Transient Ageusia and Dysgeusia Following Thalamic Cyst Drainage.

Taste consists of sensation and perception. Specific neural structures transmit a stimulus from the taste buds to the gustatory cortex to generate taste sensation. Any disruption of this pathway, whether it affects sensation or perception, can result in taste disorders. Stereotactic procedures involving the thalamus may result in gustatory complications. A 41-year-old female patient who underwent stereotactic drainage of a thalamic cyst suffered transient ageusia. Subsequently, she developed metallic taste perception. When her stereotactic plan was re-evaluated, it was noted that the posteromedial ventral thalamus nucleus was in the path of the needle tract and the needle had passed through it. Follow-up was recommended and her symptoms completely resolved within 2 months following surgery. Modern imaging techniques allow for the visualization of neural structures related to the sense of taste. Additionally, care must be taken when planning stereotactic procedures for such lesions.

Neuro-Ophthalmologic Features and Outcomes of Thalamic Infarction: A Single-Institutional 10-Year Experience.

BACKGROUND: Neuro-ophthalmologic deficit after thalamic infarction has been of great concern to ophthalmologists because of its debilitating impacts on patients' daily living. We aimed to describe the visual and oculomotor features of thalamic infarction and to delineate clinical outcomes and prognostic factors of the oculomotor deficits from an ophthalmologic point of view. METHODS: Clinical and neuroimaging data of all participants were retrospectively reviewed. Among the 12,755 patients with first-ever ischemic stroke, who were registered in our Stroke Data Bank between January 2009 and December 2018, 342 were found to have acute thalamic infarcts on MRI, from whom we identified the patients exhibiting neuro-ophthalmologic manifestations including visual, oculomotor, pupillary, and eyelid anomalies. RESULTS: Forty (11.7%) of the 342 patients with thalamic infarction demonstrated neuro-ophthalmologic manifestations, consisting of vertical gaze palsy (n = 19), skew deviation with an invariable hypotropia of the contralesional eye (n = 18), third nerve palsy (n = 11), pseudoabducens palsy (n = 9), visual field defects (n = 7), and other anomalies such as isolated ptosis and miosis (n = 7). Paramedian infarct was the most predominant lesion of neuro-ophthalmologic significance, accounting for 84.8% (n = 28) of all patients sharing the oculomotor features. Although most of the patients with oculomotor abnormalities rapidly improved without sequelae, 6 (18.2%) patients showed permanent oculomotor deficits. Common clinical features of patients with permanent oculomotor deficits included the following: no improvement within 3 months, combined upgaze and downgaze palsy, and the involvement of the paramedian tegmentum of the rostral midbrain. CONCLUSIONS: Thalamic infarction, especially in paramedian territory, can cause a wide variety of neuro-ophthalmologic manifestations, including vertical gaze palsy, skew deviation, and third nerve palsy. Although most oculomotor abnormalities resolve spontaneously within a few months, some may persist for years when the deficits remain unimproved for more than 3 months after stroke.

Strictly Lobar Microbleeds Reflect Amyloid Angiopathy Regardless of Cerebral and Cerebellar Compartments.

BACKGROUND AND PURPOSE: We aimed to determine whether lobar cerebellar microbleeds or concomitant lobar cerebellar and deep microbleeds, in the presence of lobar cerebral microbleeds, attribute to underlying advanced cerebral amyloid angiopathy pathology or hypertensive arteriopathy. METHODS: We categorized 71 patients with suspected cerebral amyloid angiopathy markers (regardless of the presence of deep and cerebellar microbleeds) into 4 groups according to microbleed distribution: L (strictly lobar cerebral, n=33), L/LCbll (strictly lobar cerebral and strictly lobar cerebellar microbleeds, n=13), L/Cbll/D (lobar, cerebellar, and deep microbleeds, n=17), and L/D (lobar and deep, n=8). We additionally categorized patients with cerebellar microbleeds into 2 groups according to dentate nucleus involvement: strictly lobar cerebellar (n=16) and dentate (n=14). We then compared clinical characteristics, Aß (amyloid-ß) positivity on PET (positron emission tomography), magnetic resonance imaging cerebral amyloid angiopathy markers, and cerebral small vessel disease burden among groups. RESULTS: The frequency of Aß positivity was higher in the L and L/LCbll groups (81.8% and 84.6%) than in the L/Cbll/D and L/D groups (37.5% and 29.4%; P<0.001), while lacune numbers were lower in the L and L/LCbll groups (1.7±3.3 and 1.7±2.6) than in the L/Cbll/D and L/D groups (8.0±10.3 and 13.4±17.7, P=0.001). The L/LCbll group had more lobar cerebral microbleeds than the L group (93.2±121.8 versus 38.0±40.8, P=0.047). The lobar cerebellar group had a higher Aß positivity (75% versus 28.6%, P=0.011) and lower lacune number (2.3±3.7 versus 8.6±1.2, P=0.041) than the dentate group. CONCLUSIONS: Strictly lobar cerebral and cerebellar microbleeds are related to cerebral amyloid angiopathy, whereas any combination of concurrent lobar and deep microbleeds suggest hypertensive angiopathy regardless of cerebral or cerebellar compartments.

Continuous epileptiform discharges during sleep as an evolutionary pattern in patients with congenital Zika virus syndrome.

Congenital Zika virus syndrome (CZVS) is associated with severe neurological deficits. Clinical characteristics of epilepsy and the electroencephalographic (EEG) pattern in CZVS were documented in infancy. In this study, we aimed to describe the EEG findings observed during the follow-up of children with CZVS. Seventy-six EEGs of 55 children (60% female; mean age = 50 months) with confirmed CZVS were analyzed, considering the background, interictal, and ictal epileptiform discharges. Continuous (or almost continuous) epileptiform discharges during non-rapid eye movement sleep were identified in 22 (40%) patients. In 20 (90.1%) patients, the pattern was symmetrical, with an anterior predominance of the epileptiform activity. All patients with this pattern had epilepsy, which was severe in 15 (68.2%) and demanded polytherapy in 19 (86.4%). Subcortical calcifications (77.3%) and multifocal EEGs (72.8%) in earlier ages occurred more often in patients with this pattern. Other unspecific interictal EEG patterns were focal epileptiform discharges in 23 (41.8%) and multifocal activity in six (10.9%). In CZVS, continuous (or almost continuous) epileptiform discharges during sleep emerge as a pattern after the second year of life. This was associated with severe and drug-resistant epilepsy, but not necessarily with an apparent regression. Subcortical calcifications and multifocal epileptiform discharges in infancy are associated with this pattern.

Endoscopic-Assisted Translateral Ventricular Transchoroidal Fissure Approach for Evacuation of Medial-Type Thalamic Hemorrhage: Case Series.

BACKGROUND: Although surgeries for intracerebral hemorrhage remain controversial, endoscopic surgery is considered a promising surgical treatment. The most fatal type of thalamic hemorrhage is the medial type, which is always combined with expansion of the hematoma into the third ventricle. The current endoscopic approach to this lesion involves injury to the mediodorsal nucleus of the thalamus (MDT). CASE DESCRIPTION: We report 5 cases of medial thalamic hemorrhage with third intraventricular involvement treated by an endoscopic-assisted translateral ventricular transchoroidal fissure approach. The preoperative average volume of the parenchymal hematomas was 9.63 mL, while the preoperative average volume of the intraventricular hematomas was 23.35 mL. The average surgical duration was 80.6 minutes. No intraoperative MDT incision was needed in any patient. The evacuation rates of parenchymal and intraventricular hematomas were 74.21%-98.84% and 85.89%-99.51%, respectively. Three months after the surgery, the average Glasgow Coma Scale scores improved to 13.8 from 7.2 preoperatively. No ventriculoperitoneal shunt was needed in any patient. CONCLUSIONS: The endoscopic-assisted translateral ventricular transchoroidal fissure approach is a safe and effective approach for evacuation of a medial thalamic hemorrhage with third intraventricular involvement. This approach allows parenchymal hematoma evacuation through the rupture of the third ventricle without incising the MDT in the lateral ventricle.

Thalamic perforating artery stroke on computed tomography perfusion in a patient with coronavirus disease 2019.

Emerging evidence suggests that patients with coronavirus disease 2019 (COVID-19) are at risk of thromboembolic complications, including ischemic strokes. We present a case illustrating the value of CT perfusion to identify acute small subcortical infarcts in a patient with COVID-19 admitted to an intensive care unit for bilateral pneumonia and pulmonary embolism presenting with sudden right limb weakness.

A New Scoring System for Prediction of Underlying Vascular Pathology in Patients with Intracerebral Hemorrhage: The Modified Secondary Intracerebral Hemorrhage Score.

BACKGROUND: Secondary intracerebral hemorrhage (SICH) score is used to predict risk of intracranial hemorrhage (ICH) associated vascular lesions. However, it has low clinical utility in identifying patients without need for neurovascular imaging. This study aims to develop a modified scoring system to capture patients with low risk of underlying vascular pathology, thereby decreasing need for vascular imaging and its associated morbidity. METHODS: A retrospective analysis of 994 patients with atraumatic ICH over 8 years was conducted, excluding known underlying pathology, subarachnoid hemorrhage, or lack of vascular imaging. Using a multivariate logistic regression model, independent predictors of vascular pathology were identified and utilized toward developing a modified Secondary Intracerebral Hemorrhage (mSICH) score. RESULTS: Of 575 patients identified, 60 (10.4%) had underlying vascular etiology. Statistically significant predictors of vascular pathology included age; female sex; admission systolic blood pressure <160 mm Hg; locations other than basal ganglia, thalamus, pons, or midbrain; presence of high-risk imaging features; and proximity to large vessel-containing cisterns. The mSICH score correlated with an increasing incidence of vascular pathology [0-1 (0%), 9 (4.3%), 12 (9.7%), 21 (40.4%), 6 (33.3%), 8 (88.9%), and 4 (100%)] and had a significantly higher number of patients receiving scores with 0% incidence of vascular lesions compared with the SICH score [159 (27.6%) versus 12 (2.1%); P < 0.001)]. CONCLUSIONS: The mSICH score can more accurately predict risk of underlying vascular pathology of ICH and identify patients with lowest risk of vascular pathology. This may minimize the cost and associated risks of invasive cerebrovascular imaging.

Characterizing ipsilateral thalamic diaschisis in symptomatic cerebrovascular steno-occlusive patients.

The clinical significance of ipsilateral thalamic diaschisis (ITD) occurring after stroke is unknown. To characterize ITD, we investigate its hemodynamic, structural, and clinical implications. A single-institution prospective cross-sectional study was conducted using 28 symptomatic cerebrovascular steno-occlusive patients undergoing both BOLD-CVR and Diamox-challenged 15(O)-H2O-PET. Follow-up was at least three months. In addition, 15 age-matched healthy subjects were included. ITD was diagnosed based on a BOLD-CVR thalamic asymmetry index (TAI) > +2 standard deviations from healthy subjects. Cerebral blood flow differences were assessed using a PET-based TAI before and after Diamox challenge. Thalamic volume masks were determined using Freesurfer. Neurological status at symptom onset and after three months was determined with NIHSS and mRS scores. ITD was diagnosed in 15 of 28 (57%) patients. PET-TAI before and after Diamox challenge were increased in patients with ITD, indicating an ipsilateral thalamic blood flow decrease. Patients with ITD exhibited a marked ipsilateral thalamic volume decrease as compared to patients without ITD and healthy subjects. Furthermore, patients with ITD had worse NIHSS and mRS at symptom onset and after three months follow-up, even after adjustment for stroke volume. The presence of ITD is characterized by thalamic volume reduction, reduced thalamic blood flow, and worse neurological performance unrelated to stroke volume.

Variant Type of Posterior Reversible Encephalopathy Syndrome Associated with Deep Brain Hemorrhage: Case Report and Review of the Literature.

BACKGROUND: Various radiologic patterns of posterior reversible encephalopathy syndrome (PRES) have been reported. Among them, PRES involving brainstem, thalamus, or deep white matter and lacking parieto-occipital edema is rare. Although PRES in general has a benign course, PRES-related intracranial hemorrhage has been associated with a poor prognosis. We report a case of variant type of PRES associated with deep brain hemorrhage and discuss the characteristics of PRES-related intracranial hemorrhage via a literature review. CASE DESCRIPTION: A woman aged 41 years with a history of untreated hypertension presented to our hospital complaining of severe headache and with an elevated blood pressure of 237/142 mmHg. Computed tomography revealed a hemorrhage in the left thalamus and basal ganglia. Magnetic resonance imaging revealed remarkable hyperintensity in the left cerebellum, pons, bilateral temporal lobes, bilateral basal ganglia, and bilateral cerebral white matter on fluid-attenuated inversion recovery imaging, which represented vasogenic edema. The parieto-occipital regions were unremarkable. Given this clinical presentation, PRES associated with deep brain hemorrhage was suspected. The patient received strict blood pressure control treatment, which resulted in gradual symptom improvement. Magnetic resonance images obtained 1 month after admission demonstrated an almost complete resolution of the edema. CONCLUSIONS: Although hemorrhage in the thalamus, basal ganglia, or brainstem is uncommon in patients with PRES, it may occur in patients with variant type of PRES involving these lesions. It is important to recognize the presence of variant patterns of clinical features and radiologic findings of PRES to allow for early identification and appropriate treatment.

Relationship Between Olfactory Disturbance After Acute Ischemic Stroke and Latent Thalamic Hypoperfusion.

Odor detection, recognition, and identification were assessed in 19 acute ischemic stroke patients who had no magnetic resonance imaging-detectable thalamic lesions but in whom technetium-99m ethyl cysteinate dimer single photon emission tomography revealed thalamic hypoperfusion. Although these patients were unaware of reduced olfactory function, they exhibited significantly lower scores in tests for odor identification and recognition threshold as compared with 9 ischemic stroke controls that had normal thalamic hypoperfusion. However, absolute odor detection thresholds were similar in the 2 groups. These results demonstrate the usefulness of cerebral perfusion scintigraphy in assessing sensory loss after ischemic stroke and provide further evidence for the role of the thalamus in olfaction.

Efficacy Analysis of Robot-Assisted Minimally Invasive Surgery for Small-Volume Spontaneous Thalamic Hemorrhage.

OBJECTIVE: To test whether robot-assisted surgery can improve prognosis of small-volume thalamic hemorrhage and to provide a surgical basis for treatment of small-volume thalamic hemorrhage. METHODS: This retrospective study included patients with thalamic hemorrhage and hematoma volume of 5-15 mL treated from December 2015 to December 2018. Patients were divided into an operation group and a nonoperation group. General data, types of hematoma, incidence of complications, Scandinavian Stroke Scale score, and modified Rankin Scale score were recorded and analyzed. RESULTS: Retrospectively, 84 cases met inclusion criteria: 35 cases in operation group and 49 cases in nonoperation group. At 90 days after onset, mortality was 11.4% in the operation group and 4.1% in the nonoperation group (P > 0.05). The Scandinavian Stroke Scale score in the operation group (43.3 ± 8.5) was higher than in the nonoperation group (36.1 ± 10.0) (P < 0.05). The modified Rankin Scale score in the operation group (2.9 ± 0.3) was lower than in the nonoperation group (3.7 ± 0.2) (P < 0.05). The incidence of pneumonia (8.6%) and renal dysfunction (14.3%) was lower in the operation group than in the nonoperation group (28.6% and 34.7%, respectively) (P < 0.05). There was no significant difference between the 2 groups in the incidence of central fever (5.7% vs. 12.2%), stress ulcer (11.4% vs. 16.3%), and ion balance disturbance (20.0% vs. 26.5%) (P > 0.05). CONCLUSIONS: Robot-assisted drainage of thalamic hemorrhage can improve prognosis and reduce the incidence of pneumonia and renal dysfunction.

Osteopontin Attenuates Secondary Neurodegeneration in the Thalamus after Experimental Stroke.

Cortical cerebral ischemia elicits neuroinflammation as well as secondary neuronal degeneration in remote areas. Locally distinct and specific secondary neurodegeneration affecting thalamic nuclei connected to cortical areas highlights such processes. Osteopontin (OPN) is a cytokine-like glycoprotein that is excreted in high amounts after cerebral ischemia and exerts various immunomodulatory functions. We here examined putative protective effects of OPN in secondary thalamic degeneration. We subjected male Wistar rats to photothrombosis and subsequently injected OPN or placebo intracerebroventricularly. Immunohistochemical and fluorescence staining was used to detect the extent of neuronal degeneration and microglia activation. Ex vivo autoradiography with radiotracers available for human in vivo PET studies, i.e., CIS-4-[18F]Fluor-D-Proline (D-cis-[18F]FPRO), and [6-3H]thymidine ([3H]thymidine), confirmed degeneration and proliferation, respectively. We found secondary neurodegeneration in the thalamus characterized by microglial activation and neuronal loss. Neuronal loss was restricted to areas of microglial infiltration. Treatment with OPN significantly decreased neurodegeneration, inflammation and microglial proliferation. Microglia displayed morphological signs of activation without expressing markers of M1 or M2 polarization. D-CIS-[18F]FPRO-uptake mirrored attenuated degeneration in OPN-treated animals. Notably, [3H]thymidine and BrdU-staining revealed increased stem cell proliferation after treatment with OPN. The data suggest that OPN is able to ameliorate secondary neurodegeneration in thalamic nuclei. These effects can be visualized by radiotracers D-CIS-[18F]FPRO and [3H]thymidine, opening new vistas for translational studies. Graphical Abstract Intracerebroventricular injection of osteopontin attenuates thalamic degeneration after cortical ischemia (pink area). Disruption of thalamocortical connections (blue) and degeneration of thalamic nuclei (encircled) leads to microglia activation. Osteopontin protects from both neurodegeneration and microglia activation as assessed by histological analysis and autoradiograpic studies.