Magnetic resonance imaging findings in central nervous system tuberculosis: A pictorial review.

Central nervous system (CNS) tuberculosis is a post-primary form of tuberculosis. It has high mortality and morbidity rates despite early diagnosis and treatment. CNS tuberculosis can manifest as subacute/chronic meningitis, parenchymal tuberculous lesions, and spinal tuberculosis. Hematogenous spread of tuberculous bacilli to the brain results in the development of so called "rich foci" on the pial surface, ependyma, and grey-white matter junction. Rupture of these "rich foci" into the subarachnoid space triggers an intense granulomatous inflammatory reaction. Tuberculous meningitis can manifest as leptomeningitis or pachymeningitis. Intracranial parenchymal tuberculous lesions may present as tuberculoma, tuberculous abscess, cerebritis, rhombencephalitis, and encephalopathy, with atypical presentations not uncommon. Complications of CNS tuberculosis encompass hydrocephalus, syrinx formation, vasculitis, infarcts, neuritis, and enduring neurological deficits. Post-contrast 3D fluid-attenuated inversion recovery (FLAIR) and post-contrast T1 spin-echo sequences excel in detecting tuberculous meningitis compared to other conventional magnetic resonance imaging (MRI) sequences. In proton magnetic resonance spectroscopy (PMRS), the presence of a lipid peak at 1.3 ppm is indicative of tuberculous lesions. Magnetization transfer (MT) imaging enhances the detection of tuberculous lesions, as the magnetization transfer ratio (MTR) of tuberculous pathologies, owing to their high lipid content, is lower than that in bacterial or fungal pathologies and higher than that in viral pathologies. This review article delves into the various typical and atypical imaging presentations of CNS tuberculosis in MRI, along with recent advances in imaging techniques.

Evaluation of variations of optic nerve course in relation to posterior paranasal sinuses in MDCT in a tertiary care center of Nepal: a retrospective cross-section study.

Background: The proximity of optic nerves to the posterior paranasal sinuses (PNS) is a critical consideration in preventing optic nerve injuries during functional endoscopic sinus surgery. Methods: A retrospective cross-sectional study was conducted on 367 patients aged 13 years and above. Four radiologists, each with 2-6 years of experience, evaluated computed tomography scans of the PNS and the head of these patients. The optic nerves were classified into four types based on DeLano's classification, and their respective prevalence rates were determined. Additionally, the prevalence of optic nerve dehiscence and pneumatization of the anterior clinoid process was assessed. Results: A total of 734 optic nerves were evaluated and categorized into four groups as per DeLano's classification. The most common type was classified as type 1 optic nerve, representing 65.4% of all optic nerves. Types 2, 3, and 4 optic nerves accounted for 16.9, 8.6, and 9.1%, respectively. The prevalence rates of type 1, type 2, type 3, and type 4 optic nerves were 76.6, 24.5, 12.3, and 14.4%, respectively. Optic nerve dehiscence was observed in 14.3% of cases, with a prevalence of 21.2% in the study. Type 3 optic nerves were most commonly associated with dehiscence, with 49.2% of them showing dehiscence in their course through the ethmoid or sphenoid sinus. The prevalence of pneumatization of the anterior clinoid process in the study population was 28.3%, with type 3 optic nerves being the most frequently associated. Conclusion: An understanding of the relationship between optic nerves and posterior PNS, as well as awareness of optic nerve dehiscence, is essential in preventing injuries during sinus surgeries. Type 1 optic nerve predominates among Nepalese patients visiting our hospital.

Delayed presentation of congenital sigmoid colon stenosis: a rare entity.

Congenital sigmoid colon stenosis is a rare entity that can mimic Hirschsprung disease. Presentation of congenital colon stenosis is usually within first few weeks of life. Our case presented with features of distal bowel obstruction at 2 years of age with the history of chronic constipation and progressive abdominal distention from first week of life and bilious vomiting for the last 1 week. Clinical diagnosis of Hirschsprung disease was made. Contrast enhanced CT abdomen showed bowel obstruction with transition point at the level of proximal sigmoid colon. There was a short segment stenosis at the level of proximal sigmoid colon. Contrast enema showed stenosis at proximal sigmoid colon. The bowel distal to stenosis was normal in calibre. Similar findings were seen during surgery. Mesocolon was present in stenosed segment of the bowel. The resected stenotic segment showed adequate ganglion cells in histopathology.

Hashimoto thyroiditis in a lingual thyroid: An interesting case.

Key Clinical Message: Whenever an enlarging mass is seen in throat, possibility of lingual thyroid should be considered. Thyroid function test should be done whenever ectopic thyroid is detected. Imaging (ultrasonography or Tc-99m scintigraphy) is adequate for diagnosis. Conservative treatment with levothyroxine helps in reducing size of lingual thyroid. Abstract: Hashimoto thyroiditis in lingual thyroid results in enlargement of the thyroid gland and oropharyngeal symptoms. Suppression therapy with levothyroxine results in reduction in size of the gland. We present an interesting case of Hashimoto disease in an adolescent female presenting as oropharyngeal mass.

Von Hippel Lindau Disease with central nervous system and multiple visceral manifestations: A case report.

Von Hippel-Lindau (VHL) disease is an autosomal-dominant syndrome caused by mutations in the VHL gene, located on the short arm of chromosome 3. Patients with VHL are likely to manifest with a spectrum of multiple benign and malignant tumors involving various organ systems. We present a case of a 28-year-old female without a remarkable family history who presented with complaints of hematuria and abdominal discomfort. Initial laboratory investigations confirmed hematuria. Subsequent abdominal computed tomography scan revealed heterogeneous enhancing solid mass in bilateral kidneys, avidly enhancing mass in the right adrenal gland, bilateral simple renal cortical cysts, and a pancreatic cyst. With a provisional diagnosis of VHL disease, an MRI of the brain and spine was performed, which showed the presence of a cerebellar hemangioblastoma. Her catecholamine and vanillylmandelic acid levels were in the normal range not in line with pheochromocytoma. The patient then underwent bilateral partial renal nephrectomy and right adrenalectomy. Histopathologic examination reported clear renal cell carcinoma and pheochromocytoma of the right adrenal gland mass. Molecular genetic testing confirmed the presence of VHL disease.

Acute hydrocephalus caused by colloid cyst of third ventricle: A case report.

Colloid cysts (CCs) of third ventricle are rare benign lesions. They present with acute hydrocephalus and its sequalae like brain herniation, infarcts resulting even death in otherwise healthy individual. We present a case of an acute hydrocephalus caused by CC of third ventricle. A middle age male was airlifted from a remote district of Nepal to our hospital with no accompanying doctor. The patient had headache, multiple episodes of vomiting, abnormal body movement, and loss of consciousness for 24 hours. On examination, vitals were stable; the Glasgow Coma Scale (GCS) score was 7. The patient was intubated in emergency and an MRI brain was done. MRI showed an obstructive lesion in third ventricle with features consistent with CC and an active hydrocephalus. There were multifocal infarcts in the bilateral cerebrum, left part of mid brain and pons, left thalamus and left superior cerebellum. We inserted external ventricular drainage in emergency operation theatre within hours and endoscopic excision of the lesion was done on the next day. In histopathology, the lesion was confirmed to be a CC.

Susceptibility of Diaphorina citri to Irradiation with UV-A and UV-B and the Applicability of the Bunsen-Roscoe Reciprocity Law.

Populations of Diaphorina citri decline with elevation and, in a study in Bhutan, were rarely found above 1200 m ASL. The impact of ultraviolet (UV) radiation, particularly UV-B, on immature stages of the psyllid was proposed as limiting factor. As no studies have been undertaken on the influences of UV radiation on the development of D. citri, we examined the effects of UV-A and UV-B on different stadia of the psyllid. In addition, compliance with the Bunsen-Roscoe reciprocity law was examined. Irradiation with UV-A marginally reduced egg hatch and the survival times of emerging nymphs. Early instar nymphs were little affected by this waveband, but the survival of adults was reduced at the higher doses used. With UV-B, egg hatch and the survival times of early and late instar nymphs declined in proportion to UV-B dose. A dose of 57.6 kJ m-2 d-1 reduced the survival time of only adult females. Female fecundity was reduced at high UV-A and UV-B doses but increased at low doses. The Bunsen-Roscoe law held true for eggs and early instar nymphs for different durations and irradiances of UV-B. Eggs and nymphs had ED50 values for UV-B lower than the daily fluxes of this wavelength experienced worldwide. Thus, UV-B could be a factor causing the psyllid to be scarce at high elevations.

Ischemic Portal Venous Gas and Pneumatosis Intestinalis Managed Conservatively in a Patient with Rheumatic Heart Disease and Warfarin Induced Coagulopathy: A Case Report.

Mesenteric ischemia is a surgical emergency. The presence of hepatic portal venous gas and pneumatosis intestinalis is a frequent finding in computed tomography. Not all hepatic portal venous gas and pneumatosis intestinalis are due to mesenteric ischemia. A 70-year-old female, with a known case of diabetes mellitus, rheumatic heart disease and atrial fibrillation under warfarin presented with diffuse abdominal pain, multiple episodes of vomiting and ecchymosis in bilateral flanks. Evaluation of the coagulation profile suggested warfarin-induced coagulopathy. Portal venous gas was detected during an ultrasound examination. Subsequent contrast-enhanced computed tomography abdomen showed hepatic portal venous gas, pneumatosis intestinalis, paucity of branches of the ileocolic artery, and reduced enhancement of caecum and ascending colon. Mild ascites were present in the pelvis. Arterial blood gas analysis revealed compensated metabolic acidosis. The patient was managed conservatively and discharged after nine days of hospital admission. Conservative approach can be considered for suspected mesenteric ischemia in surgically unfit candidates. Keywords: case reports; mesenteric ischemia; portal vein; rheumatic heart disease; warfarin.

Rhegmatogenous retinal detachment in Coats' disease: a case report.

BACKGROUND: Coats' disease was originally defined as a unilateral idiopathic exudative retinopathy in young males, characterized by abnormal retinal vascular telangiectasia with intraretinal and subretinal lipid exudation. The retinal detachment is usually exudative. Herein, we describe a case of rhegmatogenous retinal detachment with detectable retinal break in a patient with Coats' disease. CASE PRESENTATION: A 15-year-old Indo-Aryan male patient presented with sudden painless diminution of vision in his right eye of 4 days duration. Upon examination, the anterior segment in both eyes and left fundus was within normal limits. Dilated fundus evaluation of the right eye revealed telangiectasia of the retinal vessels, with subretinal exudation in superotemporal and superonasal quadrants and presence of subretinal fluid in the superotemporal area extending into fovea. There was also presence of single flap horseshoe tear in the superotemporal quadrant at around the 10 o'clock position in the equatorial region, with no secondary changes. The retina was reattached with encircling band buckle combined with vitrectomy and silicon oil tamponade. Seven months post vitrectomy, lenticular opacification developed, for which he underwent silicon oil removal, along with lens aspiration and implantation of foldable intraocular lens. Over the period of 1 year, his best corrected visual acuity improved from 6/60 to 6/18 in the affected eye at the last follow-up visit. The recovery was uneventful following the subsequent surgery. CONCLUSION: Coats' disease has a remarkable diversity in clinical presentation and morphology. The disease can also present with an underlying break, which may not be attributed to any iatrogenic modality. The treatment modalities in coats' disease should be tailored individually due to the low incidence of the disease and the great variation in severity upon presentation. Prompt management restores the best possible anatomical outcome and maintains good vision.