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D J Loes

Publications and source records attributed to D J Loes.

At least 19 recordsLinked to original sources
PubMed2003

Analysis of MRI patterns aids prediction of progression in X-linked adrenoleukodystrophy.

BACKGROUND: X-linked adrenoleukodystrophy (X-ALD) has variants with widely different outcomes, hampering clinical counseling and evaluation of therapies. OBJECTIVE: To evaluate the degree to which MRI patterns can predict lesion progression. METHODS: Two hundred six boys and men with cerebral X-ALD (median age 12.2 years, mean age 18.5 years, age range 1.7 to 73.8 years) were studied. In 140 individuals, follow-up MRI were available. Data after bone marrow transplantation (BMT) were excluded. The patterns of MRI abnormalities were subdivided into five groups based on the anatomic location of the initial T2 signal hyperintensity (pattern 1: parieto-occipital white matter, pattern 2: frontal white matter, pattern 3: corticospinal tract, pattern 4: cerebellar white matter, pattern 5: concomitant parieto-occipital and frontal white matter). The X-ALD MRI Severity Scale, a 34-point scale previously described, was used in the analysis. RESULTS: Pattern 1 patients had rapid progression if contrast enhancement was present and if the MRI abnormality manifested at an early age. The latter was also true for pattern 2 patients. Based on these variables, predictive formulas were constructed for these two patterns using multiple regressions. MRI progression was much slower in pattern 3 and 4 patients, whereas in the few pattern 5 patients, it was more rapid than in any other of the patterns. Patterns 1 and 5 occurred mainly in childhood, patterns 2 and 4 in adolescence, and pattern 3 in adults. CONCLUSIONS: MRI progression in X-ALD depends on patient age, initial MRI Severity Scale score, and anatomic location of the lesion. When used in combination, these data aid the prediction of disease course and the selection of patients for BMT.

Adolescent↗
PubMed2001

Evolution of phenotypes in adult male patients with X-linked adrenoleukodystrophy.

Our objective was to study the phenotype evolution of X-linked adrenoleukodystrophy (X-ALD) and the relation between axonal degeneration and cerebral demyelination. Although different X-ALD phenotypes are recognized, little is known about their evolution. Neuropathological and electrophysiological studies have shown that X-ALD is a disease with mixed features of axonal degeneration, leading to myeloneuropathy, and a severe inflammatory reaction in the cerebral white matter, resulting in demyelination. Retrospectively, 129 men with X-ALD were studied who were 1) at least 20 years presently or at the time of death, and 2) regularly monitored. Phenotype assignments were made at diagnosis and at present, or at death, using medical history and findings of neurological examination. Handicap was studied with the modified Rankin scale, and cerebral abnormalities with the X-ALD MRI severity (Loes) score. The mean follow-up interval was 10.1 +/- 5.0 years. Among 32 patients neurologically asymptomatic at diagnosis, 16 (50%) developed neurological deficits. Among 68 adrenomyeloneuropathy (AMN) patients initially without clinical brain involvement, 13 (19%) additionally developed cerebral demyelination. In a subset of 60 AMN patients, a moderate handicap evolved over a period of 16.2 +/- 8.9 years. Among 13 AMN patients with additional definite or probable cerebral involvement at diagnosis, eight died and one remained in a vegetative state. Most of the 16 patients with the cerebral phenotypes deteriorated. There is a high risk for adult neurologically asymptomatic patients to develop neurological deficits and for AMN patients to develop cerebral demyelination. Axonal degeneration and cerebral demyelination emerge in X-ALD independently of each other. This may have implications for the phenotype classification, the search for modifying factors, and the development and evaluation of new therapies.

Adolescent↗
PubMed2000

X-Linked adrenoleukodystrophy: overview and prognosis as a function of age and brain magnetic resonance imaging abnormality. A study involving 372 patients.

The phenotypic expression of X-linked adrenoleukodystrophy (X-ALD) ranges from the rapidly progressive childhood cerebral form to the milder adrenomyeloneuropathy (AMN) in adults. It is not possible to predict phenotype by mutation analysis or biochemical assays. This study reports on 372 patients ranging in age from less than 3 years to adulthood, who have been followed at the Kennedy Krieger Institute. With the aim of determining whether a method could be developed to predict clinical course by analysis of data available at time of first contact, the patients were subdivided into 18 subgroups on the basis of age and the extent of brain magnetic resonance (MRI) abnormality utilizing the MRI scoring system devised by Loes et al. Scores to grade degree of neurologic and neuropsychologic impairment were also developed. There was strong correlation between MRI and the neurology and neuropsychology scores at baseline. Information based exclusively on age and MRI score at time of first contact was highly predictive of future clinical course and should aid the evaluation of the effects of bone marrow transplantation and the selection of patients for this procedure, as well as the evaluation of other therapies that may be developed in the future.

Adrenoleukodystrophy↗
PubMed2000

X-linked adrenoleukodystrophy: the role of contrast-enhanced MR imaging in predicting disease progression.

BACKGROUND AND PURPOSE: Early assignment of disease progression among patients with X-linked adrenoleukodystrophy (ALD) is critical for the appropriate selection of effective therapy. We evaluated the association between contrast enhancement on T1-weighted spin-echo MR images and disease progression. METHODS: Clinical charts of patients with X-linked ALD were reviewed for age, availability of MR images of the brain, severity of neurologic impairment, and duration and number of follow-up evaluations. Forty-three male patients with X-linked ALD had undergone multiple MR imaging examinations of the brain that consisted of at least sagittal and axial T1-weighted spin-echo, axial double-echo spin-echo, and contrast-enhanced axial T1-weighted spin-echo imaging. The MR images were reviewed for the presence of contrast enhancement. In addition, global disease burden, as shown by the double-echo spin-echo images, was assessed using a visual scoring method (Loes score). RESULTS: Enhancement was seen on the initial T1-weighted spin-echo MR images of 21 (49%) patients; 18 (86%) of the 21 patients had disease progression revealed by the follow-up evaluations based on MR imaging (Loes) and neurologic scores. No enhancement was seen on the initial T1-weighted spin-echo MR images of 22 (51%) patients; for 18 (82%) of the 22 patients, no evidence of disease progression was revealed by the follow-up evaluations. CONCLUSION: There is a very strong association between the presence of contrast enhancement on T1-weighted MR images and X-linked ALD progression based on clinical evaluation and MR imaging.

Adolescent↗
PubMed1999

Globoid cell leukodystrophy: distinguishing early-onset from late-onset disease using a brain MR imaging scoring method.

BACKGROUND AND PURPOSE: Our purpose was to determine the characteristic MR features of early-onset (before age 2 years) versus late-onset (after age 2 years) globoid cell leukodystrophy (GLD). METHODS: Thirty-four brain MR images in 22 patients with GLD were reviewed. A severity score (0 to 32), based on a point system derived from the location and extent of disease and the presence of focal and/or global atrophy, was calculated for each examination. RESULTS: Of the 22 patients, three were asymptomatic and 19 were symptomatic. Ten patients had early-onset disease, whereas nine had late-onset disease. MR images of all patients showed abnormalities. In the early-onset group (n = 10; mean maximum MR score, 8.1; range, 3-18), 90% had pyramidal tract involvement, 80% had cerebellar white matter involvement, 70% had deep gray matter involvement, 60% had posterior corpus callosal involvement, 50% had parietooccipital white matter involvement, and 40% had cerebral atrophy. Serial MR imaging in four of these patients revealed progressive disease. In the late-onset group (n = 9; mean maximum MR score, 5.6; range, 4-10), 100% had pyramidal tract involvement, 100% had parietooccipital white matter involvement, 89% had posterior corpus callosal involvement, and none had cerebellar white matter involvement, deep gray matter involvement, or cerebral atrophy. Serial MR imaging in one patient with late-onset GLD did not reveal any change. A spectrum of findings was observed in the three patients who were asymptomatic. CONCLUSION: Cerebellar white matter and deep gray matter involvement are present only in early-onset GLD. Pyramidal tract involvement is a characteristic finding in both early- and late-onset GLD. This scoring method for brain MR observations will assist in the objective assessment of the impact of hematopoietic stem cell transplantation in patients with GLD.

Adolescent↗
PubMed1998

Hematopoietic stem-cell transplantation in globoid-cell leukodystrophy.

BACKGROUND: Globoid-cell leukodystrophy is caused by a deficiency of galactocerebrosidase, which results in progressive central nervous system deterioration. We investigated whether allogeneic hematopoietic stem-cell transplantation can provide a source of leukocyte galactocerebrosidase and thereby prevent the decline of central nervous system function in patients with the disease. METHODS: Five children with globoid-cell leukodystrophy (one with the infantile type and four with late-onset disease) were treated with allogeneic hematopoietic stem-cell transplantation. Measurement of leukocyte galactocerebrosidase levels, neurologic examinations, neuropsychological tests, magnetic resonance imaging of the central nervous system, cerebrospinal fluid protein assays, and neurophysiologic measurements were performed before and after transplantation, with follow-up ranging from one to nine years. RESULTS: Engraftment of donor-derived hematopoietic cells occurred in all patients and was followed by restoration of normal leukocyte galactocerebrosidase levels. In the four patients with late-onset disease, the central nervous system deterioration was reversed, and in the patient with the infantile form of the disease, signs and symptoms have not appeared. Magnetic resonance imaging showed a decrease in signal intensity in the three patients with late-onset disease who were assessed both before and after transplantation. Abnormalities in cerebrospinal fluid total protein levels were corrected in three patients with late-onset disease and substantially reduced in the patient with the infantile form. CONCLUSIONS: Central nervous system manifestations of globoid-cell leukodystrophy can be reversed by allogeneic hematopoietic stem-cell transplantation.

Central Nervous System Diseases↗
PubMed1994

CSF findings in adrenoleukodystrophy: correlation between measures of cytokines, IgG production, and disease severity.

The childhood-onset cerebral form of adrenoleukodystrophy has a devastating neurologic prognosis. Unfortunately, there is no early method of distinguishing it from the more benign forms of adrenoleukodystrophy, such as adrenomyeloneuropathy. To evaluate the manner in which this disease entity may be reflected in the cerebrospinal fluid, we studied a consecutive series of 19 patients, all with biochemically proved adrenoleukodystrophy. total protein, immunoglobulin production, cytokine levels, and cerebrospinal fluid pressure were measured. In this single sample of cerebrospinal fluid, a significant correlation existed between clinical stage of the illness and cerebrospinal fluid myelin basic protein. No correlation existed with total protein, cytokines, or measures of immunoglobulin production.

Adolescent↗
PubMed1994

Adrenoleukodystrophy: a scoring method for brain MR observations.

PURPOSE: To develop a scoring method for brain observations in patients with X-linked adrenoleukodystrophy. METHODS: One hundred seventy-five brain MR scans in 83 male subjects less than 20 years of age with proved biochemical defects were reviewed. A severity score (0 to 34), based on a point system derived from location and extent of disease and the presence of focal and/or global atrophy, was calculated for each exam. RESULTS: Fifty-five of the 83 patients showed MR findings consistent with adrenoleukodystrophy. Two major patterns were observed. A posterior pattern (mean score, 9; range, 0.5 to 25) was present in 80% of patients, and an anterior pattern (mean score, 10; range, 2 to 18) was present in 15% of patients. Serial MR imaging, positive for adrenoleukodystrophy in 34 patients (mean follow-up, 23 months; range, 2 months to 6 years 11 months), showed progressive disease in 52%, progressive disease with subsequent stabilization in 18%, stable disease in 24%, and minimal improvement in 6%. CONCLUSION: The adrenoleukodystrophy MR severity scoring method is a measure that can be used with standard MR images. When used in conjunction with clinical parameters, this scoring method may help define better the natural history of adrenoleukodystrophy and monitor response to developing therapies.

Adolescent↗
PubMed1994

Childhood cerebral form of adrenoleukodystrophy: short-term effect of bone marrow transplantation on brain MR observations.

PURPOSE: To report the serial brain MR observations in patients with childhood-onset cerebral adrenoleukodystrophy 1 to 2 years after bone marrow transplantation. METHODS: Eight boys with childhood-onset cerebral adrenoleukodystrophy have undergone successful transplantation at our institution. Seven patients (mean age, 8 years 10 months; range, 5 years 3 months to 11 years 9 months) had serial MR studies before and after transplantation. An MR severity score (0 to 34) based on disease location and the presence or absence of focal atrophy was calculated for each patient scan. RESULTS: Posttransplantation serial MR showed improvement in two patients, stabilization in three patients, and worsening of MR signal changes in two patients. The patient with the most striking progression had systemic graft-versus-host disease. Although the adrenoleukodystrophy MR severity score did not change in three patients after transplantation, two of these patients did show improved margination of disease. CONCLUSION: Bone marrow transplantation can affect brain MR observations in childhood-onset cerebral adrenoleukodystrophy. Although brain MR findings do not typically resolve, they do seem to stabilize, which is an improvement over the natural MR history of the disease.

Adrenoleukodystrophy↗
PubMed1994

Trauma to the cerebrovascular system.

Trauma to the cerebrovascular system can result in vascular injuries, such as dissection, pseudoaneurysm, thrombosis, rupture, and arteriovenous fistula. Although the diagnosis of vascular injury is usually considered in all cases of penetrating trauma, it may be overlooked in patients with nonpenetrating trauma. The possibility of vascular injury should be considered in all patients with head and neck trauma, especially those patients with acute or delayed neurologic dysfunction. Although intra-arterial angiography remains the gold standard diagnostic tool, the combination of MR imaging and MR angiography may permit noninvasive diagnosis of vascular injury. Moreover, MR readily provides detection of intracranial sequelae, such as cerebral infarction and intracranial hemorrhage.

Adolescent↗
PubMed1994

Steady-state free precession imaging of the inner ear.

The authors describe a steady-state free precession technique for imaging the inner ear. Although the signal-to-noise ratio is not as great as with other three-dimensional MR techniques, the inherent high contrast of inner ear structures makes this a valuable technique for patients with sensorineural hearing loss and for those who refuse paramagnetic contrast material.

Contrast Media↗
PubMed1994

Radiologic diagnosis, staging, and follow-up of adult central nervous system primary malignant glioma.

Glioma represents the most common primary intra-axial brain tumor. Currently, magnetic resonance (MR) imaging is the study of choice for the radiographic evaluation of patients with primary central nervous system glioma prior to and following therapeutic intervention. Computed tomography and MR imaging are frequently used for stereotactic biopsy and mapping. MR spectroscopy and/or thallium-201 single photon emission computed tomography may prove helpful in differentiating recurrent malignancy from radiation-induced necrosis.

Adolescent↗
PubMed1991

Magnetic resonance imaging and computed tomography in pediatric head and neck masses.

Fifty-three magnetic resonance imaging (MRI) and 25 computed tomography (CT) studies of 53 head and neck masses in pediatric patients were reviewed retrospectively. All lesions had pathologic proof except for 2 metastatic and 2 recurrent lesions, which only had prior pathologic confirmation at their primary sites. These included 12 malignant tumors, 23 benign tumors, 6 inflammatory masses, and 12 congenital lesions. The MRI performance ranged predominantly from good to excellent in detection of the lesion and the extent of involvement and in contrast to the surrounding tissue; when CT comparison was available, MRI proved to be equal to or better than it in detection of these factors and in preoperative diagnosis. Our results suggest that MRI should be the method of choice for the initial evaluation of the pediatric head and neck region, especially in those patients requiring multiple examinations. However, CT and MRI should be used conjunctively in complicated cases, especially those possibly involving lesions with calcifications or bony involvement.

Adolescent↗
PubMed1991

MR anatomy and pathology of the hypothalamus.

The hypothalamus, the ventral-most portion of the diencephalon, surrounds the anterior inferior portion of the third ventricle (Fig. 1). It functions primarily as an integrative mechanism for various autonomic and neuroendocrine activities including temperature regulation, water balance, behavior, and appetite. This pictorial essay illustrates the value of MR in depicting the normal anatomy and abnormalities of the hypothalamic region.

Adult↗
PubMed1990

Leukoencephalopathy in cerebral amyloid angiopathy: MR imaging in four cases.

We report four cases of biopsy proved cerebral amyloid angiopathy demonstrated by MR imaging. White matter signal hyperintensities on T2-weighted spin-echo pulse sequences were present in three patients. We believe the white matter lesions associated with cerebral amyloid angiopathy are not specific to this disorder but rather reflect hypoperfusion of distal white matter resulting from vascular disease.

Aged↗
PubMed1987

Ectopic supernumerary kidney. Functional assessment using radionuclide imaging.

A three-year old male presented with severe hydronephrosis secondary to posterior urethral valves; a pelvic supernumerary kidney was discovered postoperatively. Radionuclide imaging assisted in the management of this patient by providing estimates of relative renal function. A report of the case and a complete summary of the literature concerning this unusual duplication anomaly follows.

Child, Preschool↗