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

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 arterialized draining vein (with or without closure of the small extradural arterial afferents), whereas in the remaining 15 patients coagulation or excision of the fistulous 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.

Monitoring of motor pathways during brain stem surgery: what we have achieved and what we still miss?

Intraoperative neurophysiological monitoring (IOM) has established itself as one of the paths by which modern neurosurgery can improve surgical results while minimizing morbidity. IOM consists of both monitoring (continuous "on-line" assessment of the functional integrity of neural pathways) and mapping (functional identification and preservation of anatomically ambiguous nervous tissue) techniques. In posterior-fossa and brainstem surgery, mapping techniques can be used to identify - and therefore preserve - cranial nerves, their motor nuclei and corticospinal or corticobulbar pathways. Similarly, free-running electromyography (EMG) and muscle motor-evoked potential (mMEP) monitoring can continuously assess the functional integrity of these pathways during surgery. Mapping of the corticospinal tract, at the level of the cerebral peduncle as well as mapping of the VII, IX-X and XII cranial nerve motor nuclei on the floor of the fourth ventricle, is of great value to identify "safe entry-zones" into the brainstem. Mapping techniques allow recognizing anatomical landmarks such as the facial colliculus, the hypoglosseal and glossopharyngeal triangles on the floor of the fourth ventricle, even when normal anatomy is distorted by a tumor. On the basis of neurophysiological mapping, specific patterns of motor cranial nuclei displacement can be recognized. However, brainstem mapping cannot detect injury to the supranuclear tracts originating in the motor cortex and ending on the cranial nerve motor nuclei. Therefore, monitoring techniques should be used. Standard techniques for continuously assessing the functional integrity of motor cranial nerves traditionally rely on the evaluation of spontaneous free-running EMG in muscles innervated by motor cranial nerves. Although several criteria have been proposed to identify those EMG activity patterns that are suspicious for nerve injury, the terminology remains somewhat confusing and convincing data regarding a clinical correlation between EMG activity and clinical outcome are still lacking. Transcranial mMEPs are also currently used during posterior-fossa surgery and principles of MEP monitoring to assess the functional integrity of motor pathways are similar to those used in brain and spinal-cord surgery. Recently, current concepts in muscle MEP monitoring have been extended to the monitoring of motor cranial nerves. So-called "corticobulbar mMEPs" can be used to monitor the functional integrity of corticobulbar tracts from the cortex through the cranial motor nuclei and to the muscle innervated by cranial nerves. Methodology for this purpose has appeared in the literature only recently and mostly with regards to the VII cranial nerve monitoring. Nevertheless, this technique has not yet been standardized and some limitations still exist. In particular, with regards to the preservation of the swallowing and coughing reflexes, available intraoperative techniques are insufficient to provide reliable prognostic data since only the efferent arc of the reflex can be tested.

Haemorrhagic stroke and vasculitic-like cerebral angiography in a patient with eosinophilic fasciitis. Case report.

Cerebral vasculitis is an uncommon cause of haemorrhagic stroke. A case of intracerebral haemorrhage in a patient with eosinophilic fasciitis, a rare scleroderma-like connective tissue disease, with a possible inflammatory involvement of cerebral vessels is reported. Pathogenetic mechanism of such association and diagnostic controversies are reviewed.

Role of glycemia in acute spinal cord injury. Data from a rat experimental model and clinical experience.

While experimental and clinical evidence indicates that in brain injury blood glucose increases with injury severity and hyperglycemia worsens neurological outcome, the role of blood glucose in secondary mechanisms of neuronal damage after acute spinal cord injury has not yet been investigated. Data from spinal cord ischemia models suggests a deleterious effect of hyperglycemia, likely due to enhanced lactic acidosis, which is primarily dependent on the amount of glucose available to be metabolized. The purpose of this study is to summarize preliminary experimental and clinical observations on the role of blood glucose in acute spinal cord injury. Between 1995 and 1996 we used the New York University (NYU) rat spinal cord injury model to test the following hypotheses: 1) Blood glucose levels increase with injury severity. 2) Fasting protects from hyperglycemia and prevents secondary damage to the spinal cord. 3) Postinjury-induced hyperglycemia (dextrose 5% 2 gm/Kg) enhances spinal lesion volume. From a clinical perspective, we reviewed blood glucose records of 47 patients admitted to the Department of Neurosrgery in Verona, between 1991 and 1995, within 24 hours of acute spinal cord injury in order to determine: a) the incidence of hyperglycemia (> 140 mg/dl); b) the correlation between blood glucose and injury severity; and c) the role of methylprednisolone in affecting blood glucose. Results indicate that in a graded spinal cord injury model: 1) Early after injury, more severe contusions support significantly higher blood glucose levels. 2) Fasting overnight does not directly affect spinal cord lesion volume but influences blood gases, and we observed that a slightly systemic acidosis plays a minor neuroprotective role. Fasting also ensures more consistent normoglycemic baseline blood glucose values. 3) Postinjury-induced moderate hyperglycemia (160-190 mg/dl) does not significantly affect spinal cord injury. In the clinical study, we observed that during the first 24 hours after spinal cord injury: a) Glycemia ranges between 90 and 243 mg/dl (mean value 143 mg/dl), and close to 50% of the patients present blood glucose values higher than normal. b) Methylprednisolone administration is not associated to significantly higher blood glucose levels. c) There is a trend for larger glucose rises with more severe injury.

Lumbar epidural Ewing sarcoma. Light and electron microscopic investigation.

The clinicopathological findings in a child with extraskeletal Ewing sarcoma are described. The patient complained of pain in the lower back and difficulty walking. An extraskeletal, epidural, friable tumor, 2-3 cm long was removed from the epidural space. It had no relationship with the bone structures. Light and electron microscopic examination of the tumor led to the diagnosis of Ewing sarcoma. The morphological aspects of this neoplasia and the problem of the differential diagnosis with other small cell tumors of the epidural space are discussed.

Extradural hematoma: toward zero mortality. A prospective study.

This is a prospective analysis of 107 consecutive cases of extradural hematoma treated during the last 3 years at the Department of Neurosurgery of the University Hospital of Verona (Italy). The overall mortality was 5%; 89% of the patients made a good recovery or had only moderate residual disability. We regard this as meaningful progress compared to recent reports from other sources showing mortality rates of approximately 20%. The majority of our patients (57%) underwent operation within 6 hours of injury; 60% went into surgery with a Glasgow coma scale (GCS) score between 8 and 15. No deaths occurred among patients reaching surgery with a GCS score of 8 or better; all patients with scores of 8 to 15 made a good recovery (63 cases). Seventeen patients went into surgery while still free of neurological signs, and 8 had only one dilated pupil; all 25 made good recoveries. A flexion posture at admission cuts the chances of a good outcome by one-half; an extension posture cuts the chances to one-fourth. Ninety-five per cent of the patients had fractures of the skull; only 21% had the classical lucid interval. The cause of all 5 deaths was identified as stemming from avoidable errors in management in outlying hospitals (2 cases) or in our own department (3 cases). The results of this study indicate that zero mortality from extradural hematoma is a realistic goal for a modern, well-run care system for head-injured patients that includes prompt referral by community doctors and suitable hospital facilities for constant access to emergency neurosurgery.

The pterional approach for the microsurgical removal of olfactory groove meningiomas.

OBJECTIVE: Currently, the surgical approach to olfactory meningiomas can vary depending on the size and expansion of the tumor, although surgical treatment still relies on the anterior bilateral craniotomy. Since 1989, we have use the pterional approach as a standard procedure in the treatment of 37 consecutive cases. We present our results in an attempt to contribute an alternative and valid surgical strategy for the treatment of these tumors. METHODS: Between 1989 and 1996, a series of 37 consecutive patients underwent microsurgical tumor resection using the unilateral pterional approach; all patients except one underwent operations on the right side. In 23 patients (62%), the tumor diameter measured approximately 6 cm, and the size was less than 4 cm in only 5 patients. The clinical presentation included mental dysfunction in 27 patients and visual impairment in 16 patients. The advantages of this approach are the early recognition of the posterior cerebrovascular complex, followed by a safe, rapid, and complete devascularization of the tumor and later by a favorable dissection of the capsular area from the frontal vascular branches and parenchyma. RESULTS: Total removal was achieved in all cases. There was one death unrelated to surgery. All patients presenting with mental dysfunction or with preoperative visual deficits recovered or improved. Postoperative magnetic resonance imaging confirmed complete tumor removal and demonstrated the brain parenchyma to be preserved and intact, primarily on the side opposite from the craniotomy. CONCLUSION: Our experience with the pterional approach suggests a greater role for this procedure in the treatment of olfactory groove meningiomas.

Microsurgical removal of petroclival meningiomas: a report of 33 patients.

This is a report of 33 consecutive cases of petroclival meningioma treated surgically at our institution over the last 10 years; there were 21 women and 12 men between the ages of 27 and 68 (mean age, 52). All patients were assessed by computed tomographic scans including coronal sections and bone algorithm studies; in most cases, digital subtraction angiography and magnetic resonance imaging were also done. The largest tumor diameter was between 2 and 3.5 cm in 14 cases, 3.5 to 6 cm in 15 cases, and over 6 cm in 4 cases. Dural attachment predominantly involved the clivus and apical petrous bone on one side only; in 14 cases, however, the tumor grew over the clivus midline or crossed the tentorial notch. Cranial nerve deficit was extant in all cases and was commensurate with tumor size. Cerebellar signs and somatic motor deficits were present in 60 and 30% of cases, respectively. The surgical approaches used were the retromastoid-retrosigmoid in 23 cases, subtemporal in 5 cases, and combined retromastoid subtemporal presigmoid in the remaining 5. Total removal was achieved in 26 cases (79%); incomplete removal occurred in 7 cases (21%). The extent of tumor removal and operative morbidity were not significantly related to tumor size. Brain stem indentation, arterial and cranial nerve encasement, and epidural invasion were the main factors that prevented total tumor removal and influenced operative morbidity. There was no intraoperative mortality, but three patients (9%) died perioperatively. In the postoperative period, most patients went through momentary neurological deterioration, chiefly due to new cranial nerve deficits. The average follow-up was 4.3 years in 27 patients; of these 17 were unchanged and 10 were improved. Before surgery, only 13 patients were self-sufficient; at long-term follow-up, another 6 had achieved independence. Our experience suggests that, even though real petroclival meningiomas still represent a formidable surgical challenge, such tumors can in most cases be removed completely with low attendant mortality and acceptable morbidity.

Assessment and surgical management of posterior fossa epidermoid tumors: report of 28 cases.

OBJECTIVE: The management of a series of 28 patients operated on for posterior fossa epidermoids is reviewed, emphasizing the need for long-term follow-up. We discuss the rationale for a comprehensive classification system that may allow the comparison of results from homogeneous series. METHODS: We grouped the tumors to differentiate the surgical management according to various tumor sites and the degree of extension. Twenty patients harbored tumors located in the cerebellopontine angle, five patients harbored tumors in the fourth ventricle, and three patients harbored tumors in the posterior fossa basal. In 17 patients, extensions of tumors outside the posterior fossa included the following regions: the suprasellar/ chiasmatic (n = 5), the parasellar/temporobasal (n = 5), and the mesencephalic/pineal (n = 7). Tumor extension was also defined by the number of regions involved. Pre- and postoperative magnetic resonance imaging and computed tomographic findings collected in 17 and 28 patients, respectively, were carefully evaluated. RESULTS: Clinical features and surgical approaches varied according to location and growth pattern. Fifty-seven percent of the tumors were completely removed. A higher total removal rate was achieved in patients with tumors confined to the primary location. One patient (3%) died in the perioperative period. Approximately half of the patients presented with transient mild focal deficit impairments resulting from the manipulation of the nervous structure over a wide area. There was a higher rate of surgical complications with fourth ventricle and mesencephalic extended cerebellopontine angle tumors. The mean follow-up period was 8.6 years. Thirty percent of the patients with subtotal removal experienced symptomatic recurrences after 8.1 years, whereas all patients with total removal were still asymptomatic. The recurrence-free survival rate was 95% at 13 years for patients with total removal compared with 65% for patients with subtotal removal. Problems of identification of tumor regrowth are discussed. CONCLUSION: By assessing posterior fossa epidermoids, we determined that location and extension play a major role in the prognosis. Our data suggest that more aggressive surgery is called for at first operation, and that a second operation should be planned when regrowth becomes symptomatic and/or tends to extend outside its original site.

Prolonged posttraumatic unconsciousness: therapeutic assets and liabilities.

Prolonged coma following severe head injury is a serious condition because it implies a poor prognosis. In order to assess the magnitude of this phenomenon, the authors have reviewed 135 cases of posttraumatic unconsciousness lasting more than 2 weeks, from among the entire propulation of patients with severe head injury managed in 10 years in their neurosurgical intensive care unit. The incidence of prolonged coma was 4% of all patients with acute traumatic coma, and 0.6% of all hospitalized patients with head injury. By 1 year after trauma, 30% of the patients had died, 8% survived in a vegetative state, 31% survived with severe disabilities, and 31% had made a satisfactory recovery. The early clinical picture of prolonged unconsciousness has no predictive value as to further evolution. Patients emerge from unconsciousness in consecutive steps representing the restoration of increasingly complex neurological functions; the timing of these steps is very variable and sometimes covers several months. The time distribution of recovery steps in individual cases is of limited predictive value as to outcome. The most frequent state during the recovery process is the condition of wakefulness without awareness, which should not be pronounced "permanent" earlier than 1 year after injury.

Barbiturate effects on acute experimental intracranial hypertension.

Acute intracranial hypertension was induced in cats by progressive inflation of an epidural balloon. Changes in intracranial pressure (ICP), mean arterial pressure (MAP), cerebral perfusion pressure (CPP), heart rate (HR), electroencephalogram (EEG), and pupil size were studied in untreated animals and in animals that had received barbiturates at different stages during the experiment. In animals pretreated with barbiturates, the increase in ICP during balloon expansion was significantly less than in untreated animals (p less than 0.001). The CPP, initially higher in untreated animals, was not significantly different (P less than 0.05) as the mass lesion pressure-volume curve exceeded the inflection point. In the postdeflation period, the untreated animals developed a significant increase in ICP, whereas, in the barbiturate-pretreated group, the ICP returned to preinflation values, suggesting a protective effect of barbiturates against postcompression brain swelling. Barbiturates affected ICP and CPP differently in animals with intracranial hypertension due to the presence of an epidural balloon that was maintained inflated compared to those with postdeflation brain swelling. In the latter group, pentobarbital reduced ICP (p less than 0.05) without significantly decreasing the CPP, whereas, in the mass lesion group, barbiturates failed to reduce the ICP and caused a deterioration in CPP (p less than 0.025). Brain gross pathological changes were significantly less in the pretreated animals as compared with all other groups. The results suggest that if barbiturate treatment is to have therapeutic value, the timing of the therapy and the criteria for its initiation should be determined.

Decerebrate rigidity in acute head injury.

A comprehensive study of the motor patterns, usually grouped under the heading "decerebrate rigidity," was carried out in a series of 800 patients with severe head injuries. The incidence of these manifestations was 39.6%, and when they were present chances of survival were reduced from 79.4% to 28.1%. Clinical and electromyographic investigations revealed heterogeneous and unstable motor manifestations that did not fit into the classical groups of experimental models of decerebrate rigidity. Combinations of extensor and flexor attitudes and/or responses were frequently found in same patient, but could be separated into homogeneous groups. Each recognized postural pattern had its own distinct neurological signs and prognosis. Age did not significantly affect the outcome, however, intracranial exapnding lesions (73.5%), impairment of the brain-stem oculomotor system (49.8%), and deep coma (88.9%) all contributed to an unfavorable course. Surgical treatment was effective when performed for intracranial hematomas and in patients with incomplete extensor rigidity. Good recovery was achieved in 16% of decerebrate patients, while 12.1% survived in prolonged coma or with severe disabilities. All clinical and neuropathological data suggest that extensor motor abnormalities in the acute phase of cerebral traumatic disease do not always conclusively indicate structural brain-stem damage. A critical analysis of so-called "decerebrate rigidity" (rejecting in some instances its Sherringtonian implications) may allow for a more accurate clinical assessment of the severity of head injury.

A multicenter trial on the efficacy of using tirilazad mesylate in cases of head injury.

OBJECT: The authors prospectively studied the efficacy of tirilazad mesylate, a novel aminosteroid, in humans with head injuries. METHODS: A cohort of 1120 head-injured patients received at least one dose of study medication (tirilazad or placebo). Eighty-five percent (957) of the patients had suffered a severe head injury (Glasgow Coma Scale [GCS] score 4-8) and 15% (163) had sustained a moderate head injury (GCS score 9-12). Six-month outcomes for the tirilazad- and placebo-treated groups for the Glasgow Outcome Scale categories of both good recovery and death showed no significant difference (good recovery in the tirilazad-treated group was 39% compared with the placebo group in which it was 42% [p=0.461]; death in the tirilazad-treated group occurred in 26% of patients compared with the placebo group, in which it occurred in 25% [p=0.750]). Subgroup analysis suggested that tirilazad mesylate may be effective in reducing mortality rates in males suffering from severe head injury with accompanying traumatic subarachnoid hemorrhage (death in the tirilazad-treated group occurred in 34% of patients; in the placebo group it occurred in 43% [p=0.026]). No significant differences in frequency or types of serious adverse events were shown between the treatment and placebo groups. CONCLUSIONS: Striking problems with imbalance concerning basic prognostic variables were observed in spite of the large population studied. These imbalances concerned pretreatment hypotension, pretreatment hypoxia, and the incidence of epidural hematomas. In future trials of pharmacological therapy for severe head injury, serious consideration must be given to alternative randomization strategies. Given the heterogeneous nature of head injury and the identification of populations that do relatively well with standard therapy, target populations with a higher risk for mortality and morbidity may be more suitable for clinical trials of such agents.

CNS trauma: head injuries.

Head injuries are a common cause of death and permanent disability, particularly in the first decades of life. The high mortality and morbidity associated with head trauma is due mostly to the severity of the injury itself but also in part to the possible events that could aggravate the primary brain damage. This also occurs in patients with an initially mild head trauma. This article reviews imaging procedures, complications of head trauma, and the order of diagnostic evaluation.

One-stage decompression and stabilization in the treatment of spinal tumors.

Nowadays, extradural vertebral neoplasms which compress the spinal cord are being diagnosed earlier and therefore laminectomy for decompression relieves many patients of their neurological deficits before permanent cord damage has set in. In addition, radiotherapy and oncological treatment have prolonged life expectancy as well as the quality of life in these patients. As the indications for surgery have grown, the problem of spinal instability resulting from direct involvement of the supporting structures of the spine or due to the surgical procedure per se, must be considered. Many of these patients would rapidly return to leading their normal activities if not confined to bed rest or uncomfortable orthopedic devices. The Authors present 9 patients with extradural vertebral lesions: 4 plasmacytomas, 3 metastatic carcinomas, 1 malignant lymphoma and 1 aggressive osteoblastoma treated by simultaneous decompression and stabilization of the spine. All patients showed remarkable improvement of neurological symptoms except in one case where massive pulmonary embolism caused death a few hours after surgery. This surgical treatment offers the advantages of performing wider and better decompressive maneuvers and, at the same time, assuring fast mobilization of the patient after surgery who is often in poor general conditions, thus reducing post-operative complications due to delayed physical therapy and bed confinement.

Persistent hiccup as presenting symptom in medulla oblongata cavernoma: a case report and review of the literature.

A rare case of persistent intractable hiccup as presenting symptom of cavernous angioma in the medulla oblongata is reported. Pathophysiologic hypotheses about the triggering mechanism of hiccup are discussed, with special reference to the causes affecting the central nervous system. A review of the literature concerning medullary lesions presenting with persistent hiccup is also reported. Finally we have included some brief considerations about cavernous angiomas and the patterns of their clinical presentation, focusing on those located in the medulla oblongata.

The influence of the administration of pyritinol on the clinical course of traumatic coma.

(1) In a total of 100 patients with traumatic coma who were admitted to the intensive care unit of our Department of Neurosurgery we examined the effect of Encephabol after intravenous administration. (2) Compared to patients with the same clinico-neurological conditions who were, however, not treated with Encephabol, the cases treated by the preparation did not show any significant clinical improvement. Moreover, in the Encephabol group mortality rate in patients with an unfavourable prognosis sank to 35.3% (mortality rate in the comparative group: 54.2%). (3) Untoward effects on the clinico-neurological condition, cortical electrogenesis, vegetative functions and body fluid parameters were not observed after administration of the preparation.

Endosellar meningiomas: report of 2 cases and review of the literature.

Two cases of endosellar meningiomas are presented. The clinical and radiological picture is not always sufficiently specific to distinguish meningiomas from other types of sellar lesions, but pre-operative diagnosis is of fundamental importance in choosing the best surgical approach. In both cases, the transsphenoidal approach was used, and due to the dense consistency of the tumors, only biopsies were performed. One of the two patients was reoperated on using the sub-frontal approach for radical removal of the tumor. In the authors' experience, craniotomy proved to be the more favorable approach than the transsphenoidal route for radical excision of endosellar meningiomas. Literature on the classification of sellar meningiomas for radiological diagnosis and surgical strategy of endosellar meningiomas is reviewed.

Cavernous malformation of the internal auditory canal. A case report.

A 51 year-old male, complaining of progressive left-sided hearing loss, tinnitus, and unsteady gait, underwent surgery with a probable diagnosis of intracanalicular acoustic neuroma, based on neurological, neurotologic, Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) findings. During surgery, the Internal Auditory Canal (IAC) was opened and a reddish-colored, soft, vascular lesion was found within the VII and VIII cranial nerve complex. The lesion, which resulted to be a cavernous malformation, was removed without any postoperative deficits. This report stresses the diagnostic difficulty to differentiate preoperatively the more frequent acoustic neuromas from other lesions that may develop within the IAC.

Intradiploic meningioma of the skull. Case report and review of literature.

A case of a patient with an accidentally discovered scalp mass is presented. Radiological investigation documented an osteolytic intradiploic lesion of the cranial vault. The lesion was surgically removed and histological examination revealed a meningioma. The literature concerning these uncommon tumours of the skull is reviewed, and the differential diagnosis is discussed.