Cytogenetic damage of radiotherapy in long-term head and neck cancer survivors

PURPOSE

To evaluate cytogenetic damage of radiotherapy (RT) and chemoradiotherapy (CRT) in long-term head and neck cancer survivors.

MATERIALS AND METHODS

This study included 20 patients treated with RT (10 patients) or CRT (10 patients) for head and neck cancer. Nine healthy volunteers were included as control subjects. Cytochalasin B-blocked micronucleus (CBMN) assay was used to evaluate cytogenetic damage. To evaluate micronucleus (MN) by CBMN, the venous blood samples were drawn median 68 months (range 60-239 months) after the completion of treatment (RT or CRT) for head and neck cancer.

RESULTS

Nuclear division index (NDI) and number of MN in mononuclear and binuclear lymphocytes were significantly higher in patients with head and neck cancer than in control subjects [1.19 (1.08-1.47) vs. 1.07 (1.04-1.14), p < 0.001; 11.0 (2.0-22.0) vs. 1.0 (0-3.0), p < 0.001 and 15.0 (5.0-45.0) vs. 9.0 (2.0-15.0), p = 0.020, respectively]. NDI and number of MN in mononuclear lymphocytes were significantly lower in control subjects compared patients received CRT and those received only RT, but there was no significant difference between patients received CRT and those received only RT. Number of MN in binuclear lymphocytes was significantly lower in control subjects compared to patients received CRT, but there was no significant difference between control subjects and those received only RT. Also there was no significant difference between patients received CRT and those received only RT in terms of number of MN in binuclear lymphocytes.

CONCLUSIONS

MN frequency of mononuclear and binuclear lymphocytes in medical follow-up of patients with head and neck cancer after RT could be important in evaluating cytogenetic damage of RT. However, further investigations are needed to provide quantitative correlations between MN yields and the clinical features in post-radiotherapy period.

Primary glioblastoma of the medulla spinalis: a report of three cases and review of the literature

Primary spinal glioblastoma multiforme (spinal GBM) is not a very common entity. This paper presents an outline of this rare neoplasm, its clinical presentation, course, management and outcome and reports a 3-case series of spinal GBM. In this 3-case series with spinal GBM, one of the patients was operated for hydrocephalous 10 months later following the tumor surgery and another patient had cerebral metastasis after the surgery. In the postoperative period, two of the cases received radiotherapy and one received combined radiotherapy and chemotherapy with steroid therapy together following the tumor surgery. The review of the pertinent literature has revealed that due to the scarcity of the reported cases of primary spinal GBMs, this issue requires a closer look. GBM behaves more aggressive in medulla spinalis than it behaves when it originates from cerebrum. It may disseminate to the cerebrum during its course and it may cause hydrocephalus due to this dissemination (metastasis).

Aneurysmal bone cysts of the spine

Purpose

Aneurysmal bone cyst is a benign, relatively uncommon lesion, representing 1.4 % of primary bone tumors. The vertebral column is involved in 3–30 % of cases. This report describes clinical characteristics and treatment results of 18 patients with aneurysmal bone cyst of the spine.

Methods

Between 1991 and 2008, 18 patients with aneurysmal bone cyst of the spine were surgically treated in our department. The clinical records, radiographs, histologic sections, and operative reports were analyzed.

Results

There were 11 male and 7 female patients; mean age was 22.1 years (range 7–46 years). Localizations were cervical (3), cervicothoracic (2), thoracic (3), lumbar (4), and sacrum (6). Tumor was localized on the left side in 11 cases, on the right side in 2 and at midline in 5 patients. The two most common clinical features were axial pain (14 patients) and radicular pain (8 patients). Neurological signs were paraparesis in 3, monoparesis in 6. Mean duration of symptoms was 9 months (range 3 months–3 years). All patients underwent surgery: total removal was performed in 13 patients and subtotal resection in 5. Posterior (11), anterolateral (1), or combined anterior-posterior (6) approaches were used. Mean follow-up duration was 112.3 months (range 4–21 years). We detected four recurrences in subtotal excision group (4/5), and one recurrence in total excision group (1/13).

Conclusion

Treatment options for aneurysmal bone cysts are simple curettage with or without bone grafting, complete excision, embolization, radiation therapy, or a combination of these modalities. Radical surgical excision should be the goal of surgery to decrease the recurrence rate. Recurrence rate is significantly lower in case of total excision.

Vertebroplasty and kyphoplasty under local anesthesia: review of 91 patients

AIM

Vertebroplasty (VP) and kyphoplasty (KP) are minimally invasive methods for the treatment of vertebral compression fractures (VCF). In this study, we aimed to present our experience with VP and KP performed under local anesthesia and percutaneously.

MATERIAL AND METHODS

Between 2002 and 2008, 91 patients (total 112 vertebrae) with VCF due to osteoporosis, tumor and trauma underwent VP or KP. After radiological and routine evaluations, all patients were operated under local anesthesia. Mean operation time was 20 minutes per vertebrae. We never stopped the operation because of intolerance of any patient and all of them were discharged on the day of operation or the next day except one.

RESULTS

All patients had severe back pain. Mean preoperative Visual Analogue Scale (VAS) score for pain was 8.3 and the mean postoperative value was 2.7. Mean anterior wall and mid-vertebral body heights increased by 32% and 43%, respectively. The mean kyphotic angle decreased from 15.4 to 11.2. Cement leakage was observed in 4 patients and one of them underwent an open operation (decompression and stabilization) because of cement leakage to the epidural space. There was no other complication.

CONCLUSION

Vertebroplasty and kyphoplasty are safe, effective and minimally invasive procedures. Elderly patients can thefore avoid the potential complications of general surgery and be mobilized and discharged early.

The value of routine clinical and radiologic studies in predicting neoplastic invasion of cricoarytenoid units

BACKGROUND AND PURPOSE

Evaluation of the laryngeal cartilages is essential for the treatment strategy of patients with laryngeal carcinoma. Our aim was to assess the accuracy of preoperative clinical examinations and CT for preoperative evaluation.

MATERIALS AND METHODS

A prospective comparative study was performed at a university department on 30 patients with advanced laryngeal carcinomas. All patients were men and underwent total laryngectomy. The preoperative mobility of vocal folds was evaluated and classified as mobile, impaired, or fixed. CT was performed by using multidetector row CT. Cricoarytenoid units (CAUs) from the laryngectomy specimens were cut into sections. Histologic findings were compared with the clinical and radiologic findings.

RESULTS

The accuracy of combined clinical and CT staging in CAUs with normal mobility, impaired mobility, and absent mobility and negative CT findings was 96.5%, 50%, and 80%, respectively. These scores were 40%, 54.5%, and 83.3% for CAUs with normal mobility, impaired mobility, and absent mobility and positive CT findings, respectively.

CONCLUSIONS

Arytenoid mobility and >1 cartilage abnormality on CT were found to be reliable indicators of neoplastic cartilage invasion in patients with laryngeal carcinoma.

Effect of nasal packing and haemostatic septal suture on mucociliary activity after septoplasty: an assessment by rhinoscintigraphy

Nasal packing may influence the mucociliary clearance of the nose in the postoperative healing phase. In an attempt to overcome some of this problem, a haemostatic septal suturing technique was conceived. In this prospective study, we aimed to investigate the effects of nasal packing and septal suturing technique on mucociliary clearance by rhinoscintigraphy. Forty-eight adult patients who had undergone septoplasty were included in the investigation. Preoperatively, the patients were allocated into three groups: group 1, fingerstall packs filled with gauze and smeared with vaseline were used (11 male, 4 female); group 2, silicon septal splint packs were used (11 male, 4 female); group 3, haemostatic septal sutures were used (14 male, 4 female). Mucociliary clearance was measured by rhinoscintigraphy in all patients before surgery and 6 weeks after surgery. The nasal mucociliary clearance was presented as the velocity (mm/min) of nasal mucociliary transport of the (99m)Tc-MAA droplet. The mean velocity of nasal mucociliary clearances before and after surgery for group 1, group 2 and group 3 were 1.85 +/- 0.67 versus 2.43 +/- 0.78 mm/min, 2.36 +/- 0.80 versus 2.92 +/- 0.96 mm/min and 2.03 +/- 0.58 versus 2.62 +/- 0.65 mm/min, respectively. A significant difference in nasal mucociliary clearance was observed after surgery in all groups (p < 0.001). No significant differences were found between the groups regarding mucociliary clearance before and after surgery. Patients with septal deviation have a prolonged mucociliary transit time as compared with postoperative. Nasal packing did not significantly influence the mucociliary clearance in the postoperative healing phase.

Cervical screw missing secondary to delayed esophageal fistula: case report

Although anterior surgical approaches to the cervical spine have become popular and safe in recent years, they also have some complications. We present a case of loss of an anterior cervical plate screw by the natural tracts. The patient was a 47- year-old woman who was operated on for cervical spondylotic myelopathy at another institution. Surgical interference included two levels of anterior discectomy, iliac graft placement and fixation using plate and screws. Two years later, plate dislocation and partial migration of the upper screws were observed. After 7 years the patient complained of dysphagia and she accepted removal of the osteosynthesis. Radiographical examination showed that one of the upper screws was missing and two lower screws were broken. Esophageal perforation was found during the surgery and repaired. Further progress was favourable. Complications associated with esophageal perforation may range from massive infection and death to spontaneous recovery. Erosion of the esophageal wall due to extruded bulky constructs may lead to a persistent fistula, abscess or septic diffusion. Spontaneous perforation of the esophagus and screw loss via the gastrointestinal tract make this case interesting..

Langerhans' cell histiocytosis of the temporal lobe and pons

Intracerebral Langerhans' cell histiocytosis (LCH) is rare and tends to involve the hypothalamus. The authors report a rare case of LCH in the temporal lobe that subsequently was followed by a brainstem lesion. This appears to be the first case of temporal lobe and brainstem LCH that has been treated successfully and published. A 24-year-old man complained of cacosmia and nausea with a slight headache. He had a left temporal LCH, which was removed completely, but developed a brainstem lesion a year later. The pontine LCH was treated with radiosurgery. The follow-up period was 4 years without any neurological or radiological symptoms or signs. The 12 cases of solitary intracranial non-hypothalamic LCH reported previously are reviewed. Gamma knife radiosurgery effectively controlled the local growth of the pontine LCH without adverse effect.

Neuroanatomy of cervical sympathetic trunk: a cadaveric study

To reduce the risk of iatrogenic injury to sympathetic chain during anterior and anterolateral approaches to the cervical spine, its location has to be well defined and known by surgeons. We analyzed the course of sympathetic chain and its ganglia from C7 up to its entry into the cranial base and its relationship mainly with the longus colli (LC). Formalin fixed 20 human cadavers were dissected under operating microscope. Measurement of the dimensions of the ganglia, distance of the trunk to the LC, and the angles identifying the course of the chain were performed. Superior and inferior cervical/cervicothoracic ganglion were observed in all specimens, the middle cervical ganglion was observed in 48% of the specimens. The middle ganglion consisted of two ganglia in 10% of the dissected sides. Forty percent of the inferior cervical/cervicothoracic ganglion was at the C7 level, 25% was at C7-Th1 disc level, and 35% was at Th1 level. Vertebral ganglion was detected in only 8% of the specimens. The course of the sympathetic trunk converges medially descending from upper cervical levels to the lower levels. Anterior surgical approach to the cervical spine is a commonly used procedure. Although Horner syndrome due to sympathetic injury is not a common sequence of cervical operations, our findings support the current few reports on the subject and should be useful to any surgeon who operates in the cervical region to avoid this uncommon complication.

An Unusual Cause of Dyspnea: Myelomatous Involvement of Cricoid Cartilage

Extraosseous multiple myeloma involving the cricoid cartilage is exceedingly rare. CT is invaluable for detecting this lesion. Herein, we describe a patient with worsening dyspnea due to involvement of the cricoid cartilage with multiple myeloma. CT not only detected the lesion but also revealed additional classical lytic lesions of multiple myeloma. In patients with worsening dyspnea laryngeal involvement should be included in the differential diagnosis.

Primary tumors of the cervical spine: a retrospective review of 35 surgically managed cases

BACKGROUND CONTEXT

Primary tumors of the cervical spine are rare, and many issues regarding their surgical management remain unanswered yet.

PURPOSE

To demonstrate results of surgery for primary tumors of the cervical spine and to elucidate which factors influence outcome.

STUDY DESIGN/SETTING

Retrospective study.

PATIENT SAMPLE

Sixty-six surgeries were performed on 35 patients, ranging in age from 7 to 70 years.

OUTCOME MEASURES

Preoperative and postoperative degree of pain and neurological status were quantified. Radiological investigations were used to detect recurrence and evaluate the stability and fusion.

METHODS

Data were collected on patient characteristics, therapy, and results. Follow-up ranged from 6 months to 15 years (mean 59.9 months).

RESULTS

Posterior (26), anterolateral (24), retropharyngeal (9), combined (4), lateral (2), and transmandibular approaches (1) were used. Chordomas (n=8) and 17 different types of tumors were encountered. One patient died 3 weeks postoperatively and 5 died of their disease at follow-up. Twenty patients had no evidence of disease, and 7 patients had recurrent tumors. According to the Weinstein-Boriani-Biagini classification, tumor extension into both anterior and posterior columns of a vertebra was correlated with a poor outcome. Incomplete resections resulted in tumor recurrence which warranted subsequent surgeries (up to 9), especially in chordoma cases.

CONCLUSIONS

Complete tumor resection is the oncologically best surgical strategy and should be attempted whenever possible. However, this may not be feasible in every case because of the complexity of the cervical spine. In these cases, acceptable mortality-morbidity rates and symptom-free years could be achieved by subtotal resections, even for malignant tumors.

The relationship of the posterior inferior cerebellar artery to cranial nerves VII–XII

The posterior inferior cerebellar artery (PICA) is the largest branch of the vertebral artery. It usually arises at the anterolateral margin of the medulla oblongata close to the lower cranial nerves. The PICA had the most complex relationship to the cranial nerves of any artery and it is frequently exposed in approaches directed to the fourth ventricle. The aim of this article is to describe the anatomical relationship of the PICA to the lower cranial nerves. In this study, 12.5% of PICAs passed between the glossopharyngeal and vagus nerves, 20% between the vagus and accessory nerves, and 65% through the rootlets of the accessory nerve. The lateral medullary segment of the PICA showed a lateral loop which in 20% specimens pressed against the inferior surfaces of the facial and vestibulocochlear nerves. The lateral medullary segment of the PICA in 20% specimens passed superior to the hypoglossal nerve, in 47.5% through the rootlets of the hypoglossal nerve, and in 30% inferior to the hypoglossal nerve. The findings on the relationship of the PICA to the lower cranial nerves could be helpful in microsurgery of this region.

Tongue abscesses: MR imaging findings

BACKGROUND AND PURPOSE

A lingual abscess is difficult to diagnose in the absence of physical signs. MR imaging may provide an excellent and invaluable adjunct to clinical examination, but the literature is incomplete in defining the various MR imaging findings of abscess. The objective of this study was to determine the MR imaging features of tongue abscesses.

METHODS

Seven surgically proved tongue abscesses were evaluated with MR imaging. Four patients underwent MR imaging because of suspected tumor, and 3 patients, to show the extent and precise anatomic location of the lesion. Lesions were assessed with regard to the location, size, signal-intensity characteristics, and pattern of contrast enhancement.

RESULTS

Five lesions were located in the anterior tongue and 2, in the posterior tongue. The central parts of 4 anterior tongue abscesses were hypointense, surrounded by a hyperintense wall on T1-weighted precontrast images. On postcontrast images, marked wall enhancement was detected. On T2-weighted images, a markedly hyperintense central part surrounded by a hypointense rim was seen. In 2 of these patients, there was a hypointense halo surrounding the wall (target sign). In 3 patients, a perilesional hyperintense area that enhanced diffusely after contrast administration was detected on T2-weighted images. The smallest lesion located in the anterior tongue was hypointense on T1-weighted images and enhanced diffusely on postcontrast images. On T2-weighted images, a markedly hyperintense central part surrounded by a mildly hyperintense peripheral part was depicted. Posterior tongue lesions appeared as polypoid ill-defined masses and were hypointense on T1-weighted images and heterogeneously hyperintense on T2-weighted images. On postcontrast images, the lesion in 1 patient showed diffuse and heterogeneous contrast enhancement, whereas the lesion in another patient enhanced peripherally. The lesions were totally excised in 4 patients and drained with surgical incisions in 3 patients. No recurrence was detected on follow-up.

CONCLUSION

An abscess typically presents as a cystic lesion surrounded by an enhancing capsule formation, but lesions may also present as solid masses that enhance diffusely or peripherally.

Audio-vestibular disturbances in Behcet's patients: report of 62 cases

This study was carried out to determine the characteristics and incidence of hearing loss and vestibular disturbance in Behcet's syndrome with a large number of patients. Sixty-two patients with Behcet's syndrome were included in this study, 34 men and 28 women whose mean age was 33.7 (15-60). Sixty-two healthy normal control subjects (38 male and 24 female) were included. Patient and control groups were questioned about any history of audio-vestibular disturbance and underwent physical and ENT examination and the following audiologic tests: pure tone audiometric test (0.25, 0.5, 1, 2, 4, and 6 kHz), tympanogram, speech discrimination, short increment sensitivity index, tone-decay test, auditory brainstem response. Vestibular system was evaluated by videonistagmogram and caloric test. Cranial and brainstem magnetic resonance imagine (MRI) of patients who have vestibular disturbances were practiced to examine the central nervous system. Both the patient and the control groups were tested with the HLA-B51 antigen. Pure tone audiogram showed sensory-neural hearing loss (25 dB hearing level in at least two frequencies) in 20 of the 62 (32%) Behcet's patients while the control group were normal. There was a hearing loss involving high frequencies in the audiograms of Behcet's patients with hearing disturbances. The recruitment investigation tests and auditory brain stem response confirmed cochlear involvement in all 20 patients. Caloric stimulation tests revealed a normal vestibular function in all patient and control group. In electronystagmography, 21 (34%) patients had hypometric or hypermetric saccades and smooth pursuit tests showing that 4 (6%) patients had pathological changes while the control group was normal. HLA-B51 antigen was found positive in 15 of 20 Behcet's patient with hearing loss.

CONCLUSION

(1) The hearing and vestibular disturbances in Behcet's syndrome is more prevalent than previously recognized; (2) Hearing loss in high frequencies in Behcet's patients is an indicator of cochlear involvement in this disease; (3) There is a higher prevalence of central vestibular syndrome in Behcet's patients than it was thought before; (4) HLA-B51 antigen may be able to be a prognostic factor for sensorineural hearing loss in Behcet's patients.

The biomechanical effects of cervical multilevel oblique corpectomy

STUDY DESIGN

A repeated-measures flexibility test was performed in vitro using human cadaveric spines.

OBJECTIVES

To compare changes in cervical biomechanics associated with multilevel oblique corpectomy and standard grafted corpectomy with or without plating.

SUMMARY OF BACKGROUND DATA

Standard multilevel plated and unplated corpectomies are susceptible to instability in vitro. The authors are unaware of any previous research on the biomechanics of multilevel oblique corpectomy. METHODS.: Six human cadaveric cervical spine specimens (C3-T1) were tested: 1) normal; 2) after 2-level multilevel oblique corpectomy; 3) after expanding multilevel oblique corpectomy to represent standard grafted and plated corpectomy; and 4) after removing the anterior plate. Pure moments were applied to induce flexion, extension, lateral bending, and axial rotation while recording motion stereophotogrammetrically.

RESULTS

Compared to normal, the range of motion after multilevel oblique corpectomy increased 15% during flexion, 18% during extension, 11% during lateral bending, and 18% during axial rotation. These increases were about one-third of the increases observed after standard corpectomy without plating. Multilevel oblique corpectomy caused few alterations in locations of axes of rotation and coupling patterns, whereas standard corpectomy with or without plating significantly altered these parameters in several instances.

CONCLUSIONS

Multilevel oblique corpectomy (without graft) induced significantly less instability and altered kinematics less than standard unplated corpectomy with graft. Multilevel oblique corpectomy allowed significantly more motion than standard plated corpectomy with graft. However, the goal of standard corpectomy is fusion. Our results indicate that plating significantly limits spinal mobility after 2-level corpectomy, improving the environment for fusion.

Functional lingual thyroid as unusual cause of progressive Dysphagia

Lingual thyroid is an uncommon developmental anomaly and is the result of failure of the thyroid to descend from the foramen caecum to its prelaryngeal site. The lingual thyroid with a functioning thyroid gland in the neck is even more rare. In this report, we describe a 40-year-old female patient with a foreign body sensation and progressive dysphagia caused by ectopic lingual thyroid that is 5 x 4 x 3 cm in size. Here we present a patient with functional lingual thyroid gland who had had thyroidectomy 20 years ago. Lingual thyroid, which is like a malignant mass, was excised by external approach without complications.

Intravascular Papillary Endothelial Hyperplasia of the Central Nervous System-Four Case Reports-

Four rare cases of intracranial intravascular papillary endothelial hyperplasia (IPEH) manifesting as cranial nerve disturbances occurred in 16-, 18-, 24-, and 28-year-old females. Magnetic resonance imaging showed all lesions as isointense with strong enhancement on T1-weighted images, and as hyperintense on T2-weighted images. All lesions were removed via craniotomies. Histological examination found vascular structures and papillary spaces lined with endothelial cells showing immunoreactivity for CD31. Complete removal was curative in two cases, whereas incomplete removal resulted in cure in one case and residual deficits in one case. Iatrogenic deficits should be avoided in IPEH treatment by surgery. Differentiation from neoplasm such as angiosarcoma depends on histological characteristics.

Osteoid osteomas and osteoblastomas of the spine

OBJECT

Osteoid osteomas and osteoblastomas are rare primary bone tumors that usually do not arise in the spine. In this report the authors analyze 16 cases of osteoid osteoma or osteoblastoma of the spine that were surgically treated over a 27-year period.

METHODS

A retrospective study was conducted in which the following data were found: five patients had osteoid osteomas (two male and three female patients) and 11 had osteoblastomas (seven male and four female patients). The site of the tumor was the cervical spine in four, thoracic in six, and lumbar spine in six. In 14 patients, the tumor involved the posterior vertebral elements, with lumbar and thoracic levels being the most common. Only two patients had tumors in the body of a cervical vertebra. The mean age of the patients was 20 years for osteoid osteoma and 19 years for osteoblastoma. The most common symptom was local pain in the area of the tumor. Among 11 patients with osteoblastoma, six (two with paraparesis, four with monoparesis) had neurological deficits caused by extradural compression. None of the patients with osteoid osteoma had neurological deficits. The diameters of osteoblastomas were 3 to 8 cm (mean 4 cm), and those of osteoid osteomas were 1.5 to 2 cm (mean 1.7 cm). Although the peritumoral bone was normal in patients with osteoblastoma, a sclerotic rim was observed in all patients with osteoid osteoma. All patients were treated with resection; tumor excision was complete in 15 cases. Follow-up periods ranged from 2 months to 13 years (mean 36 months). Complete pain relief was achieved in 15 patients; the other patient described mild pain with activity. There was no tumor recurrence except one regrowth in a patient with osteoblastoma who then received radiation therapy. There were two complications: one surgery was performed at the wrong level, and there was one instrument failure that required revision.

CONCLUSIONS

With the help of modern imaging modalities that aid in diagnosis and surgical planning, a complete removal and cure may be achieved for most of these rare tumors.

Failure to detect Chlamydia pneumoniae DNA in cerebral aneurysmal sac tissue with two different polymerase chain reaction methods

OBJECTIVE

Chlamydia pneumoniae (C pneumoniae) is a common cause of a usually mild, community acquired pneumonia. This organism, however, can spread from the respiratory tract into other parts of the body and has been detected in up to 70% of atheromatous lesions in blood vessels. Although the exact mechanism of the C Pneumoniae contribution to the pathogenesis of atherosclerosis remains unknown, prophylactic antibiotic trials are planned for people at high risk for coronary disease.

METHOD

In this study the authors aimed to investigate C pneumoniae DNA content in the cerebral aneurysmal sac tissue with the aid of polymerase chain reaction (PCR) method. C pneumoniae DNA was searched in 15 surgically clipped and removed aneurysmal sac tissue and in two tumour (an ependymoma of the fourth ventricle and a craniofaringoma) samples by touchdown enzyme time release PCR (TETR PCR) targeting 16S rRNA gene and by nested PCR targeting ompA gene.

RESULTS

Both PCR methods were sensitive to detect in C pneumoniae 4x10(-2) genomes. C pneumoniae DNA was not detected in any of the 17 sample tissues of these patients.

CONCLUSION

The contribution of C pneumoniae in the development of intracranial aneurysms cannot be excluded despite the results of this study. Further studies on the possible role of C pneumoniae or any other micro-organisms in the pathogenesis of aneurysms should be performed.

Online electrochemical monitoring of nitric oxide during photodynamic therapy

Photodynamic therapy (PDT), as a novel treatment modality, is based on the use of a photosensitizing agent with an excitation light source for the treatment of various malignancies. Its effect is mediated through reactive oxygen species and nitric oxide (NO), which are shown to be present in apoptosis. Individual differences among patients and even in different areas of the same tumor in one patient may cause a major problem with PDT: dose calculation during application of the light. An electrochemical sensor is proposed for online monitoring of NO generation as a solution of this problem. 5-Aminolevulinic acid (ALA) was administered as the photosensitizer in rat cerebellum. An amperometric sensor, selective to NO, was designed and tested both in vitro and in vivo during PDT. ALA-mediated PDT resulted in rapid generation of NO, starting as early as the application of light on the tissue. Simultaneous amperometric recordings have been carried out for 5 min during PDT. The progressive increase in NO concentration peaked at 1.10 min and then the response current began to decrease until it reached a plateau at around 70% of its peak value. This study, for the first time, electrochemically demonstrates the generation of NO during PDT. Rapid and stable responses obtained by the experimental setup confirmed that this method could be used as an online monitoring system for PDT-mediated apoptosis.

Combined anterior and posterior approach for managing basilar invagination associated with type I Chiari malformation

Ventral brainstem compression is common in patients with basilar invagination associated with type I Chiari malformation. The aim of this study was to investigate the reliability of a combined one-session anterior-posterior surgical approach for these patients. Nine patients underwent transoral odontoidectomy, posterior foramen magnum decompression, occipitocervical fixation, and bone grafting. All but two patients had ventral and dorsal operations in one surgical sitting. One of these two individuals had previously undergone posterior decompressive surgery at another hospital, but his condition had deteriorated rapidly afterward. The mean follow-up time was 19 months (range, 14-30 months). There was no mortality and no significant morbidity in this series. All but one of the patients showed significant improvement in their symptoms. Chiari malformations have a surprisingly high association with basilar invagination, and patients may have symptoms in both conditions. If there is a marked anterior compression, anterior transoral and posterior decompression, fusion, and instrumentation is an optimal strategy for treating patients with basilar invagination associated with type I Chiari malformation.

Local interstitial chemotherapy with sustained release bucladesine in de novo glioblastoma multiforme: a preliminary study

This clinical study was designed to evaluate the safety and efficacy of the sustained release form of dibutryl adenosine-3',5'-cyclic monophosphate (dB-cAMP, bucladesine) placed in the tumor resection cavity at the time of recurrence of the de novo glioblastoma multiforme (GBM) patients. In a randomized prospective manner, 40 patients who were diagnosed as GBM in their first operations were included in this study. Four different therapy protocols were used: First group of 10 patients had tumor resection only. Second group assessed had only systemic chemotherapy as six i.v. infusions of fotémustine after tumor resection. Third group had implantation of bucladesine-loaded biodegradable polymeric sustained release (bcl-SR) pellets while the last group received six i.v. infusions of systemic fotémustine as in the second group in addition to local implantation of bcl-SR pellets. A biodegradable polymer, poly-DL-lactide-co-glycolide with molecular weight of 80000, was used as carrier matrix for the drug with an approximately 4-5 months of release time. Maximal doses of 20 mg of bucladesine with a mean dose of 15.5 mg were implanted. No bone marrow suppression occurred and there were no wound infections as far as the local bucladesine-loaded polymer therapy is concerned. In this randomized prospective trial of local interstitial chemotherapy with long acting bcl-SR did show a statistically significant delay of recurrence on the treatment of GBM patients. Best treatment results obtained from the local bcl-SR + systemic fotémustine treated group in which survival rate estimated by the Kaplan-Meier method was 70% in de novo GBM at 12 months.

Hemangioblastoma causing cervical neural foraminal widening

We present the MRI findings in a case of a 24-year-old woman with spinal hemangioblastoma, causing neural foraminal widening by producing a dumbbell mass in the lower cervical region. Hemangioblastomas can very rarely present as an intradural extramedullary lesions and this case is another exceptional pathology which should be considered among the differential diagnosis of enlarged intervertebral foramen due to neoplastic processes.

Efficacy of controlled-release papaverine pellets in preventing symptomatic cerebral vasospasm

OBJECT

Vasospasm as a complication of subarachnoid hemorrhage is a major concern in clinical practice. The systemic drugs in current use are of limited value. Topical, intrathecal, or intraarterial papaverine administered during surgical or angiographic procedures is a potent vasodilating drug; however, hypotension limits its systemic application. Local application of papaverine in a biodegradable controlled- or sustained-release matrix is proposed for vasospasm prophylaxis to be used in patients scheduled for aneurysm surgery.

METHODS

Controlled-release papaverine (PapaCR) drug pellets were prepared using the biodegradable aliphatic polyester poly(DL-lactide-co-glycolide) as the carrier matrix. In vitro tests were performed to determine drug kinetics. One hundred seventeen patients, 73 assigned to the control group and 44 assigned to the PapaCR-treated group, participated in this study. Patients who were deemed to be at high risk for the development of vasospasm were selected to participate in the study. During aneurysm surgery, drug pellets were placed in cisterns over arterial segments. In two patients, cerebrospinal fluid was sampled every 6 hours for the first 5 days through a lumbar catheter that had been inserted at the beginning of aneurysm surgery. The incidence of clinical vasospasm and Glasgow Outcome Scale scores in the patients were evaluated statistically. The results of in vitro studies showed that effective local concentrations of papaverine could be maintained for more than 10 days. The first-degree drug-release profile was demonstrated using this design. In clinical studies no adverse effects due to the drug were seen. The PapaCR effectively prevented development of clinical vasospasm. and outcome scores were significantly better in patients in the treated group.

CONCLUSIONS

Local application of controlled- or sustained-release papaverine can be safely used in preventing vasospasm.

Biomechanics of grade I degenerative lumbar spondylolisthesis. Part 2: treatment with threaded interbody cages/dowels and pedicle screws

OBJECT

The authors sought to determine the biomechanical effectiveness of threaded interbody cages or dowels compared with that achieved using pedicle screw instrumentation in resisting Grade I lumbar spine degenerative spondylolisthesis.

METHODS

Thirty-three levels obtained from seven cadaveric lumbar spines were instrumented with cages or dowels, pedicle screw/rod instrumentation, or both. Entire specimens were loaded with nonconstraining torques. Each level was loaded with anteroposterior shear forces while an optical system was used to measure the specimen's motion at individual levels. Pedicle screw/rods outperformed interbody cages and dowels in treating spondylolisthesis. Cages or dowels alone provided only moderate biomechanical stability, and their effectiveness depended heavily on the integrity of the ligaments and remaining annulus, whereas the success of pedicle screw fixation relied predominantly on the integrity of the bone for solid fixation. Little biomechanical difference was demonstrated between cages and dowels; both devices were susceptible to loosening with cyclic fatigue.

CONCLUSIONS

Biomechanically, cages or dowels alone were suboptimal for treating lumbar spondylolisthesis, especially compared with pedicle screw/rods. Threaded cages or dowels used together with pedicle screws/rods created the most stable construct.

Biomechanics of grade I degenerative lumbar spondylolisthesis. Part 1: in vitro model

OBJECT

The authors sought to create and to evaluate an in vitro model of Grade I degenerative (closed-arch) spondylolisthesis.

METHODS

The model of spondylolisthesis was created by two primary procedures: 1) resection of the disc; and 2) stripping of anterior and posterior longitudinal ligaments away from the vertebral bodies (VBs). In 13 vertebral levels obtained from three cadaveric lumbar spines, the tissues were resected sequentially in alternating order to determine the relative contribution of each resection to spinal instability. The entire specimens were loaded with nonconstraining torques and then individual levels were loaded with anteroposterior shear forces. The motion values were measured optoelectronically for each specimen at individual levels.

CONCLUSIONS

The integrity of the disc was more important than attachment of the ligaments to the VB, but the resection of both structures was necessary to achieve substantial destabilization. The structures of the spine are highly resilient, and destabilization is difficult to achieve without performing extensive resection. Using the techniques described in this paper to alter normal spines, a level of spinal instability (Grade I; 25% slippage) that may represent spondylolisthesis can be modeled in vitro.

The effects of melatonin on the antioxidant systems in experimental spinal injury

Melatonin has been recently shown by various in-vivo and in-vitro studies to exert potent neutralising effects on hydroxyl radicals, stimulate glutathione peroxidase (GSH-Px) activity, and protect catalase (CAT) from the destructive activity of hydroxyl radicals in neural tissue. We aimed to investigate the possible effects of pharmacological dose of melatonin on some of the antioxidant defence systems in an in-vivo study of experimental spinal injury. Seven groups of adult male Sprague Dawley rats were used in the following scheme: Group I: Naive (n = 6), Group II: Lesion (n = 8), Group III: Melatonin (n = 5), Group IV: Melatonin + Lesion (n = 8), Group V: Placebo + Lesion (n = 5), Group VI: Sham operation (n = 5), and Group VII: Placebo (n = 5). Experimental spinal injury was induced at level T7-T8 by 5 sec compression of the total cord with an aneurysm clip on anaesthetised and laminectomized animals. The total 10 mg/kg dose of melatonin (Sigma) dissolved in alcohol-water was administered i.p. four times in 2.5 mg/kg doses, at 20 min pre-, at the time of and at 1 h and 2h post-compression. At 24 +/- 2h post-injury, the rats were euthanized and the lesioned segments of cord were dissected and homogenised with special care taken to distribute equal amount of injured tissue in each sample for analysis of reduced glutathione (GSH), oxidised glutathione (GSSG), superoxide dismutase (SOD), and CAT activity. Compression injury decreased GSH/GSSG ratio significantly (p < .0001). Melatonin, by itself, significantly decreased GSSG content (p < .05) and increased CAT activity (p < .05) in the naïve rats. Melatonin treatment decreased GSSG activity, thus elevating GSH/GSSG ratio, and also increased SOD and CAT activity without reaching statistical significance in the lesioned animals. In conclusion, pharmacological dose of systemically applied melatonin seemed to support some features of the antioxidant defence systems in our hands.