Samantha Dayawansa

Dr. Samantha Dayawansa


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 January 2016 in BMC Neurology
Verified
Journal Article
Open access
PDF file
EFEkokobe Fonkem
Ekokobe Fonkem
SDSamantha Dayawansa
Samantha Dayawansa
ESEdana Stroberg
Edana Stroberg
ELEdwin Lok
Edwin Lok
PBPaul C. Bricker
Paul C. Bricker
JHJason Huang
Jason Huang
Patients with intravascular lymphoma (IVL) frequently have neurological signs and symptoms. Prompt diagnosis and treatment is therefore crucial for their survival. However, the spectrum of neurological presentations and their respective frequencies have not been adequately characterized. Our aim is to document the spectrum of clinical symptoms and their respective frequencies and to create a clinical framework for the prompt diagnosis of IVL. A comprehensive meta-analysis of 654 cases of IVL published between 1957 and 2012 was performed to provide better insight into the neurological presentations of this disease. Neurologic complications were mainly divided into central nervous system (CNS) and peripheral nervous system (PNS) presentations. There were no differences in occurrences of CNS IVL based on gender or geographic locations (Asian Vs non-Asian). However, most patients with CNS IVL were younger than 70 years of age (p < 0.05). Our limited data do not support the treatment efficacy of methotrexate. CNS symptoms were seen in 42 % of all cases. The most common CNS complications identified were cognitive impairment/dementia (60.9 %), paralysis (22.2 %), and seizures (13.4 %). PNS complications were seen in 9.5 % of cases. Out of these, muscle weakness (59.7 %), neurogenic bladder (37.1 %), and paresthesia (16.1 %) were the most common presentations. CNS complications are more common among IVL patients. Out of these, dementia and seizures outnumber stroke-like presentations.

29 May 2023 in Journal of Neuro-Oncology
Verified
Journal Article
Closed access
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SDSamantha Dayawansa
Samantha Dayawansa
GMGeorgios Mantziaris
Georgios Mantziaris
JSJason Sheehan
Jason Sheehan

1 January 2016 in Journal of Epidemiology and Global Health
Verified
Journal Article
Open access
EFEkokobe Fonkem
Ekokobe Fonkem
JDJad A. Dandashi
Jad A. Dandashi
ESEdana Stroberg
Edana Stroberg
DGDavid Garrett
David Garrett
FHFrank S. Harris
Frank S. Harris
JHJason Huang
Jason Huang
Documented meningioma cases in Central Texas (USA) from 1976 to 2013 were studied utilizing the Scott & White Brain Tumor Registry. All the cases examined were histologically diagnosed as meningiomas. Of the 372 cases, most were benign tumors (p < 0.05). A majority of the patients were females (p < 0.05). Elderly individuals (>45 years of age) superseded the younger patients in meningioma incidence (p < 0.05). Previous data regarding meningioma epidemiology in Texas showed a higher incidence in black patients when compared to white patients. By contrast, this study’s findings of Central Texas meningioma demographics show increased incidence of meningiomas in white patients (p < 0.05). This interesting find in meningioma prevalence warrants further investigation with a larger sample size, in order to establish validity and further parse out possible causes of meningioma development among white individuals.

29 October 2024 in Scientific Reports
Verified
Journal Article
Open access
PDF file
SDSamantha Dayawansa
Samantha Dayawansa
CDChloe Dumot
Chloe Dumot
GMGeorgios Mantziaris
Georgios Mantziaris
ZXZhiyuan Xu
Zhiyuan Xu
SPStylianos Pikis
Stylianos Pikis
JSJason P. Sheehan
Jason P. Sheehan
Brainstem cerebral cavernous malformations (CCM) are clinically more aggressive compared to superficial CCMs. Due to their location, resection can be challenging, making stereotactic radiosurgery (SRS) an attractive alternative for symptomatic patient. Brainstem CCM patients (n = 170) were treated with Gamma Knife SRS at 11 radiosurgical centers. Hemorrhagic risk reduction, risk factors of post-SRS hemorrhage, and clinical outcomes were retrospectively analyzed. Most patients had a single (165/170 patients) brainstem CCMs treated; the majority of CCMs (165/181) presented with bleeding. Single-session SRS decreased the risk of repeat hemorrhage in patients with hemorrhagic brainstem CCM (HR: 0.17, p < 0.001) using recurrent multivariate analysis. The annual hemorrhage rate decreased from 14.8 per 100 CCM-years before SRS to 2.3 after treatment. Using univariate Cox-analysis, the probability of a new hemorrhages after SRS was reduced for patient older than 35 years (HR = 0.21, p = 0.002) and increased with a margin dose > 13 Gy (HR = 2.57, p = 0.044). Adverse radiation effect (ARE) occurred in 9 patients (5.3%) and was symptomatic in four (2.4%). At a median follow-up of 3.4 years (Inter-quartile range: 5.4), 13 patients (8.0%) had a worsened clinical status, with the treated CCM being the cause in 5.6% (10) of the patients. Single-session SRS decreased the risk of repeat hemorrhage in patients with hemorrhagic brainstem CCM and conveyed this benefit with a low risk of advrse radiation effects (ARE) and worsening clinical status.

28 March 2016 in Neurological Research
Verified
Journal Article
Closed access
SDSamantha Dayawansa
Samantha Dayawansa
JZJun Zhang
Jun Zhang
CSChung-Hsuan Shih
Chung-Hsuan Shih
BTBinu Tharakan
Binu Tharakan
JHJason Huang
Jason Huang
Objectives: Functional data are essential when confirming the efficacy of elongated dorsal root ganglia (DRG) cells as a substitute for autografting. We present the quantitative functional motor, electrophysiological findings of engineered DRG recipients for the first time. Methods: Elongated DRG neurons and autografts were transplanted to bridge 1-cm sciatic nerve lesions of Sprague Dawley (SD) rats. Motor recoveries of elongated DRG recipients (n=9), autograft recipients (n=9), unrepaired rats (n=9) and intact rats (n=6) were investigated using the angle board challenge test following 16 weeks of recovery. Electrophysiology studies were conducted to assess the functional recovery at 16 weeks. In addition, elongated DRGs were subjected to histology assessments. Results: At threshold levels (35° angle) of the angle board challenge test, the autograft recipients’, DRG recipients’ and unrepaired group’s performances were equal to each other and were less than the intact group (p<0.05). However, during the subthreshold (30°) angle board challenge test, the elongated DRG recipients’ performance was similar to both the intact group and the autograft nerve recipients, and was better (p<0.05) than the unrepaired group. The autograft recipients’ performance was similar to the unrepaired group and was significantly different (p<0.05) compared with the performance of the intact group. During electrophysiological testing, the rats with transplanted engineered DRG constructs had intact signal transmission when recorded over the lesion, while the unrepaired rats did not. It was observed that elongated DRG neurons closely resembled an autograft during histological assessments. Conclusion: Performances of autograft and elongated DRG construct recipients were similar. Elongated DRG neurons should be further investigated as a substitute for autografting.

7 December 2021 in Cureus
Verified
Journal Article
Open access
CSCaren Stuebe
Caren Stuebe
SDSamantha Dayawansa
Samantha Dayawansa
JHJason Huang
Jason Huang
FHFrank S. Harris
Frank S. Harris
The differential for ring-enhancing lesions of the brain is extensive, with patient characteristics, particularly immunologic status, crucial to the clinical plan. In immunocompromised patients with a single ring-enhancing lesion, aspergillosis, toxoplasmosis, and nocardial infections are considered. In the case of multiple ring-enhancing lesions, metastases often supersede opportunistic infections on the differential. We present an unusual case of multiple nocardial brain abscesses mimicking metastases in an immunocompromised patient with a history of narcolepsy.