Luca Basaldella

Aquaporin(s) expression in choroid plexus tumours

Objective: It was the aim of this study to investigate the pattern of aquaporin 1 (AQP1) expression in normal and neoplastic choroid plexus, with specific reference to the association with communicating hydrocephalus or liquoral cysts. Second, to infer a new view on the cerebrospinal fluid plexus production and on the etiology of the cysts and communicating hydrocephalus occasionally associated with choroid plexus papillomas. Materials and Methods: Nineteen paraffin-embedded specimens, 10 of normal choroid plexus and 9 of choroid plexus tumours, were immunostained with a monoclonal antibody raised against the intracellular C-terminal AQP1 epitope. Results were analysed in terms of intensity and intracellular distribution of immunostaining and in terms of number of stained cells; they were considered in light of the clinical association with hydrocephalus or liquoral cysts. Results: AQP1 was heavily expressed in the apical side of the choroid epithelium in normal plexus specimens. Choroid plexus papillomas showed a very heterogeneous pattern of AQP1 expression. Immunostaining was absent in the case of choroid plexus carcinoma. Very strong to strong and diffuse AQP1 expression in large to very large papillomas was associated with liquoral cysts or communicating hydrocephalus. Conclusions: AQP1 expression characterizes normal choroid plexus and plexus papillomas. Intensity and diffusion of AQP1 expression together with the size of the tumour mass are somewhat predictive of communicating hydrocephalus or liquoral cyst, lesions possibly caused by a disturbance of cerebrospinal fluid homeostasis.

Choroid plexus and aquaporin-1 : A novel explanation of cerebrospinal fluid production

Aquaporins are selective water channel proteins that play a central role in the homeostasis of human body water. The choroid plexus (CP) is considered to be the main cerebrospinal fluid (CSF)-producing structure. In this study, six specimens of normal human CP obtained during surgery were analyzed by immunohistochemistry techniques for aquaporin-1 (AQP1) expression and distribution. Intense, uniformly distributed AQP1 immunostaining was observable in the apical but not the basolateral side of cuboid cells of the CP. Moreover, this polarized expression of AQP1 was weakly detectable in the endothelial cells of choroid microvessels and, with a different pattern, in the cells lining the tubules shaped into crypts. Selective AQP1 expression on the surface of the normal human CP might explain the role of CSF production by this complex structure.

Aquaporin 1 expression in cystic hemangioblastomas

Hemangioblastomas of the central nervous system (CNS) become clinically manifest through the development of huge associated cysts. The mechanism underlying these fluid collections is as yet largely unexplained. Aquaporins (AQPs) are cell proteins responsible for transmembrane water transport that have been extensively studied in the last 10 years. We analyzed AQP1 water channel expression by an immunostaining technique in ten specimens of operated cerebellar cystic hemangioblastomas, for which complete clinical and follow-up records were available. Tumour and associated cyst volumes were determined by neuroimaging and then compared with immunohistochemical scores. Stromal cancer cells showed surprisingly high AQP1 expression, and huge cyst volume development showed correlation with higher immunostaining scores. Heavy AQP1 expression in cystic hemangioblastomas could shed new light on the mechanisms of satellite cyst development.

Massive venous air embolism in the semi-sitting position during surgery for a cervical spinal cord tumor: anatomic and surgical pitfalls

Although venous air embolism (VAE) in neurological surgery is mainly associated with posterior fossa procedures, this complication may also occur, with comparable severity, in the posterior cervical spine approach in patients who are semi-sitting. We report a patient with a massive VAE that occurred in the semi-sitting position during a posterior approach to an extended cervical-thoracic level (C3-T2) intramedullary tumor, which interrupted the surgical procedure. We discuss the possible causes of air embolism, the anatomic and pathogenetic mechanisms, treatment and preventive measures.

Fluorescein-enhanced characterization of additional anatomical landmarks in cerebral ventricular endoscopy.

BACKGROUND Fluorescein enhancement to detect retinal disorder or differentiate cancer tissue in situ is a well-defined diagnostic procedure. It is a visible marker of where the blood-brain barrier is absent or disrupted. Little is reported in the contemporary literature on endoscopic fluorescein-enhanced visualization of the circumventricular organs, and the relevance of these structures as additional markers for safe ventricular endoscopic navigation remains an unexplored field. OBJECTIVE To describe fluorescein sodium-enhanced visualization of circumventricular organs as additional anatomic landmarks during endoscopic ventricular surgery procedures. METHODS We prospectively administered intravenously 500 mg fluorescein sodium in 12 consecutive endoscopic surgery patients. A flexible endoscope equipped with dual observation modes for both white light and fluorescence was used. During navigation from the lateral to the fourth ventricle, the endoscopic anatomic landmarks were first inspected under white light and then under the fluorescent mode. RESULTS After a mean of 20 seconds in the fluorescent mode, the fluorescein enhanced visualization of the choroid plexus of the lateral ventricle, median eminence-tuber cinereum complex, organum vasculosum of the lamina terminalis, choroid plexus of the third and fourth ventricles, and area postrema. CONCLUSION Fluorescein-enhanced visualization is a useful tool for helping neuroendoscopists recognize endoscopic anatomic landmarks. It could be adopted to guide orientation when the surgeon deems an endoscopic procedure unsafe or contraindicated because of unclear or subverted anatomic landmarks. Visualization of the circumventricular organs could add new insight into the functional anatomy of these structures, with possible implications for the site and safety of third ventriculostomy.

Endoscopic Management of Intracerebral Hemorrhage

OBJECTIVES Massive intracerebral and intraventricular hemorrhages require aggressive and rapid management to decrease intracranial hypertension. The amount of intraventricular blood is a strong prognostic predictor, and its fast removal is a priority. Neuroendoscopy may offer some advantages over more traditional surgical approaches. METHODS All relevant data described in our experience and in publications about minimally invasive treatment of intraventricular and intracerebral hemorrhage found through MEDLINE searches and related references are reviewed. RESULTS We described the technical details of neuroendoscopic management, highlighting the potential pitfalls and advantages of the techniques. CONCLUSION Early neuroendoscopic surgery is a feasible approach, allowing, in most instances, rapid clinical and radiological improvement.

Atypical cystic meningioma overexpressing AQP1 in early infancy: case report with literature review

Meningiomas in early infancy are rare lesions, worth to be reported for their exceptional occurrence. The authors report a case of an 11‐month‐old female child with asymmetric macrocephaly due to the presence of a cystic atypical meningioma associated to bilateral subdural collections.

A preliminary study of aquaporin 1 immunolocalization in chronic subdural hematoma membranes.

Aquaporin 1 (AQP1) is a molecular water channel expressed in many anatomical locations, particularly in epithelial barriers specialized in water transport. The aim of this study was to investigate AQP1 expression in chronic subdural hematoma (CSDH) membranes. In this preliminary study, 11 patients with CSDH underwent burr hole craniectomy and drainage. Membrane specimens were stained with a monoclonal antibody targeting AQP1 for immunohistochemical analysis. The endothelial cells of the sinusoid capillaries of the outer membranes exhibited an elevated immunoreactivity to AQP1 antibody compared to the staining intensity of specimens from the inner membrane and normal dura. These findings suggest that the outer membrane might be the source of the increased fluid accumulation responsible for chronic hematoma enlargement.

Spontaneous Resolution of Atraumatic Intrauterine Ping-Pong Fractures in Newborns Delivered by Cesarean Section

Two cases of spontaneous intrauterine ping-pong fractures are reported in newborns delivered by cesarean section. Skull fractures occurred with no evidence of extrinsic trauma or cephalopelvic disproportion. Subsequent clinical follow-up at 6 and 12 months revealed normal skull reshaping and growth, with no associated neurological deficits. Spontaneous intrauterine ping-pong fractures in newborns delivered by cesarean section is a distinctly rare condition. These 2 cases demonstrate that, even without complicated spontaneous vaginal delivery or history of external trauma, congenital ping-pong fracture of the skull can occur. The existence of this clinical condition and its spontaneous resolution is important knowledge that can assist in the prepartum and postpartum management of children with this pathology.

Minimal surgery for a cerebellopontine angle lipoma

A 46-year-old man presented with a left cerebellopontine angle lipoma of unusual size. The patient also complained of hearing loss and left trigeminal neuralgia, which were triggered on the same side as the lesion in the resting posture. Surgical treatment with simple debridement of the arachnoid membranes to reduce internal tension in the tumour resulted in stable pain remission and hypoacusia without additional deficit.