Neurosurgery Blog

Neurosurgery 70:283–294, 2012 DOI: 10.1227/NEU.0b013e31823020e6

Diffusion tensor (DT) imaging-based fiber tracking is a noninvasive magnetic resonance technique that can delineate the course of white matter fibers.

OBJECTIVE: To evaluate the accuracy and usefulness of this DT imaging-based fiber tracking for surgery in patients with gliomas near the pyramidal tract (PT).

METHODS: Subjects comprised 32 patients with gliomas near the PT. DT imagingbased fiber tracks of the PT were generated before and within 3 days after surgery in all patients. A tractography-integrated navigation system was used during the operation. Cortical and subcortical motor-evoked potentials (MEPs) were also monitored during resection to maximize the preservation of motor function. The threshold intensity for subcortical MEPs was examined by searching the stimulus points and changing the stimulus intensity. Minimum distance between the resection border and the illustrated PT was measured on postoperative tractography.

RESULTS: In all subjects, DT imaging-based tractography of the PT was successfully performed, preoperatively demonstrating the relationship between tumors and the PT. With the use of the tractography-integrated navigation system and intraoperative MEPs, motor function was preserved postoperatively in all patients. A significant correlation was seen between threshold intensity for subcortical MEPs and the distance between the resection border and PT on postoperative DT imaging.

CONCLUSION: DT imaging-based fiber tracking is a reliable and accurate method for mapping the course of subcortical PTs. Fiber tracking and intraoperative MEPs were useful for preserving motor function in patients with gliomas near the PT.

Spine 2012 ; 37 : 48 – 56

Study Design. A prospective study evaluating a cohort of patients with spondylotic cervical spine compression.

Objective. To analyze the potential of diffusion tensor imaging (DTI) of the cervical spinal cord in the detection of changes associated with spondylotic myelopathy, with particular reference to clinical and electrophysiological fi ndings.

Summary of Background Data. Conventional magnetic resonance imaging (MRI) may provide confusing fi ndings because of a frequent disproportion between the degree of the spinal cord compression and clinical symptoms . The DTI is known to be more sensitive to subtle pathological changes of the spinal cord compared with conventional MRI. Methods. The DTI of the cervical spinal cord was performed within a group of 52 patients with spondylotic spinal cord compression and 13 healthy volunteers on a 1.5-T MRI scanner. All patients underwent clinical examination that differentiated between asymptomatic and symptomatic myelopathy subgroups, and 45 patients underwent electrophysiological examination. We measured the apparent diffusion coeffi cient and fractional anisotropy of the spinal cord at C2/C3 level without compression and at the maximal compression level (MCL). Sagittal spinal canal diameter, cross-sectional spinal cord area, and presence of T2 hyperintensity at the MCL were also recorded. Nonparametric statistical testing was used for comparison of controls with subgroups of patients.

Results. Significant differences in both the DTI parameters measured at the MCL, between patients with compression and control group, were found, while no difference was observed at the noncompression level. Moreover, fractional anisotropy values were lower and apparent diffusion coeffi cient values were higher at the MCL in the symptomatic patients than in the asymptomatic patients. The DTI showed higher potential to discriminate between clinical subgroups in comparison with standard MRI parameters and electrophysiological fi ndings.

Conclusion. The DTI appears to be a promising imaging modality in patients with spondylotic spinal cord compression. It refl ects the presence of symptomatic myelopathy and shows considerable potential for discriminating between symptomatic and asymptomatic patients.

J Neurosurg Spine 15:648–653, 2011.DOI: 10.3171/2011.7.SPINE10843

The authors assessed the role of 3D anisotropy contrast (3DAC) in evaluating specific ascending tract degeneration in patients with cervical spondylotic myelopathy (CSM).

Methods. The authors studied 10 patients (2 women, 8 men; mean age 59.8 ± 14.6 years) with CSM and spinal cord compression below the C2–3 disc level, as well as 10 healthy control individuals (3 women, 7 men; mean age 42.0 ± 24.1 years). Images of the cervical cord at the C2–3 level were obtained using a 3.0-T MR imaging system.

Results. Three-dimensional anisotropy contrast imaging clearly made possible tract-by-tract analysis of the fas- ciculus cuneatus, fasciculus gracilis, and spinocerebellar tract. Tract degeneration identified using 3DAC showed good correlation with a decline in fractional anisotropy. Degeneration of the fasciculus gracilis detected by “vector contrast” demonstrated a good correlation with Nurick grades.

Conclusions. The study unambiguously demonstrated that 3DAC imaging is capable of assessing ascending tract degeneration in patients with CSM. Degeneration of an individual tract can be easily identified as a vector con- trast change on the 3DAC image, a reflection of quantitative changes in anisotropism, similar to fractional anisotropy. Excellent correlation between Nurick grades and fasciculus gracilis degeneration suggests potential application of 3DAC imaging for tract-by-tract clinical correlation.

J Neurosurg 115:647–658, 2011.DOI: 10.3171/2010.11.JNS102148

The aim of this paper was to measure the posterior fossa (PF) volume increase resulting from a givensized occipital craniectomy in Chiari malformation Type I surgery and to analyze its correlations with the PF size and the treatment response, with the perspective of tailoring the amount of bone removal to the patient-specific PF dimensions.

Methods. Between January 2005 and June 2006, 11 adult patients with symptomatic Chiari malformation Type I underwent a standardized PF decompression. A prospective evaluation with clinical examination, functional grading, and MR imaging measurement protocols was performed pre- and postoperatively. A method is reported for the measurement of PF volume (PFV) after surgery. The degree of PFV increase was compared with the preoperative size of the PF and with the clinical outcome.

Results. All 11 patients improved postoperatively, with complete and partial recovery in 4 and 7 patients, respectively. No postoperative complication occurred after a mean follow-up period of 45 months. The mean relative increase in PFV accounted for 10% (range 1.5%–19.7%) of the initial PFV; the increase was greater in cases in which the PF was small (r = -0.52, p = 0.09) and the basiocciput was short (r = -0.37, p = 0.2). A statistically significant positive correlation was found between the degree of PFV increase and the treatment response (p = 0.014); complete recovery was observed with a PFV increase of 15% and partial recovery with an increase of 7%.

Conclusions. The treatment response is significantly influenced by the degree of PFV increase, which is dependent on the size of the PF and the extent of the craniectomy, suggesting that the optimal patient-specific PFV increase could be predicted on the basis of preoperative MR imaging and enhancing the perspective that the craniectomy size could be tailored to the individual PFV.

Neurosurgery 69:362–368, 2011 DOI: 10.1227/NEU.0b013e31821a418

Factors that can predict the recovery of cervical spondylotic myelopathy (CSM) patients postoperatively are of significant interest to physicians and patients and their families. Magnetic resonance imaging (MRI) scans are a common method of examination after surgery, and thus of interest as a predictor of outcome.

OBJECTIVE: To investigate whether findings on MRI at 6 months postoperatively could predict recovery at 1 year in CSM patients.

METHODS: In 52 consecutive prospective patients, MRI was performed preoperatively and 6 months postoperatively. T1 and T2 signal change (area, height, and segmentation) and spinal cord re-expansion were measured. Outcome measures evaluated at 1 year postoperatively were compared with preoperative values. Univariate and stepwise multiple regressions were undertaken.

RESULTS: Using univariate analysis, patients whose cord failed to re-expand had poorer outcome according to the modified Japanese Orthopedic Association score and Nurick score (P = .014) and grip test (P = .006) postoperatively. Stepwise multivariate regression showed lack of cord re-expansion to be predictive of prognosis postoperatively in the modified Japanese Orthopedic Association score (P = .013) and Berg Balance Scale (P = .014), and walking test (P = .011). Postoperative hyperintense T2 signal change was predictive of worse outcome on the Berg Balance Scale (P = .014) and walking test (P = .020), Nurick score (P = .001), and Short Form-36 scores (P = .020). In cases in which the T2 signal intensified, there was a poorer outcome on Nurick scores (P = .013), grip test (P = .017), and Short Form-36 scores (P = .030).

CONCLUSION: Findings on postoperative MRI at 6 months is of predictive value in determining outcomes in CSM patients. The persistence and type of T2 signal change and lack of re-expansion of the cord correlate with poorer recovery and likely reflect irreversible structural changes in the spinal cord.

Neurosurgery 69:207–214, 2011 DOI: 10.1227/NEU.0b013e318218c7ae

Knowledge of the anatomic location of the deep brain stimulation (DBS) electrode in the brain is essential in quality control and judicious selection of stimulation parameters. Postoperative computed tomography (CT) imaging coregistered with preoperative magnetic resonance imaging (MRI) is commonly used to document the electrode location safely. The accuracy of this method, however, depends on many factors, including the quality of the source images, the area of signal artifact created by the DBS lead, and the fusion algorithm.

OBJECTIVE: To calculate the accuracy of determining the location of active contacts of the DBS electrode by coregistering postoperative CT image to intraoperative MRI.

METHODS: Intraoperative MRI with a surrogate marker (carbothane stylette) was digitally coregistered with postoperative CT with DBS electrodes in 8 consecutive patients. The location of the active contact of the DBS electrode was calculated in the stereotactic frame space, and the discrepancy between the 2 images was assessed.

RESULTS: The carbothane stylette significantly reduces the signal void on the MRI to a mean diameter of 1.4 6 0.1 mm. The discrepancy between the CT and MRI coregistration in assessing the active contact location of the DBS lead is 1.6 6 0.2 mm, P < .001 with iPlan (BrainLab AG, Erlangen, Germany) and 1.5 6 0.2 mm, P < .001 with Framelink (Medtronic, Minneapolis, Minnesota) software.

CONCLUSION: CT/MRI coregistration is an acceptable method of identifying the anatomic location of DBS electrode and active contacts.

Neurosurgery 67:1703–1708, 2010 DOI: 10.1227/NEU.0b013e3181fb801b

Peritumoral brain edema (PTBE) may be crucial in the clinical outcome of meningioma patients. The underlying pathogenetic key mechanism has so far not been determined. Sex, age, tumor size, location, involvement of other structures, or the histological appearance was not found to sufficiently explain PTBE formation in meningiomas.

OBJECTIVE: As PTBE formation is widely accepted to be vasogenic, we investigated the role of vascular endothelial growth factor (VEGF) and pial supplying vessels in a series of World Health Organization (WHO) grade I meningiomas.

METHODS: A total of 79 patients with WHO grade I meningiomas were immunohistochemically studied for VEGF and MIB-1. Pre- and postoperative magnetic resonance imaging including 3-dimensional reconstruction of 1.3-mm thick layers, with calculation of tumor and edema volume, was performed. Intraoperatively, the vascular supply and arachnoidal state were noted by the neurosurgeon.

RESULTS: VEGF was found to be exclusively confined to meningioma tumor cells. We identified 4 different patterns. VEGF and supplying pial vessels were found in 14 meningioma patients, pial vascular supply only in 3, VEGF expression only in 46, and neither VEGF expression nor supplying pial vessels in 16. Only the occurrence of both pial vascular supply and tumor VEGF expression was found to be correlated with PTBE formation (P , .002).

CONCLUSION: Our data suggest that VEGF may be crucial in angiogenesis and therefore indirectly in PTBE formation in World Health Organization grade I meningiomas

Neuroradiology. DOI 10.1007/s00234-010-0801-7

Diffusion-weighted imaging (DWI) can provide valuable structural information that may be useful for evaluating pathological changes of the lumbar nerve root. Diffusion-weighted magnetic resonance (MR) neurography has recently been introduced as an alternative way to visualize nerves, but to date, quantitative DWI and MR neurography have not been applied to evaluate the pathology of lumbar nerve roots.

Methods Our purpose was to visualize lumbar nerve roots and to analyze their morphology by MR neurography, and to measure the apparent diffusion coefficient (ADC) of lumbar nerve roots compressed by herniated disks using 1.5-T MR imaging. Ten consecutive patients (median age, 48.0 and range, 20–72 years) with monoradicular symptoms caused by a lumbar herniated disk and 14 healthy volunteers were studied. Regions of interests were placed on the lumbar roots at dorsal root ganglia (DRG) and distal spinal nerves on DWI to quantify mean ADC values. The spinal nerve roots were also visualized by MR neurography.

Results In the patients, mean ADC values were significantly greater in the compressed DRG and distal spinal nerves than in intact nerves. MR neurography also showed abnormalities such as nerve swelling at and below the compression in the symptomatic nerve root. Increased ADC values were considered to be because of edema and Wallerian degeneration of compressed nerve roots.

Conclusion DWI is a potential tool for analysis of the pathophysiology of lumbar nerve roots compressed by herniated disks.

Neuroradiology (2010) 52:1003–1010. DOI 10.1007/s00234-010-0671-z

“Brain surface motion imaging” (BSMI) is the subtraction of pulse-gated, 3D, heavily T2-weighted image of two different phases of cerebrospinal fluid (CSF) pulsation, which enables the assessment of the dynamics of brain surface pulsatile motion. The purpose of this study was to evaluate the feasibility of this imaging method for providing presurgical information about adhesions between meningiomas and the brain surface.

Methods Eighteen cases with surgically resected meningioma in whom BSMI was presurgically obtained were studied. BSMI consisted of two sets of pulse-gated, 3D, heavily T2-weighted, fast spin echo scans. Images of the systolic phase and the diastolic phase were obtained, and subtraction was performed with 3D motion correction. We analyzed the presence of band-like texture surrounding the tumor and judged the degree of motion discrepancy as “total,” “partial,” or “none.” The correlation between BSMI and surgical findings was evaluated. For cases with partial adhesions, agreements in the locations of the adhesions were also evaluated.

Results On presurgical BSMI, no motion discrepancy was seen in eight cases, partial in six cases, and total in four cases. These presurgical predictions about adhesions and surgical findings agreed in 13 cases (72.2%). The locations of adhesions agreed in five of six cases with partial adhesions.

Conclusion In the current study, BSMI could predict brain and meningioma adhesions correctly in 72.2% of cases, and adhesion location could also be predicted. This imaging method appears to provide presurgical information about brain/meningioma adhesions.

J Neurosurg 113:74–78, 2010. (DOI: 10.3171/2009.9.JNS09171)

In this paper, the authors’ goal was to compare the artifact induced by implanted (in vivo) adjustable shunt valves in spin echo, diffusion weighted (DW), and gradient echo MR imaging pulse sequences.

Methods. The MR images obtained in 8 patients with proGAV and 6 patients with Strata II adjustable shunt valves were assessed for artifact areas in different planes as well as the total volume for different pulse sequences.

Results. Artifacts induced by the Strata II valve were significantly larger than those induced by proGAV valve in spin echo MR imaging pulse sequence (29,761 vs 2450 mm3 on T2-weighted fast spin echo, p = 0.003) and DW images (100,138 vs 38,955 mm3, p = 0.025). Artifacts were more marked on DW MR images than on spin echo pulse sequencse for both valve types.

Conclusions. Adjustable valve–induced artifacts can conceal brain pathology on MR images. This should influence the choice of valve implantation site and the type of valve used. The effect of artifacts on DW images should be highlighted pending the development of less MR imaging artifact–inducing adjustable shunt valves.

Acta Neurochir (2010) 152:1197–1205. DOI 10.1007/s00701-010-0640-7

Early infarction that occurs at the time of initial subarachnoid hemorrhage (SAH) due to rupture of an aneurysm is a poorly understood phenomenon. We investigate the frequency of early infarction using diffusion-weighted images (DWI) at the time of admission. We then discuss the pathogenesis of infarction.

Materials and methods This study included 85 SAH patients who underwent serial DWI on admission. Early infarction detected by DWI and clinical features were investigated retrospectively.

Results The overall incidence of DWI-detected early infarction at the time of SAH onset was 8% (7 of 85 cases). In all seven patients, early infarctions were asymptomatic on admission. Types of early infarction seen on DWI included infarcts occurring in the territory of the vessel harboring a ruptured aneurysm (solitary, three cases) and infarcts occurring outside the territory of the vessel (multiple, two cases; solitary, two cases). Six of seven patients eventually developed delayed ischemic neurological deficit (DIND) and computed tomography (CT)-detected and DWI-detected delayed extensive infarction. Four of seven patients with early infarction had an unfavorable outcome. The occurrence of DWI-detected early infarction on admission was significantly correlated with delayed angiographic vasospasm, DIND, CT-detected delayed infarction, DWI-detected delayed infarction, and unfavorable outcome.

Conclusions In the present study, DWI-detected early infarction at the time of SAH onset was correlated with the occurrence of delayed extensive ischemic lesions. We believe that performing DWI at the time of admission is useful for evaluating the primary ischemic insult, which might play an important role in the pathogenesis of early brain injury and delayed vasospasm-related complications.

J Neurosurg 112:497–502, 2010. DOI: 10.3171/2009.7.JNS09572

With the expanding indications and increasing number of patients undergoing deep brain stimulation (DBS), postoperative MR imaging is becoming even more important in guiding clinical care and practice-based learning; important safety concerns have recently emerged, however. Although phantom model studies have driven conservative recommendations regarding imaging parameters, highlighted by 2 recent reports describing adverse neurological events associated with MR imaging in patients with implanted DBS systems, the risks of MR imaging in such patients in clinical practice has not been well addressed. In this study, the authors capitalized on their large experience with serial MR imaging (3 times per patient) to use MR imaging itself and clinical outcomes to examine the safety of MR imaging in patients who underwent staged implantation of DBS electrodes for Parkinson disease, tremor, and dystonia.

Methods. Sixty-four patients underwent staged bilateral lead implantations between 1997 and 2006, and each patient underwent 3 separate MR imaging sessions subsequent to DBS placement. The first of these was performed after the first DBS placement, the second occurred prior to the second DBS placement, and third was after the second DBS placement. Follow-up was conducted to examine adverse events related either to MR imaging or to DBSinduced injury.

Results. One hundred and ninety-two MR images were obtained, and the mean follow-up time was 3.67 years. The average time between the first and second, and second and third MR imaging sessions was 19.4 months and 14.7 hours, respectively. Twenty-two MR imaging–detected new findings of hemorrhage were documented. However, all new findings were related to acute DBS insertion, whereas there were no new findings after imaging of the chronically implanted electrode.

Conclusions. Although potential risks of MR imaging in patients undergoing DBS may be linked to excessive heating, induced electrical currents, disruption of the normal operation of the device, and/or magnetic field interactions, MR imaging can be performed safely in these patients and provides useful information on DBS lead location to inform patient-specific programming and practice-based learning

Acta Neurochir (2010) 152:213–219. DOI 10.1007/s00701-009-0427-x

With the frequent use of magnetic resonance imaging (MRI), patients with subtle and diffuse symptoms due to small syrinx cavities increasingly present to neurosurgical care. In this respect, a dilated central canal, hydromyelia, must be separated from patients with true syringomyelia with an underlying disorder, as they do not share clinical and radiological features. We hypothesize that a differentiation of these two entities with distinct diagnostic tools is possible.

Methods To describe the entity of hydromyelia, we excluded all patients from the syringomyelia database (n=142) with any obvious cause of a syringomyelia, any objective neurological deficits on clinical examination, pathological results on electrophysiological monitoring (SSEP, MEP, silent periods) or a widening of the spinal cord cavity of more than 6 mm on MRI [routine acquisitions with FLAIR, T1/T2-weighted images, Cine and CISS (constructive interference in steady-state) studies]. Life quality was assessed through SF-36 questionnaires and an individualized questionnaire for the clinical history, pain and alternative therapies.

Results Forty patients (15 males/25 females) matched the criteria of a hydromyelia. With a mean age of 36.7 years (range 11–62), they almost all presented with pain (79%) or dysaesthesia of the limbs, with some having been an incidental finding (10%). Over a follow-up time of 36.9 months (range 6–93) there was no neurological or radiological deterioration.

Conclusions Patients with a hydromyelia do not share clinical or radiological characteristics with patients harbouring a true syringomyelia. As hydromyelia does not represent a disease with an underlying pathology, no clinical or radiological progression has been seen. With sophisticated diagnostic tools to rule out any pathology this subset of patients can be identified.

Neuroradiology DOI 10.1007/s00234-009-0610-z

We attempted to detect alterations in the cerebrospinal fluid (CSF) space in patients with idiopathic normal pressure hydrocephalus (iNPH) using voxel-based morphometry (VBM).

Methods. We obtained sagittal volume images of the entire head by three-dimensional T1-weighted magnetic resonance imaging and compared the regional distribution of CSF in 12 patients with iNPH, 14 patients with Alzheimer’s disease (AD), and 17 healthy individuals using VBM with automatically extracted CSF objects.

Results. VBM demonstrated significant widening at the lateral ventricles and Sylvian fissures and narrowing of the CSF space at the high convexity/midline areas in iNPH patients, compared to the AD patients and healthy controls (p<0.05, after correction with a false-discovery rate). In addition, the ratio of the CSF volume in the lateral ventricle/Sylvian fissure area to that in the high convexity/midline area in iNPH patients (3.9 ± 1.2) was remarkably greater than that in AD patients (1.2 ± 0.3) ANOVA, p < 0.001; post hoc Tukey’s test, p < 0.001); we could discriminate iNPH patients from those in the other two groups without any overlap, when using a cutoff level of 1.9.

Conclusion. VBM using CSF objects can be used to delineate the characteristic alteration of the CSF space in iNPH patients, which has been evaluated by visual interpretation.

J Neurosurg Spine 11:501–507, 2009. (DOI: 10.3171/2009.5.SPINE08675)

Object. The current cross-sectional observational MR imaging study aimed to investigate the prevalence and risk factors of lumbar disc degeneration in a healthy population and to establish the baseline data for a prospective longitudinal study.

Methods. Two hundred healthy volunteers participated in this study after providing informed consent. The status of lumbar disc degeneration was assessed by 3 independent observers, who used sagittal T2-weighted MR imaging. Demographic data collected included age, sex, body mass index, episode(s) of low-back pain, smoking status, hours of standing and sitting, and Roland-Morris Disability Questionnaire scores. There were 68 men and 132 women whose mean age was 39.7 years (range 30–55 years). Eighty-two individuals (41%) were smokers, and the Roland- Morris Disability Questionnaire scores were averaged to 0.6/24.

Results. The prevalence of disc degeneration was 7.0% in L1–2, 12.0% in L2–3, 15.5% in L3–4, 49.5% in L4–5, and 53.0% in L5–S1. A herniated disc was observed at the corresponding levels in 0.5, 3.5, 6.5, 25.0, and 35.0% of cases respectively. Spondylolisthesis was observed in < 3% of this population. Multiple logistic regression analysis demonstrated that age and hours sitting were significantly related to L4–5 disc herniation. Episode of low-back pain, smoking status, body mass index, and hours standing did not affect the prevalence of disc degeneration.

Conclusions. The current study established the baseline data of lumbar disc degeneration in a 30- to 55-year-old healthy population for a prospective longitudinal study. Hours spent sitting significantly increased the prevalence of disc herniation, but episode of low-back pain, smoking status, obesity, and standing hours were not significant risk factors.

The Spine Journal 9 (2009) 822–829. doi:10.1016/j.spinee.2009.06.023

Removal of cervical dumbbell tumors can be particularly challenging because of unique exposure requirements and proximity of the vertebral artery (VA). There are no reports describing the treatment of giant cervical spine dumbbell tumors (CSDTs).

PURPOSE: To introduce an extensive posterolateral approach to CSDTs involving total lateral mass resection and laminectomy.

STUDY DESIGN: Prospective study of all the patients with multilevel CSDTs treated by  this new procedure between December 2002 and March 2006.

PATIENT SAMPLE: Sixteen patients (3 men and 13 women) with CSDTs underwent the procedure we describe. The follow-up periods ranged from 9 to 51 months (average 9 months). Average age at surgery was 45 years (range 23–68 years).

OUTCOME MEASURES: Axial symptoms and Japanese Orthopedic Association scores were recorded. Pre- and postoperative ranges of neck motion were measured on lateral flexion and extension radiographs.

METHODS: After making a midline incision, we preferred exposing the extraforaminal component of the tumor before performing a semilaminectomy and lateral mass resection. Any lateral extensión of a tumor can be attained by detachment of the adjacent three or more segments of the lateral mass muscle insertion. The most lateral portion can be separated beneath the tumor’s superficial muscle flap, and then when the tumor is retracted medially, the whole portion of the lateral component can be totally exposed. We then performed total lateral mass resection and laminectomy to expose the tumor at the foramina and cervical canal.

RESULTS: We were able to completely resect the tumors in every patient. The average duration of surgery was 150 minutes. Blood loss was minimal (average 400 mL). All patients were monitores for a minimum of 9 months (range 9–51 months; mean 28 months). The follow-up period was uneventful, and no patients developed spinal instability.

CONCLUSIONS: Extensive posterolateral exposure enables surgeons to reach the lateralmost portion of CSDTs and also facilitates septation of the VA and resection of vertebral body encroachment of the tumor.

Neurosurgery: September 2009 – Volume 65 – Issue 3 – p 450-455

Multiple cerebral cavernous malformations (MCCMs) typically occur in patients with a family history of these lesions. Literature on MCCMs is scarce, and little is known about their natural history.

Of 264 consecutive patients with cerebral cavernomas treated at the Department of Neurosurgery, Helsinki University Central Hospital, in the past 27 years, 33 patients had MCCMs. Lesions were categorized according to the Zabramski classification scale. Follow-up questionnaires were sent to all patients. Outcome was assessed using the Glasgow Outcome Scale, and amelioration of epilepsy was assessed using the Engel scale. All clinical data were analyzed retrospectively.

The mean age of patients at diagnosis was 44 years. Sex presentation was almost equal. Nine percent of all patients had a family history of the disease. Patients presented with epilepsy, acute headache, and focal neurological deficits. MCCMs were incidental findings in 2 patients. Altogether, 416 cavernomas were found: 70% supratentorial and 30% infratentorial. Fifteen patients had symptomatic hemorrhage before admission to our department. Surgery was performed on 18 patients. In most cases, the largest cavernoma was removed. Postoperatively, 1 patient experienced temporary hemiparesis, and another developed permanent motor dysphasia. No mortalities occurred. The mean follow-up time was 7.7 years. Twenty-six patients (79%) were in good condition. Among patients with epilepsy who underwent lesionectomy, 70% had an Engel class I outcome. On follow-up magnetic resonance imaging, 52 de novo cavernomas were found.

Surgical treatment of patients with MCCMs is safe. An extirpation of the clinically active cavernoma prevents further bleedings and improves outcome of epilepsy.

Surgical Neurology. Volume 72, Issue 3, Pages 223-241 (September 2009)

Background

Controversy still exists about neural basis underlying writing and its relation with the sites subserving oral language. Our objective is to study functional areas involved in writing network, based on the observations of different postoperative writing disorders in a population of patients without preoperative agraphia.

Methods

We analyzed the postoperative agraphia profiles in 15 patients who underwent surgery for cerebral LGGs in functional language areas, using electrical mapping under local anesthesia. These profiles were then correlated to the sites of the lesions, shown by preoperative cerebral imaging.

Results

Our findings showed that (1) spoken language and writing functions could be dissociated, and that (2) writing is subserved, at least partially, by a network of 5 areas located in the dominant hemisphere for language: the superior parietal region, the supramarginalis gyrus, the second and third frontal convolutions, the supplementary motor area, and the insula. Each of these areas seems to have a different role in writing, which will be detailed in this article. However, among the patients, only those with lesions of the supplementary motor area did not recover from agraphia in the postoperative period (in 50% of cases).

Conclusions

On the basis of these results, and in the light of the recent literature, we discuss the relevance of each area in this anatomo-functional network as well as the clinical implications of such better knowledge of the neural basis of writing, especially for brain surgery and functional rehabilitation.