Biomedical subjects

S Constantini

Publications and source records attributed to S Constantini.

At least 19 recordsLinked to original sources

PubMed2002

Progression of terminal syrinx in occult spina bifida after untethering.

OBJECT: The association of spinal dysraphism and terminal syringomyelia is a well-known entity, and untethering with or without syrinx drainage is usually the surgery of choice. However, progression of the previously existing syrinx after an untethering procedure is an uncommon course. The objective of this study was to discuss the diagnostic, surgical, and follow-up consequences of such an occurrence. METHODS: Four children with occult spina bifida associated with terminal syrinx at the time of initial presentation are included in this study. After the primary releasing procedure, all developed enlargement of the syrinx. Two of them were operated on for placement of a syringo-subarachnoid shunt, while the other two were followed up conservatively. One of the shunted patients also had a second releasing procedure. CONCLUSION: Progression of the pre-existing terminal syrinx after the primary untethering procedure should be kept in mind even in the absence of overt neurological progression.

Cerebrospinal Fluid Shunts↗

PubMed2002

Experimental models in focal cerebral ischemia: are we there yet?

Therapeutic options available for acute stroke management are sparse and inadequate. Therefore, new insights into stroke pathophysiology leading to new therapeutic targets are needed. In order to attain these goals, adequate animal models for cerebral ischemia are needed. In the following paper the authors will review the various animal models for stroke and emphasize their potential strengths and weaknesses.

Animals↗

PubMed2002

Experimental models of head trauma.

Traumatic brain injury is one of the most common causes for chronic disability in young people. Despite this there are currently no widely available modes of therapy that would limit the extent of brain damage secondary to trauma. Therefore, new insights into the pathological mechanisms involved in head trauma possibly leading to the identification of new therapeutic targets are urgently needed. In order to attain these goals adequate animal models for traumatic brain injury are needed. In the following paper the authors will review the various animal models for head trauma and emphasize their potential strengths and weaknesses.

Animals↗

PubMed2001

Outlet fenestration for isolated fourth ventricle with and without an internal shunt.

Conventional shunting of isolated fourth ventricle is notorious for leading to frequent and severe complications. We present four patients with isolated fourth ventricle who have been treated with open posterior fossa surgery together with either outlet fenestration alone or outlet fenestration and a fourth ventricle-spinal subarachnoid space (SSS) shunt. A survey of the relevant literature did not yield any other case reports of fourth ventricle shunting to the SSS under such circumstances. This paper discusses the reasons for choosing this mode of treatment. The main advantage of this technique is that the catheter is inserted along the anatomical long axis of the fourth ventricle. This positioning lessens the possibility of irritating or penetrating the brain stem. Moreover, as a more physiological solution, the shunt does not require a valve system. Because of these advantages, internal fourth ventricle-SSS shunting is proposed as a valid alternative to the "classic" fourth ventriculo-peritoneal shunt.

Cerebrospinal Fluid Shunts↗

PubMed2001

Association between increased central venous pressure and hydrocephalus in children undergoing cardiac catheterization. A prospective study.

OBJECTS: The relationship between increased central venous pressure (CVP) and development of hydrocephalus has been extensively discussed in the neuropediatric literature. However, the possibility of a direct connection has not been systematically examined. The purpose of this prospective study was to examine whether there was a correlation between elevated CVP and hydrocephalus in children undergoing cardiac catheterization. METHODS: We used cardiac catheterization to measure the right atrial and superior vena caval pressure in 37 children (mean age 30 months) with congenital heart malformations. The children had CVP higher than normal (mean 10.2+/-3.1 mmHg, range 4-18). To evaluate the size of the lateral and fourth ventricles, we performed CT scans of the brain on each child. Abnormal scans were found in 15/37 children, showing brain atrophy (12/37), ventriculomegaly (3/37), and focal infarction (1/37). Cerebral atrophy was more likely to occur in young children (P<0.001). The average head circumference among these children was less than 2SD below the mean for healthy children of comparable ages. Using a correlation coefficient regression model, no relationship was found between CVP and ventricular diameters or head circumference. CONCLUSIONS: These results argue against the hypothesis that mild to moderately elevated venous pressure is involved in the mechanism and development of pediatric hydrocephalus.

Cardiac Catheterization↗

PubMed2001

Ascites following ventriculoperitoneal shunting in children with chiasmatic-hypothalamic glioma.

OBJECT: Optic pathway gliomas in children can involve the optic nerve, chiasm, and hypothalamus. This uncommon, slowly growing tumor can cause hydrocephalus, which usually requires placement of a ventriculoperitoneal (VP) shunt. Symptomatic ascites may occasionally develop as a complication of the VP shunt procedure. The purpose of this study was to assess the risk factors associated with CSF ascites in children with optic pathway gliomas. METHODS: Twenty-two children (ages 4 months to 20 years) with chiasmatic-hypothalamic optic gliomas participated in this study. Four children were diagnosed with a chiasmatic glioma, 7 with a hypothalamic glioma, and 11 with a glioma involving both the optic chiasm and hypothalamus. Twelve children (55%) developed hydrocephalus and required VP shunt placement. Of the 12 shunted children, 4 (33%) developed CSF ascites. The incidence of ascites was not associated with infection, tumor metastasis, or multiple shunt revisions. There was no correlation with the size of the tumor. All 4 children with ascites had tumor involving the optic chiasm or optic nerve. None of the 5 children with pure hypothalamic glioma who underwent VP shunt placement have developed ascites. Among the 7 children suffering from chiasmatic or optic nerve gliomas who developed hydrocephalus, the risk of developing ascites as a complication of VP shunt placement was 57% (4/7). Ventriculoatrial (VA) shunt was the treatment of choice for children with VP shunt-induced ascites. After placement of a VA shunt the ascites subsided. The children did not develop further complications. CONCLUSION: We conclude that glioma involving the optic chiasm or nerve is associated with a high risk of developing ascites following VP shunt placement. VA shunt may be the treatment of choice for children with chiasmatic or optic nerve gliomas who require a CSF diversion procedure.

Adolescent↗

PubMed2001

Repeat endoscopic third ventriculostomy: is it worth trying?

OBJECT: The goal of this study was to evaluate the safety, efficacy, and indications for repeat endoscopic third ventriculostomies (ETV). METHODS AND RESULTS: We reviewed the records of 20 patients who had undergone repeat ETV from 1987 to 1999. Their ages ranged from 8 months to 53 years (mean 17 years). The primary etiologies of hydrocephalus were: primary aqueductal stenosis (9 cases), tumor (5), Chiari malformation (2), prior infection (2), prior intraventricular hemorrhage (1), and blocked foramen of Monro (1 patient). The interval between the first and second ETVs ranged from 8 days to almost 6 years (mean 12.8 months). The intraoperative findings at repeat surgery were: occlusion of the primary orifice by scar (10 cases), virginal floor of the third ventricle (5 cases), pinhole ventriculostomy (3 cases), incompletely penetrated membrane (1 case), and blood clot occluding the orifice (1 case). The follow-up period ranged from 3 to 47 months (median 20 months). Repeat ETV was successful in 13 patients (65%). These patients did not require further shunting or other procedures during follow-up. Seven patients (35%) required placement of a shunt after repeat ETV. Several complications were observed in 1 patient (5%), including seizures, elevated ICP, bilateral pulmonary edema, and cardiac arrhythmia. This patient ultimately recovered fully; the ETV was successful, and the patient did not require a shunt. CONCLUSIONS: Based on the experience of this group of patients, repeat ETV is as effective and as safe as a primary ETV procedure, and should be attempted in selected patients.

Adolescent↗

PubMed2001

Application of the orbito-cranial approach in pediatric neurosurgery.

OBJECTIVE: This study evaluates the benefits of and indications for the orbito-cranial approach (OCA) in pediatric patients. METHODS AND RESULTS: The authors report their recent experience of using the OCA in 9 pediatric patients, 6 boys and 3 girls. The patients' ages ranged from 3 to 17 years (mean 9.6+/-5.16 years). Follow-up periods varied between 6 and 21 months (mean 12.6+/-5.9 months). Five patients were operated on for craniopharyngiomas, 2 for chiasmatic-hypothalamic astrocytomas, 1 for a recurrent hypothalamic gangliocytoma, and 1 for a hypothalamic hamartoma. In 7 cases a neuronavigation system (BrainLab) was utilized. The lesions were removed totally in 5 patients, near-totally in 1, subtotally in 2, and partially in 1 patient. An average increase of 30% in the area of vertical exposure significantly decreased the need for brain retraction. There was no mortality in this series. The only complications connected with the surgical approach were transient subgaleal cerebro-spinal fluid collections in 7 of 9 children and a subgaleal-peritoneal shunt placement in another patient. CONCLUSIONS: Our experience with this series of patients suggests that the OCA is as safe and beneficial in pediatric patients as it is in adults. It facilitates tumor removal by providing shorter access to and better exposure of the suprasellar area, thereby minimizing brain retraction.

Adolescent↗

PubMed2001

Surgical treatment of hypothalamic hamartoma and refractory seizures: a case report and review of the literature.

Refractory gelastic seizures are often associated with hypothalamic hamartoma (HH). Presurgical evaluation in such children often points to a distinct cortical region as the source of the seizures. A case of a child with HH and refractory seizures is presented. Video-EEG monitoring revealed a well-defined epileptic focus in the left frontal region. In accordance with the current understanding of the nature of hamartoma-related seizures, the hamartoma was resected. Follow-up evaluations revealed a marked improvement in seizure frequency and global functioning.

Child, Preschool↗

PubMed2001

No evidence of epilepsy following endoscopic third ventriculostomy: a short-term follow-up.

Patients with ventriculo-peritoneal shunts are predisposed to various complications, including the appearance of seizures over time. The high rate of complications prompted an interest in alternative procedures such as endoscopic third venticulostomy (ETV) in selected patients. From 1996 to 1998, 42 patients underwent ETV in our center. Of the 27 operated children who were followed for an average of 32 months, none experienced seizures during that time. We conclude that, in addition to other benefits, ETV minimizes the risk of epilepsy following shunt insertion, probably due to the lack of direct cortical insult.

Child↗

PubMed2001

Safety of perioperative minidose heparin in patients undergoing brain tumor surgery: a prospective, randomized, double-blind study.

OBJECT: Thromboembolic phenomena (TEPs) continue to be a significant source of morbidity and mortality in patients undergoing neurosurgery. Although the efficacy of low-dose heparin in preventing TEPs in neurosurgical patients is well established, neurosurgeons are reluctant to use it perioperatively because of concern for increased bleeding complications. To clarify this issue, the authors used a prospective, randomized, double-blind design to evaluate the safety of minidose heparin treatment in patients undergoing surgery for supratentorial brain tumors. METHODS: One hundred three patients, all 40 years of age or older, were treated with either 5000 U of heparin (55 patients) or placebo (48 patients) starting 2 hours before surgery and continuing until full mobilization or for 7 days. Both groups were well matched for sex, weight, duration of surgery, and tumor diagnosis. Subjective and objective parameters were used to estimate and calculate the perioperative bleeding tendency in all patients. Red blood cell mass loss was calculated by assessing the preoperative and postoperative hematocrit and the patient's weight. Intraoperative blood loss was determined by measuring the quantity of blood in the suction containers and subtracting the amount of irrigation fluids. Postoperative bleeding was measured by determining the amount of fluid in the subgaleal drain, and blood cell replacement was monitored during and after the procedure. Intracranial bleeding was graded according to findings on the postoperative computerized tomography scan obtained 48 to 72 hours after surgery. In addition, the senior surgeon in each case was asked to assess each patient's bleeding tendency during the operation. The results showed that perioperative administration of heparin did not significantly alter bleeding tendency by any measured parameter. The surgeon was blinded to which group individual patients had been allocated. CONCLUSIONS: Perioperative minidose heparin is safe for use in patients undergoing craniotomy for supratentorial tumors. This relatively simple and inexpensive measure is recommended as a routine regimen for the prevention of TEPs in patients undergoing neurosurgery.

Anticoagulants↗

PubMed2001

Morphometric study of the midsagittal MR imaging plane in cases of hydrocephalus and atrophy and in normal brains.

BACKGROUND AND PURPOSE: Midsagittal morphologic changes often aid in the diagnosis of hydrocephalus. Stretching and upward displacement of the corpus callosum, widening of third ventricular recesses, and decreased mammillopontine distance have been described as indicating the possibility of hydrocephalus. Quantitative studies are scarce. We performed retrospective, quantitative analysis to verify and quantify changes in midline morphology that might differentiate hydrocephalus and ventriculomegaly due to atrophy. METHODS: Sagittal MR imaging studies of 22 patients with hydrocephalus and 32 patients with atrophy were analyzed, as were 42 studies with normal findings. The studied parameters included mammillopontine and mammillocommissural distances, callosal height at two points, and the distances between the lines passing through the chiasm (chiasmal line) and the edge of the callosal splenium. Various angles between the chiasmal line and surrounding structures were measured. Similar measurements were done with the line passing through the third ventricular floor segment anterior to the mammillary bodies (third ventricular line). RESULTS: In hydrocephalus, mammillopontine distance decreased, mammillocommissural distance increased, the third ventricular floor segment was concave in most cases, and the chiasmal line rotated clockwise. These changes were not seen in atrophy. Callosal height was increased in hydrocephalus significantly more than in atrophy. CONCLUSION: Specific changes of the midsagittal plane in hydrocephalus, some of which have not been described previously, can be observed and quantified, which might aid in differentiating this condition from atrophy.

Adolescent↗

PubMed2001

[Neurosurgical aspects in achondroplasia: evaluation and treatment].

Achondroplasia is the most common genetic disorder associated with bone dysplasia. The mode of inheritance is autosomal dominance, while most cases appear to represent a new mutation. Achondroplastic patients suffer from dwarfism, and from typical features of the head and limbs (rhizomelia, macrocephaly, frontal bossing and kyphosis). Half of the patients show various neurological complications. The most serious complication of achondroplasia is respiratory impairment, apnea and sudden infant death, resulting from compression of the medulla oblongata. This study describes the neurosurgical sequels in 10 achondroplastic patients, who underwent 12 surgical procedures. The average age was 14 years (ages ranged from 3 months to 40 years). The patients suffered from back pain, muscle weakness, incontinence, hypotonia, psychomotor delay, apnea and respiratory arrest. Four patients were diagnosed as suffering from obstructive sleep apnea. Craniocervical MRI showed: narrowing of the foramen magnum, fusion of C1, spinal stenosis, and severe cervicomedullary or spinal cord compression. In 5 patients the MRI also showed ventriculomegaly of the lateral and third ventricles. Seven patients underwent foramen magnum decompression and C1 laminectomy. Three patients with severe spinal cord compression underwent laminectomy of the involved spines (T12-L5). Two of the patients required more then one operation due to the recurrence of their neurological symptoms. There was no need for duraplasty or shunt procedures. The average hospital stay was 6 days. Eight patients showed improvement or resolution of symptoms, with an average follow-up period of 13.5 months after the last operation (ranged 6-24 months). We conclude that early neurological and MRI evaluations are required in achondroplasia patients, in order to prevent the high morbidity and mortality during infancy and childhood. In adults, MRI evaluation is needed if the patient has neurological symptoms. Early identification and immediate cervicomedulary decompression procedure can prevent the serious complications occurring in achondroplasia, including respiratory failure, apnea and sudden death.

Achondroplasia↗

PubMed2000

Increasing chronic subdural hematoma after endoscopic III ventriculostomy.

OBJECT: Endoscopic III ventriculostomy (ETV) is an effective and a rather safe treatment for noncommunicating hydrocephalus secondary to aqueductal stenosis and other obstructive pathologies. Though not devoid of risk, ETV is increasingly replacing shunt operations, and it prevents related complications, including overdrainage. METHODS: We report a rare case of a large chronic subdural hematoma (ChSDH) after ETV in a patient with aqueductal stenosis. Three weeks after he was shunted elsewhere, he presented to us with clinical symptoms of intracranial hypotension and overdrainage. ETV was performed and the shunt removed uneventfully. On routine postoperative MRI a few weeks later, a large ChSDH was noted, the patient being totally asymptomatic. Since the ChSDH grew significantly, causing a mass effect on the follow-up MRI, it was finally drained. Large and increasing ChSDHs have previously been reported secondary to overdrainage after shunt placement, but not after ETV. CONCLUSIONS: We conclude that though rare, a ChSDH may evolve even after ETV, if there is a substantial decrease in previously elevated intracranial pressure.

Adult↗

PubMed2000

Expansion of Chiari I-associated syringomyelia after posterior-fossa decompression.

UNLABELLED: Chiari I malformation (CMI) is an abnormality that involves caudal herniation of the cerebellar tonsils into the foramen magnum. CMI has been shown to be closely associated with the development of syringomyelia (SM). OBJECTS: Several theories have emerged to explain the apparent correlation between the existence of CMI with subsequent development of SM. However, the exact mechanism of the evolution of SM is still subject to controversy. We report here the case of a 12-year-old girl admitted to hospital with headache, vomiting, ataxia, and moderate pyramidal signs. METHODS: Radiological evaluation revealed the presence of CMI, accompanied by a small SM. The patient underwent posterior fossa decompression and improved significantly. She was re-admitted 6 months later with clinical evidence of progressive spinal cord dysfunction. MR revealed gross expansion of the syrinx. CONCLUSIONS: This case raises questions regarding the pathophysiology of CMI and its association with SM. The case indicates the need for neurological and radiological follow-up for patients undergoing posterior fossa decompression due to CMI, even for those without an initial syrinx. This is the first report known to us of expansion of a syrinx following decompression of an associated CMI.

Arnold-Chiari Malformation↗

PubMed2000

Repeat computed tomographic scan within 24-48 hours of admission in children with moderate and severe head trauma.

OBJECTIVE: To asses the yield and contribution of a routine predetermined repeat head computed tomographic (CT) scan within 24-36 hrs in pediatric patients with moderate to severe head trauma. DESIGN: Records review. SETTING: Five pediatric intensive care units. PATIENTS: We reviewed the charts of 173 consecutive pediatric patients with moderate to severe head trauma (Glasgow Coma Scale score of < or = 11) that survived the first 24 hrs after being admitted to five Israeli trauma centers. Clinical data collected included status at admission, at the time between the first and second CT scans, and after the second scan. Head details of the first, second, and, if performed, third CT scan were collected. Treatment strategy during each period was recorded, including any change in treatment after each CT scan. MEASUREMENTS AND MAIN RESULTS: A total of 47 (27%) of the second CT scans showed new lesions including six intracranial hemorrhages, 17 cases of worsening brain edema, and 18 newly diagnosed brain contusions. However, none of these findings necessitated surgical intervention or any change in therapy. Of the 67 patients who underwent a third CT scan, two cases required surgical intervention because of new findings in the third CT. CONCLUSIONS: A second routine prescheduled head CT scan within 24-36 hrs after admission in pediatric patients with moderate to severe head trauma is unlikely to yield any change in therapy. Clinically and intracranial pressure-oriented CT scan may better select and diagnose patients who require changes in therapy, including surgery. Studies aimed to determine the ideal timing for the second are warranted.

Adolescent↗

PubMed2000

Cyst wall enhancement in pilocytic astrocytoma: neoplastic or reactive phenomena.

Cystic pilocytic astrocytomas (CPA) consist of a mural nodule and an accompanying cyst, which may prominently enhance on MRI after contrast administration. This raises the question whether an enhanced wall represents a tumor and thus should be resected together with the solid nodule, as radical tumor surgery is associated with better prognosis. Until now, no systematic histopathological examinations of cyst walls have been reported in correlation with MRI, intraoperative appearance and postoperative clinical and MRI follow-up. We present 3 patients with CPAs and brightly enhanced cyst walls on MRI. Because of the benign, transparent appearance of the cyst wall intraoperatively, it was biopsied but not resected, and only radical removal of the nodule and its immediate surroundings was performed. Separate specimens taken from the cyst wall showed no tumor. MRI performed annually, up to 48-56 months after surgery showed no recurrence of the cyst or the tumor. In such cases of CPA, we suggest that enhancement of cyst walls may represent reactive rather than tumoral tissue, and may be left intact without risking worse prognosis. Mechanisms leading to cyst wall enhancement and the optimal surgical treatment are discussed.

Astrocytoma↗

PubMed2000

Radical excision of intramedullary spinal cord tumors: surgical morbidity and long-term follow-up evaluation in 164 children and young adults.

OBJECT: The majority of intramedullary spinal cord tumors (IMSCT) in children and young adults are low-grade gliomas. Radical resection of similar tumors in the cerebral hemisphere or cerebellum is usually curative; however, the conventional management for IMSCTs remains partial resection followed by radiotherapy because of the concern for surgical morbidity. Nevertheless, radical resection of IMSCTs without routine adjuvant treatment has been the rule at our institution since 1980. In an attempt to resolve this controversy, the long-term morbidity and survival in a large series of children have been retrospectively reviewed. METHODS: The database records and current status of 164 patients 21 years of age and younger in whom an IMSCT was resected were reviewed. A gross-total resection (>95%) was achieved in 76.8% of the surgical procedures. Subtotal resections (80-95%) were performed in 20. 1%. The majority of patients (79.3%) had histologically low-grade lesions. There were no deaths due to surgery. When comparing the preoperative and 3-month postoperative functional grades, 60.4% stayed the same, 15.8% improved, and 23.8% deteriorated. Only 13 patients deteriorated by more than one functional grade. Patients with either no deficits or only mild deficits before surgery were rarely injured by the procedure, reinforcing the importance of early diagnosis and treatment. The major determinant of long-term patient survival was histological composition of the tumor. The 5-year progression-free survival rate was 78% for patients with low-grade gliomas and 30% for those with high-grade gliomas. Patients in whom an IMSCT was only partially resected (<80%) fared significantly worse. CONCLUSIONS: The long-term survival and quality of life for patients with low-grade gliomas treated by radical resection alone is comparable or superior to minimal resection and radiotherapy. The optimum therapy for patients with high-grade gliomas is yet to be determined.

Adolescent↗