Comparisons of the clinical and radiological features and surgical management of posterior fossa meningiomas and acoustic neuromas

Meta analysis of olfactory ensheathing cell transplantation promoting functional recovery of motor nerves in rats with complete spinal cord transection

OBJECTIVE:

To evaluate the effects of olfactory ensheathing cell transplantation on functional recovery of rats with complete spinal cord transection.

DATA SOURCES:

A computer-based online search of Medline (1989–2013), Embase (1989–2013), Cochrane library (1989–2013), Chinese Biomedical Literature Database (1989–2013), China National Knowledge Infrastructure (1989–2013), VIP (1989–2013), Wanfang databases (1989–2013) and Chinese Clinical Trial Register was conducted to collect randomized controlled trial data regarding olfactory ensheathing cell transplantation for the treatment of complete spinal cord transection in rats.

SELECTION CRITERIA:

Randomized controlled trials investigating olfactory ensheathing cell transplantation and other transplantation methods for promoting neurological functional recovery of rats with complete spinal cord transection were included in the analysis. Meta analysis was conducted using RevMan 4.2.2 software.

MAIN OUTCOME MEASURES:

Basso, Beattie and Bresnahan scores of rats with complete spinal cord transection were evaluated in this study.

RESULTS:

Six randomized controlled trials with high quality methodology were included. Meta analysis showed that Basso, Beattie and Bresnahan scores were significantly higher in the olfactory ensheathing cell transplantation group compared with the control group (WMD = 3.16, 95% CI (1.68, 4.65); P < 0.00001).

CONCLUSION:

Experimental studies have shown that olfactory ensheathing cell transplantation can promote the functional recovery of motor nerves in rats with complete spinal cord transection.

Meningiomas involving the internal auditory canal: a diagnostic and surgical challenge

Meningiomas are the second most common lesion encountered within the cerebello-pontine angle (CPA) and rarely project into or originate from the internal auditory meatus (IAM). It is important to distinguish between meningiomas and acoustic neuromas preoperatively as the choice of surgical approach may differ depending on the tumour type. Fortunately, most lesions can be accurately diagnosed with gadolinium-enhanced magnetic resonunce imaging (MRI). We report six cases of meningioma involving the IAM, often leading to an incorrect preoperative MRI diagnosis. We highlight the challenges these tumors present to radiologists and surgeons.

Cationic liposome-mediated GDNF gene transfer after spinal cord injury

Glial cell line-derived neurotrophic factor (GDNF) has been shown to protect cranial and spinal motoneurons, which suggests potential uses of GDNF in the treatment of spinal cord injury (SCI) and motor neuron disease. We examined neuroprotective effect of cationic liposome-mediated GDNF gene transfer in vivo on axonal regeneration and locomotor function recovery after SCI in adult rats. The mixture of DC-Chol liposomes and recombinant plasmid pEGFP-GDNF cDNA was injected after SCI. RT-PCR confirmed the increased expression of GDNF mRNA in the injected areas at 7 days after injection. The expression of EGFP-GDNF was observed in the cells around the injection locus by fluorescence microscope at least 4 weeks after injection. Four weeks after GDNF gene transfer, regeneration of the corticospinal tracts was assessed using anterograde tract tracing. There are more HRP labeling of corticospinal tract axons across the lesion in GDNF group compared with control group. In GDNF group, the maximum distance these labeled axons extended varied in different animals and ranged from 5 mm to approximately 9 mm from the lesion. In control group, no HRP labeled axons extended caudal to the lesion. The locomotion function of hindlimbs of rats was evaluated using inclined plane test and BBB locomotor scores. The locomotion functional scores in GDNF group were higher than that in control group within 1-4 weeks after SCI (p < 0.05). These data demonstrate that in vivo transfer of GDNF cDNA can promote axonal regeneration and enhance locomotion functional recovery, suggesting that cationic liposome-mediated delivery of GDNF cDNA may be a practical gene transfer method for traumatic SCI treatment.

Clinical features and outcomes in patients with non-acoustic cerebellopontine angle tumours

OBJECTIVES

Non-acoustic tumours of the cerebellopontine angle differ from vestibular schwannomas in their prevalence, clinical features, operative management, and surgical outcome. These features were studied in patients presenting to the regional neuro-otological unit.

METHODS

A retrospective analysis of clinical notes identified 42 patients with non-acoustic tumours of the cerebellopontine angle. Data were extracted regarding presenting clinical features, histopathological data after surgical resection, surgical morbidity and mortality, and clinical outcome (mean 32 months follow up).

RESULTS

The study group comprised 25 meningiomas (60%), 12 epidermoid cysts/cholesteatomata (28%), and five other tumours. In patients with meningiomas, symptoms differed considerably from patients presenting with vestibular schwannomas. Cerebellar signs were present in 52% and hearing loss in only 68%. Twenty per cent of patients had hydrocephalus at the time of diagnosis. After surgical resection, normal facial nerve function was preserved in 75% of cases. In the epidermoid group, fifth, seventh, and eighth nerve deficits were present in 42%, 33%, and 66% respectively. There were no new postoperative facial palsies. There were two recurrences (17%) requiring reoperation. Overall, there were two perioperative deaths from pneumonia and meningitis.

CONCLUSIONS

Patients with non-acoustic lesions of the cerebellopontine angle often present with different symptoms and signs from those found in patients with schwannomas. Hearing loss is less prevalent and cerebellar signs and facial paresis are more common as presenting features. Hydrocephalus is often present in patients presenting with cerebellopontine angle meningiomas. Non-acoustic tumours can usually be resected with facial nerve preservation.

Death from a malignant cerebellopontine angle triton tumor despite stereotactic radiosurgery. Case report

Malignant vestibular nerve tumors are rare: to date, only three cases have been reported in the literature. The authors report a case of an eighth cranial nerve tumor that progressed 5 years after stereotactic radiosurgery. The patient was a 44-year-old man who underwent stereotactic radiosurgery for a 27-mm cerebellopontine angle tumor that was discovered on investigation of tinnitus and hearing loss. He developed facial weakness after 5 years, and repeated imaging revealed tumor enlargement. Despite complete microsurgical excision, the tumor rapidly recurred locally and subsequently disseminated within the neuraxis. The patient died 1 year after tumor progression was detected. Histopathological analysis revealed a malignant spindle cell neoplasm with frequent mitotic figures. The presence of positive rhabdoid elements on immunohistochemical studies confirmed that it was a triton tumor. The authors review the relevant literature concerning the classification and management of malignant vestibular nerve tumors and discuss the implications of tumor progression after stereotactic radiosurgery.

Meningiomas of the cerebellopontine angle

Meningiomas of the cerebellopontine angle (CPA) represent a clinically and surgically interesting entity. The opportunity of complete surgical excision and the incidence of impairment of nerval structures largely depend on the tumour biology that either leads to displacement of surrounding structures by an expansive type of growth or to an enveloping of nerval and vascular structures by an en plaque type of growth. As the origin and the direction of growth are very variable, the exact tumour extension in relation to the nerval structures and the tumour origin can be identified sometimes only at the time of surgery. Out of a series of 230 meningiomas of the posterior skull base operated between 1978 and 1993, data of 134 meningiomas involving the cerebellopontine angle are presented. There were 20% male and 80% female patients, age at the time of surgery ranging from 18 to 76 years, on the average 51 years. The clinical presentation was characterized by a predominant disturbance of the cranial nerves V (19%), VII (11%), VIII (67%) and the caudal cranial nerves (6%) and signs of ataxia (28%). 80% of the meningiomas were larger than 30 mm in diameter, 53% led to evident brainstem compression or dislocation and 85% extended anteriorly to the internal auditory canal. Using the lateral suboccipital approach in the majority of cases and a combined presigmoidal or combined suboccipital and subtemporal approaches in either sequence in 5%, complete tumour removal (Simpson I and II) was accomplished in 95% and subtotal tumour removal in 5%. Histologically the meningiotheliomatous type was most common (49%) followed by the mixed type (19%), fibroblastic (16%), psammomatous (7%), hemangioblastic (7%) and anaplastic (2%) types. Major post-operative complications were CSF leakage (8%) requiring surgical revision in 2% and hemorrhage (3%) requiring revision in 2%. While the majority of neurological disturbances showed signs of recovery, facial nerve paresis or paralysis was encountered in 17%, and facial nerve reconstruction was necessary in 7%. Hearing was preserved in 82% with improvement of hearing in 6%. The variability of tumour extension, the implications and limitations for complete surgical excision are discussed along with the experiences from the literature.

Embolization with temporary balloon occlusion of the internal carotid artery and in vivo proton spectroscopy improves radical removal of petrous-tentorial meningioma

A highly vascular petroclival meningioma supplied by tentorial branches of the internal carotid artery was embolized by temporary balloon occlusion of the parent vessel distal to the tumor, followed by obliteration of the tumor vascularity with polyvinyl alcohol particles. Subsequently, in vivo proton spectroscopy showed necrosis of a large portion of the tumor and helped determine the timing of surgery. Both innovative techniques considerably facilitated the subsequent radical excision of the tumor with no neurological morbidity.

Petroclival meningioma mimicking the presentation of a transient ischemic attack

A case of petroclival meningioma with pseudo-vascular clinical feature, documented by magnetic resonance imaging, is described. The location of the tumor and the persistent normality of the clinical examination excluded any surgical attempt. Such transient neurological symptoms in case of posterior fossa meningiomas have been seldom reported. Attempts for a physiological explanation are considered.