Search

Three-dimensional (3D) printing (3DP) has seen spectacular progress in recent years, making it widely available to consumers and researchers, but it has also been steadily expanding its capabilities while becoming more and more affordable. This progress has allowed 3DP technology to be seriously tested in various fields of Medicine and Biomedical Technology. Neurological Surgery is widely considered to be among the most demanding and intricate medical specialties, as it concerns fine and highly critical neural and vascular elements even during standard interventions or the most common pathological conditions. As such, advances in 3DP were quick to be applied to neurosurgical practice (depicting brain aneurysms), research and development (spine and disc models), and neurosurgical education. In the past years, we have seen progress in four main distinct directions for the use of 3DP technologies within the prism of Neurological Surgery, where we also envision future progress: (a) neurovascular physiological anatomy and its associated disorders, (b) complex central nervous system tumors and neuroanatomy, (c) spine instrumentation, deformities, and biomechanical implications, and (d) educational purposes, prototyping of implants, devices, and equipment. In this chapter, we critically review the progress of 3DP technology within each of these described directions and discuss the impact it can possibly have on specific diseases and on the Neurosurgical Specialty as a whole in the years to come.

Intervertebral disc (IVD) represents a structure of crucial structural and functional importance for human spine. Pathology of IVD institutes a frequently encountered condition in current clinical practice. Degenerative disc disease (DDD), the principal clinical representative of IVD pathology, constitutes an increasingly diagnosed spinal disorder associated with substantial morbidity and mortality in recent years. Despite the considerable incidence and socioeconomic burden of DDD, existing treatment modalities including conservative and surgical methods have been demonstrated to provide a limited therapeutic effect, being not capable of interrupting or reversing natural progress of underlying disease. These limitations underline the requirement for development of novel, innovative, and more effective therapeutic strategies for DDD management. Within this literature framework, compromised IVD replacement with a viable IVD construct manufactured with tissue-engineering (TE) methods has been recommended as a promising therapeutic strategy for DDD. Existing preliminary preclinical data demonstrate that proper combination of cells from various sources, different scaffold materials, and appropriate signaling molecules renders manufacturing of whole-IVD tissue-engineered constructs a technically feasible process. The aim of this narrative review was to critically summarize current published evidence regarding particular aspects of IVD-TE, primarily emphasizing in providing researchers in this field with practicable knowledge to enhance clinical translatability of their research and informing clinical practitioners about the features and capabilities of innovative TE science in the field of IVD-TE. Impact Statement Human intervertebral disc (IVD) pathology represents an extremely frequent condition in current clinical practice. Given the considerable limitations of available treatment options, deployment of novel and groundbreaking therapeutic modalities constitutes a rather urgent need. Tissue engineering of entire human IVD, a technically feasible process within laboratory framework, is theoretically capable of overcoming limitations that characterize currently applied therapeutic measures. Optimization of laboratory manufacturing techniques in conjunction with more diligent

Background Intracisternal Accessory Nerve Schwannomas (ANS) constitute a rare clinical entity with only a few cases reported so far. Their symptoms are usually due to brainstem compression and not manifested until they render of great size. Secondary neuropathy and muscle atrophy are other late signs. The hitherto reported literature advocates a suboccipital craniotomy as a suitable approach. In most of the cases the spinal root was the location tumor arose from. Gross total resection was possible to be carried out in most cases with only sporadic tolerable postoperative deficits reported. Case description We hereby present three cases of patients with intracisternal ANS treated in the same fashion. Two patients were male and one female. Two patients complained of mainly chronic headaches and neck pain, whereas in the third patient the lesion was found incidentally. Only one patient suffered post-operatively cerebrospinal fluid leakage and wound healing complication, which was treated with revision surgery and administration of antibiotics. None of the patients had postoperative neurological deficits. Furthermore, we conducted a review of the relevant literature where we noted that there is no consensus yet with regards to the appropriate surgical approach. Conclusions Based on relevant anatomical studies, we advocate that suboccipital subtonsilar approach provides a wide corridor to the area of lesion allowing complete and safe resection of intracisternal ANS. We thus support that, in most cases, the neurosurgeon should consider using this familiar approach for treating this rare lesion.

Stenosis due to lumbar degenerative disease is associated with aging and often requires surgical treatment to provide decompression of the neural elements and alleviation of the symptoms. We present an 83-yo female patient, with neurological claudication and bilateral L5 paresis, treated with undercutting and bilateral flavectomy at the level L4-L5 without fusion. With this case we would like to illustrate the decision-making problem for or against fusion and the operative approach for adequate decompression without causing further instability. We discuss the indications of undercutting and the evidence against routinely performing fusion and compare our presentation to the current literature.

We report a rare case of a temporal bone encephalocele after a canal wall down mastoidectomy performed to treat chronic otitis media with cholesteatoma. The patient was treated successfully via an intracranial approach. An enhanced layer-by-layer repair of the encephalocele and skull base deficit was achieved from intradurally to extradurally, using temporalis fascia, nasal septum cartilage, and artificial dural graft. After a 22-month follow-up period the patient remains symptom free and no recurrence is noted.

Background: Syringomyelia is rarely associated with cervical disc herniations and/or spinal stenosis. Case Description: A 62-year-old male presented with a 4-month history of right brachial pain and hyposensitivity in the C5 distribution. The cervical magnetic resonance (MR) imaging scan revealed a C5–C6 right anterolateral disc herniation with syringomyelia extending from C5–C6 to T1. Following a C5–C6 anterior cervical discectomy and fusion (ACDF), the patient’s symptoms resolved. The 3-month postoperative MR documented total resolution of the syrinx. Notably, due to residual neuropathic pain, the patient required a subdural spinal cord stimulator which was placed without any complications. Conclusion: Syringomyelia rarely occurs in conjunction with cervical disc disease and stenosis, and even more infrequently resolves following an ACDF. Future research should focus on the etiology of syrinx formation in these patients and should explore their response to various treatment modalities.

Neuroprosthetic control by individuals suffering from tetraplegia has already been demonstrated using implanted microelectrode arrays over the patients’ motor cortex. Based on the state of the art of such micro & nano-scale technologies, we review current trends and future prospects for the implementation of nanotechnologies in the field of Brain- Computer Interfaces (BCIs), with brief mention of current clinical applications. Micro- and Nano-Electromechanical Systems (MEMS, NEMS) and micro-Electrocorticography now belong to the mainstay of neurophysiology, producing promising results in BCI applications, neurophysiological recordings and research. The miniaturization of recording and stimulation systems and the improvement of reliability and durability, decrease of neural tissue reactivity to implants, as well as increased fidelity of said systems are the current foci of this technology. Novel concepts have also begun to emerge such as nanoscale integrated circuits that communicate with the macroscopic environment, neuronal pattern nano-promotion, multiple biosensors that have been “wired” with piezoelectric nanomechanical resonators, or even “neural dust” consisting of 10-100μm scale independent floating low-powered sensors. Problems that such technologies have to bypass include a minimum size threshold and the increase in power to maintain a high signal-to-noiseratio. Physiological matters such as immunological reactions, neurogloia or neuronal population loss should also be taken into consideration. Progress in scaling down of injectable interfaces to the muscles and peripheral nerves is expected to result in less invasive BCI-controlled actuators (neuroprosthetics in the micro and nano scale). The state-of-the-art of current microtechnologies demonstrate a maturing level of clinical relevance and promising results in terms of neural recording and stimulation. New MEMS and NEMS fabrication techniques and novel design and application concepts hold promise to address current problems with these technologies and lead to less invasive, longer lasting and more reliable BCI systems in the near future.

Primary meningeal gliomas are uncommon tumors in the subarachnoid space, their primary characteristic being the absence of any obvious connection to the brain parenchyma. Rarely, they are quite malignant and assume a bulky, well circumscribed appearance rendering the differential diagnosis from other CNS neoplasms difficult. A 53-year-old man presented with a history of persistent headaches and left sided weakness. Magnetic resonance imaging revealed a temporoparietal mass attached to the dura that strongly resembled a meningioma. At surgery, the outer layer of the dura mater was intact and there was a clear brain-tumor interface without obvious pial disruption. Histological examination showed a biphasic pattern consisting of benign connective tissue intermingled with bundles of what seemed to be a glioblastoma. The mass demonstrated strong positivity for GFAP and the MIB labeling index focally exceeded 20%. The tumor was identified as a primary meningeal glioblastoma. The patient was disease-free for 42 months, after which he developed a recurrence for which he was re-operated. This time, the pathological findings of the tumor were those of a typical glioblastoma multiforme. We discuss the origin of the initial neoplasm and also the differential diagnosis that needs to include meningioma, aggressive glioblastoma infiltrating the dura and a recently recognized bimorphic CNS tumor: the desmoplastic glioblastoma.

We report a rare case of anterolateral meningioma of the foramen magnum (FMM) and high cervical spine presenting both intradural and extradural growth in a 7.5-year-old boy. We also performed a review of the relevant peer-reviewed literature. The patient presented with progressive tetraparesis and gait instability. Neuroimaging revealed an anterolateral tumor of the foramen magnum, C1 and C2 cervical spine level. The patient was treated in two stages: During the first operation, the extradural part was resected while the intradural part was removed in a second operation. Following the second operation, the patient showed almost complete neurological recovery as a result of cervical spinal cord and brainstem decompression but was complicated with cerebrospinal fluid leakage and infection by Acinetobacter. He sustained two further operations for dural sealing and external ventricular drainage and was treated with intraventricular administration of antibiotics. Histopathology of the tumor confirmed a meningotheliomatous meningioma. At the 6-month post-op follow-up examination, the patient exhibited complete neurological recovery and no radiological tumor recurrence. To the authors’ best knowledge, we report the third case of sporadic pediatric meningioma of the foramen magnum and high cervical compartments with an extradural growth. Accurate pre-operative estimation of possible extradural growth is crucial towards surgical planning and sufficient treatment. Treatment of choice is total resection in a single operating session to avoid re-operations and increased risk of complications. If not possible, a re-operation should always attempt to secure the desired result.

Ventriculoperitoneal shunting (VPS) remains one of the alternative choices for the surgical treatment of hydrocephalus. During the last two decades laparoscopy has been utilized to facilitate the placement of the abdominal portion of the shunt. We describe a minimally invasive laparoscopic technique, which facilitates the rapid, safe and direct placement of the peritoneal component of the VPS. A side frontal ventricular catheter is placed through a small burr hole and connected to the valve at the postauricular region. An infra-umbilical trocar is placed, using the Hasson technique, and after the pneumoperitoneum is established, a 10-mm laparoscope is introduced for identification of a VPS entry side free of adhesions. A 5-mm skin incision is made at the decided point of catheter insertion, usually at the right upper quadrant. Using a tunneler, the VPS catheter is placed subcutaneously from abdomen insertion point, to the postauricular region, where it is connected to the valve. A split type, 10-12 Fr and 12-15 cm long metallic puncture cannula, like those used for suprapelvic percutaneous bladder drainage, is introduced into the abdomen. Under direct laparoscopic vision the peritoneal portion of the VPS is passed into the abdomen through the cannula. The catheter is leaded to a desirable location by pointing the needle accordingly. Alteration of the position of the catheter can also be attained by entraining the catheter with the laparoscope and without using auxiliary graspers. The function of the VPS is confirmed under direct visualization. Suturing the abdominal and cranial incisions completes the procedure. We used this technique in a series of 12 patients with excellent outcome. There were no intra- or postoperative complications and no mortalities. Our technique is less invasive than a minilaparotomy, embraces all laparoscopic benefits and does not require auxiliary forceps or guidewires. It uses easy available materials with low cost, and attains an easy, rapid, and safe placement of the abdominal portion of the VPS.

The possible effects of radiofrequency (RF) radiation on prenatal development has been investigated in mice. This study consisted of RF level measurements and in vivo experiments at several places around an “antenna park.” At these locations RF power densities between 168 nW/cm2 and 1053 nW/cm2 were measured. Twelve pairs of mice, divided in two groups, were placed in locations of different power densities and were repeatedly mated five times. One hundred eighteen newborns were collected. They were measured, weighed, and examined macro- and microscopically. A progressive decrease in the number of newborns per dam was observed, which ended in irreversible infertility. The prenatal development of the newborns, however, evaluated by the crown-rump length, the body weight, and the number of the lumbar, sacral, and coccygeal vertebrae, was improved. Bioelectromagnetics 18:455–461, 1997. © 1997 Wiley-Liss, Inc.

The aim of this study was to report a rare pediatric case of spontaneous spinal epidural hematoma (SSEH) mimicking Guillain-Barre syndrome (GBS), secondary to an epidural arteriovenous malformation (AVM). Furthermore, a case-based update and insight into the entity is attempted. An 8-year-old male presented with progressing severe lower limb weakness and no traumatic history. Presentation was mimicking GBS with ascending symptoms. Magnetic resonance (MR) scan revealed a dorsal epidural mass, extending from C6–C7 to T2, compressing the spinal cord. Emergency laminoplasties and surgical evacuation of the hematoma were performed. An up-to-date review of reported SSEH cases in children was conducted, with emphasis on underlying vascular malformations (epidural AVMs in particular). Pathogenesis, predisposing factors, imaging, diagnosis, treatment and outcome are discussed. The hematoma was successfully evacuated. A vascular membrane on the dura was peeled off and sent for histopathology. There was no evidence of intradural vascular penetration. The patient improved postoperatively and was able to walk with support 7 months later. Histology revealed closely packed thin-walled angiomatous structures with wide lumens (filled with red blood cells) with walls composed of collagen and smooth muscle fibers, findings consistent with AVM. Non-traumatic SSEH is rare in the pediatric population. Although vascular malformations are suspected, they are extremely rarely identified histopathologically. This case represents one of the very few reports of pediatric SSEH caused by a histologically proven, purely epidural AVM. High index of clinical suspicion and low threshold for MR can lead to timely diagnosis and prompt treatment with good functional outcome.

IntroductionThe transverse and sagittal inner and outer pedicle diameter of thoracic and lumbar vertebrae were measured with an electronic caliper and with CT scan. To determine the validity of CT scan measurements, comparing with those taken by an electronic caliper.Material and MethodsA total of 12 anatomic skeletal specimens were acquired from T1 to L5 in the mean age of 69.6 years. Each vertebral pedicle was measured with an electronic caliper and CT scan. A total of 1632 measurements of 408 pedicles were taken. The data were collected and analyzed using the t-test. The comparison of the measurements between left and right pedicle, males and females, as well as between electronic caliper and CT scan was evaluated.ResultsThe sagittal diameter of the pedicle was always bigger than 7mm. In the mid-thoracic area (T3-T8), the transverse outer diameter could be less than 4mm, so there is need of use of pediatric screws (

Pilomyxoid astrocytoma (PMA) is a recently described glial tumor with similarities to pilocytic astrocytomas, yet with distinct histopathological characteristics and a more aggressive behavior. It occurs predominantly in the hypothalamic/chiasmatic region. Only four patients with spinal cord PMA have been reported in the pediatric population. The 2007 WHO Working Group recognized PMA as a new variant and recommended an assignment to WHO grade II. The purpose of this paper was to report a rare location, address the aggressive behavior and rapid progression, and based on the specific patient, to review the literature and discuss current treatment strategies. A 12-year-old girl presented with motor and sensory deficits of the left side as well as gait disturbance. Imaging revealed an intramedullary tumor extending from C2 to C7. The patient improved impressively after surgical resection. Histopathological findings were consistent with PMA. Three months later, the patient presented with rapid neurological deterioration. Histopathology after the second operation was consistent with glioblastoma. The outcome was fatal 12 months after initial diagnosis, despite adjuvant therapy. This is the fifth pediatric spinal cord PMA in literature. Furthermore, it is the only documented patient with rapid recurrence and progression within 3 months into a glioblastoma. The question of a sampling error affecting initial pathology is raised. Based on contemporary literature data, we discuss the further treatment options, as there are no guidelines yet. Efforts towards registries should be encouraged, as the documentation of PMA might lead to more evidence based treatment strategies.

Effects of nonthermal radiofrequency radiation (RFR) of the global system of mobile communication (GSM) cellular phones have been as yet mostly studied at the molecular level in the context of cellular stress and proliferation, as well as neurotransmitter production and localization. In this study, a simulation model was designed for the exposure of pregnant rats to pulsed GSM-like RFR (9.4 GHz), based on the different resonant frequencies of man and rat. The power density applied was 5 microW/cm2, in order to avoid thermal electromagnetic effects as much as possible. Pregnant rats were exposed to RFR during days 1-3 postcoitum (p.c.) (embryogenesis, pre-implantation) and days 4-7 p.c. (early organogenesis, peri-implantation). Relative expression and localization of bone morphogenetic proteins (BMP) and their receptors (BMPR), members of a molecular family currently considered as major endocrine and autocrine morphogens and known to be involved in renal development, were investigated in newborn kidneys from RFR exposed and sham irradiated (control) rats. Semi-quantitative duplex RT-PCR for BMP-4, -7, BMPR-IA, -IB, and -II showed increased BMP-4 and BMPR-IA, and decreased BMPR-II relative expression in newborn kidneys. These changes were statistically significant for BMP-4, BMPR-IA, and -II after exposure on days 1-3 p.c. (P

People have always considered the exposure to non-ionising radiation with scepticism. The prospect that exposure to electromagnetic fields (EMF) can have a deleterious effect or any effect on cellular behaviour has been debated in scientific and journalistic circles for some years. The drive to determine whether EMFs were involved in cellular behavioural changes is critical since environmental proximity to high voltage power lines and electric stations or the routine use of household appliances and cellular phones is increasing exponentially. Support for a deleterious effect gained impetus with the report that children whose homes were close to power lines had a higher frequency of leukemia. If cell signalling is influenced by EMF exposure, it provides further impetus to determine whether EMF exposure can cause or alter the propensity to cancer or have other deleterious effects in cells. Numerous laboratory studies both in vitro and in vivo have provided evidence that exposure to EMF induces a wide range of responses in biological systems.