Preoperative Identification of Facial Nerve in Vestibular Schwannomas Surgery Using Diffusion Tensor Tractography

Objective

Facial nerve palsy is a common complication of treatment for vestibular schwannoma (VS), so preserving facial nerve function is important. The preoperative visualization of the course of facial nerve in relation to VS could help prevent injury to the nerve during the surgery. In this study, we evaluate the accuracy of diffusion tensor tractography (DTT) for preoperative identification of facial nerve.

Methods

We prospectively collected data from 11 patients with VS, who underwent preoperative DTT for facial nerve. Imaging results were correlated with intraoperative findings. Postoperative DTT was performed at postoperative 3 month. Facial nerve function was clinically evaluated according to the House-Brackmann (HB) facial nerve grading system.

Results

Facial nerve courses on preoperative tractography were entirely correlated with intraoperative findings in all patients. Facial nerve was located on the anterior of the tumor surface in 5 cases, on anteroinferior in 3 cases, on anterosuperior in 2 cases, and on posteroinferior in 1 case. In postoperative facial nerve tractography, preservation of facial nerve was confirmed in all patients. No patient had severe facial paralysis at postoperative one year.

Conclusion

This study shows that DTT for preoperative identification of facial nerve in VS surgery could be a very accurate and useful radiological method and could help to improve facial nerve preservation.     

Gamma knife radiosurgery for orbital tumors

Objective

This study was performed to investigate the radiological and functional outcomes of patients with orbital tumors treated by gamma knife radiosurgery (GKS).

Patients and methods

Fifteen patients with orbital tumors (7 meningiomas, 3 cavernous hemangiomas, 2 schwannomas, 2 metastatic tumors and 1 adenoid cystic carcinoma of the lacrimal gland) were treated. Seven patients with preserved vision and tumors located near the optic nerve were treated with multisession (3 or 4 fractions) radiosurgery. The mean tumor volume was 3695 mm³ (737–13,300). The median marginal dose was 14 Gy (13–20) in single-session radiosurgery, and the median cumulative marginal dose was 20 Gy (15–20) in multisession radiosurgery.

Results

After a mean follow-up of 20.9 months (6–50), tumor control was confirmed in 12 of 15 patients. Three patients with malignant lesions had to undergo another operation due to tumor progression. Of the 13 patients whose preoperative vision was preserved, 6 patients showed improvement in visual acuity and/or visual field, 4 patients showed no change in vision, and 3 patients showed deterioration (2 related to tumor progression).

Conclusions

As with intracranial tumors with similar pathologies, GKS may be an effective treatment option for orbital tumors. Multisession radiosurgery may be a good strategy for increasing the possibility of visual function preservation in selected cases in which the lesion is adjacent to the optic apparatus.     

The microsurgical treatment of cranio-orbital tumors assisted by intraoperative electrophysiologic monitoring and neuronavigation

Objective

Total resection of cranio-orbital tumors without any major complications is still a challenge for neurosurgeons. Intraoperative electrophysiologic monitoring and neuronavigational system have been widely used in microneurosurgery, but their effects during microsurgical treatment of cranio-orbital tumors warrant further investigation.

Methods

Thirty-eight patients with cranio-orbital tumors admitted to our hospital underwent microsurgery assisted by intraoperative electrophysiologic monitoring. We also simultaneously performed intraoperative neuronavigation in 20 patients. A retrospective review of clinical notes, operation records and prognoses of all patients was performed.

Results

Gross total resection was achieved in 29 patients (76%), near total resection in 5 (13%), subtotal resection in 3 (8%) and partial resection in 1 (3%). With the helps of electromyogram (EMG) monitoring of levator palpebrae superioris (LPS) muscle and navigation system, no surgical damages to the oculomotor nerve and other important structures occurred. A follow-up study showed that 31 patients (82%) resumed normal lives (Glasgow Outcome Scale (GOS) score 5), 5 patients (13%) had independent lives (GOS score 4), and 2 patients (5%) were unable to live independently (GOS score 3).

Conclusion

Microsurgical treatment assisted by intraoperative electrophysiologic monitoring and neuronavigation might be a useful method for resection of cranio-orbital tumors, especially better for protection of the important cranial nerve and structure in the kull base.     

Morbidity following sural nerve harvesting: A prospective study

Objective

To evaluate donor site morbidity following sural nerve harvesting, with special attention to the recovery of sensory loss.

Methods

We prospectively followed 38 subjects who underwent sural nerve harvest, including two with bilateral nerve excision. Symptoms related to sural nerve excision were evaluated and demarcation of the area with reduced touch sensation was quantified. Assessments were performed periodically up to 1 year after surgery and the results of different sensory evaluations were compared.

Results

A significant reduction of sensory deficit was identified between consecutive evaluations (p < 0.05). Decreases of 26.85%, 20.69% and 24.29% were observed 3, 6 and 12 months after surgery, respectively. Shock-like pain (7.5%), stabbing pain (7.5%), and numbness (5%) were the most frequently reported symptoms. All symptoms were brief and resolved spontaneously 3–6 months after surgery.

Conclusion

Sural nerve harvest can be performed with acceptable morbidity. When present, symptoms resolve between the third and sixth month after surgery and a significant reduction of sensory loss in the area innervated by the sural nerve was observed during the first year of follow-up.     

Which electrophysiological measure is appropriate in predicting prognosis of facial paralysis?

Objective

The prognostic value of electrophysiology and its significance in the prediction facial function outcome in facial palsy patients remains unclear because of the different methodologies used in previous studies. We aimed to establish the prognostic value of electrophysiological testing in a group of patients with facial palsy.

Methods

We prospectively analyzed facial nerve electrophysiology results and compared them with the House–Brackmann scale in 65 patients. The treatment consisted of a standard corticosteroid plus antiviral regimen. Clinical evaluation comprised the House–Brackmann grading system and electrophysiological tests (nerve excitability, nerve conduction study (NCS), needle electromyography (EMG), and blink reflex) conducted on the 5th, 20th, and 90th days after paralysis onset.

Results

In predicting the prognosis, the nerve excitability test in the acute phase, NCS in the subacute phase, blink reflex in the acute and subacute phases and needle EMG in the subacute phase provided statistically significant results.

Conclusion

Prognosis can be determined, and excessive tests can be eliminated with proper timing and electrophysiological testing.

Significance

In determining the prognosis of facial paralysis, the nerve excitability test should be used in the acute phase, and NCS and needle EMG should be used in the subacute phase. Blink reflex studies are helpful in both the acute and subacute phases.     

Efficacy of temozolomide as adjuvant chemotherapy after postsurgical radiotherapy alone for glioblastomas

Objectives

The aim of this study was to assess the efficacy of adjuvant TMZ chemotherapy for newly diagnosed GBM patients who were treated with surgery followed by radiotherapy alone.

Material and methods

Between January 2003 and April 2005, 59 consecutive GBM patients underwent radiation therapy after surgical resection and subsequently received TMZ chemotherapy. For the comparative analysis, we selected 60 clinically matched GBM patients who underwent radiotherapy followed by nitrosourea-based chemotherapy (NUBC), at the same institution between June 1995 and April 2005. The study cohort was divided into two groups, those with adjuvant TMZ treatment and with NUBC.

Results

59 patients with adjuvant TMZ treatment were assigned to the treatment group and 60 patients with NUBC to the control group. The median overall survival for the treatment group was 18.2 months (95% CI, 11.7–24.7 months), compared with the survival of 14.5 months (95% CI, 11.2–17.7 months) for the control group (p = 0.019). The progression-free survival for the treatment group was 5.6 months (95% CI, 4.4–6.7 months), while the control group showed progression-free survival of 3.3 months (95% CT, 3.2–6.0 months) (p = 0.030). Uni- and multivariate analysis revealed that extent of surgical resection, age ≥55 years and postoperative KPS were significantly associated with survival.

Conclusion

Adjuvant TMZ chemotherapy provided a clinically relevant benefit of survival, as compared with NUBC. Thus, we suggest that adjuvant TMZ chemotherapy may be effective even for patients who did not receive concomitant chemoradiotherapy for GBM.     

The Anatomical Location and Course of the Facial Nerve in Vestibular Schwannomas : A Study of 163 Surgically Treated Cases

Objective

The aim of this study was to identify the anatomical location and course of the facial nerve (FN) and their relationship to the tumor size in surgically treated vestibular schwannomas.

Methods

A retrospective study was conducted on 163 patients who had been treated by the microsurgical resection for a newly diagnosed vestibular schwannoma between 1995 and 2005 (mean age of 46.1 years; 108 females and 55 males). Surgery was carried out via retrosigmoid approach in all patients with the electromyographic monitoring for the FN function. The anatomical location and course of the FN along the tumor surface were verified in each patient during the microsurgery, and were classified into 4 groups : 1) the FN displaced along the ventral and superior surface of the tumor (VS); 2) the ventral and central (VC); 3) the ventral and inferior (VI); and 4) the dorsal (Do).

Results

The FN displacement was identified as the followings : VS in 91 patients (55.8%); VC in 57 (35.0%); VI in 14 (8.6%); and Do in 1 (0.6%). In the subgroup with tumors less than 2 cm in diameter (n=23), the FN was displaced along the ventral and central surface of the tumor in the majority (65.2%), whereas, in the patients with tumors larger than 2cm (n=140), it was displaced along the ventral and superior surface most frequently (59.3%).

Conclusion

The FN can be displaced variably in vestibular schwannomas, and most frequently along the ventral and superior surface of the tumor, especially in large ones.     

Long-term follow-up of vanishing tumors in the brain: How should a lesion mimicking primary CNS lymphoma be managed?

Objectives

The spontaneous disappearance of a tumor is referred to as a vanishing tumor. Most vanishing tumors in the brain are eventually diagnosed as malignant tumors or multiple sclerosis. However, their long-term clinical course remains unclear. This study aims to elucidate the management of vanishing tumors in the brain.

Patients and methods

We defined a vanishing tumor as a case in which the tumor spontaneously disappeared or decreased to less than 70% of the initial tumor volume before definitive diagnosis and treatment (other than steroid treatment). Ten cases of vanishing tumors are reviewed.

Results

Nine patients underwent biopsy at least once. Five patients, all of whom had malignant tumors (primary central nervous system lymphoma: 4, germinoma: 1) that recurred in 4–45 months (median: 7 months), underwent a second biopsy after the reappearance of the tumors. Five patients (tumefactive demyelinating lesion: 1, undiagnosed: 4) who had no relapse are alive, and their median follow-up time is 44 months. No cases have yet been reported of malignant brain tumors that recurred more than 5 years after spontaneous regression.

Conclusions

Patients with vanishing tumors should be followed up carefully by magnetic resonance imaging for at least 5 years, even after the disappearance of an enhancing lesion.     

Pregabalin in patients with primary brain tumors and seizures: a preliminary observation

Objectives

Patients with brain tumors and seizures should be treated with non-enzyme-inducing antiepileptic drugs (AED). Some of the newer drugs seem particularly suited in these patients.

Methods

Here we describe our experience with pregabalin (PGB); its effectiveness was retrospectively studied in nine consecutive patients with primary brain tumors and seizures.

Results

Six subjects had secondarily generalized and three simple partial seizures. Patients mostly suffered from WHO grade IV gliomas. PGB replaced enzyme inducing, inefficacious or bad tolerated AED, as add-on or monotherapy. Median follow-up was 5 (2–19) months; three patients died of their tumor. Daily median dosage was 300 mg. All subjects experienced at least a 50% seizure reduction, six were seizure-free. Side effects were reported in four patients, leading to PGB discontinuation in two.

Conclusion

PGB appears to have a promising effectiveness in this setting, even as a monotherapy. Based on these results we embarked on a prospective controlled trial.     

An analysis of related factors of surgical results for patients with craniopharyngiomas

Objective

The objective of this study was to retrospectively review the surgical results following gross total resection and partial resection with or without radiotherapy for craniopharyngiomas and analyze the related factors of surgical results.

Methods

From 1994 to 2009, 214 patients underwent 219 procedures for craniopharyngiomas. We retrospectively reviewed the pre- and postoperative data of patients, reported the perioperative and long-term surgical results and analyzed the influencing factors and the relationship between hypothalamic involvement and postoperative quality of life.

Results

Gross total resection was achieved in 154 procedures (70.3%). Perioperative mortality was 5%. Perioperative hyperpyrexia was the most significant risk factor for perioperative mortality. A total of 151 patients were followed from 6 months to 190 months. There were significant differences in recurrence rate and overall survival between gross total resection and limited resection (P < 0.05). There was significant difference in recurrence rate between limited resection and limited resection with radiotherapy (P < 0.01), but it did not reach statistical difference between gross total resection and gross total resection with radiotherapy. The factors strongly influencing overall survival include old patients, partial resection and recurrent tumors. The preoperative hypothalamic involvement negatively correlates with the postoperative quality of life in patients with craniopharyngiomas.

Conclusion

The preoperative CT/MR imaging provides clues of the relationship between tumor and surrounding structures. Gross total resection should be achieved in the treatment of craniopharyngiomas on the condition that hypothalamus is preserved. The patients who undergo limited resection should receive conventional radiotherapy or gamma knife surgery.     

Pre-chiasmatic transection of the optic nerve can save contralateral vision in patients with optic nerve sheath meningioms

Objectives

With respect to its characteristic pattern of growth from the orbit into the intracranial space toward the chiasm, patients with optic nerve sheath meningiomas (ONSM) are threatened to loose function of both optic nerves. Fortunately, in less than 5% both optic nerves are involved initially. Hence, prevention of vision of the contralateral eye is the foremost aim of any therapy. Performing pre-chiasmatic transection might offer a further treatment option to avoid further tumor growth toward the chiasm.

Patients and methods

In this retrospective study 12 patients with ONSM and blindness of the affected eye were included. The surgical approach was performed either from pterional intradural or as a combined approach from pterional extra- and intradural.

Results

Without any exceptions, vision of the contralateral eye could be preserved and did not show any deterioration after surgery or during the follow-up time of 50.6 months. Furthermore in 58.3% of patients gross total tumor resection could be achieved. During follow up observation in 67% of patients no further tumor progress or recurrences could be observed. 4 patients, however, showed delayed tumor progress or recurrences that were treated by radiotherapy.

Conclusion

Pre-chiasmatic transection of the optic nerve might offer a surgical treatment option to control tumor growth and to preserve vision of the contralateral eye.     

Facial motor evoked potentials in cerebellopontine angle surgery: technique, pitfalls and predictive value

Objective

To obtain information on functional integrity of the facial nerve by transcranial electrical motor evoked potentials independent of nerve visualization and to improve prediction of postoperative function.

Patients and methods

In a prospective clinical study, 68 patients with cerebello-pontine angle tumors and 5 patients with trigeminal neuralgia were investigated by facial motor evoked potentials (FMEP) elicited by multi-pulse transcranial electrical motor cortex stimulation. For recording the same electrode set-up was used as for continuous EMG monitoring of the orbicularis oculi and oris muscles. Pre-surgical FMEP amplitudes and latencies were correlated with tumor extensions. End to start amplitude ratios were compared to early and long-term facial nerve function by House-Brackmann-Grading (HB) documented by pre- and post-operative photo and video documentation.

Results

Reliable FMEP were obtained in 57 patients. FMEP responses at the start of surgery correlated with the degree of tumor extension. Largest FMEP amplitudes and shortest latencies were found in patients with trigeminal neuralgia. FMEP quality was reduced with increasing tumor extension (P < 0.05). The ratio of end-operative to start-operative FMEP-amplitude showed a positive correlation with early and late facial nerve function. Correlation was especially close with early function: an amplitude preservation rate of 86% led to HB°1 or HB°2, of 67% to HB°3, at 33% to HB°4 and at 15% or lower to HB°5 or HB°6.

Discussion

Initial FMEP amplitudes correlate with the presumed pre-operative nerve affection by space occupying tumors, a phenomenon reported here for the first time. Intact FMEP are highly reliable for preserved nerve continuity and hereby are of special help to the neurosurgeon for those surgical phases where the facial nerve is not visible and still covered by tumor and where conventional EMG monitoring is of very limited use. The end-to-start amplitude ratio of the FMEP is closely related to early and late clinical function. Amplitude reduction by 30% or more should result in a change of microsurgical action to enable fast recovery.

Conclusion

As an adjunct to intraoperative EMG, FMEP are superior in two respects, first in identifying pre-surgical latent nerve lesions and second in monitoring nerve integrity without direct nerve visualization. FMEP are highly reliable in predicting early and late postoperative function.     

Impact of facial burns: relationship between depressive symptoms,self-esteem and scar severity

Objective

This study assessed the role of self-reported facial scar severity as a possible influencing factor on self-esteem and depressive symptoms in patients with facial burns.

Method

A prospective multicentre cohort study with a 6 months follow-up was conducted including 132 patients with facial burns. Patients completed the Patient and Observer Scar Assessment Scale, the Rosenberg Self-esteem Scale and the Hospital Anxiety and Depression Scale. Structural Equation Modeling was used to assess the relations between depressive symptoms, self-esteem and scar severity.

Results

The model showed that patient-rated facial scar severity was not predictive for self-esteem and depressive symptoms six months post-burn. There was, however, a significant relationship between early depressive symptoms and both patient-rated facial scar severity and subsequent self-esteem. The variables in the model accounted for 37% of the variance in depressive symptoms six months post-burn and the model provided a moderately well-fitting representation of the data.

Conclusion

The study suggests that self-esteem and depressive symptoms were not affected by self-reported facial scar severity but that earlier depressive symptoms were indicative for a more severe self-reported facial scar rating. Therefore, routine psychological screening during hospitalisation is recommended in order to identify patients at risk and to optimise their treatment.     

Atypical onset in a series of 122 cases with FacioScapuloHumeral Muscular Dystrophy

Introduction

FacioScapuloHumeral Muscular Dystrophy (FSHD), a disease linked to a heterozygous D4Z4 deletion on chromosome 4q35, typically starts with shoulder-girdle and facial muscle involvement. Atypical presentations have occasionally been reported, but their frequency has still not been defined.

Patients and methods

We studied the occurrence rate of FSHD with atypical onset in 122 symptomatic subjects from 76 unrelated families with genetically confirmed FSHD. These 75 males and 47 females, with a mean age of 49 years (range: 11–85), had a mean EcoRI fragment of 25 kb (range: 11–38).

Results

Typical shoulder-girdle or facial weakness at onset was reported by 88 patients (72%). Unusual presentations included: foot drop in 16 (13%) and proximal lower limb weakness in eight patients (7%). Two cases at onset manifested quite atypical, apparently non-FSHD-related syndromes: a 42-year-old woman presented with infantile epilepsy and a 41-year-old man with myoglobinuria. In the latter patient, DNA analysis detected a 4q35 deletion associated to an heterozygous CAPN3 mutation.

Conclusion

FSHD presentation with foot drop or lower limb proximal weakness appeared to be more frequent than expected. This type of weakness at onset has to be considered premature, but still representative of disease-related muscle involvement. Quite atypical onset appears very rare and calls for further investigation on non-FSHD-related etiology.     

Management of hydrocephalus secondary to pineal region tumors

Background

Hydrocephalus is often secondary to pineal region tumors. Hydrocephalus can lead to high intracranial pressure, which in turn results in disturbance of consciousness, cerebral hernia, and even death. Hydrocephalus management is important in the treatment of pineal region tumors. It is still controversial regarding to when and how to treat hydrocephalus secondary to pineal region tumors. The objective of this study is to investigate the management of hydrocephalus secondary to pineal region tumors.

Methods

We retrospectively analyzed records for 51 patients admitted to the department of Neurosurgery, Jinling Hospital from April 1997 to September 2010 with hydrocephalus secondary to pineal region tumors treated through occipital transtentorial approach.

Results

Preoperative ventricular drainage was performed on one patient, and ventriculoperitoneal shunts were performed on two patients. Intraoperative ventriculocisternal shunts were performed on 35 patients (the remission rate was 88.6%), no treatments on 15 patients (the remission rate was 46.7%), and ventricular drainages on three patients. VP shunts were performed on 12 patients with no remission after the operation.

Conclusion

Pineal region tumors resection usually should be performed before shunting, unless there is an acute obstructive hydrocephalus. The posterior third ventricle should be opened after tumor resection. Intraoperative third ventriculostomy and ventriculocisternal shunt are reliable ways to manage hydrocephalus secondary to pineal region tumors.     

Surgery for perirolandic epilepsy: Epileptogenic cortex resection guided by chronic intracranial electroencephalography and electric cortical stimulation mapping

Subject

The objective of this study was to assess outcome with regard to seizure status and neurological function in patients undergoing resective surgery involving the perirolandic area.

Method

All 15 patients who underwent perirolandic cortical resection between October 2006 and September 2007 at the Comprehensive Epilepsy Centre of Beijing Xuanwu Hospital were included in the study. The locations of functional cortical areas, ictal onset zones and epileptogenic lesions were mapped by chronic intracranial EEG recordings and electric cortical stimulation. Seizure outcome was determined using the modified classification of Engel and colleagues. Motor and sensory deficits were monitored.

Results

At last follow-up 5 patients (33%) were in Engel class I, 4 (27%) were in class II, 3 (20%) were in class III, and 3 (20%) were in class IV. Nine patients suffered immediate functional deficits; 8 of these recovered completely within 2 weeks to 3 months of surgery. One had mild persistent loss of finger motor control.

Conclusion

After accurate presurgical evaluation using invasive recordings and functional brain mapping, epileptogenic cortical resection can give excellent results and few deficits in patients with perirolandic epilepsy.     

Purely subcortical tumors in eloquent areas: Awake surgery and cortical and subcortical electrical stimulation (CSES) ensure safe and effective surgery

Objective

To analyze the efficacy and safety of cortical and subcortical electrical stimulation CSES and awake surgery to approach purely subcortical tumors in highly functional locations, particularly in guiding the choice of the best transcortical path.

Patients and methods

Prospective analysis of the surgical, neurological, and radiological outcome of patients harboring supratentorial, subcortically located brain tumors or vascular malformations who are operated on through awake surgery and CSES. Functional magnetic resonance (fMRI; either sensory-motor or language, based on the location) was performed in order to confirm the proximity to functional cortical areas. Major white matter tracts were investigated by MRI diffusion tensor fiber tracking (DTI-ft). The Rankin modified score was chosen to express the pre and postoperative functional neurological status. Immediate postoperative MRI was used to evaluate the extent of resection.

Results

Seventeen patients were selected. The main distance of the tumors from the cortical surface was 18.2 mm (range 9–48 mm). Neuronavigation was used to show the most direct route to the tumor (transsulcal or transgyral), but CSES was fundamental to adapt the surgical corridor to the functional topography both cortically and subcortically. If the transgyral route was chosen, CSES helped to detect a non-eloquent area. When a transsulcal route was preferred, CSES documented the presence or absence of function in the deep sulcus. The transient postoperative morbidity was 76.4%, but at last follow-up (range 4–20 months), all the patients regained preoperative status and 2 improved. Postoperative MRI demonstrated complete resection in all cases.

Conclusions

Approaching purely subcortical tumors requires microsurgical skills, but in eloquent areas, functional topography monitoring is mandatory to allow safe surgery. CSES in an awake patient is a method that produces very good results in terms of resection and neurological outcome.     

Patients in a vegetative state following traumatic brain injury display a reduced intracortical modulation

Objective

Patients in coma who fail to wake develop a condition known as a vegetative state (VS). While we know that some cortical activities exist in patients in VS, it remains unclear whether interneuronal modulation can be abnormal in the cerebral cortex of these patients. The aim of the study was to evaluate the inhibitory and excitatory interneuronal circuits in patients in VS following a traumatic brain injury.

Methods

Cortical excitability was studied in 5 VS patients and in 10 healthy subjects using paired pulses transcranial magnetic stimulation (TMS). Resting motor threshold and intracortical inhibition and facilitation at short intervals (2 and 10 ms, respectively) were evaluated. Two patients were studied again after their level of consciousness transitioned into a minimally conscious state (MCS).

Results

Both intracortical inhibition and facilitation were significantly reduced in patients compared to healthy subjects (p < 0.05). In addition, these results did not significantly change in the 2 patients who evolved into a MCS.

Conclusions

This is the first report showing an abnormal cortical excitability in patients in VS.

Significance

Our findings suggest a pathophysiological base for future work aiming to restore the lack of interneuronal transmission in patients in VS.