Leveraging high-resolution 7-tesla MRI to derive quantitative metrics for the trigeminal nerve and subnuclei of limbic structures in trigeminal neuralgia

Background Trigeminal Neuralgia (TN) is a chronic neurological disease that is strongly associated with neurovascular compression (NVC) of the trigeminal nerve near its root entry zone. The trigeminal nerve at the site of NVC has been extensively studied but limbic structures that are potentially involved in TN have not been adequately characterized. Specifically, the hippocampus is a stress-sensitive region which may be structurally impacted by chronic TN pain. As the center of the emotion-related network, the amygdala is closely related to stress regulation and may be associated with TN pain as well. The thalamus, which is involved in the trigeminal sensory pathway and nociception, may play a role in pain processing of TN. The objective of this study was to assess structural alterations in the trigeminal nerve and subregions of the hippocampus, amygdala, and thalamus in TN patients using ultra-high field MRI and examine quantitative differences in these structures compared with healthy controls. Methods Thirteen TN patients and 13 matched controls were scanned at 7-Tesla MRI with high resolution, T1-weighted imaging. Nerve cross sectional area (CSA) was measured and an automated algorithm was used to segment hippocampal, amygdaloid, and thalamic subregions. Nerve CSA and limbic structure subnuclei volumes were compared between TN patients and controls. Results CSA of the posterior cisternal nerve on the symptomatic side was smaller in patients (3.75 mm2) compared with side-matched controls (5.77 mm2, p = 0.006). In TN patients, basal subnucleus amygdala volume (0.347 mm3) was reduced on the symptomatic side compared with controls (0.401 mm3, p = 0.025) and the paralaminar subnucleus volume (0.04 mm3) was also reduced on the symptomatic side compared with controls (0.05 mm3, p = 0.009). The central lateral thalamic subnucleus was larger in TN patients on both the symptomatic side (0.033 mm3) and asymptomatic side (0.035 mm3), compared with the corresponding sides in controls (0.025 mm3 on both sides, p = 0.048 and p = 0.003 respectively). The inferior and lateral pulvinar thalamic subnuclei were both reduced in TN patients on the symptomatic side (0.2 mm3 and 0.17 mm3 respectively) compared to controls (0.23 mm3, p = 0.04 and 0.18 mm3, p = 0.04 respectively). No significant findings were found in the hippocampal subfields analyzed. Conclusions These findings, generated through a highly sensitive 7 T MRI protocol, provide compelling support for the theory that TN neurobiology is a complex amalgamation of local structural changes within the trigeminal nerve and structural alterations in subnuclei of limbic structures directly and indirectly involved in nociception and pain processing.

Prevalence and severity of neurovascular compression in hemifacial spasm patients

Hemifacial spasm is typically caused by vascular compression of the proximal intracranial facial nerve. Although the prevalence of neurovascular compression has been investigated in a cohort of patients with classical trigeminal neuralgia, the prevalence and severity of neurovascular compression has not been well characterized in patients with hemifacial spasm. We aimed to investigate whether presence and severity of neurovascular compression are correlated to the symptomatic side in patients with hemifacial spasm. All patients in our study were evaluated by a physician who specializes in the management of cranial nerve disorders. Once hemifacial spasm was diagnosed on physical exam, the patient underwent a dedicated cranial nerve protocol magnetic resonance imaging study on a 3 T scanner. Exams were retrospectively reviewed by a neuroradiologist blinded to the symptomatic side. The presence, severity, vessel type, and location of neurovascular compression along the facial nerve was recorded. Neurovascular compression was graded as contact alone (vessel touching the facial nerve) versus deformity (indentation or deviation of the nerve by the culprit vessel). A total of 330 patients with hemifacial spasm were included. The majority (232) were female while the minority (98) were male. The average age was 55.7 years. Neurovascular compression (arterial) was identified on both the symptomatic (97.88%) and asymptomatic sides (38.79%) frequently. Neurovascular compression from an artery along the susceptible/proximal portion of the nerve was much more common on the symptomatic side (96.36%) than on the asymptomatic side (12.73%), odds ratio = 93.00, P < 0.0001. When we assessed severity of arterial compression, the more severe form of neurovascular compression, deformity, was noted on the symptomatic side (70.3%) much more frequently than on the asymptomatic side (1.82%) (odds ratio = 114.00 P < 0.0001). We conclude that neurovascular compression that results in deformity of the susceptible portion of the facial nerve is highly associated with the symptomatic side in hemifacial spasm.

Risk factors for need of reoperation in bilateral chronic subdural haematomas

Background Chronic subdural haematoma (CSDH) is one of the most common neurosurgical diseases. A subtype of CSDH is bilateral chronic subdural haematoma (bCSDH) which represents 20–25% of patients with CSDH and has a higher recurrence rate. There is no clear consensus on how bCSDH should be treated regarding upfront unilateral- or bilateral evacuation of both haematomas. The purpose of this study was to identify risk factors associated with reoperation of bCSDH. Methods A total of 326 patients with radiological evidence of bCSDH were included in this retrospective cohort study where 133 (40.8%) patients underwent primary bilateral evacuation and 193 (59.2%) primary unilateral evacuation. The two centres operated using different surgical approaches. Analyses were performed to identify risk factors associated with reoperation of bCSDH. Reoperation rate was defined as reoperation of CSDH on either side of the hemisphere within 3 months after primary evacuation. Results The cohort had a total reoperation rate of 26.4%. Patients which underwent unilateral evacuation had a reoperation rate of 32.1%, and the bilateral group had a reoperation rate of 18.0% (p=0.005). Multivariable logistic regression identified unilateral evacuation (OR 1.91, p=0.022) and complications according to Ibanez (OR 2.20, p=0.032) to be associated with the need of reoperation of bCSDH. One-burr hole craniostomy with active subgaleal drain was primarily performed in bilateral approach (69.4%) whereas patients operated with minicraniotomy with passive subdural drain were primarily operated by unilateral evacuation of the larger symptomatic side (92.8%). Conclusions Unilateral evacuation of bCSDH was associated with a higher risk for reoperation than upfront bilateral evacuations in this study. There is a need to further discuss the criteria for uni- or bilateral evacuation since patients are treated differently at different centres.

Trigeminal neurovascular contact in SUNCT and SUNA: a cross-sectional magnetic resonance study

Emerging data points towards a possible aetiological and therapeutic relevance of trigeminal neurovascular contact in short lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and perhaps in short lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). We aimed to assess the prevalence and significance of trigeminal neurovascular contact in a large cohort of consecutive SUNCT and SUNA patients and evaluate the radiological differences between them. The standard imaging protocol included high spatial and nerve-cistern contrast resolution imaging acquisitions of the cisternal segments of the trigeminal nerves and vessels. MRI studies were evaluated blindly by two expert evaluators and graded according to the presence, location and degree of neurovascular contact. The degree of contact was graded as with or without morphological changes. Neurovascular contact with morphological changes was defined as contact with distortion and/or atrophy. A total of 159 patients (SUNCT = 80; SUNA = 79) were included. A total of 165 symptomatic and 153 asymptomatic trigeminal nerves were analysed. The proportion of neurovascular contact on the symptomatic trigeminal nerves was higher (80.0%) compared to the asymptomatic trigeminal nerves (56.9%). The odds on having neurovascular contact over the symptomatic nerves was significantly higher than on the asymptomatic nerves [odds ratio (OR): 3.03, 95% confidence interval (CI) 1.84–4.99; P < 0.0001]. Neurovascular contact with morphological changes were considerably more prevalent on the symptomatic side (61.4%), compared to the asymptomatic side (31.0%) (OR 4.16, 95% CI 2.46–7.05; P < 0.0001). On symptomatic nerves, neurovascular contact with morphological changes was caused by an artery in 95.0% (n = 77/81). Moreover, the site of contact and the point of contact around the trigeminal root were respectively proximal in 82.7% (67/81) and superior in 59.3% (48/81). No significant radiological differences emerged between SUNCT and SUNA. The multivariate analysis of radiological predictors associated with the symptomatic side, indicated that the presence of neurovascular contact with morphological changes was strongly associated with the side of the pain (OR: 2.80, 95% CI 1.44–5.44; P = 0.002) even when adjusted for diagnoses. Our findings suggest that neurovascular contact with morphological changes is involved in the aetiology of SUNCT and SUNA. Along with a similar clinical phenotype, SUNCT and SUNA also display a similar structural neuroimaging profile, providing further support for the concept that the separation between them should be abandoned. Furthermore, these findings suggest that vascular compression of the trigeminal sensory root, may be a common aetiological factor between SUNCT, SUNA and trigeminal neuralgia thereby further expanding the overlap between these disorders.

Neurovascular contact plays no role in trigeminal neuralgia secondary to multiple sclerosis

Introduction A demyelinating plaque and neurovascular contact with morphological changes have both been suggested to contribute to the etiology of trigeminal neuralgia secondary to multiple sclerosis (TN-MS). The aim of this study was to confirm or refute whether neurovascular contact with morphological changes is involved in the etiology of TN-MS. Methods We prospectively enrolled consecutive TN-MS patients from the Danish Headache Center. Clinical characteristics were collected systematically. MRI scans were done using a 3.0 Tesla imager and were evaluated by the same experienced blinded neuroradiologist. Results Sixty-three patients were included. Fifty-four patients were included in the MRI analysis. There was a low prevalence of neurovascular contact with morphological changes on both the symptomatic side (6 (14%)) and the asymptomatic side (4 (9%)), p = 0.157. Demyelinating brainstem plaques along the trigeminal afferents were more prevalent on the symptomatic side compared to the asymptomatic side (31 (58%) vs. 12 (22%), p < 0.001). A demyelinating plaque was highly associated with the symptomatic side (odds ratio = 10.6, p = 0.002). Conclusion The primary cause of TN-MS is demyelination along the intrapontine trigeminal afferents. As opposed to classical trigeminal neuralgia, neurovascular contact does not play a role in the etiology of TN-MS. Microvascular decompression should generally not be offered to patients with TN-MS. The study was registered at ClinicalTrials.gov (number NCT04371575)

Plaque Distribution Correlates With Morphology of Lenticulostriate Arteries in Single Subcortical Infarctions

Background and Purpose: We aimed to use novel whole-brain vessel-wall magnetic resonance imaging (WB-VWI) to investigate the association between plaque distribution of middle cerebral artery (MCA) and morphological changes of the lenticulostriate arteries (LSAs) in single subcortical infarctions. Methods: Forty single subcortical infarction patients with no relevant MCA disease on magnetic resonance angiography were prospectively enrolled. Plaque location in the MCA was dichotomized as proximal (located adjacent to the LSA origin) or distal (located distal to the LSA origin) on whole-brain vessel-wall magnetic resonance imaging. The MCAs with proximal plaques were divided into the symptomatic and asymptomatic side, and asymptomatic side MCAs without proximal plaques were the control group. The morphological characteristics of the LSAs and features of proximal plaques were analyzed. Results: A total of 71 MCAs in 40 patients were analyzed (31 on the symptomatic side, 22 on the asymptomatic side, and 18 in the control group). Superior-wall plaques of MCAs were observed more frequently on the symptomatic side than the asymptomatic side (45.2% versus 9.1%, P =0.005). The wall area index, plaque burden, and remodeling index did not differ significantly between the symptomatic and asymptomatic side. The number of LSA branches was smaller ( P =0.011) in the symptomatic side (5.48±1.88) compared with the control group (6.83±1.92). The symptomatic side exhibited shorter average length of the LSAs (23.23±3.44 versus 25.75±3.76 mm, P =0.025) and shorter average distance of the LSAs (16.47±3.11 versus 21.53±4.76 mm, P <0.001) compared with the asymptomatic side. Conclusions: Superiorly distributed MCA plaques at the LSA origin are closely associated with morphological changes of the LSA in symptomatic MCAs, suggesting that the distribution, rather than the inherent features of plaques, determines the occurrence of single subcortical infarctions. Our findings provide insight into the etiologic mechanism of branch atheromatous disease in single subcortical infarctions.

Sonographic Evaluation of Plantar Fasciitis and its Relation to Body Mass Index and Heel Pad Thickness

Introduction: To study the sonographic appearance of plantar fascia in clinically suspected cases of plantar fasciitis (PFs) using both quantitative and qualitative parameters, and to establish the correlation between plantar fasciitis, body mass index (BMI) and heel pad thickness (HPT). Methods: In this case controlled analytical study, we sonographically evaluated 100 patients with clinical plantar fasciitis (unilateral: 90, bilateral: 10 with mean age 46.9yrs) and control group of 60 (120 heels) healthy volunteers with mean age 45.3yrs. Plantar Fascia Thickness (PFT), HPT, hypoechogenity, biconvexity, perifascial fluid, intrafascial calcification and subcalcaneal spurs were evaluated sonographically. PFT was measured 5mm distal to the calcaneal insertion of plantar aponeurosis. The unloaded HPT was measured from the skin surface to the nearest calcaneal tuberosity. Results: Mean Plantar Fascia Thickness (PFT) and Heel Pad Thickness (HPT) are greater on the symptomatic side for patients with unilateral and bilateral PFs than on the asymptomatic side for patients with unilateral PFs, and also control subjects (PFT values are 4.41 ± 0.59, 4.63 ± 0.55, 2.83 ± 0.36, 2.62± 0.37 mm, and HPT values 17.64 ± 1.07, 17.28 ± 1.10, 16.91 ± 1.06, 16.73 ± 1.13 mm, respectively) (p <0.0001). Mean BMI values of the case and control groups are 26.14 ± 1.9 and 24.42 ± 0.89 Kg/m2, respectively (p <0.05). We found hypoechogenicity of plantar fascia in 80 cases (72.7%), calcaneal spur in 69 cases (62.7%), biconvexity in 11 cases (10%) and perifascial fluid in 16 cases (14.5%) within the plantar fasciitis group (110 symptomatic heels). Conclusion: Increased plantar fascia thickness, increased heel pad thickness and hypoechogenicity of plantar fascia are consistent sonographic findings in plantar fasciitis. Its occurrence has significant relation to high BMI.

Multiple contralateral recurrence of bilateral chronic subdural hematoma: case report and literature review

We report a case of bilateral chronic subdural hematoma (CSDH) operated with a single burr-hole on the more symptomatic side (left) followed by a symptomatic expansion of the contralateral (right) hematoma 7 days after the surgery treated again with a burr-hole on the other side. A week later the patient presented again a bilateral CSDH that was re-operated on both side with a good outcome at 6 months follow-up. Relevant literature was reviewed, and we believe that the multiple recurrence of these hematomas in the opposite hemisphere resulted from the rapid drainage of the hematoma, which caused the rupture of weak bridging veins during drainage. Slow decompression is recommended to avoid rapid intracranial changes during drainage of a subdural hematoma.

HOUT-04. ASSOCIATION OF COMMON PATIENT-REPORTED IMMUNOTHERAPY SYMPTOMATIC SIDE EFFECTS AND PSEUDOPROGRESSION IN PATIENTS WITH PRIMARY CENTRAL NERVOUS SYSTEM (CNS) TUMORS

BACKGROUND Immunotherapy agents have unique symptomatic side effects; patient-reported outcomes (PROs) can help to characterize the benefits and burdens associated with therapy. Common immunotherapy-associated symptoms include pain, fatigue, shortness of breath, and irregular bowel patterns. The purpose of this study was to assess the severity of symptoms and their association with imaging changes in CNS tumor patients undergoing single agent or combination treatment with immune checkpoint inhibitors (ICIs). METHODS Patients completed the MDASI-BT or MDASI-SP at baseline and longitudinally (every 8 weeks), and results through cycle 4 are reported. Neuro-imaging was categorized as stable, possible ICI-related pseudoprogression, or progression by clinical team review. RESULTS 29 Brain Tumor (BT) and 6 Spinal Tumor patients participated; the majority of which were male (62%) and white (91%), ranging 24-74yo (mean = 46). Glioblastoma was the most common diagnosis (31%) followed by medulloblastoma (16%), with 56% of patients having greater than 2 recurrences prior to the study. At baseline, both brain and spine tumor patients reported moderate to severe fatigue (Brain=4, Spine=6) and pain (Spine=5) with shortness of breath and pain worsening over time. BT patients with pseudoprogression were more likely to report increased fatigue (87%) and pain (63%) compared to those with stable (29%) or true progressive (17%) disease on imaging. BT patients with pseudoprogression also reported worsening of cognitive (43%) and neurologic (57%) symptom burden. CONCLUSIONS In contrast to the common pseudoprogression after chemoradiation, treatment-specific symptoms were worse with ICI-related pseudoprogression by MRI where an immunologic reaction was the likely cause of the imaging worsening. These results suggest that commonly used symptom and functional assessments to distinguish true progression from pseudoprogression may not be helpful with immunotherapy. Additional studies including those with pathologic confirmation of progression or pseudoprogression combined with outcomes measures are needed to develop more accurate determinations of disease status.

Assessment of the utility of ultrasonography and microbiology in the treatment of peritonsillar abscess in children

Introduction. Peritonsillar abscess is the most common deep neck and head space infection. It mostly occurs in young adults and teenagers, usually during the infectious season; at the turn of November and December as well as April and May. The peak incidence coincides with the highest incidence of streptococcal pharyngitis. Aim. A clinical analysis was performed in patients with peritonsillar abscess symptoms to determine the role of ultrasound imaging as a diagnostic tool confirming this condition. Material and methods. A retrospective, non-randomised study conducted in a group of 20 patients aged between 1 and 17 years, who were hospitalised due to peritonsillar abscess or infiltration in the Department of Paediatric Otolaryngology. Ultrasonography of the neck was performed in all patients in the study group to assess the presence of a fluid reservoir on the symptomatic side. Results. Ultrasound imaging revealed the presence of fluid indicative of abscess in 12 cases. Incision and puncture were performed in all these patients. Purulent content was obtained in 11 cases. Conclusions. Ultrasound was found useful in detecting the presence of an abscess and differentiating between peritonsillar infiltration and abscess.