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J A Lazareff

Publications and source records attributed to J A Lazareff.

12 recordsLinked to original sources
PubMed1992

The probable role of hydrocephalus in the development of intraventricular septa. An observation of one case.

Multiloculated cerebral ventricles are a well-known complication of neonatal meningitis secondary to gram-negative bacteria. Their presence often hampers the proper functioning of the multiple shunts required for draining the ventricles. To determine whether the associated hydrocephalus may contribute to the development of the ventricular septa, we analyzed the histological structure of the ventricular wall and of the ventricular septa of a child who died as a consequence of Escherichia coli meningitis and unilateral hydrocephalus. Our results show that the ventricular septa are formed by glial protrusion into the ventricles. The ependymal wall of the grossly dilated ventricle was disrupted, but not that of the contralateral ventricle. We hypothesize that the presence of an insufficiently controlled hydrocephalus may have been one of the factors that induced the formation of the septa. It is suggested that an external ventricular derivation should be used during the active phase of the infection.

Cell Division↗
PubMed1991

A probe for simultaneous sampling in stereotactic brain biopsy. Technical note.

A probe for stereotactic brain biopsy which allows to obtain two different samples along a single trajectory tract is presented. It consists of a cylindrical stainless steel probe which has two separate grooves. The pieces of tissue are shredded from the lesion by sliding a polyethylene cannula that fits around the probe.

Biopsy↗
PubMed1990

Histological differences between rootlets sectioned during selective posterior rhizotomy by two surgical techniques.

During selective posterior rhizotomy, for the treatment of spasticity in infantile cerebral palsy, the rootlets to be divided are chosen by the type of electromyographic response elicited by intraoperative electrical stimulation. Two different surgical techniques were used for exposing the lumbar roots. The first approach was to expose the conus medullaris through a T 12-L 1 laminectomy, while the other approach to the dorsal roots was distally in the cauda equina through a L 2-L 3 to S1 laminectomy. Although the clinical results obtained with either of them are not very different, there is anatomical evidence that suggests that the histological structure of the divided rootlets may be different in the two techniques. We designed our study to determine of a significant difference in the number of large myelinated fibers was found between rootlets divided close to the conus medullaris and those divided distally in the cauda equina. Two groups of five children with spasticity secondary to cerebral palsy where randomly designed to be operated upon by one of the techniques. The divided rootlets were processed with standard histological techniques and the large myelinated fibers were counted on enlarged (40 x) photomicrograph of the rootlet. A significantly (p less than 0.001) larger number of large myelinated axons was found in the rootlets dissected and divided close to the conus medullaris.

Cauda Equina↗
PubMed1990

Limited selective posterior rhizotomy for the treatment of spasticity secondary to infantile cerebral palsy: a preliminary report.

A limited selective posterior rhizotomy was performed on 30 children suffering from spasticity secondary to infantile cerebral palsy. As opposed to standard techniques that stimulate and divide the dorsal rootlets from L2 to S1, we dissected L4, L5, and S1 dorsal roots through an L5 to S1 laminectomy. Eight to 12 rootlets from each root were electrically stimulated with two unipolar electrodes (pulse width, 50 microseconds; 10-50 V). The muscle responses were observed visually and registered by electromyography. Those rootlets associated with an abnormal motor response as evidenced by sustained muscular contraction or by prolonged electromyographic response were divided. Spasticity was scored from 0 to +. The muscular groups assessed were those involved in the flexion of the shoulder, elbow and wrist in the upper limbs, and those involved in flexion and adduction of the hip, flexion of the leg, and plantar flexion in the lower limbs. The patients were assessed 1 week before and 6 months after the operation. Reduction of spasticity was observed in all the muscular groups, and all the patients presented functional improvement of motor abilities. These preliminary results indicate that a limited procedure that reduces the extension of the laminectomy and the length of the operation could be effective for treating spasticity secondary to infantile cerebral palsy.

Cerebral Palsy↗
PubMed1990

[Chiari malformation].

The Chiari malformation (CHM) is a congenital disease of unknown etiology. It is presumed that a defective closure of the neural tube produces at least one of its three types. It has also been related to traumatic delivery. Type II is closely associated to the myelomeningocele. The clinical picture is determined by the chronic compression of the cervical cord by the cerebellar tonsils. Low cranial nerve palsy and muscular hypotonia are some of its predominant features. Syringomyelia complicates type I. CAT scan and NMR are the preferred radiological studies for diagnosing MCH. Treatment is surgical. Posterior fossa decompression and cervical laminectomy are sufficient if the ventricular shunt is patent. If treatment is installed before permanent structural damage is present, up to 88% of the patients have significant remission of the symptoms.

Arnold-Chiari Malformation↗
PubMed1990

[Selective limited posterior rhizotomy at 3 dorsal levels. A variant for the neurosurgical treatment of spasticity].

INTRODUCTION: Selective posterior rhizotomy (SPR) is effective for reducing spasticity associated to infantile cerebral palsy (ICP). To avoid excessive muscular hypotone a different surgical technique is proposed. PATIENTS AND METHODS: Sixteen children with spasticity secondary to ICP were evaluated before and after rhizotomy. The degree of spasticity was compared in the lower an in the upper limbs. Dorsal roots of levels L4, L5, and S1 were analyzed and sectioned according to the results yielded by intraoperative electrical stimulation. RESULTS: Spasticity was reduced in all the muscular groups analyzed. One of the patients had bladder incontinence. CONCLUSIONS: The limited surgical procedure is sufficient for reducing spasticity.

Afferent Pathways↗
PubMed1987

Childhood brain tumours in Cape Town.

Brain tumours are the commonest solid tumours of childhood; 145 patients under the age of 14 years with intracranial tumours treated between 1979 and 1985 are presented. Of the tumours 63% were situated in the posterior fossa while 37% were supratentorial. Medulloblastomas accounted for 25% of the entire series. Modern methods of treatment are outlined.

Brain Neoplasms↗
PubMed1986

Spinal tumours of childhood.

Spinal tumours in children have different features and require different management than in adults; 20 patients under the age of 14 years are reported--the common presenting features were limb weakness, pain and spinal deformity. Eight tumours were extradural and 12 intradural of which 3 were intramedullary. The 6 patients who did not do well postoperatively were found to have a malignant tumour or were completely paraplegic or quadriplegic before surgery. If detected and treated early, results are excellent in many cases, since the tumours are usually benign.

Adolescent↗