Radiosurgery of Intracranial Cavernous Malformations

Summary.  Background: The efficacy of radiosurgery in cases of surgically high risk symptomatic cavernous malformations (CMs) for reducing haemorrhagic risk and for seizure control has not been clearly documented and the radiation-induced complications of radiosurgery remain problematic. The authors present a retrospective clinical analysis of 22 cases of CMs treated by radiosurgery.  Methods: Twenty-two patients with symptomatic CMs were treated by linear accelerator (LINAC) radiosurgery or Gamma knife (GK) between 1995 and 1998. Medical records including radiological investigations were carefully reviewed to the last follow-up. The mean age of the patients was 34.1 years (12–56) and the male to female ratio was 12:10. Twenty patients reported at least one episode of bleeding and four had undergone microsurgery before radiosurgery. The remaining two patients presented with seizure without evidence of recent haemorrhage. In 16 cases, the CMs were deep-seated, and the others were located in the cerebral hemispheres; four were located at an eloquent area. LINAC radiosurgery using computed tomography scan was performed in 11 cases until May 1997, after which GK radiosurgery using magnetic resonance (MR) image was performed in 11 cases. The volume of the lesion ranged from 0.09 cc to 4.8 cc (mean 1.42 cc) and the mean marginal dose was 16.1 Gy (8–24). The median follow-up period after radiosurgery was 38.3 months (21–67). The rate of haemorrhage, seizure, and neurological deterioration following radiosurgery was analyzed, and the rate of haemorrhage was compared to that seen in natural course reports.  Findings: There was one case of haemorrhage during the follow-up period and the seizure was well controlled with anticonvulsants. In the group with prior haemorrhage, the bleeding rate of cavernous malformation after radiosurgery (1.55%/year) was lower than that of pre-radiosurgical period (35.5%/year, t=1.296, P=0.04). Six patients showed neurological deterioration following radiosurgery, however, the neurological deficits persisted in only two of the patients with LINAC. The radiosurgical modality (LINAC vs. GK) showed a possible correlation to radiation induced neurological deficits (P=0.06). On the MR images at the last follow-up, the lesion was decreased in eleven patients, increased in one, and no change was found in 10 cases. The T2 weighted MR images revealed a perilesional high signal change in nine patients. This signal change was not statistically related to lesion size (P=0.236), location (P=0.658), nor radiation dose (P=0.363), but was dependent on the treatment modality (P=0.02). New-enhancing lesion and a new cyst were each found in one case, respectively, during the follow-up.  Interpretation: Radiosurgery may be a good alternative option for treatment of surgically high risk CMs. However, the optimal radiosurgical technique, dose adjustment, and proper delineation of the mass are prerequisites. Radiosurgery induced complications are still problematic and post-radiosurgery MR image changes need to be further elucidated. Published online September 2, 2002 Acknowledgment  This work was partly supported by grants from the Clinical Research Institute, Seoul National University Hospital. Correspondence: Dong Gyu Kim, M.D., Department of Neurosurgery, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea.     

Minor Head Injuries: One Year Experience According to the New Italian Guideline

Summary  Background. The data concerning a consecutive series of 4,536 adult patients suffering from minor head injuries treated at the Department of Neurosurgery over a period of one year are reported.  Method. The patients' age, sex and the circumstances of the injury have been taken into consideration. The patients, according to the new method, were divided into four groups.  Group 0 (3,864 patients) included all patients with Glasgow Coma Scale (GCS) score 15. They did not present any clinical features such as loss of consciousness (LOC), post-traumatic amnesia (PTA), headache or vomiting. No risk factors (RF) such as coagulopaties, alcoholism, drug abuse, epilepsy, previous neurological treatment or disabled elderly patients were detected.  Group 1 (600 patients) included patients with GCS score 15. The patients presented one or more clinical features (LOC, PTA, headache, vomiting). No RF were presented.  Group 2 (24 patients) included patients with GCS score 14 with or without clinical features (LOC, PTA, headache, vomiting) and with or without RF.  Group 0-1R (48 patients) included patients with GCS score 15 with or without clinical features (LOC, PTA, headache, vomiting). All of them presented RF.  The presence of focal neurological signs, open injury and GCS score≦13 were considered criteria for exclusion.  Findings. All the patients from groups 1, 0-1R, 2 and 187 patients from group 0 underwent CT scan for a total of 859 exams which are analyzed and discussed. 458 patients were admitted and are divided as follows: 216 from group 0, 192 from group 1, 26 from group 0-1R and all the 24 belonging to group 2. Six patients were treated surgically (3 extradural haematomas, 2 lobe contusions, 1 acute subdural haematoma) and one of them (0.02% of the total) died (extradural haematoma). The patients who were not admitted were sent home with an information sheet after at least a six hour observation period.  Interpretation. The authors draw the conclusion that they have evaluated the applicability and efficacy of guidelines, developed by the study group on head injury of the Italian Society of Neurosurgery [19]. A critical part of our guidelines is not only to identify all the intracranial lesions, but to identify patients harbouring relevant intracranial mass before clinical deterioration.     

Meningiomas of the sellar region presenting with visual impairment: impact of various prognostic factors on surgical outcome in 62 patients

Summary  Background. Meningiomas of the supra- and parasellar region can cause insidious visual loss by optic nerve compression. 62 cases with such tumours affecting the anterior optic pathways were analysed to assess the surgical results and prognostic factors with particular attention to visual outcome.  Method. In all patients, visual deterioration was the first clinical manifestation. Eleven lesions had their origin at the anterior clinoid process, 24 at the tuberculum sellae, 10 at the planum sphenoidale, two in the optic canal, 10 in the medial sphenoidal wing, and five in the olfactory groove. All patients underwent microsurgical tumour resection. Median age at the time of operation was 54 years, median duration of symptoms seven months. The mean follow-up time was 5.2 years (range 2 to 8 years). Statistical analysis of prognostic factors (gender, age, tumour location, tumour size, duration of symptoms, brain tumour interface, resection grade, preoperative visual loss, Glascow Outcome Score) was performed using univariate and multivariate analysis.  Findings. The severe morbidity rate was 6,4%. Two patients died within the first 30 postoperative days. Overall, vision improved in 39 (65%) patients, in 11 (18%) it was unchanged, and worse in 10 (17%). Visual prognosis was favourably affected by age under 54 years (p<0,025), duration of symptoms of less than seven months (p<0,037), and the presence of an intact arachnoid membrane around the lesion (p<0,001). Severe preoperative loss of visual acuity (<0,02) appeared to be an unfavourable prognostic factor (p<0,047).  Interpretation. Possible difficulties and surgical outcome in such patients can be predicted successfully. These facts in connection with new therapeutic modalities (radiosurgery, adjuvant therapies) will demand a careful risk assessment and should influence the treatment strategies and the degree of operative aggressiveness in the future.     

Open MRI-Guided Microsurgery of Intracranial Tumours in or Near Eloquent Brain Areas

Summary  Objectives. Preservation of brain function while maximizing resection is the main aim of brain tumour surgery. The purpose of this study was to evaluate the efficacy of intra-operative magnetic resonance imaging to preserve brain function in patients with tumours in or near eloquent brain areas.  Methods and Material. Between August 1997 and January 1999 fifty-eight craniotomies for intracranial tumours or vascular malformations have been performed at the University of Leipzig using a 0.5 T superconducting MR system “SIGNA SP” (General Electric Medical Systems, USA). In 32 of these patients (15 male/17 female) with intracranial tumours, located in or near eloquent brain areas (sensorimotor cortex/speech center), 34 craniotomies were performed using the image guidance of the interventional MRI.  Results. Using intra-operative MRI criteria, complete tumour removal could be achieved in 28 (82%) of 34 procedures. In 3 patients only subtotal tumour removal was possible, because the residual tumour was not visible on the intra-operative MR images, but could be identified on early diagnostic follow-up MR-scans. In 3 patients, incomplete tumour resection was performed in order to avoid neurological impairment. In these patients intra-operative MR-images revealed residual tissue abnormalities involving or encroaching on deep brain structures or motor/language cortex. Pre-operative neurological status was unchanged in 24 patients (70%), worsened in 4 patients (12%) and improved in 6 patients (18%).  Conclusions. Intra-operative MRI is helpful for navigation as well as to demonstrate the tumour margins to achieve a complete and safe resection of intracranial lesions located in or near eloquent brain areas. It enables an image based functional monitoring of the brain which is critical for motor, sensory or language function. Complications related to the surgical procedure are reduced and the risk of neurological deterioration due to tumour removal and postoperative complications is minimized.     

Endoscopic third ventriculostomy for hydrocephalus: early and late efficacy in relation to aetiology

Summary.  Objectives: The aim of the study was to analyse the effectiveness and usefulness of treatment of hydrocephalus by Endoscopic Third Ventriculostomy (ETV). We sought to relate rates of failure to the cause of hydrocephalus, distinguishing between early and late outcome.  Patients and methods: Between September 1999 and April 2001, 30 patients underwent ETV. In 23 patients hydrocephalus was caused by an expansive mass (tumour). Three groups of patients were distinguished, according to the different aims of ETV. Thus in group T – ETV was carried out to eliminate hydrocephalus prior to the main surgery (53%), in C – ETV was the definite treatment of choice (30%), and in group P – ETV was a palliative treatment (17%). The results were assessed in the early postoperative period and in long term follow-up using clinical relief of symptoms, and radiological criteria (pre- and postoperative computed tomography and/or magnetic resonance scans).  Results: In the early postoperative period ETV was rated to be effective by clinical criteria in 29 patients, and by radiological criteria in 27. According to late assessment the method was successful in 25 patients using clinical criteria, and in 21 using radiological criteria. There was no peri-operative mortality. A transient complication (wound CSF leak) occurred in two patients.  Conclusions: ETV is effective in well chosen patients in relieving symptoms of hydrocephalus. It is valuable before a definitive major operation to remove the cause of hydrocephalus, as a palliative treatment, and in itself as a method of definitive management when indications are correct. Published online March 3, 2003 Acknowledgments  The authors wish to thank professor B. L. Bauer from the Department of Neurosurgery in Hannover for his help in the training and also the team from the Department of Paediatric Neurosurgery in Warsaw led by professor Marcin Roszkowski for their help in the practical use of the neuroendoscopic method at our department.  Correspondence: Stanisław J. Kwiek MD, Ph.D., Department of Neurosurgery, Medical University of Silesia, ul. Medyków 14, 40-752 Katowice, Poland.     

Open MRI-Guided Microsurgery of Intracranial Tumours. Preliminary Experience Using a Vertical Open MRI-Scanner

Summary ? Objectives. A number of different image-guided surgical techniques have been developed during the past decade. None of these methods can provide the surgeon with information about the dynamic changes that occur intra-operatively. The development of open configurated MRI-scanners leads to new perspectives in the intra-operative management and resection control of intracranial tumours.  Material and Method. Using a vertical open 0.5 T MRI-scanner for intra-operative MR image guided neurosurgery, forty-four patients (20 female/24 male) with different intracranial tumours have been operated on since August 1997. The patients ranged in age from 20 to 70 years (mean±standard deviation=47.2±15.9 ys).  Results. In 36 (82%) of 44 patients the tumours were completely removed with the aid of MR image-guidance. In 8 cases (18%) complete removal was not achieved. Postoperatively 6 (14%) of 44 patients developed neurological deficits which were transient in 5 cases (paresis, dysphasia). In these patients the tumours were located in or near eloquent brain areas (sensorimotor cortex/speech center).  Conclusion. Intra-operative MRI is helpful for navigation as well as determining of tumour margins to achieve a complete and safe resection of intracranial lesions. Complications related to the surgical procedure are reduced and the risk of neurological deterioration due to tumour removal and postoperative complications is minimized. It can be concluded that the intra-operative application of interventional MRI technology may represent a major step foreward in the field of neurosurgery.     

Third ventriculocisternostomy in cerebellar haematomas

Summary. Summary.   Background: We prospectively evaluated the role of endoscopic third ventriculocisternostomy in the management of acute obstructive hydrocephalus created by cerebellar hematomas.   Method: Following a therapeutic diagram based on clinical and radiological signs, endoscopic third ventriculocisternostomy was used to treat hydrocephalus associated with cerebellar hematomas in 8 patients (male: 5, female: 3, mean age: 67 years-old). Causes of cerebellar hemorrhage were spontaneous in 6 cases, traumatic in 1 case, and acute bleeding of a posterior fossa tumor (lung metastasis) in the remaining case. Deeply comatose patients (Glasgow Coma Score between 3 and 5) and patients with signs of brainstem compression were initially excluded from this study.   Findings: Overall clinical improvement after third ventriculocisternostomy was achieved in all patients and was associated with the decrease of the ventricle size on follow-up CT scans. One patient who initially had a clot evacuation associated with an external ventricular drainage and persistant hydrocephalus had a successful third ventriculocisternostomy in the post operative course. No complication related to the procedure was noted.   Interpretation: In selected patients, third ventriculocisternostomy can be used to treat hydrocephalus associated with posterior fossa hematomas.     

Prognostic Factors in Postraumatic Severe Diffuse Brain Injury

Summary  It is usually defficult in clinical practice to establish factors affecting final outcome in patients suffering severe diffuse brain injury (SDBI), due to the absence of specific semiology.  Methods. We studied retrospectively 160 consecutive patients with criteria of SDBI. We performed a statistical analysis of epidemiological, clinical and radiological factors, and relationship with final outcome.  Result. 35% of patients with severe head injury presented SDBI. Sixty percent were 15–35 year old and 73% male. More than 45% of the patients presented GCS 3 or 4. On CT performed during the first 24 h, haemorrhagic lesions appeared in white matter in 35% and subarachnoid haemorrhage was observed in 28%. During the first 24 h., 66% of patients presented values of intracranial pressure (ICP) above 20 mm Hg and a 33% below 20 mm Hg. Twenty percent of the patients had ICP>20 mm and no response to treatment. According to the Glasgow Outcome Scale (GOS), mortality of more than 50% and 25% of patients with persistent vegetative state or severe disability were observed.  Conclusions. Clinical evaluation, early CT findings, ICP values and their response to medical treatment and clinical complications were found to be related (p<0.05) to final outcome (GOS).     

Gamma-Knife Radiosurgery for Brain Metastases of Renal Cell Carcinoma: Results in 23 Patients

Summary  From Jan. 1993 to Sept. 1995 23 patients suffering from brain metastases from renal cell carcinoma were treated with the Leksell Gamma Knife at the University of Vienna. At the time of diagnosis 13 patients had single and 10 patients presented with multiple metastatic lesions with a total of 44 metastases in MRI scans. Median tumour volume was 5500 cmm (range 100–24000 cmm). Predominant neurological symptoms and signs were different forms of hemiparesis, focal and generalized seizures, cognitive deficit, headache, dizziness, ataxia and CN XII paresis.  Fourteen patients received Gamma Knife Radiosurgery (GKRS) with a median dose of 22 Gy (range 8–30 Gy) at the tumour margin. Nine patients underwent a combined treatment of a radiosurgical boost with a median dose of 18 Gy (range 10–22 Gy) at the tumour margin followed by Whole Brain Radiotherapy (total dose 30 Gy/2 weeks).  In 20 patients tumour volume reduction up to 30% of the primary tumour volume was found after 4 weeks, evaluated on CT or MRI. A total remission was seen in 4 cases 3 months after GKRS. We achieved a local tumour control of 96%. Rapid neurological improvement after GKRS was seen in 17 patients. The median survival time was 11 months; the one-year actual survival in this unselected group was 48%. Five long term survivors were still alive, 18 patients had subsequently died, 15 of them of general tumour progression.  GKRS induces a significant tumour remission accompanied by rapid neurological improvement and therefore provides the opportunity for extended high quality survival. Neither local tumour control was improved nor CNS relapse free survival was prolonged significantly by additional WBRT.     

Gamma Knife Radiosurgery of Skull Base Meningiomas

Summary  Background. The standart surgical treatment of meningiomas is total resection of the tumour. The complete removal of skull base meningiomas can be difficult because of the proximity of cranial nerves. Stereotactic radiosurgery (SRS) is an effective therapy, either for adjuvant treatment in case of subtotal or partial tumour resection, or as solitary treatment in asymptomatic meningiomas.  Method. Between September 1992 and October 1995, SRS using the Leksell Gamma Knife was performed on 46 patients (f:m=35:15), ranging in age from 35 to 81 years, with skull base meningiomas at the Neurosurgical Department of the University of Vienna. According to the indication of gamma knife radiosurgery (GKRS) the patients (n=46) were devided into two subgroups. Group I (combined procedure: subtotal resection followed by GKRS as a planned procedure or because of a recurrent meningioma), group II (GKRS as the primary treatment). Histological examination of tumour tissue was available for 31 patients (67%) after surgery covering 25 benign (81%) and 6 malignant (19%) meningioma subtypes.  Findings. The overall tumour control rate after a mean follow-up period of 48 months (ranging from 36 to 76 months) was 96% (97.5% in benign and 83% in malignant meningiomas). Group I displayed a 96.7% tumour control rate, followed by group II with 93.3% respectively. Neurological follow-up showed an improvement in 33%, stable clinical course in 58% and a persistant deterioration of clinical symtoms in 9%. Remarkable neurological improvement after GKRS was observed in group II (47%), whereas in group I (26%) the amelioration of symptoms was less pronounced.  Interpretation. GKRS in meningiomas is a safe and effective treatment. A good tumour control and low morbidity rate was achieved in both groups (I, II) of our series, either as a primary or adjunctive therapeutic approach. The planned combination of microsurgery and GKRS extends the therapeutic spectrum in the treatment of meningiomas. Reduction of tumour volume, increasing the distance to the optical pathways and the knowledge of the actual growing tendency by histological evaluation of the tumour minimises the risk of morbidity and local regrowth. Small and sharply demarcated tumours are in general ideal candidates for single high dose-GKRS, even after failed surgery and radiation therapy, and in special cases also in larger tumour sizes with an adapted/reduced margine dose.     

Nodular intracerebral lesions can reveal an asymptomatic systemic lymphoma

Summary. Summary.   Object: To investigate whether a systemic workup is useful to assess the primary or secondary nature of brain lymphoma in immunocompetent patients suffering from nodular intracerebral lesions.   Methods: We retrospectively studied a consecutive series of 62 immunocompetent patients suffering from non-Hodgkin's brain lymphoma and analyzed two parameters: (1) the results of a partial systemic workup and (2) the pattern of relapse for all patients who are currently followed up or were so until death.   Results: The workup was conducted with chest X-ray and blood analysis in all cases, total body CT scan in 31 cases, bone marrow biopsy in 30 and serum lactate dehydrogenase in 29.  Asymptomatic systemic lymphomatous lesions were found in 9.6% of the cases (n=6/62). Two were nodal lymphomas and four were extranodal (maxillary sinus, testis, cutaneous and osseous). No systemic localization was observed during the follow-up of patients in whom the primary nature of the lymphoma was assessed after their initial negative workup (56/62). In this group, all relapses occurred within the central nervous system, even in those exclusively treated with cerebral radiotherapy (29/56).   Conclusions: Our results indicate that nodular intracerebral lesions can reveal asymptomatic systemic lymphoma. When brain lymphoma is suspected or diagnosed, systemic workup including clinical, biological and radiological examinations is mandatory before assessing the primary or secondary nature of the disease. Node areas, skin, testis, Waldeyer's ring and adjacent structures are of special interest and should be carefully explored.     

Microsurgical Treatment of Spontaneous and non-Spontaneous Spinal Epidural Haematomas: Neurological Outcome in Relation to Aetiology

Summary  Background. This retrospective study evaluated the neurological outcome of 26 patients with spontaneous and non-spontaneous spinal epidural haematoma (SEH) who underwent microsurgical clot removal. It was the objective of the present study to investigate whether the aetiology of the SEH has an influence on the neurological outcome.  Methods. The medical records and radiological investigations of 26 patients with SEH were re-examined, and the latency between symptom onset and operation, and the size of the haematoma were determined. Motor and sensory function had been evaluated before surgery and 90 days after discharge.  Findings. Fourteen patients with non-spontaneous SEH and 12 patients with spontaneous SEH were identified. After surgery, neurological deficits improved in 9 of the patients with spontaneous (75%) and in 13 of the patients with non-spontaneous SEH (93%). In cases of spontaneous SEH, the median latency between symptom onset and operation was longer (72 hrs vs 7 hrs) and the median extent of the haematoma was larger (3.5 vs 2 spinal segments), than in the non-spontaneous cases.  Interpretation. Neurological outcome seems to be related to the aetiology of the SEH. Better outcome was observed in patients with surgically treated non-spontaneous SEH. Two explanations for this finding are worth considering. First, patients with non-spontaneous SEH usually are already under medical surveillance and can undergo medullary decompression more rapidly. Second, the compression of the spinal cord is possibly less severe in non-spontaneous SEH because of their smaller size.     

Posteroventral Pallidotomy in Parkinson's Disease

Summary ? Objective. We analyse the clinical aspects, results and reliability of posteroventral pallidotomy (PVP) carried out as treatment for the principal symptoms and treatment induced complications in patients with Parkinson's disease (PD).  Patients and Methods. Between August 1995–January 1998, 17 patients with PD were treated surgically, 13 patients with PVP. A pre- and post-surgical clinical evaluation was carried out. Riechert's Stereotactic System (MHT, Freiburg, Germany) was used. Ventriculography under stereotactic conditions was used in the PVP procedures, Laitinen's co-ordinates as anatomical target, and electrical stimulation for physiological determination. 3–4 radiofrequency lesions were made at 83°C for 20^″. The mean age was 60±10.8 years, ages ranging from 45–79 years. 8 (60.5%) of the patients were male. The cardinal symptoms of the series were bradykinesia and rigidity. The duration of the illness ranged from 8.6±3.7 years with a range of 4–15 years. 7 (53.8%) presented with a duration of 10 years or more. 6 (46,2%) of the patients underwent left PVP, the remaining 7 (53.8%) right PVP. Only one patient received treatment with right PVP and ipsilateral thalamotomy in the same surgical procedure. The mean post-surgical follow up was 16±7 months, with a range of 2 to 26 months.  Results. An up to date evaluation was carried out on all patients showing significant changes after PVP in UPDRS motor (P<0.005), complete rigidity relief (P<0.005), bradykinesia relief (P<0.005) and complete tremor relief (P<0.005). An important improvement in contralateral dyskinesia was noted after PVP. A subjective evaluation of the results showed excellent results in 4 (30.8%) patients, good in 6 (46.2%) and fair in 3 (23%). No significant correlation was found between age and duration of illness (P=0.7). Two patients suffered slight side effects, one patient with worsening of hypophonia whilst the other suffered subjective visual impairment controlled by normal post operative ophthalmological examinations. There was no peri-operative mortality.  Conclusion. PVP is considered a safe and effective surgical method for the treatment of both the principal symptoms of PD and the complications of DOPA medication.     

Microsurgical management of cerebral aneurysms based in CT angiography with three-dimensional reconstruction (3D-CTA) and without preoperative cerebral angiography

Summary  Objective. To study the posibilities of the microsurgical management of ruptured intracranial aneurysms with the sole preoperative information provided by computed tomography angiography with three-dimensional reconstruction (3D-CTA).  Methods. Patients were studied with 3D-CTA after diagnosis of subarachnoid hemorrhage. If the study had an adequate quality and revealed an aneurysm congruent with the clinical findings or neurological examination and/or with the location of the bleeding on computed tomography (CT) scan an early microsurgical clipping of the lesion was done. When the quality of the 3D-CTA study was not adequate or the quality being adequate displayed no lesions or the findings were not accurate enough to warrant direct microsurgical treatment, the patient was studied with cerebral digital substraction (DS) angiography. A total of 44 consecutive patients harbouring a total of 47 intracranial aneurysms diagnosed by 3D-CTA and without preoperative DS angiography were submitted to microsurgical clipping and included in the study.  Results. The overall mortality was 15.9% and the favourable results evaluated 6 months after discharge by means of the Glasgow Outcome Scale reached 70.4%. All lesions were successfully clipped. Surgery was done a mean of 4.1 days after the admission bleeding. A total of four microlesions undiagnosed by 3D-CTA were found at surgery and clipped. Postoperative DS angiography and necropsy findings were also used as control of the 3D-CTA findings but no additional information was provided excepting the finding in DS angiography of an asymptomatic intracavernous aneurysm. Therefore the sensitivity of the 3D-CTA for diagnosis of symtomatic aneurysms was 100% and the overall sensitivity 90.4%.  Conclusions. We have reached similar results in patients operated on with or without preoperative angiography. 3D-CTA provides very valuable anatomical information, which has an additional value in the microsurgical treatment of aneurysms of the anterior communicating artery complex. Finally, selected cases of ruptured intracranial aneurysms can be successfully managed with the preoperative information provided by 3D-CTA and without DS angiography.     

Efficacy of Lumbo-Peritoneal Versus Ventriculo-Peritoneal Shunting for Management of Chronic Hydrocephalus Following Aneurysmal Subarachnoid Haemorrhage

Summary ? Background. The clinical usefulness of lumboperitoneal (LP) shunts in selecting patients with communicating hydrocephalus after aneurysmal subarachnoid haemorrhage (SAH) was compared with that of ventriculoperitoneal (VP) shunts.  Method. Chronic hydrocephalus was defined as clinically and radiographically demonstrated hydrocephalus which lasted 3 weeks or longer after the original haemorrhage and which required shunting. Indications for a CSF shunt were assessed on the basis of neurological symptoms and signs, CT findings, and isotope cisternogram findings. The patients were treated with either LP or VP shunts. A significant response to shunting was defined as an improvement of function to a higher grade. The functioning of the shunt was evaluated by the location of the catheter on x-ray studies, CT features, and isotope cisternograms. The operation groups were checked for comparability of demographic and clinical variables including age, Fisher grade, hypertension, vasospasm, shunt interval, preshunt functional grade, and CT findings. A comparative analysis of the outcome was carried out between the two operation groups.  Findings. Fifty-six patients underwent shunt placements (LP shunts: 22, VP shunts with medium pressure valve: 2, VP shunts with high pressure valve: 32). There was no statistically significant difference in patient demographics and clinical characteristics between the patients with LP shunts and those with VP shunts. A follow-up time of 3 months to 8 years revealed clinical improvement in 11 cases (50.0%) of patients with LP shunts and 31 cases (91.1%) in VP shunts was seen (Fisher's exact test, P<0.005).  Interpretation. These findings suggest that VP shunts are a better choice of treatment than LP shunts in treating chronic hydrocephalus after aneurysmal SAH.     

Surgical treatment of spinal dural arterio-venous fistulae: long-term results and analysis of prognostic factors

Summary   Background. Spinal dural arterio-venous fistulae (SDAVF) are slow-flow extramedullary vascular lesions which account for 75–80% of all spinal vascular malformations. At present there is no agreed view with regard to the best therapeutic option being surgical or endovascular, and several reports favour one or other form of management. This is so because of lack of consistent literature, as well as knowledge, concerning the long-term clinical outcome of the patients. The objective of this study is to retrospectively analyse the results obtained with patients operated for a SDAVF at the Department of Neurosurgery of Verona during a 15-year period and to evaluate possible prognostic factors related to neurological outcome. Patients and methods. Between January 1987 and May 2002, 29 patients with SDAVF were operated at the Department of Neurosurgery of Verona. For 25 of these patients we were able to obtain a clinical follow-up using telephone interviews. The patients were evaluated with the Aminoff and Logue’s scale and subsequently stratified into three classes of disability. An overall score (gait and micturition, G + M) of 0–3 indicates a mild disability, a score between 4 and 5 indicates a moderate disability and a score between 6 and 8 a severe disability. All patients underwent surgical treatment which was mainly the first therapeutic option. Following surgery, the patients were re-evaluated with the same neurological scale. We also investigated with statistical analysis the possible impact on clinical outcome of the major clinical, neuroradiological and surgical variables. Results. The epidemiological, clinical, radiological and pathological features of our group of patients are very similar to those previously described in the literature. For 10 patients surgery consisted simply of the interruption of the intradural arterialised draining vein (with or without closure of the small extradural arterial afferents), whereas in the remaining 15 patients coagulation or excision of the fistolous dura was also accomplished. At the last follow-up (mean 7.3 years; in 19 patients longer than 5 years), 10 patients had improved (40%), 11 were stable (44%) and 4 had deteriorated (16%). We determined that only the pre-operative neurological status, described by the G value in the Aminoff and Logue’s scale and the class of disability, had an impact on clinical outcome. Conclusions. This retrospective study confirms that the surgical treatment results of SDAVF are satisfactory even if evaluated after many years. Given these results, and in accordance with the majority of the literature, we concur that surgery should be the first choice treatment for these spinal vascular lesions in order to avoid a dangerous delay and consequently further neurological deterioration. In our group of patients the only prognostic factor statistically related to clinical outcome was the pre-treatment neurological status, particularly the grade of paraparesis and the class of disability. Correspondence: Dr. Paolo Cipriano Cecchi, Operative Unit of Neurosurgery, Regional General Hospital, Via Boehler 5, 39100 Bolzano, Italy.     

Risk Factors Predicting Recurrence in Patients Operated on for Intracranial Meningioma. A Multivariate Analysis

Summary  The authors undertook a follow-up study of 286 patients who underwent surgical treatment for intracranial meningioma between 1973 and 1994, in order to analyse clinical, radiological, topographic, histopathological and therapeutic factors significantly influencing tumour recurrence.  All patients were followed by using either computed tomography (CT) or magnetic resonance from 3 months to 17 years since first surgery (mean follow-up: 4.1 years). Forty-four (15.4%) recurrences were detected during this time period. Overall recurrence rates were 14%, 37% and 61% at 5, 10 and 15 years, respectively.  Factors significantly associated with tumour relapse in bivariate analysis were: tumour location at petroclival and parasagittal (middle third) regions, incomplete surgical resection (assessed by Simpson's classification), atypical and malignant histological types (WHO classification), presence of nucleolar prominence, presence of more than 2 mitosis per 10 high-power fields, and heterogeneous tumour contrast enhancement on the CT scan.  The multivariate analysis using the Cox's proportional hazards model identified the following risk factors for recurrence: incomplete surgical resection (Relative risk: 2.2; 95% Confidence interval: 1.33–3.64), non conventional histological type (RR: 2.13; 95%CI: 1–4.53), heterogeneous contrast enhancement on the CT scan (RR: 2.25; 95%CI: 1.1–4.72) and presence of more than 2 mitosis per 10 high-power fields (RR: 2.28; 95%CI: 0.99–5.27). Patients without any of these features showed low recurrence rates (4% and 18% at 5 and 10 years), and thus, they need less clinical and radiological controls through the follow-up than patients with some of these risk factors.     

MRI Findings and Clinical Manifestations in Rathke's Cleft Cyst

Summary  We retrospectively analysed patients with histologically proven Rathke's cleft cyst (RCC) in relation to the clinical manifestations and MRI findings, in particular, of cyst size and intensity in order to obtain an insight into their growing mechanisms, clinical presentations and their management.  Eleven patients with RCC were divided into two groups based on T1 weighted images(WI). The A group consisted of 4 patients with cyst of low intensity in T1 WI. The age averaged 64.5 years. Their initial complaints were visual field defects(VFD). Their complaints were rather insidious. The maximum cyst size averaged 27.8±2.4 mm. The B group consisted of 7 patients with cyst of iso- or high-intensity in T1 WI. Two patients in the B group showed mixture of low and high and iso- and high-intensity, suggesting the presence of bleeding at the onset of symptoms or growing mechanism of the cysts. In the B group the age averaged 39.9 years, being lower than that in the A group. (P=0.0140 with Mann-Whitney's U test) The 5 patients out of 7 showed headache of insidious type or acute onset and the 3 showed a fluctuation of the VFD. The average size was 21.7±3.5 mm and smaller than that of the A group. (P=0.0298 with Mann-Whitney's U test)  Our study has shown that the cyst with iso-to high intensity on T1 WI may cause clinical symptoms with a smaller size than cysts of the low intensity. In the former cyst pattern the onset and growing mechanism may be related to bleeding. The patients with this pattern are more likely to have acute and/or fluctuation of clinical presentations. Knowing these various clinical manifestations based on MRI pattern will be of help in following and managing patients with RCC.     

Small Acoustic Neuromas: Monitoring the Growth Rate by MRI

Summary  In a proportion of small acoustic neuroma patients, monitoring with magnetic resonance imaging shows no volumetric increase of tumour size over the years. The object of the study was to identify some indications for the clinical choice between immediate surgery (with the related risks) and watchful waiting.  We performed a retrospective study of 47 non-surgically-treated patients affected by acoustic neuroma and monitored by gadolinium-enhanced MRI between January 1990 and February 1999. Six clinical variables (tumour size, sex, age, initial symptoms, ABR pattern and duration of the symptoms) were examined by univariate analysis. Chi-square test and variance analysis were performed to evaluate the statistical significance.  In 30/47 (63.8%) cases, no growth was observed during the entire period of follow-up. In the remaining 17/47 (36.2%) patients, a volumetric increase was detected, most often within the first year of observation. The clinical factors examined did not significantly correlate with growth.  Despite the relatively short period of observation, we believe that immediate surgery does not need to be considered mandatory for small acoustic neuromas, even in young patients. However the irregular behaviour of the tumour underlines the importance of monitoring with MRI at least once a year.     

Gamma Knife Radiosurgery for Glomus Jugulare Tumours

Summary  The aim of this clinical study was to determine the tumour control rate, clinical outcome and complication rate following gamma knife treatment for glomus jugulare tumours. Between May 1992 and May 1998, 13 patients with glomus tumours underwent stereotactic radiosurgical treatment in our department. The age of these patients ranged from 21 to 80 years. The male : female ratio was 2 : 11. Six patients had primary open surgery for partial removal or recurrent growth and subsequent radiosurgical therapy. Radiosurgery was performed as primary treatment in 7 cases. The median tumour volume was 6,4 cm³ (range: 4,6–13,7 cm³). The median marginal dose applied to an average isodose volume of 50% (30–50%) was 13,5 Gy (12–20 Gy). In 10 patients, a total of 48 MRI and CT follow-up scans were available. The remaining three patients have been excluded from the postradiosurgical evaluation since the observation time (t<12 months) was too short or patients were lost to follow up. The median interval from Gamma Knife treatment to the last radiological follow-up was 37,6 months (5–68 months). In 4 patients (40%) decreased tumour volumes were observed and in 6 cases (60%) the tumour size remained unchanged. Neurological follow-up examinations revealed improved clinical status in 5 patients (50%), a stable neurological status in 5 patients (50%) and no complications occurred. According to our preliminary experience Gamma Knife radiosurgery represents an effective treatment option for glomus jugulare tumours.