A tribute to Dr. A. Earl Walker.

Doctor Walker died on January 1, 1995, at the age of 87 years. His contributions to neuroscience and neurosurgery are presented and discussed, together with his impact on national and international organizations of neurosurgery. A short account of his background and professional career is given, with emphasis on his 25 years at The Johns Hopkins Hospital as Chief of Neurosurgery.

Why did we not see the light? A retrospective analysis of ideas in neurosurgery.

Based on personal experience, a retrospective analysis of the changes in neurosurgical thinking during the past 50 years is presented. The four phases of the organisational pattern are discussed. The contributions of a few pioneer neurosurgeons are emphasized. The impact of revolutionary technical improvements on future neurosurgeons should be balanced by sound clinical judgement--as "novelty is not equal to creativity."

Comparison of patients with and without emotional/behavioral deterioration during the first year after traumatic brain injury.

The records of 34 patients who showed evidence of emotional deterioration 6 months or more following traumatic brain injury were compared with a group of patients matched for severity of initial neuropsychiatric impairment who did not show deterioration. The deterioration group was more likely to have been involved in assaults and less likely to have been involved in a motor vehicle accident than the improvement group. The deterioration group was also more likely to have a prior history of alcohol abuse and to have sustained a skull fracture with left parietal lobe injury than the improvement group. Agitation, hostility, apathy, lability of mood, emotional withdrawal, and depression were the symptoms most likely to worsen over time. This deterioration may have been due to premorbid personality characteristics or to the nature of long-term neuronal response to injury.

Thoracolumbosacral laminectomy in achondroplasia: long-term results in 22 patients.

Neurologic problems caused by vertebral stenosis in the thoracolumbosacral (TLS) region are common in achondroplasia. Surgical decompression by means of laminectomy is recommended often, but its long-term results have not been assessed. We reviewed the clinical history of 22 achondroplastic patients who had at least one TLS laminectomy performed before 1981. Symptoms predated the first TLS laminectomy by a mean of 2.3 years (range 0.1-17 years). Preoperatively, 91% of patients had motor function impairment, 86% had sensory dysfunction, 86% had neurogenic claudication, 77% had radicular pain, 59% had symptomatic bladder dysfunction, and 32% had fecal incontinence. Only upper motor neurons were affected in 45%, only lower motor neurons in 27%, and both in 27%. Follow-up after the first TLS laminectomy averaged 8 years. Of the 20 patients who initially improved neurologically, 12 had functional improvement for more than 5 years. However, 11 of these 12 subsequently regressed and 10 had additional laminectomies. Long-term neurologic and functional improvement was associated with both a short duration of symptoms preoperatively and absence of cervical stenosis. Because of hypertrophic scarring, 9 patients developed compression at the site of the initial TLS laminectomy and required re-operation 6.4 years (range 1-11 years) later. We conclude that TLS laminectomy is an effective treatment for spinal stenosis if performed early in the course of the neurologic syndrome. However, some patients have, or later develop, compression adjacent to the myelographic site of stenosis, and some develop hypertrophic scarring at the site of initial decompression. We therefore suggest that the first TLS laminectomy extend (1) 3 levels cephalad to the myelographic block, (2) at least to S2, and (3) laterally at least to the facets.

Cerebellopontine angle lipoma.

Lipomas rarely occur intracranially. Moreover, the cerebellopontine angle is one of the more unusual sites of such hamartomas. Of the 11 reported cases, all but three caused symptoms related to compression of the cranial nerves in the cerebellopontine angle. Only three separate cases have been studied by computed tomography, and in one the fat density was not recognized. This report deals with the clinical presentations, surgical management, and radiologic assessment of these lesions.

Pure motor hemiplegia and lower cranial nerve palsies in a primary medullary tumor with review of the literature.

A case is described of pure motor hemiplegia and lower cranial nerve palsies in a primary medullary tumor. The literature is reviewed to support the contention that this is a case of primary medullary glioma and to show the uniqueness of the presentation of pure motor hemiplegia with a tumor in this location. A discussion of the problems of brainstem tumor is presented; surgical exploration is recommended if indicated, followed by radiation therapy.

Myelography in achondroplasia: value of a lateral C1-2 puncture and non-ionic, water-soluble contrast medium.

Because of technical difficulties and diagnostic limitations encountered with other myelographic techniques in patients with achondroplasia, the authors employed a lateral C1-2 puncture and non-ionic, water-soluble contrast medium in 18 achondroplastic patients with spinal compression (21 procedures). This technique proved most appropriate for identifying the upper limit of degenerative osteophytes causing exacerbation of congenital spinal stenosis, which is crucial in planning decompressive surgery. A potentially important additional finding was the presence of degenerative lower cervical spine disease in the majority of patients. There were no serious complications. The authors recommend this technique as safe and effective in achondroplastic patients with severe congenital spinal stenosis.

Spinal epidural extramedullary hematopoiesis with cord compression in a patient with refractory sideroblastic anemia. Case report.

Spinal cord compression by epidural extramedullary hematopoiesis (EMH) is a rare phenomenon. A case of acute compressive myelopathy is reported in a 72-year-old man with EMH secondary to sideroblastic anemia. Technetium colloid scanning was used to document extensive ectopic marrow formation. The patient improved following surgery and radiotherapy. A review of the literature revealed 23 other cases of symptomatic spinal epidural EMH. The underlying hematological disorder varied but was always of long duration. Eighty-eight percent of the patients were males. Symptoms lasted longer than 1 week in 90% of cases, and 91% demonstrated incomplete neurological deficits. Plain x-ray films were rarely helpful in establishing the diagnosis. Technetium sulfur colloid bone marrow scanning has been used successfully to detect EMH and has led to preoperative diagnosis in one case. Decompressive laminectomy with or without postoperative irradiation is the suggested therapy, although there is evidence that radiotherapy alone may be adequate in some cases. Good recovery is the rule despite long-standing neurological deficits.

Lumbosacral skin lesions as markers of occult spinal dysraphism.

Early treatment of occult spinal dysraphism may prevent progressive neurological deficits. However, diagnosis is often delayed until the onset of irreversible neurological damage. A review of data from the literature and patients at Johns Hopkins Hospital suggests that lumbosacral skin abnormalities such as tufts of hair, hemangiomas, lipomas, skin tags, or pigmented nevi should alert the physician to search for occult spinal dysraphism. In the asymptomatic patient with a skin lesion, roentgenography of the lumbosacral spine is a useful screening procedure for identifying treatable underlying problems.

Medulloblastoma causing a corticosteroid-responsive optic neuropathy.

A 25-year-old man had signs of optic nerve dysfunction. A diagnosis of optic neuritis was made and was supported by rapid resolution of signs and symptoms with use of corticosteroids. After initial negative radiologic investigations, his corticosteroid dosage was tapered, and the recurrence of his symptoms and signs prompted repeat computed tomographic scans. A suprasellar mass and a posterior-fossa mass were observed, and frontal craniotomy disclosed typical medulloblastoma, confirmed histologically. Although visual signs and symptoms in medulloblastoma have been reported secondary to optochiasmatic arachnoiditis and to papilledema, to the best of our knowledge this is the first reported case in which direct compression of the optic nerve has occurred as a result of extension of a posterior-fossa medulloblastoma. The favorable response of this compressive tumor to corticosteroids, stimulating an inflammatory optic neuritis, emphasizes the importance of reassessing any optic neuritis that follows an atypical course.

Results and complications in 55 shunted patients with normal pressure hydrocephalus.

This retrospective study of 55 shunted patients with "normal pressure" hydrocephalus evaluates the surgical results. Sixty percent of these patients had objective improvement following cerebrospinal fluid diversion but 44% had shunt-related complications of which 9% were fatal. Those patients who received a single theco-peritoneal shunt had a higher improvement rate and a lower incidence of postoperative complications. Successfully treated complications did not preclude postoperative improvement.

The so-called Dandy-Walker syndrome: analysis of 12 operated cases.

Twelve patients between the years of 1964 and 1971 underwent surgical treatment for the so-called Dandy-Walker syndrome at the Johns Hopkins Hospital. Five patients belonged to an early group (1-8 weeks); four patients to an intermediary group (3-20 months); and a late group consisted of three patients (3 years, 14 years and 34 years). The value of the various diagnostic studies is discussed on the basis of an analysis of the plain skull X-rays, cerebral angiograms, and combined air studies. The importance of a careful delineation of the underlying pathological condition is stressed to enable the surgeon to choose the appropriate technique. The diagnostic studies confirmed the diagnosis of a true Dandy-Walker syndrome in six of the twelve cases. The remaining six proved to have either an independent posterior fossa cyst with communication of the subarachnoid space and occasionally with the ventricles; or an isolated posterior fossa cyst with no communication but with impingement on the aqueduct and on the midline structures. In six patients, a primary simple shunt procedure was performed which had to be followed by a posterior fossa craniectomy in one and by a double-shunt (ventricle and posterior fossa cyst) in another. Four patients underwent a posterior fossa craniectomy; as the primary and only procedure (2), craniectomy followed by a ventriculoperitoneal shunt (1), or an unsuccessful shunt followed by craniectomy (1). In two patients, a so-called 'double shunt' was performed as a second operation, draining simultaneously the right lateral ventricle and the posterior fossa cyst. There was no death in this series. Three children had evidence of infected shunts; they responded to adequate therapy. Four had excellent results, with normal neurological examination and normal development. Four had good results, performing in school (working) was markedly improved; two had fair results with residual neurological deficit and some mental retardation. Two patients had to be considered as poor results. Both of them, however, have shown evidence of concomitant severe congenital abnormalities of the cerebellum on the diagnostic studies. The follow-up period ranged from 1 1/2 to 7 1/2 years.