The Emerging Clinical Utility of Neurosonology During COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 infection. Over the last 2 years the virus has spread worldwide with enormous implications on the healthcare systems. COVID-19 patients suffer from mild upper-airway manifestations to pneumonia and severe acute respiratory distress syndrome and their hospitalizations are often prolonged. Neurological manifestations of the disease are common. Neurosonology (transcranial Doppler & cervical duplex ultrasound) is an easily repeatable diagnostic imaging modality that can be simply applied at the bedside of COVID-19 patients with cerebrovascular diseases or in critically ill patients in the intensive care unit. Neurosonology may provide hemodynamic assessment of cerebral circulation, quantitative evaluation of increased intracranial pressure and detection of micro-embolic signals in real-time. Consequently, it may assist substantially in the diagnosis, risk stratification and therapeutic approach of COVID-19 patients with or without cerebrovascular complications. In the present narrative review, we discuss the emerging clinical utility of neurosonology during COVID-19 pandemic and highlight the upgraded role of neurosonology resulting from the combination of the established applications coupled with the reduced risk of virus spreading during ultrasound evaluation compared to other imaging modalities including computed tomography and magnetic resonance imaging.

Vascular Overload Index Predicts Cerebral Small Vessel Disease in a Neurologically Healthy Population

Background: Arterial stiffness has been suggested as one of the major pathological mechanisms of cerebral small vessel diseases (cSVDs). In this study, we confirmed this hypothesis by evaluating the association between vascular overload index (VOI), which is a physiologically good indicator of arterial stiffness, and cSVD.Methods: We evaluated participants who visited Seoul National University Hospital Health Promotion Center for health check-ups between 2006 and 2013. VOI was calculated by the following formula: VOI (mmHg)=1.33×systolic blood pressure -0.33×diastolic blood pressure-133.3. cSVDs were measured including white matter hyperintensity (WMH), lacunes, and cerebral microbleeds (CMBs). We quantitatively measured the WMH volume and rated the presence and number of lacunes and CMBs qualitatively.Results: A total of 3,231 participants were evaluated (mean age 57±9 years, male sex 53.9%). In multivariable linear regression analysis, VOI was significantly associated with WMH volume after adjusting confounders (β=0.004, 95% confidence interval=0.002–0.006). VOI also showed a close association with lacunes in multivariable logistic regression analysis (adjusted odds ratio=1.01, 95% confidence interval=1.00–1.02). There was no statistical association with CMBs. In subgroup analysis according to the presence of hypertension, VOI was closely associated with WMH volume/lacunes only in patients without hypertension. In patients with hypertension, these statistical associations disappeared.Conclusion: A high VOI was associated with cSVD in a neurologically healthy population, especially in patients without hypertension. This marker of arterial stiffness could be convenient and useful predictor of cSVD.

An Adverse Case of Spinal Tumor Embolization with Gelfoam in a Patient Whose Vertebral Artery Has Shared Origin with Ipsilateral Costocervical Trunk

Tumor embolization is performed before surgical excision. The Gelfoam temporarily occludes the vessels supplying the tumor by facilitating thrombus formation. We report an adverse case of Gelfoam embolization in a patient with a certain vascular anatomy. A 75-year-old man previously diagnosed with lung cancer in 2015 was admitted to Korea University Guro Hospital. He had bilateral arm paresthesia and lower extremity weakness that had progressed for 2 weeks. Cervical spine magnetic resonance imaging revealed a metastatic pathologic fracture of the C6 vertebral body and subsequent cord compression. A C6 corpectomy was scheduled, and preoperative spinal tumor embolization was planned. Angiography revealed that the left deep cervical artery (DCA) and the ipsilateral vertebral artery shared origin. Two Nester coils were positioned at the right distal DCA, one at the left DCA, and two at the left proximal DCA. Gelfoam was infused in each location. However, the patient’s mental status worsened after the left DCA embolization. A diffusion-weighted image showed diffuse cytotoxic edema in the posterior circulation without significant lesions on magnetic resonance angiography. In Gelfoam embolization, special attention is required with neurological monitoring when maneuvering DCA if it has a nearby entrance with a vertebral artery.

Laterality of Skin Temperature and Magnetic Resonance Imaging in Patients with Wallenberg Syndrome

Background: Recently, lateral differences in body surface temperature (BST) have been reported as a symptom of Wallenberg syndrome (WS), resulting from disturbances in the sympathetic nerve pathway. This study aimed to investigate the relationship between the laterality of BST and brain magnetic resonance imaging (MRI) findings in 12 patients with WS.Methods: BST was measured using an infrared thermal camera at 7±3 days and 90±30 days after symptom onset. The MRI findings were categorized as rostral, middle, and caudal medulla rostrocaudally and typical, ventral, large, dorsal, and lateral types in the horizontal direction.Results: MRI revealed medullary lesions on the right in five patients and on the left in seven patients. Two patients without lateralized BST had lateral caudal medullary infarction, and one patient had a dorsal middle medullary infarction. One patient with lateralized BST had a rostral medullary infarction and the other had a typical or large middle medulla infarction. Lateralized BST in patients with WS may disturb the sympathetic nervous system pathway that descends from the rostral ventrolateral medulla oblongata. Deficits in sweating and skin blood flow may cause BST laterality.Conclusion: This study showed that lateralized BST in patients with WS may be associated with disturbances in the sympathetic nervous pathway descending from the rostral ventrolateral medulla. These results support the assumption that autonomic dysfunction may be related to abnormal sensory symptoms in patients with WS.

Neuroimaging Findings in Racemose Neurocysticercosis: Case Description and Literature Review

Neurocysticercosis (NCC), the most common central nervous system (CNS) parasitic infection among the immunocompetent population can imitate every clinical feature of brain-diseases accurately, drawing attention away from the real culprit and delaying the proper treatment. There are two types of NCC, the parenchymal and the extraparenchymal form. The extraparenchymal NCC include the ventricular cysticercosis, the subarachnoid cysts including giant cysts or racemose cysticercosis with chronic meningitis, the spinal (intra- or extramedullary) cysticercosis and the ophthalmic cysticercosis. It is estimated that about 30% of epilepsy cases in endemic countries are due to NCC and especially the racemose NCC is more aggressive and associated with higher mortality rates. There is a significant heterogeneity in clinical phenotypes, regarding the racemose NCC, which depends on the parasite load and evolutionary stage in association with its location in CNS and the host’s immune response. Crucial for the management of the racemose NCC is the early recognition of the symptoms and the swift initiation of antiparasitic therapy with anti-inflammatory agents in combination with the shunt-insertion in cases of obstructive hydrocephalus. In view of the former considerations we conducted a narrative literature review on racemose NCC and described the diagnostic challenges of a relevant case that we had evaluated in our Department of Neurology.

Vessel Wall Magnetic Resonance Imaging Findings of Bilateral Middle Cerebral Artery Stenosis Associated with Nilotinib

Nilotinib is a Bcr-Abl tyrosine kinase inhibitor used to treat chronic myelogenous leukemia. There have been case reports of nilotinib-related vasculopathy. However, most cases present peripheral artery disease, whilst reports of nilotinib-related cerebrovascular disease are quite uncommon. Herein, we report a case of nilotinib-induced intracranial stenosis in a patient with recurrent transient ischemic attacks and discuss the results of serial vessel wall magnetic resonance imaging.

Intractable Progressive Cerebral Infarction with Multiple Atypical Aneurysms in Systemic Lupus Erythematosus

We report a case of intractable progressive cerebral infarction with multiple fusiform aneurysms in a 34-year-old female patient with systemic lupus erythematosus (SLE), non-responsive to massive immunotherapy. The patient visited the emergency department with dysarthria and left-sided hemiparesis that occurred 2 days before. She was diagnosed with SLE involving the brain and received 12 cycles of cyclophosphamide 12 years prior. Brain diffusion-weighted imaging showed acute infarctions involving the pons and medulla. Additionally, multifocal microbleeding-like signals in various cisternal spaces were detected using susceptibility-weighted imaging. Digital subtraction angiography revealed multiple fusiform aneurysms. Despite antithrombotic treatment with trif lusal and immunotherapies, including corticosteroids, mycophenolate mofetil, and immunoglobulins, for cerebral vasculitis associated infarction, her neurologic deficits worsened with recurrent cerebral infarction. Further investigation for accurate diagnosis and treatment is required.

Relationship between Methylenetetrahydrofolate Reductase C677T Homozygous Mutation and Cerebral Small Vessel Disease Subtypes

Background: Neuroimaging detects cerebral small vessel disease (CSVD) subtypes, including infarction, asymptomatic lacunes, cerebral microbleeds, white matter hyperintensities (WMHs), and enlarged perivascular space. Methylenetetrahydrofolate reductase (MTHFR) plays an essential role in the metabolism of folic acid and homocysteine. The purpose of this study was to investigate the relationship between the MTHFR C677T mutation and CSVD subtypes.Methods: A total of 144 patients with acute ischemic stroke who visited the Korea University Guro Hospital between April 2020 and August 2020 were retrospectively reviewed. After excluding 24 patients, due to missing laboratory, clinical, or imaging information, a total of 120 patients were analyzed.Results: Among the 120 participants, 25% were included in the MTHFR C677T homozygous mutation group, which had significantly lower folic acid levels (6.24±4.21 ng/mL vs. 8.24±4.21 ng/mL, p=0.03) and higher total homocysteine levels (17.09±14.07 μmol/L vs. 9.65±3.19 μmol/L, p<0.01). Using multiple logistic regression analysis, the homozygous mutation (adjusted odds ratio [aOR]=4.29; 95% confidence interval [CI]=1.16–15.90) and age (aOR=1.06; 95% CI=1.01–1.11) were independently associated with moderate to severe WMHs. Additionally, moderate to severe WMHs were more frequent in the homozygous mutation group (86.7% vs. 66.7%, p=0.01). In a detailed analysis, the homozygous mutation group showed a significantly higher rate of moderate to severe periventricular WMH (PWMH) (86.7% vs. 65.6%, p<0.01).Conclusion: The MTHFR C677T homozygous mutation was positively correlated with moderate to severe PWMH subtypes of CSVD.

Lower Cranial Nerve Palsy due to Prevertebral Tuberculosis Infection

Prevertebral tuberculosis is a rare infectious disease that often affects immunocompromised patients in developing countries. We present the case of a patient who complained of headache, dysarthria, and dysphagia. Neurological examination revealed multiple cranial nerve palsies, including the hypoglossal, glossopharyngeal, and vagus nerves. Brain magnetic resonance imaging demonstrated an infiltrative lesion in the prevertebral space, and the biopsy revealed chronic inflammation. On suspicion of immune-mediated inflammation, the patient was treated with intravenous dexamethasone and oral prednisolone, with minimal response. Eleven months after the initial diagnosis, the patient’s neurological symptoms were aggravated, and we detected newly developed pulmonary tuberculosis. After the treatment of pulmonary tuberculosis, his neurological symptoms improved, and the imaging study demonstrated improvements. Although we lacked positive laboratory or biopsy results for tuberculosis, we suspect that the lesions were distant tuberculosis infections. Tuberculosis should be considered in patients with unknown infiltrative mass-like lesions in the prevertebral spaces.