Detection of a chemical cue from the host seaweed Laurencia dendroidea by the associated mollusc Aplysia brasiliana

Chemical cues from sessile hosts can attract mobile and associated organisms and they are also impotant to maintain associations and overall biodiversity, but the identity and molecular structures of these chemicals have been little explored in the marine environment. Secondary metabolites are recognized as possible chemical mediators in the association between species of Laurencia and Aplysia, but the identity of the compounds has not been established. Here, for the first time, we experimentally verify that the sesquiterpene (+)-elatol, a compound produced by the red seaweed Laurencia dendroidea, is a chemical cue attracting the associated sea hare Aplysia brasiliana. In addition to revealing the nature of the chemical mediation between these two species, we provide evidence of a chemical cue that allows young individuals of A. brasiliana to live in association with L. dendroidea. This study highlights the importance of chemical cues in Laurencia-Aplysia association.

Endoscopic Transnasal Odontoidectomy With Anterior C1 Arch Preservation and Anterior Vertebral Column Reconstruction in Patients With Irreducible Bulbomedullary Compression by Complex Craniovertebral Junction Abnormalities: Operative Nuance

BACKGROUND

During the past decades, the transoral transpharyngeal approach has been advocated as the standard route for the removal of odontoid causing an irreducible symptomatic neural compression. However, it may be potentially associated with a significant built-in morbidity because of the splitting of the soft palate for an adequate working angle, tracheostomy, and incision of the oral mucosa, causing exposure to a higher risk of infection by oral flora.

OBJECTIVE

To describe our experience with the minimally invasive pure endoscopic transnasal odontoidectomy in patients with bulbomedullary compression affected by complex anterior craniovertebral junction abnormalities.

METHODS

Five patients underwent a pure endoscopic neuronavigation-assisted transnasal odontoidectomy with anterior C1 arch preservation. Moreover, the anterior cervical spine column was reconstructed by filling the gap between the C1 arch and the residual C2 body with autologous/artificial bone. Neither tracheostomy nor enteral tube feeding were needed in any case.

RESULTS

A postoperative neurological improvement was observed in all patients. Postoperative imaging confirmed a satisfactory spinal cord decompression with cervical anterior column arthrodesis, and without evidence of instability at follow-up, so far.

CONCLUSION

The endoscopic transnasal approach seems to represent an efficient and safe alternative to the transoral route for the resection of odontoid process causing irreducible bulbomedullary compression. It provides a straightforward and minimally invasive natural surgical corridor to the anterior craniocervical junction, allowing a better working angle with preservation of spine biomechanics, while minimizing potential comorbidities.

Delayed diagnosed intermuscular lipoma causing a posterior interosseous nerve palsy in a patient with cervical spondylosis: the "priceless" value of the clinical examination in the technological era

BACKGROUND

Posterior interosseous nerve (PIN) palsy may present with various symptoms, and may resemble cervical spondylosis.

CASE REPORT

We report about a 59-year-old patient with cervical spondylosis which delayed the diagnosis of posterior interosseous nerve (PIN) palsy due to an intermuscular lipoma. Initial right hand paraesthesias and clumsiness, together with MR findings of right C5-C6 and C6-C7 foraminal stenosis, misled the diagnostic investigation. The progressive loss of extension of all right hand fingers brought to detect a painless mass compressing the PIN. Electrophysiological studies confirmed a right radial motor neuropathy at the level of the forearm.

RESULTS

Surgical tumor removal and nerve decompression resulted in a gradual motor deficits recovery.

CONCLUSIONS

A thorough clinical examination is paramount, and electrophysiology may differentiate between cervical and peripheral nerve lesions. Ultrasonography and MR offer an effective evaluation of lipomas, which represent a rare cause of PIN palsy. Surgical decompression and lipoma removal generally determine excellent prognoses, with very few recurrences.

Minimally Invasive Supraorbital Key-hole Approach for the Treatment of Anterior Cranial Fossa Meningiomas

The most important target of minimally invasive surgery is to obtain the best therapeutic effect with the least iatrogenic injury. In this background, a pivotal role in contemporary neurosurgery is played by the supraorbital key-hole approach proposed by Perneczky for anterior cranial base surgery. In this article, it is presented as a possible valid alternative to the traditional craniotomies in anterior cranial fossa meningiomas removal. From January 2008 to January 2012 at our department 56 patients underwent anterior cranial base meningiomas removal. Thirty-three patients were submitted to traditional approaches while 23 to supraorbital key-hole technique. A clinical and neuroradiological pre- and postoperative evaluation were performed, with attention to eventual complications, length of surgical procedure, and hospitalization. Compared to traditional approaches the supraorbital key-hole approach was associated neither to a greater range of postoperative complications nor to a longer surgical procedure and hospitalization while permitting the same lesion control. With this technique, minimization of brain exposition and manipulation with reduction of unwanted iatrogenic injuries, neurovascular structures preservation, and a better aesthetic result are possible. The supraorbital key-hole approach according to Perneckzy could represent a valid alternative to traditional approaches in anterior cranial base meningiomas surgery.

Surgical treatment of cervical spine trauma: Our experience and results

Objective and Background:

The objective of this study is to evaluate how the neurological outcome in patients operated for cervical spinal cord injury (SCI) is influenced by surgical timing, admission American Spinal Injury Association (ASIA) grading system, and age.

Materials and Methods:

From January 2004 to December 2011, we operated 110 patients with cervical SCI. Fifty-seven of them (44 males and 13 females) with preoperative neurological deficit, were included in this study with a complete follow-up. Age, sex, associated comorbidities (evaluated with Charlson comorbidity index [CCI]), mechanism of trauma, preoperative and follow-up ASIA score, time elapsed from injury to surgical treatment, preoperative cervical computed tomography scan or magnetic resonance imaging, type of fractures, and surgical procedure were evaluated for each patient. The patient population was divided into two groups related to the timing of surgery: Ultra-early surgery group (within 12 h from the trauma, 27 patients) and early surgery (within 12–72 h from the trauma, 30 patients).

Statistical Analysis Used:

The univariate analysis of data was carried out by the Chi-square test for discrete variables, the t-test for the continuous ones. Logistic regression was used for the multivariate analysis.

Results:

Neurological outcome was statistically better in ultra-early surgery group (<12 h) than in patient underwent surgery within 12–72 h (82.14% vs. 31%, multivariate analysis P = 0.005). The neurological improvement was also correlated with the age and the ASIA grade at admission in the univariate analysis (P = 0.006 and P = 0.017 respectively) and in the multivariate 1 (P = 0.037 and P = 0.006 respectively) while the CCI was correlated with the improvement only in the univariate analysis (P = 0.007).

Conclusion:

Nowadays, in patients with cervical SCI early surgery could be associated with improved outcome, most in case of young people with mild neurological impairment.

Candida Albicans Dural Granuloma: Case Report

Candida albicans dissemination to the central nervous system (CNS) may occur in immunocompromised patients even without prior cranial surgery. In such cases, intracerebral lesions are most frequent, meningeal or cerebrospinal fluid involvement being rare. We, here, describe a case of Candida albicans granuloma developing exclusively inside the width of the dura mater, successfully treated by surgical excision followed by antimycotic therapy. A 75-year-old man, previously affected by urinary sepsis from Candida albicans, was admitted to the emergency department of our hospital because of the acute appearance of sensory obtundation, blurred speech, and right hemiparesis. Emergency computed tomography (CT) scan and magnetic resonance imaging (MRI) with and without contrast enhancement disclosed a huge, left fronto-parietal mass, causing severe brain compression. At surgery, the lesion appeared to develop exclusively inside the dural envelope, and was completely removed. At pathology, a totally intradural Candida albicans granuloma was observed and appropriate antimycotic treatment was started. After an uneventful postoperative course the patient was sent to rehabilitation. Five months later he was admitted again because of a bone flap infection, leading to bone removal and further cranioplasty, with full neurological recovery. At 2 years follow-up, no neuroradiological or clinical evidence of residual/relapsing intracranial infection was found. Isolated intradural granuloma from Candida albicans has never been described before. Even though surgical excision may lead to complete resolution of mass effect in these patients, prolonged observation should be maintained, to disclose further, potentially lethal, complications.

A rare case of chordoma and craniopharyngioma treated by an endoscopic endonasal, transtubercular transclival approach

Co-occurrence of different brain tumors is rarely observed, being more frequent in patients affected by genetic syndromes like phacomatoses. Different histological types of intracranial lesions may present at different times in the clinical history of the patient or, more rarely, they may occurr at the same moment. In these last cases, particularly for tumors located in adjacent areas of the brain, diagnostic difficulties may arise. Moreover, even when the correct diagnosis is established, treatment strategy becomes complex and a single staged approach could be ineffective in obtaining successful tumor removal. We report a case of simultaneous sellar-suprasellar craniopharyngioma and intradural clival chordoma, successfully treated by a single staged, extended, fully endoscopic endonasal approach, which required no following adjuvant therapy. We also discuss the potential etiopathogenesis of the two lesions, reviewing the literature.

Neurological outcome in a series of 58 patients operated for traumatic thoracolumbar spinal cord injuries

Background:

Traumatic thoracolumbar spinal fractures represent approximately 65% of all traumatic spinal fractures and are frequently associated to permanent disability with significant social and economic impact. These injuries create severe physical limitations depending on neurological status, level of fracture, severity of injury, patient age and comorbidities. Predicting neurological improvement in patients with traumatic spinal cord injuries (SCIs) is very difficult because it is related to different preoperative prognostic factors. We evaluated the neurological improvement related to the preoperative neurological conditions and the anatomic level of spinal cord injury.

Methods:

From January 2004 to June 2010, we operated 207 patients for unstable thoracolumbar spinal fractures. We carried out a retrospective analysis of 69 patients with traumatic SCIs operated on by a posterior fixation performed within 24 hours from the trauma. The preoperative neurological conditions (ASIA grade), the type of the fracture, the anatomic level of spinal cord injury and the postoperative neurological improvement were evaluated for each patient.

Results:

The ASIA grade at admission (P = 0,0005), the fracture type according to the AO spine classification (P = 0,0002), and the anatomic location of the injury (P = 0,0213) represented predictive factors of neurological improvement at univariate analysis. The preoperative neurological status (P = 0,0491) and the fracture type (P = 0,049) confirmed a positive predictive value also in the multivariate analysis.

Conclusions:

Our study confirms that the preoperative neurological status, the fracture type and the anatomic location of the fracture are predictive factors of the neurological outcome in patients with spinal cord injury.

Shape modifications of porous hydroxyapatite prostheses to improve rigid implant fixation: Experience in 12 cases

BACKGROUND

Various methods of fixation have been described for custom made hydroxyapatite cranial implants. Their poor malleability limits most of the common used fixation techniques because of the high risk of cranioplasty's fracturing or higher exposure to infections. We present our experience with a new fixation technique, based on an appositely premodified hydroxyapatite implants.

METHODS

In a 2-year time period, 12 patients underwent cranioplasty by a modified custom made porous hydroxyapatite implant. Once the three-dimensional computer model of the prostheses was performed, three semicircular extensions placed at strategic positions were drawn and the final prosthesis was realized. At surgery, holes fitting the extensions were drilled into the skull borders and the implant was easily embedded inside the defect. Small titanium meshes overlying the extensions were fixed by screws to the surrounding bone.

RESULTS

A minimal increase of operative times was recorded, with drilling and fixation requiring additional 30 and 15 minutes, respectively. Optimal contact between cranioplasty and skull borders was always observed at control computed tomography (CT) scans. Permanent rigid fixation was obtained in all cases, with good functional and aesthetic results at follow-up.

CONCLUSIONS

Modifications of hydroxyapatite implants are obtained without additional costs. The minimal increase of operative times is largely counterbalanced by optimal fixation results. Finally, the bone drilling and the immediate proximity of bone to prosthesis might enhance the potential for osteogenesis and osteointegration.

Endoscopic endonasal approach for the treatment of a large clival giant cell tumor complicated by an intraoperative internal carotid artery rupture

Giant cell tumors (GCTs) are primary bone neoplasms that rarely involve the skull base. These lesions are usually locally aggressive and require complete removal, including the surrounding apparently healthy bone, to provide the best chance of cure. GCTs, as well as other lesions located in the clivus, can nowadays be treated by a minimally invasive fully endoscopic extended endonasal approach. This approach ensures a more direct route to the craniovertebral junction than other possible approaches (transfacial, extended lateral, and posterolateral approaches). The case reported is a clival GCT operated on by an extended endonasal approach that provides another contribution on how to address one of the most feared complications attributed to this approach: a massive bleed due to an internal carotid artery injury.

Endoscopy-verified occult subependymal dissemination of glioblastoma and brain metastasis undetected by MRI: prognostic significance

Although various prognostic indices exist for patients with malignant brain tumors, the prognostic significance of the subependymal spread of intracranial tumors is still a matter of debate. In this paper, we report the cases of two intraventricular lesions, a recurrent glioblastoma multiforme (GBM) and a brain metastasis, each successfully treated with a neuroendoscopic approach. Thanks to this minimally invasive approach, we achieved good therapeutic results: we obtained a histological diagnosis; we controlled intracranial hypertension by treating the associated hydrocephalus and, above all, compared with a microsurgical approach, we reduced the risks related to dissection and brain retraction. Moreover, in both cases, neuroendoscopy enabled us to identify an initial, precocious subependymal tumor spreading below the threshold of magnetic resonance imaging (MRI) detection. This finding, undetected in pre-operative MRI scans, was then evident during follow-up neuroimaging studies. In light of these data, a neuroendoscopic approach might play a leading role in better defining the prognosis and optimally tailored management protocols for GBM and brain metastasis.

An unusual instrumentation-related s1 radiculopathy in a patient treated for a primary vertebral (l3) lymphoma

Paravertebral titanium rod migration represents an unusual and potentially fatal complication of vertebral stabilization surgical procedures. This condition, which requires a prompt and rapid diagnosis, is often mistaken for other more common diseases, or scotomized. We present a case of a 69 years old female affected by a non-Hodgkin lymphoma with evidence of migration of both rods five years after the posterior stabilization procedure for a pathological L3 fracture. Unusual clinical onset was represented by a left S1 radiculopathy without other symptoms. For several months, the symptoms were attributed to a possible radicular infiltration by the lymphoma. We conclude that paravertebral rod migration could happen not only within the spinal canal, but could also rarely damage blood vessels or parenchymal organs. This is generally a long-term complication, probably due to an insufficient fixation. Strict long-term follow-up monitoring is mandatory since this unusual complication can mimic other more common pathological conditions.

Minimally invasive surgery for benign intradural extramedullary spinal meningiomas: experience of a single institution in a cohort of elderly patients and review of the literature

Meningiomas of the spine are the most common benign intradural extramedullary lesions and account for 25%–46% of all spinal cord tumors in adults. The goal of treatment is complete surgical resection while preserving spinal stability. Usually, these lesions occur in the thoracic region and in middle-aged women. Clinical presentation is usually nonspecific and the symptoms could precede the diagnosis by several months to years, especially in older people, in whom associated age-related diseases can mask the tumor for a long time. We report a series of 30 patients, aged 70 years or more, harboring intradural extramedullary spinal meningiomas. No subjects had major contraindications to surgery. A minimally invasive approach ( hemilaminectomy and preservation of the outer dural layer) was used to remove the tumor, while preserving spinal stability and improving the watertight dural closure. We retrospectively compared the outcomes in these patients with those in a control group subjected to laminectomy or laminotomy with different dural management. In our experience, the minimally invasive approach allows the same chances of complete tumor removal, while providing a better postoperative course than in a control group.

Rare synchronous association of vestibular schwannoma and indolent insular oligodendroglioma in a patient without neurofibromatosis: controversial issue of timing for surgical treatment of asymptomatic low-grade gliomas

The co-occurrence of a vestibular schwannoma and a low-grade glioma is rare, and even rarer is the association with an oligodendroglioma. Although various authors have addressed the problem of treating patients with incidentally discovered indolent low-grade gliomas, an established protocol does not exist to date. The common approach is to reserve surgery until there is radiological evidence of tumor growth or high-grade transformation. However, because incidental low-grade glioma may represent the first stage of unavoidable pathological progression towards high-grade glioma, early and radical surgical resection should be advocated in order to increase the chance of a "cure" and prolonged survival. This case report supports this view, and suggests reflection on a possible change from a conservative philosophy to preventative surgical treatment.

Piezosurgery for osteotomies in orbital surgery: Our experience and review of the literature

INTRODUCTION

Piezoelectric bone surgery, simply known as Piezosurgery(®), is a new promising technique for bone cutting based on ultrasonic microvibrations that allows to perform precise and thin osteotomies with soft tissue sparing.

PRESENTATION OF CASE

A 45-years-old woman presenting with progressive left ocular pain, diplopia on the lateral left gaze, and visible exophthalmos was admitted to our department. CT scan and MRI images documented a left supero-lateral orbital lesion. A left lateral orbitotomy using the piezoelectric scalpel was performed. The tumour (lacrimal gland lymphoma) was completely removed with no injuries to the orbital structures and with a perfect realignment of the bone stumps.

DISCUSSION

High powered pneumatic osteotome are commonly used to perform craniotomies. Large bone cutting groove and high temperatures developing at the contact site could produce an uneasy bone healing. The use of a piezoelectric scalpel allows to realize precise and thin osteotomies, facilitating craniotomy's borders ossification and avoiding injuries to non-osseous structures.

CONCLUSION

Widely used in Oral and Maxillofacial Surgery, Piezosurgery(®) can also be useful in neurosurgical approaches in order to obtain a faster bone flap re-ossification, a better aesthetic result, and a lower risks of dural layer and soft tissue damage.

Acute tension pneumocephalus secondary to whole spine pneumorrhachis as an unusual presentation of a colon cancer complicated by a transsacral cerebrospinal fluid leak

A 52-year-old woman who was having chemotherapy for treatment of an adenocarcinoma of the colon, was admitted to the emergency department because of a moderate neurological impairment. Head CT scan showed bifrontal pneumocephalus without fractures or discontinuities of the skull base. A few hours later, following the patient's neurologic deterioration, a new CT scan showed tension pneumocephalus with air diffusion throughout the posterior cranial fossa and cervical spine. Because of air bubbles into the cervical spine, an MRI of the entire spinal canal was done. This exam revealed a whole spine pneumorrhachis along with a transforaminal air passage through the first right sacral foramen and a pyogenic collection anterior to sacral bone. An abdomen CT scan showed a massive relapse of the colon cancer and confirmed a hypodense collection contiguous to the anterior sacral surface, causing erosion of the sacral bone and dural layer with air penetration into the spinal canal. Neurosurgical treatment by a lumbosacral laminectomy and duraplasty was followed by tumour removal and omental covering of the pelvis. Her neurological symptoms were resolved completely. One month later, the patient began adjuvant chemotherapy.