Enrico Marchese

A survey of the first complication of newly implanted CSF shunt devices for the treatment of nontumoral hydrocephalus

The results of an international multicenter study concerning the first complication of newly implanted cerebrospinal fluid shunts in nontumoral hydrocephalus are the subject of the present report. The authors have collected information on 773 cases from four continents. In particular, the following data were evaluated in relation to the general incidence of complications recorded in the first follow-up year: the patients age at the operation, the etiology of hydrocephalus, the type of CSF shunt device used, and the modality of the surgical procedures. The overall complication rate in the series was 29%. Age and etiology of hydrocephalus appear to play a major role in influencing the complication rate; on the other hand, the choice of a specific CSF shunt device seems to be less important in this respect.

A Scan of Chromosome 10 Identifies a Novel Locus Showing Strong Association with Late-Onset Alzheimer Disease

Strong evidence of linkage to late-onset Alzheimer disease (LOAD) has been observed on chromosome 10, which implicates a wide region and at least one disease-susceptibility locus. Although significant associations with several biological candidate genes on chromosome 10 have been reported, these findings have not been consistently replicated, and they remain controversial. We performed a chromosome 10–specific association study with 1,412 gene-based single-nucleotide polymorphisms (SNPs), to identify susceptibility genes for developing LOAD. The scan included SNPs in 677 of 1,270 known or predicted genes; each gene contained one or more markers, about half (48%) of which represented putative functional mutations. In general, the initial testing was performed in a white case-control sample from the St. Louis area, with 419 LOAD cases and 377 age-matched controls. Markers that showed significant association in the exploratory analysis were followed up in several other white case-control sample sets to confirm the initial association. Of the 1,397 markers tested in the exploratory sample, 69 reached significance (P

Recurrent Ventriculoperitoneal Shunt Infection Caused by Small-Colony Variants of Staphylococcus aureus

Phenotypic variants of Staphylococcus aureus may be misidentified by routine microbiological methods, and they may also respond poorly to antibacterial treatment. Using molecular methods, we identified small-colony variants of methicillin-resistant S. aureus (which were misidentified by 3 widely used automated identification systems as methicillin-susceptible coagulase-negative staphylococci) as the cause of recurrent ventriculoperitoneal shunt-related meningitis.

Callosotomy for severe epilepsies with generalized seizures: Outcome and prognostic factors

SummaryThe purpose of the present study was to verify the effect of callosotomy on generalized seizures, to check the effect on other seizure types and to search for possible prognostic factors.Twenty patients with a minimum follow-up of one year (mean 3.5 years) were available for our analysis. In six of them the callosotomy was performed in two stages (total: 26 surgical procedures). Age ranged from 14 to 40 years (mean 23 years). Different aetiologies were known in 15 patients. Duration of epilepsy ranged from 6 to 23 years (mean 15 years). The frequency of seizures ranged between 19 and 750 per month.The most significant effect of surgery was the complete suppression of the generalized seizures associated with falling in 9/19 and their reduction of more than 80% in 7/19 patients (total “good results”: 16/19). The generalized tonic-clonic seizures were less affected. The surgical effect on the partial seizures was very variable, the partial simple seizures being the most affected. A positive statistical association with the outcome of the generalized seizures with fall was found for a presurgical seizure frequency below 90 per month, a prevalent bilateral EEG epileptic activity and, to a less extent, the absence of cerebral structural lesions. The role of age, aetiology, duration of the disease, single or more seizure types, mental impairment and extent of callosotomy remains uncertain. Disconnection syndrome does not appear if the splenium is spared.The present findings confirm that the main indication for callosotomy is the occurrence of generalized seizures with fall. Surgery can be initially limited to the anterior 2/3 of the corpus callosum; further posterior section of the corpus, excluding the splenium, should be regarded as a second step, when necessary.

On the Treatment of Subependymal Giant Cell Astrocytomas and Associated Hydrocephalus in Tuberous Sclerosis

Between 1980 and 1992, 10 children affected by tuberous sclerosis and intraventricular subependymal giant cell astrocytomas were surgically treated at the Institute of Neurosurgery, Section of Pediatric Neurosurgery, Catholic University of Rome. Nine patients presented with signs and/or symptoms of intracranial hypertension; in all of them the neuroradiological investigations demonstrated the presence of a space-occupying lesion in the region of the foramen of Monro with secondary ventricular dilation. In the remaining patient, a 5-month-old male infant, an intraventricular mass was discovered by means of an ultrasound examination performed after the first epileptic fit. Three patients underwent a ventriculoperitoneal CSF shunt as first surgical procedure; in 2 of them it was subsequently necessary to remove the intraventricular tumor due to the frequent occlusion of the CSF shunt device. Seven subjects underwent the direct surgical excision of the lesion. In all of them the procedure resulted in the control of the associated hydrocephalus. On the basis of such an experience, the authors conclude that the surgical removal of the intraventricular tumors in patients with tuberous sclerosis and hydrocephalus is the most appropriate treatment. In fact, in the series considered here, the removal of the tumor was not accompanied by significant morbidity, and was followed by improvement in clinical conditions. In particular, in cases in whom the occurrence of hydrocephalus was associated with a worsening in the seizure disorder, the tumor removal and the correction of intracranial hypertension was followed by a significant reduction in frequency or even by the disappearance of the seizures. However, in no case presenting with mental impairment was a significant improvement observed in mental performances as a consequence of the surgical treatment.

Metopic synostosis: in favour of a "simplified" surgical treatment

Metopic synostosis is a relatively simple form of craniosynostosis, resulting from premature fusion of the metopic suture. In this pathology different degrees of dysmorphia of the anterior cranial fossa and the presence of associated anomalies of the skull might enable specific subgroups to be identified. Since most functional and cosmetic anomalies benefit from early surgical treatment, over the last few years neurosurgeons have been forced to elaborate less drastic, but nonetheless effective, surgical techniques. In the present report we analyze the surgical results obtained in a series of 62 infants with trigonocephaly operated on within their 1st year of life. Patients were subdivided into two groups (group I: 8 patients; group II: 54 patients) according to the specific dysmorphic characteristics of the frontal bone and anterior cranial fossa, and the presence of compensatory deformities affecting the anterior cranial base and temporo-parietal region. All the patients were treated using one of two relatively simple surgical techniques (procedure A: inversion of two hemifrontal bone flaps-48 cases; procedure B: the “shell” operation-14 cases). Both surgical procedures appeared to be effective, allowing adequate functional and cosmetic correction of the cranial deformity. In patients operated on following procedure B surgical time and and blood loss were dramatically reduced. Long-term outcomes were satisfactory in all cases, irrespective of the surgical technique used. In the group II patients, however, progressive normalization of the interorbital distance was constantly observed, suggesting a different degree of stenotic involvement at the level of the anterior cranial base in these patients.

Reconstruction of peripheral nerves: the phenomenon of bilateral reinnervation of muscles originally innervated by unilateral motoneurons.

It is well known that after reconstruction of sectioned peripheral nerves in adult mammals, denervated muscles are reinnervated by the axotomized motoneurons lying in the original motonucleus. It is less well known that these muscles can also be reinnervated by uninjured motoneurons lying in the homologous contralateral motonucleus. Therefore, after nerve reconstruction, bilateral motoneuron reinnervation of muscles can occur. Contralateral motoneurons sprout axons that cross the midline, grow in the reconstructed nerve, and reach muscle targets. This phenomenon was observed after reconstruction of several different peripheral nerves in adult mammals, including the oculomotor nerve in guinea pigs and the facial and sciatic nerves in rats. The retrograde axonal transport of horseradish peroxidase was used for the study of the organization of the brainstem and spinal cord motonuclei. Horseradish peroxidase was injected into the medial rectus muscle, the stylohyoid muscle, and the trunk of the sciatic nerve. The distance between the homologous motonuclei of both sides influenced the occurrence of this phenomenon. In fact, bilateral reinnervation of muscles after nerve reconstruction was found in 36% (sciatic nerve), 50% (facial nerve), and 100% (oculomotor nerve) of the operated animals. The total number of contralateral motoneurons found were 14% (oculomotor nerve), 8% (facial nerve), and 5% (sciatic nerve). Bilateral reinnervation of muscles was evoked by both immediate and delayed peripheral nerve repair and was a stable phenomenon, seen between 3 and 21 months after facial nerve reconstruction.

Experimental studies on spinal cord injuries in the last fifteen years

Experimental studies on spinal cord (SC) injuries published from 1975 to 1989 in some of the most widely circulating neurosurgical journals were reviewed. The relatively large number of animal species utilized as well as the intensely variable dynamic or static methods employed to induce SC injury represent elements of confusion more than objective necessities in this field of research. In fact, the objective of SC injury research should be to solve the problem of severe SC injuries by either preventing and/or repairing SC damage, rather than looking for modalities to provoke a large spectrum of SC injuries with the result of establishing a correlation between for example, the clinical picture and trauma magnitude. It should be time to study all variables and treatments mainly in only one experimental model. The rat with a permanent paraplegia should represent such a model; the abdominal aorta occlusion for 45 minutes, distal to the renal arteries in rabbits should be the experimental model of choice for ischaemia. If a significant result, such as reversing permanent paraplegia, were obtained in rats, it would be logical to repeat the study in higher mammals and if successful, in humans. For the last decade of this century it is necessary to further study all the mechanisms implied in secondary SC damage as well as to attempt to repair definitive SC damage by using grafts and enhancing the potential regenerative ability of the SC with known and new growth factors. Presently, methylprednisolone, dexametasone, thiopental, naloxone, and hypothermia seem to have some clinical potentials that require studies in humans.

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)

Indocyanine green video-angiography in neurosurgery: A glance beyond vascular applications

OBJECTIVE Indocyanine green video angiography (ICG-VA) is a non invasive, easy to use and a very useful tool for various neurosurgical procedures. Initially introduced in vascular neurosurgery since 2003, its applications have broadened over time, both in vascular applications and in other neurosurgical fields. The objective of our study is to review all published literature about ICG-VA, cataloguing its different applications. METHODS A systematic review of all pertinent literature articles published from January 2003 to May 2014 using Pubmed access was performed using pertinent keywords; cross check of references of selected articles was performed in order to complete bibliographical research. Results of research were grouped by pathology. RESULTS AND CONCLUSIONS The paper systematically analyses ICG-VA different applications in neurosurgery, from vascular neurosurgery to tumor resection and endoscopic applications, focusing on reported advantages and disadvantages, and discussing future perspectives.