Constant light and pinealectomy disrupt daily rhythm in song production and negatively impact reproductive performance in zebra finches.

We assessed the circadian clock control of singing and reproductive performance in zebra finches. Experiment 1 examined changes in body mass, testis size, and plasma corticosterone and testosterone levels in male birds exposed to constant light (LL, 100 lx) and constant darkness (DD, 0.5 lx), with controls on 12L:12D (L = 100 lx, D = 0.5 lx). There was a significant increase in the body mass and testis size under LL and a decrease in testis size under the DD. Using a similar design, experiment 2 assessed the persistence of the circadian rhythm in singing along with activity-rest pattern in cohort I birds that were entrained to 12L:12D and subsequently released in DD or LL, and in cohort II birds that were entrained to 12L:12D and following pinealectomy were released in DD. Both activity and singing patterns were synchronized with the light phase under 12L:12D, free-ran with a circadian period under DD, and were arrhythmic under the LL. There was an overall decreased and increased effect on singing under DD and LL, respectively, albeit with differences in various song parameters. The pinealectomy disrupted both activity and singing rhythms but did not affect singing or the overall song features. Pinealectomized bird pairs also exhibited a significant reduction in their nest-building and breeding efforts, resulting in a compromised reproductive performance. These results suggest a circadian clock control of singing and more importantly demonstrate a role of the pineal clock in breeding behaviors, leading to a compromised reproductive performance in diurnal zebra finches.

[Neurosurgical treatment of tumors of the pineal region - literature review and overview of cases at OMIII]. / A pineális régió tumorainak idegsebészeti ellátása ­ irodalmi áttekintés és az OMIII beteganyagának vizsgálata.

Pineal region tumors account for less than 1% of adult supratentorial tumors. Their treatment requires a multimodality approach. Previously, the treatment of choice was direct surgery, which is associated with high surgical risk. Advances in minimally invasive techniques and onco-radiotherapy offer a safe and multimodal personalized therapy. The aim of our study was to describe the practice of our Institute based on combined endoscopic and radiotherapy techniques. We performed a retrospective clinical study. We processed data from 23 adult patients who underwent endoscopic third ventricle fenestration and pineal tumor biopsy between 2014 and 2023. Descriptive statistics, t-test, Fisher's exact test and Kaplan-Meier analysis were performed. Clinical improvement with endoscopic intervention was achieved in 78.3% of cases. Significant increase in preoperative performance status was observed in the postoperative period (p=2.755e-5), and radiotherapy resulted in regression or stable disease. Our results suggest a safe treatment with good clinical outcome and an excellent alternative to direct surgery.

Simultaneous Single-Trajectory Endoscopic Biopsy and Third Ventriculostomy in Pineal Region Tumors: A Systematic Review and Single Arm Meta-Analysis.

OBJECTIVE: To assess the efficacy and surgical outcomes of the simultaneous single-trajectory endoscopic biopsy and third ventriculostomy (ETV) in pineal region tumors. METHODS: A systematic review and meta-analysis adhering to Cochrane Standards and PRISMA framework were conducted. PubMed, Embase, and Web Of Science databases were searched until December 2023. Outcomes included rate of histopathologic diagnosis success, ETV success, complications, required VPS, and mortality. RESULTS: Seventeen studies (N = 388) met inclusion criteria. Histopathologic diagnosis success rate was 90% for general population (95% CI: 86%-95%; I2 = 42%) and 94% for pediatric patients (95% CI: 89%-98%; I2 = 19%). ETV Success rate was 93% (95% CI: 88%-97%; I2 = 60%). An estimated risk of postoperative ETV complications was found to be 16% for the general population (95% CI: 5%-28%; I2 = 90%) and 5% for pediatric patients (95% CI: 0%-13%; I2 = 51%). The risk of requiring VPS was estimated as 2% (95% CI: 0%-4%; I2 = 39%) and for the pediatric population it was 7% (95% CI: 0%-16%; I2 = 69%). Mortality risk was found to be 1% (95% CI: 0%-3%; I2 = 0%). CONCLUSIONS: Simultaneous endoscopic biopsy and ETV demonstrated high diagnostic and therapeutic success rates. The procedure's safety profile, with low mortality and complications, supports its role in treating hydrocephalus associated to pineal region tumors. Subgroup analyses revealed higher diagnostic success rates and required VPS in the pediatric population, whilst it had lower complication rates.

Papillary Tumors of Pineal Region: A Single-Center Experience in Management of 11 Cases.

BACKGROUND: Papillary tumors of pineal region (PTPR) comprise a very rare subset of pineal region tumors that have been recently described. Literature on the management and outcome of PTPR is scarce owing to the rarity of these tumors. To address this lacuna, we analyzed our experience in management of PTPR. METHODS: We retrospectively analyzed the outcome of 11 patients with histopathologically proven PTPR who underwent surgical excision at our center. RESULTS: Mean patient age was 33.3 years (range, 12-45 years), and male-to-female ratio was 1.75:1. Headache was the most common presentation followed by visual disturbances, altered sensorium, Perinaud syndrome, and seizures. Cerebrospinal fluid diversion was required in 6 patients. Krause approach was the most common approach used for tumor excision (9/11 cases). There was no perioperative mortality. Two patients were lost to follow-up. In the remaining 9 patients, the average follow-up period was 45 months (range, 12-79 months). On first postoperative magnetic resonance imaging, 8 patients showed no evidence of residual tumor (gross total resection), while 1 patient had small residual tumor (near-total resection) that remained stable during follow-up. Four patients underwent adjuvant chemoradiotherapy. None of the patients developed recurrence during follow-up. CONCLUSIONS: PTPR are a rare subgroup of pineal region tumors with distinct cells of origin but presentation similar to other pineal region tumors. Surgical resection constitutes the mainstay of management, and the extent of resection appears to be the most important determinant of prognosis. The role of adjuvant therapy still needs to be determined.

The role of melatonin deficiency induced by pinealectomy on motor activity and anxiety responses in young adult, middle-aged and old rats.

BACKGROUND: Aging affects anxiety levels in rats while the pineal gland, via its hormone melatonin, could modulate their inherited life "clock." The present study aimed to explore the impact of plasma melatonin deficiency on anxiety responses and the possible involvement of the hypothalamic-pituitary-adrenocortical (HPA) axis and heat shock proteins (Hsp) 70 and 90 in the frontal cortex (FC) and the hippocampus in young adult, middle-aged and elderly rats with pinealectomy. RESULTS: Melatonin deficiency induced at different life stages did not affect the lifespan of rats. Pinealectomy abolished the circadian rhythm of motor activity, measured for 48 h in the actimeter, in young adult but not in middle-aged rats. Pinealectomy reduced the motor activity of the young adult rats during the dark phase and impaired the diurnal activity variations of old rats. The same generations (3- and 18 month-old rats with pinealectomy) had lower anxiety levels than the matched sham groups, measured in three tests: elevated-plus maze, light-dark test, and novelty-suppressed feeding test. While the activity of the HPA axis remained intact in young adult and middle-aged rats with melatonin deficiency, a high baseline corticosterone level and blunted stress-induced mechanism of its release were detected in the oldest rats. Age-associated reduced Hsp 70 and 90 levels in the FC but not in the hippocampus were detected. Pinealectomy diminished the expression of Hsp 70 in the FC of middle-aged rats compared to the matched sham rats. CONCLUSIONS: Our results suggest that while melatonin hormonal dysfunction impaired the motor activity in the actimeter and emotional behavior in young adult and elderly rats, the underlying pathogenic mechanism in these generations might be different and needs further verification.

Pineal anlage tumor: clinical and diagnostic features, and rationales for treatment.

PURPOSE: To provide a treatment-focused review and develop basic treatment guidelines for patients diagnosed with pineal anlage tumor (PAT). METHODS: Prospectively collected data of three patients with pineal anlage tumor from Germany was combined with clinical details and treatment information from 17 published cases. RESULTS: Overall, 20 cases of PAT were identified (3 not previously reported German cases, 17 cases from published reports). Age at diagnosis ranged from 0.3 to 35.0 (median: 3.2 ± 7.8) years. All but three cases were diagnosed before the age of three years. For three cases, metastatic disease at initial staging was described. All patients underwent tumor surgery (gross-total resection: 9, subtotal resection/biopsy: 9, extent of resection unknown: 2). 15/20 patients were alive at last follow-up. Median follow-up for 10/15 surviving patients with available follow-up and treatment data was 2.4 years (0.3-6.5). Relapse was reported for 3 patients within 0.8 years after diagnosis. Five patients died, 3 after relapse and 2 from early postoperative complications. Two-year-progression-free- and -overall survival were 65.2 ± 12.7% and 49.2 ± 18.2%, respectively. All 4 patients who received intensive chemotherapy including high-dose chemotherapy combined with radiotherapy (2 focal, 2 craniospinal [CSI]) had no recurrence. Focal radiotherapy- and CSI-free survival rates in 13 evaluable patients were 46.2% (6/13) and 61.5% (8/13), respectively. CONCLUSION: PAT is an aggressive disease mostly affecting young children. Therefore, adjuvant therapy using intensive chemotherapy and considering radiotherapy appears to comprise an appropriate treatment strategy. Reporting further cases is crucial to evaluate distinct treatment strategies.

Microsurgical Treatment of Pineal Tumors: Anatomy and Techniques.

Pineal region tumors are challenging lesions in terms of surgical accessibility and removal.1 The complexity is compounded by the infrequency and heterogeneity of pineal neoplasms.2,3 In Video 1, we present the case of a 39-year-old woman who presented with progressive headaches and vision impairment. She underwent microsurgical resection for a pineal parenchymal tumor of intermediate differentiation. We discuss the rationale, risks, and benefits of treatment for this patient, as well as provide a detailed overview of the alternative approaches that may be considered. Additionally, we discuss the unique anatomic considerations for each approach and include a virtual reality-compatible 3-dimensional fly-through to highlight the relationship between the tumor and relevant venous anatomy. The patient tolerated the procedure well with excellent neurologic outcome, and her follow-up imaging showed no evidence of tumor recurrence.

Infragalenic triangle as a gateway to dorsal midbrain and posteromedial thalamic lesions: descriptive and quantitative analysis of microsurgical anatomy.

OBJECTIVE: Anatomical triangles provide neurosurgeons with the specificity required to access deep targets, supplementing more general instructions, such as craniotomy and approach. The infragalenic triangle (IGT), bordered by the basal vein of Rosenthal (BVR), precentral cerebellar vein (PCV), and the quadrangular lobule of the cerebellum, is one of a system of anatomical triangles recently introduced to guide dissection to brainstem cavernous malformations and has not been described in detail. This study aimed to quantitatively analyze the anatomical parameters of the IGT and present key nuances for its microsurgical use. METHODS: A midline supracerebellar infratentorial (SCIT) approach through a torcular craniotomy was performed on 5 cadaveric heads, and the IGT was identified in each specimen bilaterally. Anatomical measurements were obtained with point coordinates collected using neuronavigation. Three cadaveric brains were used to illustrate relevant brainstem anatomy, and 3D virtual modeling was used to simulate various perspectives of the IGT through different approach angles. In addition, 2 illustrative surgical cases are presented. RESULTS: The longest edge of the IGT was the lateral edge formed by the BVR (mean ± SD length 19.1 ± 2.3 mm), and the shortest edge was the medial edge formed by the PCV (13.9 ± 3.6 mm). The mean surface area of the IGT was 110 ± 34.2 mm2 in the standard exposure. Full expansion of all 3 edges (arachnoid dissection, mobilization, and retraction) resulted in a mean area of 226.0 ± 48.8 mm2 and a 2.5-times increase in surface area exposure of deep structures (e.g., brainstem and thalamus). Thus, almost the entire tectal plate and its relevant safe entry zones can be exposed through an expanded unilateral IGT except for the contralateral inferior colliculus, access to which is usually hindered by PCV tributaries. Exposure of bilateral IGTs may be required to resect larger midline lesions to increase surgical maneuverability or to access the contralateral pulvinar. CONCLUSIONS: The IGT provides a safe access route to the dorsal midbrain and reliable intraoperative guidance in the deep and complex anatomy of the posterior tentorial incisura. Its potential for expansion makes it a versatile anatomical corridor not only for intrinsic brainstem lesions but also for tumors and vascular malformations of the pineal region, dorsal midbrain, and posteromedial thalamus.

The Paramedian Supracerebellar Infratentorial Approach: 2-Dimensional Operative Video.

INDICATIONS: The supracerebellar-infratentorial approach uses the plane between the tentorium and the superior surface of the cerebellum to expose the pineal region. ANATOMIC ESSENTIALS: The bone opening is just underneath the level of the transverse sinus, and so its position must be noted preoperatively. The anatomy of the internal cerebral veins and the veins of Galen and Rosenthal should be examined as well. ESSENTIALS STEPS OF THE PROCEDURE: The sitting position allows gravity-assisted expansion of the supracerebellar corridor, and a paramedian approach provides the biggest working space in the TIGER triangle, delineated by the tentorial surface of the cerebellum, the internal cerebral vein/Galen complex, and the vein of Rosenthal. The veil of arachnoid beyond the triangle must be carefully opened to expose the pineal region. PITFALLS/AVOIDANCE OF COMPLICATIONS: For the sitting position, the operative team must be careful about air emboli. A patent foramen ovale is a contraindication for the position. The deep veins must be handled delicately to avoid complications. VARIANTS AND INDICATIONS FOR THEIR USE: Several variations are shown in this video. For visualization, augmented reality is helpful, but since current augmented reality technology is microscope-based, its use can be ergonomically challenging if the tentorium is steep. 1 Our current preference is to use the exoscope for the major portion of the procedure until most of the tumor is out and then switch to hand-held endoscopes with various angles to finish the operation.The patients consented to the surgery, and all relevant participants consented to publication of their images.

Surgical corridor formation by minimally invasive lateral occipital infracortical supra-/transtentorial (OICST) approach in pineal region tumor surgery: A review of 11 cases.

INTRODUCTION: The pineal region is a hard-to-reach part of the brain. There is no unequivocal opinion on the choice of a surgical approach to the pineal region. The surgical approaches described differ in both trajectory (infra- and supratentorial, interhemispheric) and size of craniotomy. They have advantages and disadvantages. The minimally invasive lateral occipital infracortical supra-/transtentorial (OICST) approach we have described has all the advantages of the standard supratentorial approach and minimizes its disadvantages, namely, compression and contusion of the occipital lobe. The minimally invasive craniotomy and small surgical corridor facilitate that. METHODS: We describe 11 consecutive patients with various pineal region tumors (7 cases of pineal cysts, 2 cases of pinealocytoma, 1 case of medulloblastoma, and 1 case of meningioma) who were operated on in our hospital using the lateral OICST approach. Preoperative planning was performed using Surgical Theater®. The surgical corridor was formed using a retractor made from half of a syringe shortened according to the length of the surgical corridor. Preoperative lumbar drain was used. RESULTS: The pineal region tumors were completely resected in all cases. The mean craniotomy size was 2.22 × 1.79 cm. No long-term neurological deficits were reported. CONCLUSIONS: The use of semicircular retractors and intraoperative CSF drainage via a lumbar drain allows to form a small surgical corridor to the pineal region via minimally invasive craniotomy. This reduces traction and traumatization of the occipital lobe, as well as minimizes intra- and postoperative risks.

The TIGR triangle of the pineal region: a virtual reality anatomic study.

BACKGROUND: In this morphometric study, we describe the anatomy of the TIGR triangle, which is bordered by the tentorial surface of the cerebellum, the internal cerebral vein and vein of Galen complex, and the vein of Rosenthal. These structures define the window, or deep keyhole, to access the pineal region in non-midline supracerebellar infratentorial approaches. METHODS: The posterior fossa anatomy of 16 patients was studied in virtual reality (VR), and the TIGR triangles were defined and measured with special attention on its angular orientation in the posterior fossa. The angular expanse of the posterior fossa was measured and recorded as the transverse-sigmoid junction (TSJ) angle. Because a perpendicular corridor through an anatomic aperture provides the best exposure, we studied the starting point along the TSJ angle that offers the best exposure of TIGR. RESULTS: In the 31 posterior fossa sides included in the study, the perpendicular trajectory through the TIGR triangle was on average 27.13° CI 95% (range: 5.97°-48.53°) from the midline. When comparing the SCIT variants, both the paramedian and lateral approaches provided near-perpendicular trajectory through the TIGR triangle in a majority of specimens. However, the modified paramedian approach, with starting point defined as TSJ angle/3, provided the most perpendicular path through the TIGR triangle. CONCLUSION: We studied the size, spatial orientation, and morphology of the TIGR triangle. Our data indicated that the best exposure of TIGR is through a modified paramedian SCIT approach, in which the starting point one third of the way from midline to the TSJ.

Pineal cysts in children: a paediatric series treated over the last twenty years in Lyon.

BACKGROUND: Pineal cysts are a rare lesion of the pineal gland. Pineal cysts are benign lesions, generally asymptomatic, and are usually an incidental discovery on MRI performed for other problems. The management of pineal cysts in children remains a matter for debate. Here, we report our own retrospective paediatric cases that have been surgically treated and review the paediatric literature on this topic. METHODS: This is a retrospective monocentric study. All patients operated by the senior author (CM) for a benign pineal cyst from 2000 to 2021 were included. All other pineal region cystic lesions were excluded. Medical and surgical data were extracted from the hospital medical database. RESULTS: Twelve patients were included. The clinical symptomatology was characterized by headaches in seven patients, visual troubles in two patients, precocious puberty in one patient, signs of intracranial hypertension in two patients, seizures associated with headache in one patient, and headaches associated with behavioural troubles in another patient. No major post-operative complications were observed in this series. It is to noted that surgery was performed because a suspicion of a true pineal parenchymal tumour has been made. Histopathological study came back with the diagnosis of pineal cyst. CONCLUSIONS: Pineal cyst is rare. If the radiological diagnosis is clear, no surgery is advocated except in cases associated with hydrocephalus and rapid growth. In case of a suspicion of a true pineal parenchymal tumour, a surgery may be needed to confirm the diagnosis. Lastly, we stress that only cystic lesions of the pineal gland itself should be considered as pineal cyst.

Primary Gamma Knife Radiosurgery for pineal region tumors: A systematic review and pooled analysis of available literature with histological stratification.

Pineal region tumors (PTs) represent extremely rare pathologies, characterized by highly heterogeneous histological patterns. Most of the available evidence for Gamma Knife radiosurgical (GKSR) treatment of PTs arises from multimodal regimens, including GKSR as an adjuvant modality or as a salvage treatment at recurrence. We aimed to gather existing evidence on the topic and analyze single-patient-level data to address the efficacy and safety of primary GKSR. This is a systematic review of the literature (PubMed, Embase, Cochrane, Science Direct) and pooled analysis of single-patient-level data. A total of 1054 original works were retrieved. After excluding duplicates and irrelevant works, we included 13 papers (n = 64 patients). An additional 12 patients were included from the authors' original series. A total of 76 patients reached the final analysis; 56.5% (n = 43) received a histological diagnosis. Confirmed lesions included pineocytoma WHO grade I (60.5%), pineocytoma WHO grade II (14%), pineoblastoma WHO IV (7%), pineal tumor with intermediate differentiation WHO II/III (4.7%), papillary tumor of pineal region WHO II/III (4.7%), germ cell tumor (2.3%), neurocytoma WHO I (2.3%), astrocytoma WHO II (2.3%) and WHO III (2.3%). Presumptive diagnoses were achieved in the remaining 43.5% (n = 33) of cases and comprised of pineocytoma (9%), germ cell tumor (6%), low-grade glioma (6%), high-grade glioma (3%), meningioma (3%) and undefined in 73%. The mean age at the time of GKSR was 38.7 years and the mean lesional volume was 4.2 ± 4 cc. All patients received GKSR with a mean marginal dose of 14.7 ± 2.1 Gy (50% isodose). At a median 36-month follow-up, local control was achieved in 80.3% of cases. Thirteen patients showed progression after a median time of 14 months. Overall mortality was 13.2%. The median OS was not reached for all included lesions, except high-grade gliomas (8mo). The 3-year OS was 100% for LGG and pineal tumors with intermediate differentiation, 91% for low-grade pineal lesions, 66% for high-grade pineal lesions, 60% for germ cell tumors (GCTs), 50% for HGG, and 82% for undetermined tumors. The 3-year progression-free survival (PFS) was 100% for LGG and pineal intermediate tumors, 86% for low-grade pineal, 66% for high-grade pineal, 33.3% for GCTs, and 0% for HGG. Median PFS was 5 months for HGG and 34 months for GCTs. The radionecrosis rate was 6%, and cystic degeneration was observed in 2%. Ataxia as a presenting symptom strongly predicted mortality (odds ratio [OR] 104, p = .02), while GCTs and HGG histology well predicted PD (OR: 13, p = .04). These results support the efficacy and safety of primary GKSR treatment of PTs. Further studies are needed to validate these results, which highlight the importance of the initial presumptive diagnosis for choosing the best therapeutic strategy.

The sub-occipital transtentorial approach for pineal region tumors: how I do it.

BACKGROUND: Two major approaches exist for the surgical removal of pineal region tumors: the supracebellar infratentorial and the sub-occipital transtentorial. METHODS: We present the Lyon's technique of the sub-occipital transtentorial approach for pineal region tumors and our tricks to avoid complications. The principle is to expose the pineal region under the occipital lobe and not through the interhemispheric fissure. CONCLUSIONS: The sub-occipital transtentorial approach is a direct, extra cerebral, safe, and effective way to access tumors of the pineal region.

Neurosurgical application of pineal region tumor resection with 3D 4K exoscopy via infratentorial approach: a retrospective cohort study.

BACKGROUND: The pineal region tumors are challenging for neurosurgeons and can lead to secondary hydrocephalus. The introduction of the exoscope has provided clinical interventions with high image quality and an ergonomic system for pineal region tumor operations. In this study, the authors describe the exoscopic approach used to facilitate the surgical resection of pineal region tumors and relieve hydrocephalus. MATERIALS AND METHODS: In this retrospective cohort study, we consecutively reviewed the clinical and radiological data of 25 patients with pineal region lesions who underwent three-dimensional exoscopic tumor resection at a single center. RESULTS: The patient cohort consisted of 16 males and 9 females, with an average age of 34.6 years (range, 6-62 years; 8 cases aged ≤18). Pathological examination confirmed eight pineal gland tumors, four gliomas, nine germ cell neoplasms, two ependymomas, and two metastatic tumors. Preoperative hydrocephalus was present in 23 patients. Prior to tumor resection, external ventricular drainage (EVD) with Ommaya reservoir implantation was performed in 17 patients. Two patients received preoperative endoscopic third ventriculostomy (ETV), and five patients received a ventriculoperitoneal (VP) shunt, including one who received both procedures. Gross total resection was achieved in 19 patients (76%) in the 'head-up' park bench position using the exoscope. Eight patients (31.6%) with third ventricle invasion received subtotal resection, mainly in glioma cases, which was higher than those without invasion (0%), but not statistically significant ( P =0.278, Fisher's exact test). No new neurological dysfunction was observed after surgery. Two patients (8%) developed intracranial and pulmonary infections, and two patients (8%) suffered from pneumothorax. Hydrocephalus was significantly relieved in all patients postoperatively, and four patients with relapse hydrocephalus were cured during the long-term follow-up. Postoperative adjuvant management was recommended for indicated patients, and a mean follow-up of 24.8±14.3 months showed a satisfied outcome. CONCLUSIONS: The exoscope is a useful tool for pineal region tumor resection and hydrocephalus relief, particularly with posterior third ventricle invasion, as total resection could be achieved without obvious complication. The special superiority of the exoscope for the indicated pineal region tumors should be highlighted.

Absence of melatonin during development impairs craniofacial and dental onset in rats.

OBJECTIVE: Herein, we evaluated pinealectomy-induced melatonin absence to determine its effects on craniofacial and dental development in the offspring. DESIGN: Female Wistar rats in three groups, i.e., intact pregnant rats, pinealectomized pregnant rats (PINX), and pinealectomized pregnant rats subjected to oral melatonin replacement therapy, were crossed 30 days after surgery. The heads of 7-day-old pups were harvested for cephalometric and histological analyses, and maxillae and incisors were collected for mRNA expression analysis. RESULTS: The PINX pups exhibited a reduction in neurocranial and facial parameters such as a decrease in alveolar bone area, incisor size and proliferation, and an increase in odontoblasts and the dentin layer. Based on incisor mRNA expression analysis, we found that Dmp1 expression was upregulated, whereas Col1a1 expression was downregulated. Maxillary mRNA expression revealed that Rankl expression was upregulated, whereas that of Opn and Osx was downregulated. CONCLUSION: Our results demonstrated that the absence of maternal melatonin during early life could affect dental and maxillary development in offspring, as well as delay odontogenesis and osteogenesis in maxillary tissues. CLINICAL RELEVANCE: Our findings suggest that disruptions or a lack of melatonin during pregnancy may cause changes in craniofacial and dental development, at least in animal experiments; however, in humans, these feedings are still poorly understood, and thus careful evaluations of melatonin levels in humans need to be investigated in craniofacial alterations.

Stereotactic radiosurgery for tumors of the pineal region: A single-center experience.

Tumors of the pineal region (TPRs) are rare neoplasms that are surgically challenging to resect. Conventional treatment strategies are available, but gamma knife radiosurgery (GKRS) is an alternative approach. This study presents a single-center experience with GKRS performed for TPR with and without histopathological diagnoses. The cases of 25 patients with TPRs treated with GKRS were retrospectively analyzed. Thirteen of these 25 patients had histopathological confirmation, and 13 had elevated serum alpha-fetoprotein and beta-human chorionic gonadotropin levels. The 25 patients had a mean follow-up duration of 61 months. The total response rate to GKRS was 60%, and a 53.8% decrease in the alpha-fetoprotein and beta human chorionic gonadotropin levels was observed. The findings of this study indicate that GKRS is a safe procedure for TPRs, even in the event of insufficient histopathological findings. This treatment approach provides increased Karnofsky performance scores and an extended life expectancy.

The surgical intervention for pineal region tumors.

Histological and molecular characterization is essential for the diagnosis of pediatric brain tumors. In the pineal region tumors, it is necessary to remove a sufficient tumor volume to make a diagnosis. However, surgery in this region is challenging due to its deep anatomical location and surrounded by critical structures and complex venous system. Knowledge of the anatomy and function of the pineal region and tumor histological types is imperative for the successful management of pineal region tumors. This article describes surgical approaches to pineal tumors, focusing on the occipital transtentorial approach and adding the author's experience to what has been known in the literature. Recent innovations have made this approach more popular and can be applied to occipital fossa lesions.

Benign and Malignant Tumors of the Pineal Region.

Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors. Genetic and transcriptional studies have identified key chromosomal alterations in germinomas (RUNDC3A, ASAH1, LPL) and in pineocytomas/pineoblastomas (DROSHA/DICER1, RB1). Pineal region tumors generally present with symptoms of hydrocephalus including nausea, vomiting, papilledema, and the classical Parinaud's triad of upgaze paralysis, convergence-retraction nystagmus, and light-near pupillary dissociation. Workup requires neuroimaging and tissue diagnosis via biopsy. In germinoma cases, diagnosis may be made based on serum or CSF studies for alpha-fetoprotein or beta-HCG making the preferred treatment radiosurgery, thereby preventing the need for unnecessary surgeries. Treatment generally involves three steps: CSF diversion in cases of hydrocephalus, biopsy through endoscopic or stereotactic methods, and open surgical resection. Multiple surgical approaches are possible for approach to the pineal region. The original approach to the pineal region was the interhemispheric transcallosal first described by Dandy. The most common approach is the supracerebellar infratentorial approach as it utilizes a natural anatomic corridor for access to the pineal region. The paramedian or lateral supracerebellar infratentorial approach is another improvement that uses a similar anatomic corridor but allows for preservation of midline bridging veins; this minimizes the chance for brainstem or cerebellar venous infarction. Determination of the optimal approach relies on tumor characteristics, namely location of deep venous structures to the tumor along with the lateral eccentricity of the tumor. The immediate post-operative period is important as hemorrhage or swelling can cause obstructive hydrocephalus and lead to rapid deterioration. Adjuvant therapy, whether chemotherapy or radiation, is based on tumor pathology. Improvements within pineal surgery will require improved technology for access to the pineal region along with targeted therapies that can effectively treat and prevent recurrence of malignant pineal region tumors.