Unilateral developmental absence of internal carotid artery with contralateral middle cerebral artery occlusion.

PURPOSE: Developmental absence of the internal carotid artery (ICA) is a rare congenital anomaly that results from an insult to the third aortic arch or dorsal aorta during early embryogenesis. Patients are often asymptomatic and are diagnosed incidentally during imaging to investigate neurological complaints. METHODS: We report a rare finding of an absent ICA during a workup of stroke in a middle-aged patient. RESULTS: CT brain perfusion (CTP) and CT angiography (CTA) revealed the right middle cerebral artery (MCA) thrombotic stroke with the demonstration of contralateral left ICA absence. The patient showed spontaneous recovery, and no thrombolysis or neurointervention was considered. CONCLUSIONS: This article highlights the importance of screening the head CT on bone window settings in case of the non-visualization of ICA to differentiate congenital absence from a steno-occlusive disease. It also illustrates the role of Magnetic resonance imaging (MRI) and MR Angiography (MRA) in demonstrating further possible vascular anomalies, structural brain malformations, and collateral circulation.

Case 302: Supratentorial Lymphocytic Inflammation with Parenchymal Perivascular Enhancement Responsive to Steroids.

HISTORY: Part one of this case appeared 4 months previously and may contain larger images. A 21-year-old immunocompetent man who was a long-term resident of Qatar presented to the emergency department with recurrent episodes of unprovoked generalized tonic-clonic seizures lasting 2-3 minutes that spontaneously resolved and were associated with postictal confusion. The patient also had progressive mild diplopia, intermittent dizziness, and numbness in the left arm over the course of 3 months. The patient did not have any other systemic symptoms or chronic medical diseases. He did not have any history of intake of illicit drugs, supplements, or regular medications; he had not received any recent vaccinations; and he had not undergone any surgical procedures. He had no history of travel. At presentation, vital signs were normal. Neurologic examination showed mild left homonymous hemianopia, normal gait with no cerebellar signs, and preserved sensations, power, tone, and reflexes in all four limbs. An electroencephalogram showed no epileptiform discharges. Chest CT and extensive laboratory work-up, including viral, fungal, bacterial, and parasite work-up, thyroid function tests, and immunologic blood tests yielded normal results. Those included normal complete and differential blood counts and normal serum chemistry. Serum analysis was negative for antinuclear antibody, Sjögren syndrome antigens A and B, cytoplasmic antineutrophil cvtoplasmic antibody, and paraneoplastic profile. Serum evaluation was also negative for human immunodeficiency virus type 1 and type 2 RNA, and Brucella, Schistosoma, and toxoplasma antibodies. Venereal Disease Research Laboratory (VDRL) and rapid plasma regain (RPR) test results were negative. Cerebrospinal fluid (CSF) analysis revealed clear fluid and normal pressure and biochemistry, except for elevated protein concentration (0.48 g/L) (normal range, 0.15-0.45 g/L). There were 43 leukocytes/µL (99% lymphocytes) (normal range, 0-5 leukocytes/µL; lymphocytes range, 40%-80%), with no atypical or malignant cells. CSF Gram staining, acid-fast staining, cryptococcal antigen, varicella-zoster virus polymerase chain reaction (PCR), herpes simplex virus PCR, VDRL, and RPR test results were negative. CSF cultures did not show any evidence of growth of bacteria, fungi, or acid-fast bacillus. CSF flow cytometry did not show a monoclonal lymphoid population. No CSF oligoclonal bands were detected. Conventional brain MRI with intravenous administration of contrast material and perfusion study were performed and included different sequences (Figs 1-3).

Case 302.

History A 21-year-old immunocompetent man who was a long-term resident of Qatar presented to the emergency department with recurrent episodes of unprovoked generalized tonic-clonic seizures lasting 2-3 minutes that spontaneously resolved and were associated with postictal confusion. The patient also had progressive mild diplopia, intermittent dizziness, and numbness in the left arm over the course of 3 months. The patient did not have any other systemic symptoms or chronic medical diseases. He did not have any history of intake of illicit drugs, supplements, or regular medications; he had not received any recent vaccinations; and he had not undergone any surgical procedures. He had no history of travel. At presentation, vital signs were normal. Neurologic examination showed mild left homonymous hemianopia, normal gait with no cerebellar signs, and preserved sensations, power, tone, and reflexes in all four limbs. An electroencephalogram showed no epileptiform discharges. Chest CT and extensive laboratory work-up, including viral, fungal, bacterial, and parasite work-up, thyroid function tests, and immunologic blood tests yielded normal results. Those included normal complete and differential blood counts and normal serum chemistry. Serum analysis was negative for antinuclear antibody, Sjögren syndrome antigens A and B, cytoplasmic antineutrophil cvtoplasmic antibody, and paraneoplastic profile. Serum evaluation was also negative for human immunodeficiency virus type 1 and type 2 RNA, and Brucella, Schistosoma, and toxoplasma antibodies. Venereal Disease Research Laboratory (VDRL) and rapid plasma regain (RPR) test results were negative. Cerebrospinal fluid (CSF) analysis revealed clear fluid and normal pressure and biochemistry, except for elevated protein concentration (0.48 g/L) (normal range, 0.15-0.45 g/L). There were 43 leukocytes/µL (99% lymphocytes) (normal range, 0-5 leukocytes/µL; lymphocytes range, 40%-80%), with no atypical or malignant cells. CSF Gram staining, acid-fast staining, cryptococcal antigen, varicella-zoster virus polymerase chain reaction (PCR), herpes simplex virus PCR, VDRL, and RPR test results were negative. CSF cultures did not show any evidence of growth of bacteria, fungi, or acid-fast bacillus. CSF flow cytometry did not show a monoclonal lymphoid population. No CSF oligoclonal bands were detected. Conventional brain MRI with intravenous administration of contrast material and a perfusion study were performed and included different sequences (Figs 1-3).

A genomic map of climate adaptation in Mediterranean cattle breeds.

Domestic species such as cattle (Bos taurus taurus and B. t. indicus) represent attractive biological models to characterize the genetic basis of short-term evolutionary response to climate pressure induced by their post-domestication history. Here, using newly generated dense SNP genotyping data, we assessed the structuring of genetic diversity of 21 autochtonous cattle breeds from the whole Mediterranean basin and performed genome-wide association analyses with covariables discriminating the different Mediterranean climate subtypes. This provided insights into both the demographic and adaptive histories of Mediterranean cattle. In particular, a detailed functional annotation of genes surrounding variants associated with climate variations highlighted several biological functions involved in Mediterranean climate adaptation such as thermotolerance, UV protection, pathogen resistance or metabolism with strong candidate genes identified (e.g., NDUFB3, FBN1, METTL3, LEF1, ANTXR2 and TCF7). Accordingly, our results suggest that main selective pressures affecting cattle in Mediterranean area may have been related to variation in heat and UV exposure, in food resources availability and in exposure to pathogens, such as anthrax bacteria (Bacillus anthracis). Furthermore, the observed contribution of the three main bovine ancestries (indicine, European and African taurine) in these different populations suggested that adaptation to local climate conditions may have either relied on standing genomic variation of taurine origin, or adaptive introgression from indicine origin, depending on the local breed origins. Taken together, our results highlight the genetic uniqueness of local Mediterranean cattle breeds and strongly support conservation of these populations.

Neuro-Behcet's disease presenting as solitary midbrain lesion with paroxysmal ataxia and dysarthria (PAD) case report.

Paroxysmal dysarthria and ataxia (PDA) is a rare neurological manifestation of stereotyped attacks of sudden ataxic symptoms lasts for few seconds to minutes. We report a case of PDA in a 61-year-old male with a solitary homogenously enhancing solitary midbrain lesion and positive HLA-B51 (Allele 2), controlled with lacosamide.

Neuro-schistosomiasis with palm tree contrast enhancement pattern, a report of three cases, and review of literature.

We describe three cases of neuroschistosomiasis, two cases with cerebral schistosomiasis due to Schistosoma japonicum, with multiple pseudotumoral lesions presented with seizures and hemiparesis respectively, and a spinal cord conus medullaris schistosomiasis due to Schistosoma mansoni presented with conus medullaris syndrome. In the two cases with cerebral schistosomiasis imaging with CT revealed multiple areas of brain edema, and gyriform calcifications in both cerebral hemispheres, which suggested cerebral parasitemia, chronic venous hypertension, multifocal cerebral vascular malformation, or a forme fruste Sturge Weber syndrome. Further MRI revealed corresponding blooming, T2W (weighted) -FLAIR (fluid attenuated inversion recovery) ibright signal intensity and enhancing lesions. In the third case with spinal cord involvement MRI revealed signal abnormality on T1W and T2W images with patchy and punctate post i.v. contrast enhancement of the conus medullaris. Excision biopsy and histopathological examination were undertaken for the first brain case and spinal cord case and showed multiple schistosomal granulomas in different evolution phases. In the second brain case, the diagnosis was suggested based on our experience with prior cases, positive laboratory tests, and urinary bladder wall biopsy. Neuroschistosomiasis must be considered in the differential diagnosis of multiple cerebral calcifications, and multiple nodular and linear like lesions with characteristic arborized enhancement pattern, especially for patients coming from endemic areas for Schistosomiasis.

Spinal cord infarction in a 41-year-old male patient with COVID-19.

The severe acute respiratory syndrome coronavirus disease 2019 (COVID-19) pandemic, became rapidly recognised by variable phonotypic expressions that involve most major body organs. Neurological complications of severe acute respiratory syndrome coronavirus disease are increasingly encountered in patients with COVID-19 infection, more frequently in patients with severe infection, and develop as a consequence of the neurotropic potential of this virus, secondary cytokine storm and acquired syndrome of COVID-19 coagulopathy. Spinal cord involvement after COVID-19 more commonly includes infectious transverse myelitis, para and post infection myelopathy and, rarely, spinal cord ischaemia related to increased coagulopathy with thromboembolic consequences. We herein report a COVID-19-positive patient with increased coagulopathy and vertebral artery thrombosis leading to posterior circulation and subsequent spinal cord infarction.

The demographics of Tolosa-Hunt syndrome in Qatar.

BACKGROUND: Tolosa Hunt syndrome (THS) is a rare disease that manifests mainly as painful unilateral ophthalmoplegia. It is caused by an inflammatory process of unknown aetiology within the cavernous sinus with a rare intracranial extension. The International Classification of Headache Disorders (ICHD)- 3 diagnostic criteria aids in its diagnosis. There is limited literature on its varied presentations, diagnosis, and management. Steroids are used in the treatment of THS with varied success. METHODS: We conducted a single-center-retrospective-study and included all patients admitted with a diagnosis of THS from January 2015 to December 2020. Descriptive and summary statistics were used to describe the study cohort's socio-demographic parameters. RESULTS: Among 31 THS patients (predominantly Asians (18) and Arabs (9)), visual disturbance was commonest presenting complaint. Third-nerve paralysis was seen in 70.9% cases. Magnetic-resonance-imaging (MRI) was abnormal in 64.5%. 93.5% patients received steroids, with a response-rate of 70.9% and a recurrence-rate of 9.7%. A previous history of THS and female gender were associated with recurrence (p-value 0.009 and 0.018). Recurrence was seen in 66.7% fully recovered and 33.3% partially recovered cases (p-value 0.04). Among the benign and inflammatory subtypes of THS, the ICHD-3 criteria were applicable in 85% of inflammatory THS. CONCLUSIONS: THS is a rare disease with ethnic variation in presentation and response to treatment. In our cohort female gender and a previous history of THS were associated with recurrence. ICHD-3 diagnostic criteria had a higher validity in our patients compared to prior studies, especially among the inflammatory THS.

Spectrum of neuroimaging findings in COVID-19.

An outbreak of corona virus disease 2019 (COVID-19) began in China in December 2019, and rapidly spread to become a worldwide pandemic. Neurological complications encountered in hospitalized patients include acute arterial ischemic cerebrovascular stroke, cerebral venous thrombosis, critical illness-associated cerebral microbleeds, hypertensive hemorrhagic posterior reversible encephalopathy, meningoencephalitis/flare up of infections, flare up of multiple sclerosis, acute disseminated encephalomyelitis, cerebral hemodynamic/hypoxic changes such as watershed ischemic changes and hypoxic ischemic encephalopathy, and spine manifestations of Guillain Barre syndrome and viral myelitis. The purpose of our study is to illustrate the different neuroimaging features in critically ill hospitalized COVID-19 positive patients in the State of Qatar.

Syphilitic arteritis involving the origin of the cervical internal carotid artery.

We report a case of meningovascular syphilis in a young adult woman presenting with left hemiparesis due to near occlusion of proximal cervical internal carotid with subacute middle cerebral artery territory infarction. Diagnosis was made on the basis of positive serum, and spinal fluid serology for syphilis, carotid Doppler, and magnetic resonance angiography, as well as improvement after intravenous penicillin therapy. In this case report, the imaging findings were described and related literature was reviewed.

Vogt-Koyanagi-Harada Disease: A Case Report With Distinct Brain MRI Enhancement Patterns.

Vogt-Koyanagi-Harada disease is a rare autoimmune granulomatous panuveitis with significant associated morbidity. While ocular and meningeal signs are typically observed in the acute stage, the associated classic tegumentary findings are observed subsequently. This case report highlights the imaging findings associated with this entity that serves to emphasize the role of contrast-enhanced brain MRI in early disease detection, which allows for prompt treatment initiation and better disease outcome.

Decompressive Craniectomy: A Preliminary Study of Comparative Radiographic Characteristics Predicting Outcome in Malignant Ischemic Stroke.

OBJECTIVE: Decompressive craniectomy (DC) has been advocated as a lifesaving procedure in management of patients with raised intracranial pressure due to malignant ischemic stroke (MIS). The aim of this study was to identify comparative radiologic parameters after DC to predict functional outcome at 6 months in patients with MIS. METHODS: A retrospective analysis (2015-2018) of patients (median age 54 years; range, 29-80 years) with MIS who underwent postoperative computed tomography within 24 hours of DC was performed. Multivariate regression analysis was computed to predict clinical outcome at 6 months based on the Glasgow Coma Outcome Scale Extended. RESULTS: With median National Institutes of Health Stroke Scale score of 20 (range, 3-33), mean preoperative stroke volume was 250 ± 75 cm3. Median Glasgow Coma Outcome Scale Extended score at 6 months was 4. Multivariate regression analysis showed that the comparative radiographic characteristics of absence of effacement of cortical sulci (odds ratio 2.88; 95% confidence interval, 1.22-20.71; P = 0.02), absence of hemorrhagic transformation (odds ratio 1.09; 95% confidence interval, 1.99-12.89; P = 0.03), and absence of compression of lateral ventricles (odds ratio 3.75; 95% confidence interval, 1.28-22.4; P = 0.05) on postoperative computed tomography scan were significant independent predictors of good functional outcome (Glasgow Coma Outcome Scale Extended score 5-8). CONCLUSIONS: The comparative radiographic characteristics of absence of effacement of cortical sulci, hemorrhagic transformation, and compression of the lateral ventricles after DC in patients with MIS bore a significant relationship to predicting clinical outcome at 6 months.

Comparative Radiographic Factors Predicting Functional Outcome After Decompressive Craniectomy in Severe Traumatic Brain Injury.

OBJECTIVES: Decompressive craniectomy (DC) is a last-tier therapy in the treatment of raised intracranial pressure after traumatic brain injury (TBI). We report the association of comparative radiographic factors in predicting functional outcomes after DC in patients with severe TBI. METHODS: A retrospective analysis of a prospectively maintained database of cases between 2015 and 2018 at an academic tertiary care hospital was carried out. Univariate and multivariable regression analyses were performed for an array of comparative radiographic variables (pre- and post-DC) in relationship to functional outcome according to Glasgow Outcome Scale Extended (GOSE) at 180 days. GOSE was further dichotomized into favorable (GOSE:5-8) and unfavorable (GOSE:0-4) functional outcomes. All associations were reported as odds ratio (OR) with 95% confidence interval (CI). RESULTS: Statistical analysis included a cohort of 43 patients with a median age of 30.5 years (range: 18-62 years). The median GOSE at 180 days was 7. Multivariable regression analysis after adjusting for confounding variables (age, sex, comorbidities, site of surgery and size of decompression) showed that comparative radiographic findings of midline shift (MLS) > 10 mm (OR 3.2 (95% CI 1.25-8.04); P = 0.01); external cerebral herniation (ECH) > 2.5 cm (OR 2.5 [95% CI 1.18-5.2]; P = 0.02); and effacement of basal cisterns (OR 3.9 [95%CI 1.1-13.9]; P = 0.03), were significant independent predictors of poor functional outcome at 180 days after DC for severe TBI. However, the presence of infarction (OR 2.7 [95%CI 0.43-17.2]; P = 0.28) and absence of gray-white matter differentiation (OR 0.18 [95%CI 0.03-1.2]; P = 0.07) did not reach statistical significance. CONCLUSIONS: The comparative radiographic findings that include MLS > 10mm, ECH > 2.5cm, and effacement of basal cisterns are predictive of poor functional outcome in severe TBI.

Functional magnetic resonance imaging of head and neck cancer: Performance and potential.

Functional magnetic resonance imaging (MRI) of tumors of the head and neck usually encompasses diffusion-weighted imaging (DWI) and intravenous (IV) contrast T1 dynamic perfusion imaging (DCE-MRI or PWI). Both techniques can characterize different tissues by probing into their microstructure, providing a novel approach in oncological imaging. In this pictorial review, we will cover the important technical aspects of DWI and PWI, the pathophysiological background and the current applications and potential of these functional MRI techniques in the imaging of head and neck cancer.

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids, with Cranial and Caudal Extension.

A 23-year-old lady presented with vertigo and imbalance in walking, blurring of vision, diplopia, and headache, in addition to numbness in the lower limbs over a period of six days. On examination patient had nystagmus, ataxia, positive Romberg test, and hyperreflexia. MRI examination of the brain and spinal cord showed evidence of faint bright signal intensity foci in T2/FLAIR involving bilateral cerebral hemispheres, subcortical deep white matter, bilateral thalami, posterior pons and left brachium pontis, and basal ganglia, with small nodular enhancement that aligned along curvilinear structures; those lesions also were apparent along the spinal cord at multiple levels. The clinical and radiological features suggested CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) syndrome. Symptoms improved dramatically with high dose oral corticosteroids. Our report addresses the radiological and clinical pattern of a case of CLIPPERS rhombencephalitis, with added superior and inferior extension to involve the brain and spinal cord, which is to emphasize the importance of raising the awareness of this disease and the combined role of radiologist and physicians for the diagnosis of this potentially treatable entity, responsive to glucocorticosteroid immunosuppression.

Anterior clinoid mucocele causing optic neuropathy: A case report and review of literature.

A 66 year old Indian gentleman presented with a 3 days history of headache and gradual progressive loss of vision in his eft eye, ophthalmological assessment showed no light perception in his left eye with papilledema and afferent papillary defect. Computed tomography (CT) and Magnetic Resonance Imaging (MRI) were done and showed an expanding lesion in the left anterior clinoid process encroaching upon the left orbital apex and optic nerve with features suggestive of a mucocele. Patient was started on dexamethasone, and urgent craniotomy was undertaken, where marsupialization and resection of left anterior clinoid mucocele was done, and histopathologic examination of the operative specimen was consistent with a mucocele. Post-operatively, patient was kept on dexamethasone for few days, with uneventful outcome, and his follow up at 6 months showed complete recovery of his vision from no light perception to 6/12 in the affected eye.

A voxel-based morphometric magnetic resonance imaging study of the brain detects age-related gray matter volume changes in healthy subjects of 21-45 years old.

Previous and more recent work of analyzing structural changes in the brain suggest that certain brain regions such as the frontal lobe are among the brain regions profoundly affected by the aging process across males and females. Also, a unified model of structural changes in a normally aging brain is still lacking. The present study investigated age-related structural brain changes in gray matter from young to early middle-age adulthood for males and females. Magnetic resonance images of 215 normal and healthy participants between the ages of 21-45 years were acquired. Changes in gray matter were assessed using voxel-based morphometry and gray matter volumetric analysis. The results showed significant decrease in gray matter volume between the youngest and oldest groups in the following brain regions: frontal, temporal, and parietal lobes. Grey matter loss in the frontal lobe was among the most widespread of all brain regions across the comparison groups that showed significant age-related changes in grey matter for both males and females. This work provides a unique pattern of age-related decline of normal and healthy adult males and females that can aid in the future development of a unified model of normal brain aging.

Novel brain MRI abnormalities in Gitelman syndrome.

Gitelman syndrome is an autosomal recessive renal tubular disorder characterized by hypokalemic metabolic alkalosis, hypomagnesemia and hypocalciuria. The syndrome is caused by a defective thiazide-sensitive sodium chloride co-transporter in the distal convoluted tubules of the kidneys. Gitelman syndrome could be confused with Bartter syndrome; the main differentiating feature is the presence of low urinary calcium excretion in the former. Descriptions of neuroradiological imaging findings associated with Gitelman syndrome are very scarce in the literature and include basal ganglia calcification, idiopathic intracranial hypertension and sclerochoroidal calcification. Cauda equina syndrome-like presentation has been reported, but without any corresponding imaging findings on lumbar spine MRI. We report a 13-year-old male with Gitelman syndrome who presented with altered mental status following a fall and scalp laceration and unremarkable brain CT, followed during hospitalization by somnolence and seizures. Metabolically the patient demonstrated hypokalemia and hypomagnesemia. MRI demonstrated features of encephalopathy including predominantly right-sided cerebral hemispheric signal abnormality and cytotoxic edema, with bilateral symmetric involvement of the thalami, midbrain tegmentum and tectum and cerebellar dentate nuclei. MRI after five months obtained during a later episode of encephalopathy showed resolution of the signal abnormalities with setting in of brain atrophy and also areas of newly developed cytotoxic edema in the left thalamus, bilateral dorsal midbrain and right greater than left dentate nuclei. The described abnormalities, either recurrent or in isolation, have not previously been published in patients with Gitelman syndrome. We believe that the findings are due to alteration of respiratory chain function secondary to the metabolic derangement and hence have a similar imaging appearance as encephalopathy related to mitochondrial cytopathy or metabolic encephalopathy.

Perineural tumour spread from colon cancer, an unusual cause of trigeminal neuropathy--a case report.

Malignant trigeminal neuralgia due to perineural spread along the branches of the trigeminal nerve, is known to commonly occur secondary to squamous cell carcinomas, lymphomas and adenoid cystic carcinomas in the head and neck region. Rarely metastases to the trigeminal nerve have been reported in breast cancer, prostate cancer and colon cancer. To the best of our knowledge trigeminal neuropathy due to skull base metastases and perineural spread along the maxillary (V2) and mandibular (V3) branches of the trigeminal nerve, secondary to colon cancer, has not been previously reported. The diagnosis in our index case was made on magnetic resonance imaging, and patient was treated accordingly by fractionated stereotactic radiotherapy, with subsequent relief of her pain.