± 0.74 mm on the right side, and 1.54 ± 0.99 mm on the left side (p = 0.96). There were 2% of incomplete PF. The PF was located over the SSS in 70.3% on the right side and 53.8% on the left side. No significant differences were observed between the PF topography parameters and sex or laterality. CONCLUSION: The present study for the first time reports the baseline data of PF topography in a large sample of CT scans in the Arab population. The geography and race influence the PF topography differences. PF may be used as a reliable landmark of SSS. The morphological characteristics and distribution of PF reported in this study have clinical implications for imaging diagnosis, intracranial navigation of vascular disorders, and treatment.

Does Frontal Recess Cell Variation Associate with the Development of Frontal Sinusitis? A Narrative Review.

Chronic rhinosinusitis (CRS) can have a significant impact on quality of life. With persistent symptoms and the failure of initial medical treatments, surgical management is indicated. Despite the excellent results of endoscopic sinus surgery for persistent CRS, it is quite a challenging procedure for frontal sinusitis given the complex anatomy and location of the frontal sinus. Frontal recess cells significantly contribute to the complexity of the frontal sinus, and numerous studies have sought to establish their association with sinusitis. This review offers a comprehensive understanding of frontal recess cells, their different classifications, their prevalence among different populations, and their relationship to sinusitis. After an extensive review of the current literature, the International Frontal Sinus Anatomy Classification (IFAC) is the most recent classification method and a preferred practical preoperative assessment tool. Although the agger nasi cell is the most prevalent cell among all reported populations, ethnic variations are still influencing the other cells' distribution. Studies are inconsistent in reporting a relationship between frontal recess cells and sinusitis, and that is mainly because of the differences in the classification methods used. More research using a standardized classification method is needed to understand the association between frontal recess cells and sinusitis.

Partial ectopic posterior pituitary: A rare imaging entity with literature review.

Abnormal development of the posterior pituitary gland can lead to an ectopic location of the neurohypophysis, commonly seen at the median eminence of the hypothalamus or along the infundibular stalk. A partial ectopic posterior pituitary (PEPP) is a very rare variant of the ectopic posterior pituitary, defined as the presence of a double bright spot of neurohypophysis seen in both orthotopic and ectopic locations. We report a two-year-old male toddler with bilateral optic nerve hypoplasia and severe visual impairment who presented to the endocrine outpatient clinic for hypopituitarism evaluation. Magnetic resonance imaging (MRI) of the brain revealed a hypoplastic pituitary gland and infundibulum with a double bright spot of neurohypophysis in the expected normal location and along the median eminence. Severe hypoplasia of both optic nerves and the optic chiasm was also seen. Septum pellucidum was present with no evidence of other brain malformations. The findings are in the septo-optic dysplasia spectrum associated with hypothalamic-pituitary dysfunction and a very rare entity called PEPP. To our knowledge, only a handful of reported cases of this rare entity exist in the literature.

Expanding the clinical spectrum of cytosolic phosphoenolpyruvate carboxykinase deficiency: novel PCK1 variants in four Arabian Gulf families.

BACKGROUND: In metabolic stress, the cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) enzyme is involved in energy production through the gluconeogenesis pathway. PEPCK-C deficiency is a rare childhood-onset autosomal recessive metabolic disease caused by PCK1 genetic defects. Previous studies showed a broad clinical spectrum ranging from asymptomatic to recurrent hypoglycemia with/without lactic acidosis, encephalopathy, seizures, and liver failure. RESULTS: In this article, we discuss the occurrence of PEPCK-C deficiency in four families from the United Arab Emirates and Oman. All patients presented with unexplained hypoglycemia as a common feature. Two out of the seven patients presented with episodes of encephalopathy that resulted in seizures and neuroregression leading to global developmental delay and one patient had a neonatal presentation. Observed biochemical abnormalities include elevated lactate, transaminases, and tricarboxylic acid cycle metabolites in most patients. Elevated creatine kinase was documented in two patients. Whole exome sequencing revealed two novel (c.574T > C, and c.1268 C > T) and a previously reported splice site (c.961 + 1G > A) PCK1 variant in the affected families. CONCLUSION: Patients become vulnerable during intercurrent illness; thus, prevention and prompt reversal of a catabolic state are crucial to avoid irreversible brain damage. This report will help to expand the clinical understanding of this rare disease and recommends screening for PEPCK-C deficiency in unexplained hypoglycemia.

Anatomical variations of the frontal sinus: A computed tomography-based study.

Background: The pneumatization of the frontal sinus is variable between individuals, including monozygotic twins. The volumetric anatomic variants of the frontal sinus are classified into aplasia, hypoplasia, medium-sized, and hyperplasia. We aimed to study the frontal sinus morphology in Omani patients using computed tomography (CT) evaluations. Methods: Retrospectively, 1220 frontal sinus CT scans from 610 patients investigated at Sultan Qaboos University Hospital, Oman, from January 2019 to December 2020 were reviewed. The frontal sinus morphology was classified according to the classification proposed by Guerram et al. The Chi-square test was used to determine the influence of sex. Results: With regard to the unilateral occurrence, the most prevalent frontal sinus category observed was medium-sized (13.3%), followed by hyperplasia (7.9%), hypoplasia (5.4%), and aplasia (2%) categories. Similarly, in bilateral occurrence, the most common frontal sinus category observed was medium-sized (53%), followed by hyperplasia (13.1%), hypoplasia (3.4%) and aplasia (2%) categories. Right and left frontal sinus aplasia were observed in 2.1% and 1.8% of cases, respectively. In terms of sex influence, the left unilateral ( p<0.01) and the bilateral hypoplasia ( p<0.05) were significantly higher in females. On the other hand, the left unilateral ( p<0.01) and the bilateral hyperplasia ( p<0.05) were higher in males. Conclusions: The baseline data of frontal sinus category frequencies reported in the present study is helpful in the diagnostic evaluation of sinusitis in the clinical setting. The preoperative recognition of frontal sinus types, particularly frontal sinus aplasia in multiplanar CT scans, is crucial to avoid unexpected complications while performing endoscopic sinus surgery.

Guillain-Barré Syndrome Associated with SARS-CoV-2 in Two Pediatric Patients.

Guillain-Barré syndrome (GBS) is a recognised complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We report two children with GBS associated with SARS-CoV-2 who presented to a tertiary centre in Muscat, Oman in 2021: The first patient was a three-month-old female infant who presented with bradypnea, encephalopathy, and generalised weakness that required mechanical ventilation. Polymerase chain reaction (PCR) testing of the nasopharyngeal swabs (NPS) was positive for SARS-CoV-2. She had axonal variant GBS based on a nerve conduction study, cerebrospinal fluid analysis, and neuroimaging findings. The second patient was a six-year-old girl with fever, vomiting, and diarrhea followed by ascending weakness who presented with quadriplegia and facial weakness. Subsequently, she developed respiratory muscle weakness and required mechanical ventilation. PCR testing of NPS was negative for SARS-Cov-2, however IgG serology analysis was positive. The clinical course of these two patients was rapidly progressive and both of them required mechanical ventilation. The patient with axonal variant GBS made an incomplete recovery.

Autosomal Recessive NOTCH3-Related Leukodystrophy in Two Siblings and Review of the Literature.

BACKGROUND: NOTCH3, a large type I transmembrane receptor expressed on arterial smooth muscle cells and capillary pericytes, features a diverse extracellular domain with 34 epidermal growth factor-like repeats. It exhibits distinct phenotypes due to variant zygosity and type; missense mutations cause CADASIL with cerebral vasculopathy, while null mutations lead to severe congenital manifestations. METHODS: This report describes two cases with homozygous loss- of- function variants in NOTCH3 along with their clinical manifestations. RESULTS: These patients presented with a severe congenital phenotype, including eye misalignment, visual impairment, epilepsy, global developmental delay, and subsequent development of pyramidal signs. Biallelic nonsense variants were discovered in both the cases (NM_000435.3:c.2203 C > T (p. [Arg735Ter]). Livedo reticularis was not reported in our cases, although it was present in previously reported patients. Autosomal recessive NOTCH3-related leukodystrophy is usually caused by biallelic null mutations in NOTCH3. CONCLUSIONS: The phenotype of biallelic null variants is associated with a more severe phenotype than the dominantly inherited form of the disease.

Alveolar Soft Part Sarcoma of the Tongue: A Rare Tumor at an Unusual Location.

Alveolar soft part sarcoma (ASPS) is a rare type of soft tissue sarcoma that typically affects adolescents and young adults, though it can occur at any age. We report a case of ASPS of the tongue, which is extremely rare at this location. The patient presented with a polypoidal lesion on the tongue, a biopsy of which showed granular and alveolar morphology. A definitive diagnosis was not rendered due to limited tissue. The case was discussed with the treating surgeon, and excision was recommended with clear margins. Excision of the lesion showed typical ASPS. A TFE-3 immunohistochemical stain was done, which showed strong immunoreactivity, thereby confirming the diagnosis of ASPS. This tumour is rare, and its presence in the tongue makes it extremely infrequent.

Physiological Intracranial Calcifications in Children: A computed tomography-based study.

Objectives: This study aimed to examined the frequency of physiological intracranial calcifications (PICs) in paediatric population using computed tomography (CT). Methods: The brain CT scans of consecutive patients (age range: 0-15 years) who had visited Sultan Qaboos University Hospital, Muscat, Oman, from January 2017 to December 2020 were retrospectively assessed for the presence of PICs. The presence of calcifications was identified using 3 mm-thick axial images and coronal and sagittal reformats. Results: A total of 460 patients were examined, with a mean age of 6.54 ± 4.94 years. The frequency of PIC in boys and girls was 35.1% and 35.4%, respectively. PICs were most common in choroid plexus, observed in 35.2% (age range: 0.4-15 years, median: 12 years) of subjects, followed by the pineal gland in 21.1% (age range: 0.5-15 years, median: 12 years) and the habenular nucleus in 13.0% of subjects (age range: 2.9-15 years; median: 12 years). PICs were less common in falx cerebri, observed in 5.9% (age range: 2.8-15 years; median: 13 years) of subjects, and tentorium cerebelli, observed in 3.0% (age range: 7-15 years, median: 14 years) of subjects. PICs increased significantly with increase in age (P <0.001). Conclusion: Choroid plexus is the most frequent site of calcification. Choroid plexus and pineal gland calcifications may be present in infants younger than one year. Recognising PICs is clinically important for radiologists as they can be mistaken for haemorrhage or pathological entities such as neoplasms or metabolic diseases.

Case report: Cyclosporine A-induced extrapyramidal syndrome following hematopoietic stem cell transplantation.

Introduction: Cyclosporine A-associated neurotoxicity has been reported in up to 40% of patients and its wide range of neurological adverse effects have been reported, ranging from mild tremors to fatal leukoencephalopathy. Extrapyramidal (EP) neurotoxicity is a rare manifestation of cyclosporine. Cyclosporine-induced extrapyramidal syndrome remains a rare adverse reaction. Design/methods: A database search was performed for studies in patients from all age groups. We found a total of 10 articles reporting EP as an adverse effect of cyclosporine A. A total of 16 patients were found, and a thorough review of these patients was performed. A comparison of patients was performed to highlight common clinical presentations, investigations during the symptomatic phase, and prognosis. In addition, we describe an 8-year-old boy who developed cyclosporine-related extrapyramidal signs on day 60 post-hematopoietic stem cell transplantation for beta-thalassemia. Conclusion: Cyclosporine A can induce neurotoxicity resulting in diverse symptoms. Signs of EP are rare manifestations of cyclosporine neurotoxicity and should be considered when evaluating post-transplant recipients of cyclosporine when they are present with any EP symptoms. Discontinuation of cyclosporine results in good recovery in most patients.

Spinal Cord Infarct Due to Fibrocartilaginous Embolism in an Adolescent Boy: A Case Report and Literature Review.

Fibrocartilaginous embolism (FCE) is one of the rare causes of acute spinal cord infarction. We report the case of a previously healthy 14-year-old boy with this condition. A few hours after lifting heavy objects, he developed sudden quadriparesis. On examination, he had asymmetric hypotonic quadriparesis and normal dorsal column function but absent spinothalamic function in all limbs with sensory level to shoulder. Magnetic resonance imaging (MRI) of the spine confirmed the diagnosis of spinal infarction secondary to FCE. The patient initially received methylprednisolone and plasma exchange. A follow-up visit after neurorehabilitation showed improvement but with residual neurological deficit. Although FCE is rare, it should be kept as one of the differential diagnoses of an acute neurological deficit of the spinal cord.

Absence of Meckel's Cave with Trigeminal Neuralgia: A Case Report.

Trigeminal neuralgia (TN) is a disabling painful condition along the course of the sensory distribution of the trigeminal nerve that most commonly occurs due to vascular compression or conflict at the root entry zone of the trigeminal nerve. We report a 27-year-old female patient who presented with pain and an electric shock-like sensation on the right side of her face that started three years ago. Magnetic resonance imaging of the brain was done and revealed no neurovascular conflict along the course of the trigeminal nerve. The absence of Meckel's cave with atrophy of the cisternal segment of the trigeminal nerve on the affected side was reported. The absence of Meckel's cave is an exceedingly rare cause of TN, and only a handful of reported cases in the literature suggest the association between them.

Radiologic Assessment of Orbital Dimensions among Omani Subjects: A computed tomography imaging-based study at a single tertiary centre.

Objectives: This study aimed to determine the orbital dimensions of Omani subjects who had been referred for computed tomography (CT) of the brain at Sultan Qaboos University Hospital, Muscat, Oman. Good knowledge of the normal orbital dimensions is clinically essential for successful surgical outcomes. Racial, ethnic and regional variations in the orbital dimensions have been reported. Methods: A total of 273 Omani patients referred for CT scans of the brain were retrospectively evaluated using an electronic medical records database. The orbital dimensions were recorded using both axial and sagittal planes of CT images. Results: The mean orbital index (OI) was found to be 83.25 ± 4.83 mm and the prevalent orbital type was categorised as the mesoseme. The mean orbital index was 83.34 ± 5.05 mm and 83.16 ± 4.57 mm in males and females, respectively, with their difference not being statistically significant (P = 0.76). However, a statistically significant association was observed between the right and left orbits regarding horizontal distance (P <0.05) and vertical distance (P <0.01) of orbit and OI (P <0.05). No significant difference between the OI and age groups was observed in males and females. The mean interorbital distance and interzygomatic distance were found to be 19.45 ± 1.52 mm and 95.59 ± 4.08 mm, respectively. These parameters were significantly higher in males (P <0.05). Conclusion: Results of the present study provide reference values of orbital dimensions in Omani subjects. Mesoseme, a hallmark of Caucasian people, is discovered to be the prevalent orbital type of Omani subjects.