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Biomedical subjects

S J Haines

Publications and source records attributed to S J Haines.

At least 19 recordsLinked to original sources

Knotted bowel: small-bowel obstruction from coiled peritoneal shunt catheters. Report of two cases.

Knotting of a peritoneal catheter around a loop of bowel is a rare occurrence, which may lead to bowel obstruction. The incomplete removal of two ventriculoperitoneal shunts resulted in two cases of iatrogenically knotted peritoneal catheters. One patient underwent a laparotomy for relief of obstruction and the other was successfully treated by uncoiling the catheter by means of a wire passed into its lumen. A plan for management of a knotted peritoneal catheter is outlined.

Cerebrospinal Fluid Shunts

Review of skull base surgery approaches: with special reference to pediatric patients.

The techniques of skull base surgery attempt to maximize the exposure of a cranial base lesion while using the least amount of brain retraction. Cranial base surgery is not a 'new' area of neurosurgical or otolaryngologic interest, but instead represents a resurgence of efforts to treat difficult lesions involving the cranial base. This resurgence of interest and effort is a product of recent advances in microanatomical knowledge of the cranial base, advances in microsurgical technique, improved neurophysiologic monitoring, and improved collaborative relationships between neurosurgery, otolaryngology and plastic surgery. Furthermore, improved neuroanesthetic techniques allow the surgeon to proceed with surgery without undue concern about time, and improved neuroimaging techniques provide the surgeon with detailed knowledge of the three dimensional characteristics of the tumor and surrounding structures. This review will focus on the surgical management of cranial base tumors primarily affecting the pediatric population. Little has been written on the techniques of skull base surgery as they apply to the pediatric population, since cranially-based tumors are a relatively rare occurrence in this patient population. In most instances, however, many of the 'standard' skull base approaches can be applied to the pediatric patient with few modifications, and in our experience, the pediatric patients have tolerated these approaches as well as their adult counterparts.

Adolescent

Effects of 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP)-induced hemiparkinsonism on the kinematics of a two-dimensional,multijoint arm movement in the rhesus monkey.

The effects of the selective dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) on the kinematics of two-dimensional arm movements in the primate were studied. Two rhesus monkeys were trained to move a manipulandum at various distances and directions in horizontal space from a centrally located target box. Several kinematic parameters including reaction time, and time and amplitude of peak tangential velocity were analysed. Following an extensive control evaluation period, the animals were unilaterally injected with MPTP into the internal carotid artery. The animals were restudied for up to 289 days following induction of hemiparkinsonism. Larger-amplitude movements (greater than 3.5 cm) were more severely affected than smaller amplitude movements. Both animals exhibited marked changes in the arm movements including increased time-to-peak velocity and decreased peak velocity. The degree of the kinematic changes was spatially dependent, with the decrease in velocity as well as the time-to-peak velocity being more pronounced for the larger, outward movements. Reaction time increased but showed no spatial dependency. Kinematic deficits persisted over the entire time-period studied. Also, the kinematic changes were reduced by levo-3,4 dihydroxyphenylalanine in a dose-dependent manner. Tyrosine hydroxylase immunohistochemistry documented extensive cell loss in the substantia nigra. These results show that both the timing as well as the amplitude of the velocity profiles are disrupted by MPTP consistent with the known akinesia and bradykinesia of parkinsonism. Although abnormalities were present for all directions and distances, a spatial dependency to the deficits was detected. The observation of more pronounced changes for larger, outward movements suggests a role for the basal ganglia in production of larger-amplitude movements directed away from the body.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine

Microsurgical management of craniopharyngiomas.

A retrospective analysis of 34 patients who underwent microsurgical therapy for craniopharyngioma from 1975 to 1989, a period when CT imaging was routinely used, is presented. Mean follow-up was 6.4 years with no patients lost to follow-up. Those who underwent subtotal resection with adjuvant radiation had a significantly better recurrence-free interval compared with those who either underwent total or subtotal surgical resection only (p < 0.05 and p < 0.025). Among patients treated with surgery alone, the total resection group had a recurrence rate of 20% and those with a subtotal resection 60%. Those with subtotal resection and radiation had a 12% rate of recurrence. Endocrine and visual deficits were common after surgery. Based on this review, our results suggest that with a policy of attempted total resection where possible, subtotal removal along with adjuvant radiation, in cases where total resection was deemed unsafe, may be more effective than aggressive total resection alone as the initial management of craniopharyngioma.

Adolescent

Pediatric skull, skull base, and meningeal tumors.

Calvarial neoplastic and non-neoplastic tumors are routinely encountered by all neurosurgeons. Benign and malignant skull base and meningeal tumors are relatively rare lesions in children. Interdisciplinary approaches to those tumors more frequently encountered in the pediatric population in these locations are discussed. Unique aspects of the diagnosis, treatment, and prognosis for infants and children are discussed.

Child

Esthesioneuroblastoma presenting as sudden unilateral blindness. Histopathologic confirmation of optic nerve demyelination.

We report here a case of esthesioneuroblastoma an 11-year-old girl presenting as acute loss of vision with minimal evidence of orbital, nasal, or paranasal sinus disease, a rare presenting symptom for this tumor. The initial diagnosis was postviral optic neuritis, a pattern of presentation not previously reported. When vision failed to improve, magnetic resonance imaging revealed a lesion in the posterior ethmoid and sphenoid sinuses. After a biopsy, the tumor was excised through the cranium and paranasal sinuses. A mass completely surrounding the optic nerve without invasion was found. Histochemical staining suggested demyelination secondary to compression, confirming the clinical impression of optic neuritis. Anti-Leu 7 monoclonal antibody is useful in characterizing of this tumor, since other immunochemical stains can be misleading. Radiation and chemotherapy were given after the tumor was removed. Two years later, the patient has had neither recurrence nor complications.

Antineoplastic Combined Chemotherapy Protocols

Infections in neurologic surgery. The intraventricular use of antibiotics.

Intraventricular antibiotic therapy appears to be a useful treatment modality in those CSF infections in which systemic therapy may fail. Consideration should be given to using this form of treatment when infecting organisms are only sensitive to antibiotics with poor penetration of the CSF (e.g., aminoglycosides and vancomycin) and for cases in which intravenous therapy has failed to sterilize the CSF, toxicity from systemic therapy precludes further increases in dosages, and shunts or other CSF hardware might be expected to reduce the efficacy of systemic therapy by providing a foreign body to harbor organisms. Shunts or reservoirs that are infected may be successfully sterilized with IVT therapy alone or in conjunction with systemic therapy, but this has a lower success rate than cases in which the shunt is removed. There is a wealth of clinical experience with IVT vancomycin and gentamicin that suggests that they are relatively safe. Until more data are available on other aminoglycosides and newer antibiotics, these two agents should be considered the antibiotics of choice for IVT therapy. In situations in which the organism is sensitive to both vancomycin and gentamicin, vancomycin should be used in view of the documented neurotoxicity seen with gentamicin. When gentamicin resistance occurs, amikacin and tobramycin are appropriate alternatives. The high risk of epilepsy with the penicillins and cephalosporins makes them less suited for IVT therapy, although the newer cephalosporins have some promise for IVT therapy. CNS fungal infections can be treated effectively with IVT amphotericin B but with a high risk of significant toxicity. Miconazole appears to be safer than amphotericin B but there is less clinical experience with this drug. Table 1 summarizes the dosages, indications, and toxicity of those antibiotics commonly used for intraventricular administration, which have been reported previously.

Anti-Bacterial Agents

Antibiotic prophylaxis in neurosurgery. The controlled trials.

Systemic antibiotics are effective in reducing the risk of infection after clean neurosurgical procedures. They are less effective in preventing shunt infection, but are strongly recommended in institutions experiencing a shunt infection rate exceeding 15%. The role for antibiotic prophylaxis using topical agents and in the prevention of meningitis associated with cerebrospinal fluid drainage is uncertain.

Anti-Bacterial Agents

Lesioning of the striatum reverses motor asymmetry in the 6-hydroxydopamine rodent model of parkinsonism.

In the rat several paradigms of grafting of adrenal medulla into the striatum were studied following the induction of a parkinsonian model, using a unilateral 6-hydroxydopamine (6-OHDA) lesion of the substantia nigra. Direct autologous grafting of adrenal medulla into the caudate-putamen complex, a radiofrequency lesion of the striatum alone, and a radiofrequency lesion followed by delayed grafting of adrenal medulla were compared by analyzing rotational behavior. Direct grafting of adrenal medulla produced an overall reduction in apomorphine induced turning behavior by 43.5% when compared with controls. Radiofrequency lesioning of the striatum without graft showed the best improvement over control animals with a 92% reduction in the total number of rotations induced by apomorphine. Delayed grafting into the caudate lesion cavity also produced a dramatic reduction in motor asymmetry but did not improve the behavioral outcome over that of the lesion alone. Animals receiving only radiofrequency lesions exhibited a band of increased tyrosine hydroxylase like immunoreactivity bordering the lesion cavity. Graft survival was limited in the non-lesioned animals but appeared enhanced in the animals whose striatum was previously lesioned. Lesion location within the striatum influenced the behavioral outcome. Large reductions in apomorphine-induced rotations could result from small lesions of the dorso-lateral striatum. These findings indicate that selective destruction of the caudate-putamen complex without tissue transplantation produces a dramatic reduction in the motor asymmetry of 6-OHDA treated rats. Suggested explanations for the decrease in induced rotational behavior with radiofrequency lesions include a decrease in the number of striatal dopamine receptors following cell destruction and lesion-induced recovery of host dopaminergic afferents. Striatal damage in critical areas can reverse some of the motor behavior associated with the 6-OHDA model and needs to be considered when evaluating the effects of neural grafting in this model.

Adrenal Medulla

Intraoperative monitoring of the facial nerve during decompressive surgery for hemifacial spasm.

In 11 consecutive patients, intraoperative electromyographic (EMG) recordings were made from the facial muscles during microvascular decompression for hemifacial spasm. In one patient, recordings could not be obtained for technical reasons, and two patients had no abnormality. In the remaining eight patients, the abnormal response resolved before decompression in two, resolved immediately at the time of decompression in five, and failed to resolve in one. All patients were relieved of their hemifacial spasm. In the five patients whose abnormalities resolved at the time of decompression, there was a precise intraoperative correlation between decompression of the nerve and disappearance of the abnormal EMG response. In three cases, this was a useful guide to the need to decompress more than one vessel. These results confirm the findings of Møller and Jannetta, support the use of this technique for intraoperative monitoring of facial nerve decompression procedures, and provide strong circumstantial evidence that vascular cross-compression is an important etiological factor in hemifacial spasm.

Electromyography

Familial hemifacial spasm associated with arterial compression of the facial nerve. Case report.

This report of an 88-year-old woman with familial hemifacial spasm includes the first published postmortem description of hemifacial spasm with cross-compression of the seventh cranial nerve root exit zone by a redundant loop of the anterior inferior cerebellar artery and associated vascular plexus. Histological examination of the seventh and eighth cranial nerve complex suggested nerve degeneration because increased numbers of corpora amylacea were present just distal to the compression concavity. There was no evidence of demyelination or gliosis of the nerve. This case suggests that vascular compression of the nerve root exit zone is an important condition in the etiology of most of these cases. This is the third reported case of familial hemifacial spasm; to date, all such patients have had left facial involvement. The family pedigree in this case suggests a pattern of autosomal-dominant inheritance with partial penetrance. The genetic basis for familial hemifacial spasm may involve anatomical variants or anomalies of the posterior circulation, since both posterior inferior cerebellar arteries were congenitally absent in this case.

Aged

Relative value of diagnostic tests for small acoustic neuromas.

Auditory brainstem response is now widely employed as a screening test for acoustic neuromas because it is equally sensitive when standardized against computed tomography. We have detected eight small (less than 10 mm) acoustic neuromas using gadolinium enhanced magnetic resonance imaging. In three of these cases, the auditory brainstem response was falsely negative. In contrast, 19 patients with larger tumors (greater than or equal to 10 mm) were found to have no false negative auditory brainstem responses. Auditory brainstem response appears to be less sensitive for detecting small, symptomatic acoustic neuromas.

Adult

Subependymoma of the cervical spinal cord. A case report of long-term survival.

Subependymomas of the cervical spinal cord are relatively rare tumors. Thirteen cases have been reported in the literature with the longest reported follow-up and survival being six years. This paper describes a woman who survived for 14 years in reasonably good health after her diagnosis of cervical spinal cord intramedullary subependymoma. A review of reported cases and a discussion of subependymomas and their characteristics is included.

Adult

Current treatment of Chiari malformations types I and II: A survey of the Pediatric Section of the American Association of Neurological Surgeons.

The membership of the Pediatric Section of the American Association of Neurological Surgeons was surveyed with regard to attitudes in current practice in the treatment of Chiari malformations Types I and II. Ninety-six of 152 (63%) valid questionnaires were returned. The median number of malformations treated yearly by the respondents was 3 for Type I and 6 for Type II. There was substantial agreement that surgery should not be carried out on asymptomatic patients and that surgery was indicated for the treatment of brain stem dysfunction, cranial nerve dysfunction,, hydromyelia, and scoliosis associated with these malformations. There was substantial disagreement about lesser indications for surgery. The respondents also expressed dissatisfaction with the current classification of Chiari malformations. Chiari malformations are complex abnormalities, and their anatomy is being better delineated with magnetic resonance imaging. Carefully designed scientific clinical investigations are needed to improve our understanding and treatment of Chiari malformations.

Adolescent

Dorsal midbrain encephalitis caused by Propionibacterium acnes. Report of two cases.

A syndrome of dorsal midbrain dysfunction in association with a central nervous system anaerobic diphtheroid infection is described. Two cases of infection with Propionibacterium acnes manifested as shunt malfunctions with a clinical dorsal midbrain syndrome. Magnetic resonance images showed increased signal in the midbrain tectum which has decreased slowly over time. The evidence suggesting that this syndrome represents bacterial midbrain encephalitis is discussed.

Adolescent