Postoperative management of incidental durotomy in minimally invasive lumbar spinal surgery.

Unintended durotomy is a relatively common complication in spine surgery, with a reported incidence up to 14%. Traditional management has been mandatory bed rest for at least 48 h following repair, with or without placement of a drain. With the muscle-splitting approach and decreased potential (dead) space created during minimally invasive spinal surgery (MISS), there is less potential likelihood of symptoms such as spinal headaches or cerebrospinal fluid fistulas. We reviewed the cases of 5 patients undergoing lumbar MISS complicated by an incidental dural tear. Surgical treatment consisted of primary repair and/or use of DuraGen followed by application of either DuraSeal or Tisseel. Although the duration of bed rest varied, postoperative management involved early mobilization less than 48 h after surgery without the use of a drain. One patient was mobilized early on the second postoperative day, 2 patients were mobilized the morning after surgery, and 2 patients were mobilized immediately upon recovery from anesthesia. None of the patients developed symptoms related to durotomy. Although this represents a small series, early postoperative mobilization appears to be a reasonable option and results in shorter hospitalization.

Treatment of hydromyelia in spina bifida.

BACKGROUND: Cavitation of the spinal cord (hydrosyringomyelia) seems to be common in spina bifida patients, although the overall clinical and radiological incidence has very rarely been analyzed. The real incidence of the condition is, in fact, difficult to assess as patients with this complication may remain relatively asymptomatic. The mechanisms accounting for the occurrence of hydrosyringomyelia in myelodysplasia are still a subject of debate. Similarly, the indications for the surgical treatment are still to be defined and its results to be assessed. METHODS: In this study, 142 patients with spina bifida were screened with magnetic resonance imaging (MRI) to determine the incidence of hydromyelia. Thirty-two patients presented a cavitating lesion on MRIs of which 18 were not a cause of symptoms and 14 were. Clinical characteristics of the lesions and their correlation to the radiological picture were analyzed. All the symptomatic children underwent surgical treatment. Outcomes were evaluated and correlated also with the MRI findings. RESULTS: A correlation between the presence of symptomatology and the extension and/or dilation of the hydromyelia was observed. A significant relationship between the presence of symptoms and adequate control of associated hydrocephalus was also noted. No correlation was observed between the presence of hydromyelia and the level of the myelomeningocele or the degree of ventricular dilation in those cases that presented with hydrocephalus. The mean age at hydromyelia diagnosis for all patients affected was 3.9 years and, in particular, 4 years for those patients who presented with symptoms. A total of 15 operations were performed in the 14 symptomatic patients. Seven direct procedures were carried out to drain the hydromyelia: five hydroperitoneal shunt insertions and two hydrosubarachnoid shunting procedures. Eight indirect treatments were performed to eliminate the filling mechanism of the hydromyelia: five posterior fossa decompressions, two ventriculoperitoneal shunt revisions, and one spinal cord untethering procedure with terminal syringostomy. All patients improved postoperatively, except one who remained clinically stable at follow-up. This patient had undergone a posterior fossa decompression followed by a hydrosubarachnoid shunting procedure. CONCLUSIONS: The incidence of syringohydromyelia is actually higher than that reported in the literature, although not all lesions are symptomatic. The radiological picture may be helpful in planning a more careful follow-up program for patients theoretically at risk for neurologic deterioration. Surgical treatment is possible with good results in the majority of cases and should be carried out as soon as possible before further deterioration occurs. Not all symptoms respond equally to treatment. Generally, improvement of clinical status correlates with a reduction in size of the hydromyelic cavity on MRI.

The tethered spinal cord: diagnosis, significance, and management.

Tethered cord is the result of fixation of the spinal cord, which limits motion in the caudal-rostral direction. Most children either have cutaneous markers or a predisposing condition. Prophylactic release of the spinal cord can prevent the long-term disabilities associated with this condition. Although delayed release, following the onset of a neurological deficit, may reverse some lost function, it is unlikely to restore bladder and bowel function.

Motonuclear changes after cranial nerve injury and regeneration.

Little is known about the mechanisms at play in nerve regeneration after nerve injury. Personal studies are reported regarding motonuclear changes after regeneration of injured cranial nerves, in particular of the facial and oculomotor nerves, as well as the influence that the natural molecule acetyl-L-carnitine (ALC) has on post-axotomy cranial nerve motoneuron degeneration after facial and vagus nerve lesions. Adult and newborn animal models were used. Massive motoneuron response after nerve section and reconstruction was observed in the motonuclei of all nerves studied. ALC showed to have significant neuroprotective effects on the degeneration of axotomized motoneurons. Complex quantitative, morphological and somatotopic nuclear changes occurred that sustain new hypotheses regarding the capacities of motoneurons to regenerate and the possibilities of new neuron proliferation. The particularities of such observations are described and discussed.

Presentation and management of hydromyelia in children with Chiari type-II malformation.

Hydromyelia in patients with myelomeningocele and Chiari-II malformation is a relatively frequent finding on MRI studies. However, not all children develop symptoms from the hydromyelia that requires treatment. Furthermore, treatment of hydromyelia in spina bifida patients is rather complex due to the associated malformations. The authors retrospectively analyzed 231 MRI studies carried out on spina bifida patients who presented neurological deterioration. Hydromyelia was found in 48.5% of the patients. Forty-five children with severe hydromyelia required treatment. These patients were first divided into 2 groups: those with holocord hydromyelia, and those with a segmental lesion. Fifteen patients presented symptoms characteristic of symptomatic Chiari-II malformation: neck rigidity; swallowing difficulty; pain in the upper extremeties; weakness or spasticity in the upper extremeties. Eighteen patients presented symptoms typical of the tethered cord syndrome: scoliosis; worsening bladder and/or bowel function; pain in the lower extremeties; weakness or spasticity in the lower extremeties. Twelve patients presented a mixed-type symptomatology. These patients subsequently underwent posterior cervical decompression, tethered cord release or insertion of a hydromyelia-pleural shunt according to the type of presenting symptoms and to the extent of the hydromyelic lesion. A pattern of successful treatment was identified for each type of presenting clinical and radiological picture. This has allowed the authors to determine an algorithm for optimal treatment of hydromyelia associated with Chiari-II malformation and myelomeningocele, which is proposed here.

Importance of patient evaluation for long-term survival in medulloblastoma recurrence.

Recurrence is a major cause of death in patients with medulloblastoma. Although the exact protocol for regular radiographic evaluation is sometimes a matter of debate, continuous follow up is necessary. We report a case of long-term survival after surgical removal of a subfrontal recurrent medulloblastoma, which occurred more than 3 years after total gross excision of the primary lesion and radiation therapy. The asymptomatic recurrence, which was detected by routine follow-up neuroimaging tests, was excised. The patient subsequently received gamma knife irradiation of the tumor bed followed by a course of "8 in 1" chemotherapy. "Early delayed radionecrosis" occurred 13 months after gamma knife treatment, which resolved spontaneously. Particularities of the case are discussed with reference to the location of the recurrent tumor, the possible pathogenetic causes and the side effects of treatment. We believe that this case and others reported in the literature underline the importance of continuous MRI surveillance of patients operated on for medulloblastoma.

Spinal lipomas in children: outcome of 270 procedures.

Spinal lipomas are a common cause of spinal cord tethering. Recently, prophylactic surgical removal of spinal lipomas has been questioned, especially of the conus medullaris. Unfortunately, few statistically significant series have been reported. A total of 213 children with spinal lipomas were operated on at the Children's Memorial Hospital in Chicago, Ill., USA, on whom 270 procedures were carried out between 1975 and 1995. The status of these children was retrospectively reviewed to determine the differences in outcome between patients prophylactically operated on before the onset of symptoms and those operated on after the onset of symptoms. Fifty-five patients presented with a lipoma of the filum terminale and 158 with a lipoma of the conus medullaris. In the filum terminale group, 28 were asymptomatic at the initial operation, and 27 presented with symptoms. Of the asymptomatic children with filum terminale lipomas, none worsened after surgery, and all remained asymptomatic throughout follow-up (mean follow-up: 3.4 years). Benefits were also observed for the symptomatic patients in this group as no cases of further deterioration were noted, and 5 patients returned to normal clinical status. In the conus group, 71 patients were asymptomatic at initial surgery, and 87 presented with symptoms. In the case of conus medullaris lipomas, 9 of the 71 children who were operated on prophylactically, later deteriorated (mean follow-up: 6.2 years) and required a second untethering operation which resolved all symptoms in 4 cases. Thus, 5 of 71 deteriorated, while 66 remained normal (93%) throughout the period of follow-up. On the other hand, of the 87 patients operated on after the onset of symptoms, 36 (41%) deteriorated further and required subsequent reoperations. In these 87 children, the final outcome at the end of follow-up (mean follow-up: 6.6 years) showed that 20 (23%) patients had deteriorated compared to initial presentation and 44 (51%) remained at initial clinical baseline, while 23 (26%) improved or returned to normal clinical status. Prophylactic surgery in the case of the asymptomatic infant with a spinal lipoma showed a clear benefit. Good outcome was also observed when surgery was carried out after the onset of symptoms. Prophylactic surgery also had a better general outcome by actuarial calculations when only patients with a follow-up of more than 5 years were considered. Deterioration occurred in 5 (16.7%) of the 30 children with a follow-up of more than 5 years, while 25 (83.3%) remained normal. Furthermore, in cases which had prophylactic surgery, there was not only a smaller incidence of deterioration requiring a reoperation, but this group of patients also experienced a longer time interval between initial surgery and the need for reoperation compared to the patients operated on after the onset of symptoms. The authors conclude that spinal lipomas should be operated on as soon as possible on a prophylactic basis, and careful and constant follow-up should be carried out to permit prompt reintervention in cases with deterioration.

Shunt complications in the first postoperative year in children with meningomyelocele.

The authors analyze the incidence of early mechanical and infective CSF shunt complications and various factors that might be correlated with the incidence in a series of 170 children affected by hydrocephalus and meningomyelocele (MM), with the aim of the finding to this specific risk factors related to this particular type of hydrocephalus. Factors investigated for correlation with CSF shunt malfunction are the following: level of spinal malformation, age of the patient at MM repair, age at diagnosis of hydrocephalus, degree of ventricular dilatation, age at shunt implantation, modality of the surgical procedure, characteristics of CSF at operation. In the first postoperative year following CSF shunting, 45.9% of the patients presented one shunt malfunction, three-quarters of which were due to mechanical causes, and one quarter to infection. Age of the patient at diagnosis of hydrocephalus and at CSF shunt operation did not significantly influence shunt patency, nor did the surgical modality (programmed vs emergency procedure). On the other hand, MM level did influence the outcome of CSF shunting: a higher percentage of malfunctions (and in particular of infective complications) was observed among the patients with "high level" MMs than in the group with more caudal location of the spinal defect. Similarly, the degree of ventricular dilatation correlated with the incidence of complications (more severe ventricular dilatation was associated with the highest incidence of complications). The order in which MM repair and CSF shunting were carried out and the age of the patients at MM repair did not affect the occurrence of mechanical complications, whereas they had a significant effect on the incidence of infective complications. In fact, the rate of overall complications, and of infective complications in particular, was proportional the age at MM repair. Furthermore, the group of children who underwent to MM repair and CSF shunting simultaneously scored the lowest percentage of complications, although these were mainly infections; the highest incidence of complications (and in particular of infective ones) was observed in the children who underwent CSF shunting first. The most striking correlation, however, was found with the characteristics of CSF. While normal CSF values correlated with an overall incidence of complications of 39.2%, abnormal CSF values were correlated with a rate of complications of 90.9%; in particular, the rates of infective complications were 2.7% and 77.3%, respectively. On the grounds of these observations a protocol is proposed of temporary CSF external drainage in children requiring prompt relief of increased intracranial pressure but at risk for the presence of a leaking spinal defect or of a MM left unrepaired for more than 48 h.

Superior cervical ganglion regenerating axons through peripheral nerve grafts and reversal of behavioral deficits in hemiparkinsonian rats.

The superior cervical ganglion (SCG) has been grafted to the brain of adult rats in an attempt to reverse the parkinsonian syndrome that follows destruction of central dopamine systems. However, the main limitation to this approach is the massive cell death that occurs in the grafted SCG after direct transplantation into the brain. In adult rats, 6-hydroxydopamine (6-OHDA) was stereotactically injected into the right substantia nigra (SN). One month later, dopamine denervation was assessed using the apomorphine-induced rotational test. In rats with a positive test, an autologous peripheral nerve (PN) graft was tunneled from the right cervical region to the ipsilateral parietal cortex. One end of PN graft was sutured to the transected postganglionic branch of the SCG and the other end was inserted into a surgically created cortical cavity. The apomorphine test was repeated at 3 days and again at 1, 3, and 5 months after surgery. The brain, SCG, and PN graft were studied under light and electron microscopy and with the tyrosine hydroxylase immunohistochemical and horseradish peroxidase tracing methods. Three days after grafting, there were no significant differences on the apomorphine test as compared to the preoperative test. Conversely, 1,3, and 5 months after grafting, the number of rotations was reduced by 69% (+/-20.2), 66.6% (+/-17.1), and 72.5% (+/-11.3), respectively. Control rats that received a free PN graft to the brain and underwent section of the postganglionic branch of the SCG did not show significant changes on the apomorphine test after surgery. Histological examination revealed that the PN graft was mostly reinnervated by amyelinic axons of small caliber. Approximately 40% of the SCG neuronal population that normally projects to the postganglionic branch survived axotomy and regenerated the transected axons into the PN graft. Axons arising from the SCG elongated the whole length of the graft, crossed the graft-brain interface and extended into brain regions adjacent to the denervated striatum up to 2037 micrometer from the graft insertion site. This work shows that the ingrowth of catecholamine-regenerating axons from the SCG to dopamine-depleted brain parenchyma significantly reduces behavioral abnormalities in hemiparkinsonian rats. This effect cannot be ascribed either to the brain cavitation or to the PN tissue placement in the brain.

Case report: uneventful treatment of a giant prostate.

OBJECTIVE: Redefine the meaning of the old term "giant adenoma" and evaluate the diagnosis and safest method of treatment of such cases. METHOD: The world literature was reviewed, particularly concerning diagnostic approaches and therapeutic techniques. RESULTS: The open surgery technique appears to be the safest in the treatment of giant adenoma. CONCLUSIONS: We recommend further study of the factors affecting growth of giant prostatic adenoma.

Effects of levo-acetylcarnitine on second motoneuron survival after axotomy.

Little is known about factors that regulate the survival of cranial motoneurons which project to peripheral targets. Various neurotrophic factors of central and peripheral origin have been isolated. In this study, we examined thirteen newborn Wistar rats to determine the effects of acetyl-L-carnitine treatment on the survival of motoneurons within the facial nucleus after transection of the facial nerve. Acetyl-L-carnitine was administered for 7 days in seven rats after nerve transection, while saline solution was injected in 6 rats used as controls. Both the motoneuron number and the motoneuron diameter were significantly higher in the facial nucleus of the rats treated with acetyl-L-carnitine than in the facial nucleus of the control rats. The results obtained suggest that acetyl-L-carnitine can rescue a substantial number of facial motoneurons from axotomy-induced cell death. Compared to neurotrophic factors, because of its simple molecular structure, acetyl-L-carnitine permits a safe oral and parenteral administration. It is suggested that acetyl-L-carnitine could be considered for use as a therapeutic agent in neurodegenerative disorders.

Preoperative chemotherapy with carboplatin alone in high risk medulloblastoma.

Few studies have been carried out regarding preoperative chemotherapy utilized in the treatment of primitive neuroectodermal tumors/medulloblastomas (PNET/MB). In this paper, the authors report 3 cases of children under three years of age, with a presumed diagnosis of PNET/MB, who were preoperatively treated with chemotherapy consisting of high doses of carboplatin alone. The treatment improved the childrens' clinical condition prior to surgery and facilitated tumor removal, resulting in partial regression of the tumor. The preoperative single-drug therapy did not affect the histological diagnosis or prevent the presence of an effective degree of tumor sensitivity to the drug. All three children are still disease-free, after a mean follow-up period of 42 months.

Quantitative, morphological, and somatotopic nuclear changes after facial nerve regeneration in adult rats: a possible challenge to the "no new neurons" dogma.

The anatomic reorganization of the subnucleus that controls the stylohyoid muscle (the stylohyoid subnucleus) within the brain stem facial nucleus was studied after regeneration of the facial nerve in adult rats. Horseradish peroxidase was injected into the right stylohyoid muscle 3 to 21 months after transection and repair of the right facial nerve at the level of the stylomastoid foramen. Position, number, and soma diameter of retrogradely horseradish peroxidase-labeled motoneurons were established, as well as the rostro-caudal extension of the stylohyoid subnucleus. In experimental rats, the stylohyoid subnucleus showed either an ipsilateral (50% of the rats) or a bilateral representation. In all of the experimental rats, the motoneurons composing the stylohyoid subnucleus had a more dispersed horizontal distribution pattern when compared with controls. More than 80% of the motoneurons were located outside the borders of the normal stylohyoid subnucleus, either ventrally or, especially in the rostral sections, dorsally closer to the floor of the fourth ventricle. The mean rostro-caudal length of the stylohyoid subnucleus was 2028.6 +/- 152.7 microns. The mean motoneuron number was 481.4 +/- 109.5 (2.20-fold greater than control values), and the motoneuron diameter distribution ranged from 7 to 43 microns. This study demonstrates that after regeneration of the facial nerve in adult rats, major changes occur in both the location and number of motoneurons that make up the stylohyoid subnucleus.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous spinal epidural hematoma in toddlers: description of two cases and review of the literature.

The cases of two children under the age of two who presented with spontaneous spinal epidural hematoma (SSEDH) are reported. The patients were operated on soon after the diagnosis had been confirmed by magnetic resonance imaging examination. The present paper highlights the fact that in toddlers the diagnosis of SSEDH based on a mere clinical picture is particularly difficult, and that this pathology presents a good prognosis following the surgical treatment. The pertinent literature is reviewed.