Merih Can YILMAZ

Dr. Merih Can YILMAZ

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

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

Representative Publications

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4 November 2024 in Cureus
Verified
Journal Article
Open access
PDF file
MYMerih Can YILMAZ
Merih Can YILMAZ
KAKeramettin Aydin
Keramettin Aydin
KAKerameddin Aydin
Kerameddin Aydin
Spontaneous spinal epidural hematoma (SSEH) during pregnancy is an extremely rare neurological emergency, often presenting with sudden neck pain and progressive limb weakness. This report describes a 26-year-old pregnant woman at 26 weeks of gestation who developed paraplegia and severe muscle weakness without prior trauma. MRI revealed a cervical epidural hematoma, leading to an emergency C6 and C7 laminectomy. Despite surgery, the patient remained quadriplegic, with follow-up MRI showing persistent myelomalacia. This case highlights the challenges of diagnosing and managing SSEH during pregnancy, emphasizing the need for prompt intervention and ongoing research to improve outcomes for affected patients.

2 November 2025 in Fetal and Pediatric Pathology
Verified
Journal Article
Closed access
MBMustafa Bilici
Mustafa Bilici
MYMerih Can YILMAZ
Merih Can YILMAZ
BBBilge Bilgic
Bilge Bilgic
MSMuzaffer Saglam
Muzaffer Saglam
HIHulya Ince
Hulya Ince
KAKeramettin Aydin
Keramettin Aydin
Melanocytes and Schwann cells share a neural crest origin. Giant congenital melanocytic nevi (CMN) are linked to neurocutaneous melanocytosis (NCM), melanoma risk, and CNS anomalies. We report a case of giant CMN with a holocord intradural nerve sheath tumor. A 19-month-old male with CMN presented for spinal mass treatment. History included recurrent pulmonary infections, severe neurological impairment, and developmental delay. Spinal MRI revealed an intradural-intramedullary mass extending from C5 to L1 (up to 2 cm thick), compressing nerve roots. Partial resection was performed, though the thoracic portion adhered irreversibly to the cord and roots. Pathology identified a hybrid nerve sheath tumor. To our knowledge, this is the first reported case of a spinal nerve sheat tumor associated with CMN in a pediatric patient. The surgery and pathology of the case demonstrated distinctive features. This unique case and its management are shared with the literature.

26 May 2026 in Diagnostics
Verified
Journal Article
Open access
PDF file
MYMerih Can YILMAZ
Merih Can YILMAZ
ÖÖÖzgür Özaydın
Özgür Özaydın
KAKeramettin Aydin
Keramettin Aydin
Background /Objectives: Lumbar spondylosis is a degenerative disorder that may require decompression and stabilization surgery. Rigid titanium rods provide strong fixation, whereas polyetheretherketone (PEEK) rods have been proposed to offer a more flexible load distribution profile. This study compared the radiological outcomes after PEEK versus rigid rod stabilization and evaluated whether the preoperative degenerative findings contributed independently to the postoperative adjacent segment radiological status. Methods: A retrospective cohort of 106 patients undergoing lumbar decompression and posterior stabilization (2020–2025) was analyzed. Rod allocation followed routine clinical practice rather than randomization. Radiological parameters (foraminal area, canal diameter, disc height, and facet volume) were measured preoperatively and at one year postoperatively. Baseline-adjusted ANCOVA models with HC3 robust inference compared PEEK and rigid rods across the two-, three-, and four-segment constructs. Additional models assessed the independent effects of preoperative facet effusion and Modic changes. Results: PEEK rods were associated with the statistically reliable preservation of spinal canal diameter, foraminal area, disc height (particularly in the three- and four-segment constructs), and reduced facet joint volume increase compared with rigid rods after multiple-comparison correction. The findings for the two-segment constructs were less consistent and partly influence-sensitive. Preoperative facet effusion and Modic changes showed no statistically reliable independent association with postoperative radiological outcomes after adjustment. Conclusions: PEEK rod systems were associated with favorable baseline-adjusted radiological preservation patterns, especially in long-segment stabilization. These findings should be interpreted as radiological associations rather than proof of clinical superiority or causal reduction in adjacent segment disease, because rod allocation was nonrandom and clinical, and fusion-related outcomes were not assessed.

28 February 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
MYMerih Can YILMAZ
Merih Can YILMAZ
ÖÖÖzgür Özaydın
Özgür Özaydın
CCCengiz Cokluk
Cengiz Cokluk
KAKeramettin Aydin
Keramettin Aydin
Background and Objectives: Spinal infections represent a heterogeneous group of diseases where primary or secondary etiological classification is fundamental for diagnosis and clinical decision-making. The aim is to present multicenter data evaluating etiological patterns associated with comorbidity. This study investigated the etiological distribution of spinal infections in a multicenter cohort and examined the relationships between chronic kidney disease (CKD) and diabetes mellitus (DM) and primary and secondary spinal infection etiologies, which emerged in the study and are thought to contribute to the literature. Materials and Methods: For this early-phase exploratory modelling study, a ridge-penalized logistic regression (L2) model was trained using repeated nested cross-validation (outer 5-fold stratified CV ×10 repetitions; inner 5-fold CV) to generate out-of-fold (OOF) probabilities. The penalty parameter (C) was optimized by minimizing log-loss. All preprocessing was performed within the CV pipeline to prevent data leakage. A supplementary Firth-penalized analysis was conducted as a plausibility check, using the CKD0/DM0 group as reference. Results: The model demonstrated effective discrimination between spinal infection probabilistic profiles (OOF AUC 0.762; conditional OOF bootstrap 95% CI 0.608–0.885). A contrasting probabilistic profile concordance was observed: DM-only patients had a high likelihood of secondary infection (observed secondary risk 93.3%; mean OOF estimated probability 84.4%), compared to a higher likelihood of primary infection in CKD-only patients (observed secondary risk 15.4%, which translates to a primary risk of 84.6%; mean OOF estimated probability 21.8%). Calibration was near-ideal (intercept 0.069; slope 1.028). Decision curve analysis showed a clear utility between the thresholds of 0.15 and 0.84. There were no CKD+DM+ cases (n = 0); analyses were restricted to supported strata. Conclusions: In this multicenter analysis of spine infections, CKD was predominantly related to primary spine infection etiology, whereas DM was more frequently related to secondary spine infections. These findings emphasize the potential role of comorbidity profiles in etiologic classification and need to be confirmed in larger multicenter cohorts.

Verified
Journal Article
Open access
PDF file
MYMerih Can YILMAZ
Merih Can YILMAZ
KAKeramettin Aydin
Keramettin Aydin
Background/Objectives: This study presents a case of chronic internal carotid artery [ICA] occlusion initially misinterpreted as ICA agenesis on magnetic resonance angiography (MRA). The report underscores the importance of retrospective review of prior imaging, particularly computed tomography angiography [CTA], in establishing the correct diagnosis. Case Report: A 70-year-old man presented with persistent headache, pulsatile tinnitus, and intermittent dizziness. Neurological examination and laboratory results were unremarkable. Initial cranial MRA demonstrated absence of flow in the left ICA, raising suspicion of congenital agenesis. However, retrospective evaluation of a CTA performed nine years earlier revealed a well-formed left carotid canal without ICA opacification, confirming the diagnosis of chronic ICA occlusion. Results: Current imaging again showed lack of enhancement in the left ICA, with adequate cerebral perfusion supplied via the contralateral ICA and vertebrobasilar system. Recognition of the preserved carotid canal on earlier CTA clarified the diagnosis as chronic occlusion rather than agenesis. Although surgical or endovascular revascularization was recommended, the patient opted for conservative management. At three months of follow-up, symptoms had improved and clinical monitoring continues. Conclusions: This case underscores the importance of distinguishing ICA agenesis from chronic occlusion, particularly by evaluating the carotid canal on CT. The presence of a carotid canal strongly indicates prior patency of the ICA and supports a diagnosis of occlusion. Careful differentiation is critical to avoid misinterpretation and to guide appropriate clinical management. In addition, reviewing prior imaging can be valuable when current findings are inconclusive or potentially misleading. Since this is a single case report, these observations should be regarded as hypothesis-generating rather than definitive, and further studies are needed to validate their broader applicability.

3 September 2025 in Reports
Verified
Journal Article
Open access
PDF file
MYMerih Can YILMAZ
Merih Can YILMAZ
KAKeramettin Aydin
Keramettin Aydin
Background and Clinical Significance: Posteriorly migrated lumbar disc herniation [PMLDH] is a rare entity that may present with atypical clinical and radiological features, often mimicking other spinal pathologies. Migration of sequestered fragments through the interlaminar space is exceptionally uncommon, and diagnostic challenges are further amplified in the presence of spinal instability. While MRI and CT are generally sufficient for diagnosis, undetected lesions on preoperative imaging may complicate clinical management. Case Presentation: A 59-year-old male presented with acute low back pain and left-sided radiculopathy. Examination revealed mild motor weakness in ankle dorsiflexion. MRI showed L4–L5 segmental instability with central canal stenosis but no migrated disc fragment. Owing to neurological deficit, decompressive laminectomy with posterior instrumentation was performed. Intraoperatively, a posteriorly migrated sequestered fragment compressing the thecal sac was excised and confirmed as degenerative disc material. Postoperatively, the patient’s neurological deficit and radicular pain resolved, with no new complaints at 3-month follow-up. Conclusions: This case highlights an unusual presentation of PMLDH in a patient with lumbar stenosis and spinal instability, undetected on preoperative imaging. Recognition of the biomechanical predisposition at the L3–4 and L4–5 levels is important in understanding such rare migrations. Although literature emphasizes early surgical intervention for PMLDH, our patient required urgent surgery due to neurological deficits rather than a definitive preoperative diagnosis. Further studies are warranted to clarify the relationship between instability and posterior migration.