Lior Ungar

Dr. Lior Ungar

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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11 February 2020 in Acta Neurochirurgica
Verified
Journal Article
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LULior Ungar
Lior Ungar
HRHershkovitch Rotem
Hershkovitch Rotem
NUNissim Uzi
Nissim Uzi
SRSpiegelmann Roberto
Spiegelmann Roberto

29 May 2026 in Diagnostics
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Journal Article
Open access
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SSShachar Zion Shemesh
Shachar Zion Shemesh
PKPaz Kelmer
Paz Kelmer
JAJose Antonio Asprilla
Jose Antonio Asprilla
LULior Ungar
Lior Ungar
IGItay Goor-Aryeh
Itay Goor-Aryeh
LULior Ungar
Lior Ungar
Background: Trigeminal neuralgia (TN), a facial pain disorder classically characterized by recurrent brief electric-shock-like paroxysms in one or more trigeminal divisions, frequently traverses dental pathways before specialist evaluation. Conversely, dental extraction, endodontic treatment, implant procedures, and third-molar surgery may injure the inferior alveolar, superior alveolar, mental, or lingual nerves and generate painful post-traumatic trigeminal neuropathy. We sought to define the diagnostic interface between classical TN and post-dental/alveolar nerve-related trigeminal pain in a tertiary referral cohort. Methods: We performed a retrospective single-center diagnostic-pathway study using a clinical dataset comprising 672 unique patients. A dental-interface trigeminal candidate cohort was assembled from aggregated patient-level source notes and adjudicated into five prespecified phenotypes: confirmed alveolar neuropathy, post-extraction neuropathic onset, odontogenic diagnostic misclassification, mixed/uncertain dental-interface pain, and clean classical TN. Extracted variables included demographics, trigeminal branch documentation, sensory deficit, dental procedure history, post-extraction onset, MRI and neurovascular conflict language, secondary structural disease, TN-directed medication exposure, invasive treatment exposure, documented outcomes, and time from first specialist documentation to first dated invasive treatment. Results: Among 201 dental-interface trigeminal candidates, 19 patients (9.5%) had confirmed alveolar neuropathy, 31 (15.4%) had post-extraction neuropathic onset, 20 (10.0%) represented odontogenic diagnostic misclassification, 115 (57.2%) remained mixed/uncertain, and 16 (8.0%) fulfilled a clean classical TN phenotype. Overall, 114 patients (56.7%) carried explicit TN terminology somewhere in the chart. Non-classical alveolar/post-dental syndromes comprised 70 patients (34.8%). Compared with clean classical TN, this non-classical group had higher rates of documented oral sensory deficit (38.6% vs. 0.0%, p = 0.002), post-extraction onset (52.9% vs. 0.0%, p < 0.001), extraction history (61.4% vs. 0.0%, p < 0.001), and secondary structural disease (22.9% vs. 0.0%, p = 0.035). Neurovascular conflict or vascular-loop language did not distinguish non-classical alveolar/post-dental syndromes from clean classical TN (38.6% vs. 37.5%, p = 1.000). Conclusions: A substantial minority of tertiary dental-interface trigeminal referrals represented alveolar/post-dental syndromes rather than clean classical TN, even while carrying TN labels and accumulating TN-directed treatment exposure. Post-extraction onset, lower-lip/chin or intraoral sensory change, and pain persisting despite extraction should prompt careful phenotyping before classical TN-directed escalation. The alveolar–trigeminal interface can be operationalized as a recognizable diagnostic pathway with direct implications for multidisciplinary facial-pain evaluation.

PKPaz Kelmer
Paz Kelmer
SSShachar Zion Shemesh
Shachar Zion Shemesh
JAJose Antonio Asprilla
Jose Antonio Asprilla
OCOmri Cohen
Omri Cohen
ZCZvi R. Cohen
Zvi R. Cohen
LULior Ungar
Lior Ungar
Objective: On 28 February 2026, Israel entered direct large-scale hostilities with Iran under Operation Roaring Lion. The opening phase was characterized by repeated missile alerts, civilian protected-space instructions, and rapid reorganization of hospital activity into protected areas. We observed an apparent increase in strict spontaneous intracerebral hemorrhage admissions during March 2026 within our linked neurology/neurosurgery services dataset. The aim of this preliminary single-center study was to determine whether March 2026 was temporally associated with a higher proportional burden of strict spontaneous intracerebral hemorrhage admissions compared with March cohorts from the preceding decade and whether this pattern was also observed for acute ischemic stroke or non-traumatic subarachnoid hemorrhage. Methods: We performed a retrospective observational cohort study of all unique March admissions captured within a linked neurology/neurosurgery services dataset from 2016 through 2026. Hospitalizations were deduplicated by admission number. March 2026 was treated as the first full March occurring after the onset of direct Israel–Iran hostilities on 28 February 2026. Strict spontaneous ICH was defined using diagnosis-text phenotyping that included intraparenchymal or intracerebral hemorrhage terminology while excluding trauma, subarachnoid hemorrhage, subdural hematoma, aneurysm, arteriovenous malformation, tumor-related hemorrhage, cavernoma, venous sinus thrombosis, dissection, and other clearly secondary etiologies. Comparator phenotypes included acute ischemic stroke and non-traumatic subarachnoid hemorrhage (SAH). Results: Across 3855 unique March admissions, 68 met criteria for strict spontaneous ICH. In March 2026, 9 of 223 admissions (4.0%) were classified as strict spontaneous ICH, compared with 59 of 3632 admissions (1.6%) across March 2016–2025, yielding a rate ratio of 2.48 (95% CI 1.25–4.94; p = 0.015). Patients with strict spontaneous ICH in March 2026 were older (mean age 72.3 vs. 65.8 years), and 7 of 9 cases (77.8%) occurred in patients aged ≥70 years compared with 25 of 59 (42.4%) historically (p = 0.073). Acute ischemic stroke did not increase in March 2026 (7.6% vs. 9.4%; p = 0.475), and non-traumatic SAH showed only a non-significant numerical increase (2.7% vs. 1.4%; p = 0.147). Sensitivity analyses showed a directionally consistent but statistically non-significant increase when March 2026 was compared with March 2025 alone (4.0% vs. 1.2%; rate ratio 3.36, 95% CI 0.92–12.27; p = 0.076) and with a rolling 3-year March baseline from 2023 through 2025 (4.0% vs. 2.1%; rate ratio 1.93, 95% CI 0.88–4.23; p = 0.143). In-hospital mortality among strict spontaneous ICH patients was 1 of 9 (11.1%) in March 2026 versus 4 of 59 (6.8%) in March 2016–2025. Conclusions: In this preliminary single-center neurology/neurosurgery services cohort, March 2026 showed a higher proportional burden of strict spontaneous intracerebral hemorrhage admissions than March cohorts from the preceding decade, while acute ischemic stroke did not increase. Sensitivity analyses using March 2025 alone and a rolling 3-year March baseline were directionally consistent but did not reach statistical significance. These findings should therefore be interpreted as a hypothesis-generating temporal association rather than evidence of causality or population-level incidence. Wartime-related psychological stress, sleep disruption, altered healthcare access, blood pressure dysregulation, and medication nonadherence are biologically plausible contributors, but individual-level blood pressure, medication exposure, body mass index, time-to-admission, direct stress exposure, and detailed outcome data were not available in the present dataset. Multicenter, hospital-wide, and registry-based validation with seasonal and systems-level sensitivity analyses is required.

2 February 2026 in Dentistry Journal
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Journal Article
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SSShachar Zion Shemesh
Shachar Zion Shemesh
PKPaz Kelmer
Paz Kelmer
LULior Ungar
Lior Ungar
Background: Burning Mouth Syndrome (BMS) is a chronic orofacial pain condition characterized by a burning sensation in the oral cavity without identifiable lesions. It predominantly affects women (especially postmenopausal) but can occur in men. BMS is considered a multifactorial neuropathic pain disorder involving both peripheral small-fiber neuropathy and central dysregulation, often accompanied by taste alterations (dysgusia) and xerostomia despite normal oral exams. Treatment is challenging, with modest responses to agents like clonazepam, tricyclic antidepressants, or gabapentinoids. Observations: We present a 67-year-old male with recalcitrant primary BMS who showed complete remission temporally associated with occipital nerve blockade, likely affecting central trigeminocervical pathways. Initial therapy with amitriptyline (25 mg) and gabapentin (900 mg/day) yielded ~30% pain relief. Given suspected central sensitization, greater and lesser occipital nerve (GON) blocks were administered in series. After the first, second, and third ON blocks, pain was reduced by ~50%, 80%, and 100%, respectively. Remission persisted at one-year follow-up under continued medications. A mild recurrence (~20% of baseline pain) responded fully to a fourth GON block, maintaining another year of pain-free status. Lessons: This case underscores the complex central mechanisms in BMS and illustrates that modulating central pain circuits via occipital nerve blockade, through trigeminocervical convergence mechanisms, without direct trigeminal intervention. We discuss the diagnostic challenges of BMS, the rationale of occipital neuromodulation, and how this novel therapeutic strategy compares with current literature, supporting the hypothesis of central sensitization in BMS.

21 May 2026 in Neurology International
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Journal Article
Open access
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SSShachar Zion Shemesh
Shachar Zion Shemesh
PKPaz Kelmer
Paz Kelmer
JAJose Antonio Asprilla
Jose Antonio Asprilla
YHYotam Hadari
Yotam Hadari
OCOmri Cohen
Omri Cohen
LULior Ungar
Lior Ungar
Background: Trigeminal neuralgia (TN) is clinically defined, but patients presenting to tertiary practice with trigeminal-region pain are often diagnostically heterogeneous and may follow prolonged medication, dental, imaging, and procedural pathways before a stable phenotype is established. We aimed to characterize diagnostic phenotypes, secondary causes, and treatment-escalation patterns in a large retrospective tertiary-center trigeminal pain cohort derived from routine free-text clinical documentation. Methods: We conducted a retrospective single-center cohort study based on a clinical dataset containing 18,007 note fragments linked to 672 unique patient records between 12 October 2010 and 21 April 2026. A rule-based natural-language-processing-assisted chart review framework was used to identify patients with trigeminal pain and to extract documentation-derived demographic features, pain distribution, secondary causes, dental pathway variables, imaging signals, medication exposure, procedures, and outcome language. Patients were grouped into primary/classical TN, secondary TN/trigeminal pain, and dental-first or mimic pathways using predefined operational criteria. Results: A total of 455 patients met criteria for the analytic trigeminal pain cohort; 311 (68.4%) carried explicit TN terminology. Mean age was 58.7 years, median age 60 years, and 267 of 428 patients with recoverable sex data (62.4%) were women. Trigeminal branch involvement could be extracted in 351 patients (77.1%), with V2 involvement documented in 256 (56.3%), V3 involvement in 218 (47.9%), and V1 involvement in 138 (30.3%). The final NLP-derived phenotypic distribution comprised 201 primary/classical TN cases (44.2%), 146 secondary TN/trigeminal pain cases (32.1%), and 108 dental-first or mimic presentations (23.7%). MRI was documented in 384 patients (84.4%), neurovascular conflict or vascular loop in 253 (55.6%), multiple-sclerosis-related disease in 69 (15.2%), and tumor-related trigeminal involvement in 84 (18.5%). Prior dental evaluation was identified in 169 patients (37.1%), and prior dental procedures in 114 (25.1%). Carbamazepine exposure was documented in 367 patients (80.7%), pregabalin in 221 (48.6%), gabapentin in 150 (33.0%), oxcarbazepine in 116 (25.5%), and phenytoin in 73 (16.0%). At least one invasive or image-guided procedure was documented in 390 patients (85.7%), including nerve blocks/injections in 355 (78.0%), radiofrequency procedures in 126 (27.7%), balloon compression in 90 (19.8%), microvascular decompression in 113 (24.8%), and stereotactic radiosurgery in 55 (12.1%). Dental-first patients were significantly more likely to have undergone prior dental procedures (65.7% vs. 3.5% in primary/classical TN and 24.7% in secondary TN; p < 0.001), whereas secondary TN/trigeminal pain was associated with higher use of radiofrequency procedures (36.3%; p = 0.017), higher use of stereotactic radiosurgery (19.9%; p = 0.002), higher recurrence documentation (70.5%; p = 0.001), and a higher rate of complete pain relief documented at last follow-up (46.6%; p = 0.004). Conclusions: In tertiary practice, trigeminal pain is substantially broader than a formal TN label. Secondary disease and dental-first pathways account for a large fraction of referrals, and management is characterized by heavy medication burden, frequent escalation, and recurrent retreatment. A structured phenotyping approach may help convert routine clinical documentation into a clinically meaningful framework for diagnostic triage and treatment selection, although imaging and outcome variables require cautious interpretation when derived from retrospective free text.

25 May 2026 in Journal of Neurosurgery: Case Lessons
Verified
Journal Article
Open access
SSShachar Zion Shemesh
Shachar Zion Shemesh
PKPaz Kelmer
Paz Kelmer
TFTsvia Fay-Karmon
Tsvia Fay-Karmon
SHSharon Hassin-Baer
Sharon Hassin-Baer
LULior Ungar
Lior Ungar
BACKGROUND: Chronic migraine is a highly disabling neurological disorder. A subset of patients develop chronic daily headaches refractory to all standard therapies. MR-guided focused ultrasound (MRgFUS) ventral intermediate nucleus (VIM) thalamotomy is an incisionless treatment for medication-refractory essential tremor (ET). OBSERVATIONS: A 76-year-old woman with a 40-year history of chronic migraine with near-daily attacks, characterized predominantly by right-sided headaches and unresponsive to multiple preventive and acute treatments, underwent MRgFUS VIM thalamotomy for severe ET. After the procedure, her tremor resolved, and her chronic migraines were no longer reported during long-term follow-up. Shortly after the procedure, she developed burning mouth syndrome (BMS), characterized by bilateral oral burning dysesthesias with left-sided predominance involving the lips and oral mucosa. She was treated with gabapentin and amitriptyline, with partial symptomatic improvement. Postprocedure MRI confirmed the intended VIM lesion with slight medial extension toward the adjacent ventral posteromedial nucleus (VPM) of the thalamus, which relays trigeminal somatosensory input. LESSONS: This unique case illustrates that ablative neuromodulation of thalamic networks may be followed by marked improvement or remission of chronic refractory migraine, further supporting a possible role for the thalamus in migraine pathophysiology and pain transmission. It also highlights a potential trade-off: lesion extension toward nearby sensory nuclei, including the VPM, may be associated with focal central pain manifesting as BMS. https://thejns.org/doi/10.3171/CASE251040