The clinical course of neuromyelitis optica (Devic's syndrome)

OBJECTIVES

To evaluate the spectrum of neuromyelitis optica (NMO), including characteristics of the index events (optic neuritis [ON]) and myelitis), neuroimaging, CSF, and serologic studies, and to evaluate the long-term course.

METHODS

Review of 71 patients with NMO evaluated at the Mayo Clinic between 1950 and 1997.

RESULTS

NMO was either monophasic or relapsing. Patients with a monophasic course (n = 23) usually presented with rapidly sequential index events (median 5 days) with moderate recovery. Most with a relapsing course (n = 48) had an extended interval between index events (median 166 days) followed within 3 years by clusters of severe relapses isolated to the optic nerves and spinal cord. Most relapsing patients developed severe disability in a stepwise manner, and one-third died because of respiratory failure. Features of NMO distinct from "typical" MS included >50 cells/mm3 in CSF (often polymorphonuclear), normal initial brain MRI, and lesions extending over three or more vertebral segments on spinal cord MRI.

CONCLUSIONS

Clinical, laboratory, and imaging features generally distinguish neuromyelitis optica from MS. Patients with relapsing optic neuritis and myelitis may have neuromyelitis optica rather than MS. Patients with a relapsing course of neuromyelitis optica have a poor prognosis and frequently develop respiratory failure during attacks of cervical myelitis.

The natural history of multiple sclerosis: implications for trial design

The understanding of the natural history of multiple sclerosis has many implications for the design and interpretation of randomized controlled trials. Selection criteria, patient stratification, outcome measurements, and definitions of treatment failure can influence randomized controlled trial results and limit comparisons among trials. The focus of future studies should shift from short-term determinations of efficacy to definitive evaluations of long-term effectiveness. This will require novel investigative strategies such as the use of historic controls derived from natural history studies.

Genetic variants in the tumor necrosis factor receptor 1 gene in patients with MS

We scanned for all genetic variants in functionally important regions of the tumor necrosis factor receptor 1 gene (TNF-R1) in 100 to 111 MS patients from Olmsted County, MN, and analyzed selected variants for an association with disease course and severity. Ten genetic variants were uncovered. Only one variant, a silent substitution, was found in coding sequence. One intronic variant may generate a novel splice-junction sequence. We did not find an association between either this intronic variant or another common promoter variant and the course or severity of MS.

Paraneoplastic encephalomyelitis and seminoma: importance of testicular ultrasonography

We report two patients with paraneoplastic limbic and brainstem encephalitis associated with occult nonmetastatic testicular seminoma. In each patient, the neoplasm was detectable only by testicular ultrasonography. Male patients with this syndrome in whom lung cancer is not found should undergo testicular ultrasonography as part of the search for an extrapulmonary neoplasm. A normal clinical testicular examination is insufficient to exclude an occult seminoma.

Denaturation fingerprinting: two related mutation detection methods especially advantageous for high G + C regions

Two versions of denaturation fingerprinting (dnF2R and dnF1R are described for detecting mutations. DnF2R is a sensitive screening method in which fingerprints are generated by performing denaturing gel electrophoresis on bidirectional "cycle-sequencing" reactions with each of two dideoxy terminators, e.g. ddATP and ddCTP. When the fingerprints generated by ddATP and ddCTP are combined, all sequence changes are expected to result in one extra and one absent segment. DnF2R was performed on 246- and 318-bp segments of the human factor IX gene, and the products were electrophoresed through a 6% Long Ranger gel with 7 M urea. All 32 single-base mutations were detected in hemizygous males with hemophilia B. DnF2R has been applied to detect a total of seven heterozygous sequence changes in large-scale screening and was found to be especially suitable for high G+C regions. In a blinded analysis, all of twenty-four additional single-base mutations were detected, but 7 of 31 heterozygous mutations were missed (23%). To reduce the effort of dnF2R by almost twofold while retaining the ability to detect all types of single-base changes, one fingerprint (dnF1R) was generated by performing a single reaction with ddATP and a second chemically modified terminator (e.g., ROX-conjugated ddCTP), which retards the mobility of the same termination products. The sensitivity and specificity of dnF1R equaled that of dnF2R, with the exception that the blinded analysis of heterozygotes in the 318-bp segment, which revealed the presence of an additional mutation. DnF under partially denaturing conditions may have optimal sensitivity for the detection of heterozygotes.

Cerebral venous thrombosis complicated by hemorrhagic infarction: factors affecting the initiation and safety of anticoagulation

BACKGROUND AND PURPOSE

Anticoagulation (AC) may improve outcome in cerebral venous thrombosis (CVT), even when complicated by pretreatment hemorrhagic infarction (HI). The HI characteristics which affect the decision to initiate AC therapy and its outcome are unknown. We reviewed our experience with AC treatment for patients with CVT and HI.

METHODS

Retrospective study.

RESULTS

Two groups of patients were compared: those who received AC (n = 6) and those who did not (n = 6). Hemorrhage volumes ranged from petechial to large (93 cm3) hematoma with mass effect. Anticoagulated patients received treatment a mean of 11.3 days after symptom onset. Each had exclusively extratemporal HI without midline shift and had stable hemorrhage volumes and clinical status for at least 24 h prior to AC. AC did not increase HI volume or worsen clinical outcome. All 6 non-AC patients had enlarging hematomas. Four of these 6 patients had temporal HI; and two required hematoma resection.

CONCLUSIONS

AC therapy was avoided in CVT patients with HI that were located in the temporal lobe, caused midline shift or were enlarging. AC was safely initiated within several days in clinically stable patients with non-temporal-lobe HI of unchanging volume. We suggest that the location and unchanged volume on serial CT may be important factors influencing the safety of AC therapy in patients with CVT and HI.

Clinical outcome measures and rating scales in multiple sclerosis trials

In this review, we analyzed clinical outcome measures used in multiple sclerosis (MS) clinical trials in which the primary goal is to slow or arrest progression of disease. In addition, we examined rating scales that quantify symptomatic complications of MS (for example, spasticity) and the current role of magnetic resonance imaging in MS treatment trials. Each proposed scale has advantages and deficiencies, and none meets all the criteria for an ideal outcome measure. The validity of trial design may be improved by using combinations of selected components of current scales as well as new instruments targeted to specific variables (such as motor strength). Symptom-specific rating scales are most appropriately used in trials of symptomatic therapeutic strategies for MS. Until serial magnetic resonance imaging changes are definitely known to predict long-term impairment and disability in patients with MS, clinical outcome measures will remain the primary means of assessing therapeutic efficacy in phase III clinical trials.

Multifocal brain MRI artifacts secondary to embolic metal fragments

We report a patient with unusual MRI abnormalities that had the physical characteristics of ferromagnetic artifact. We believe that the MRI artifacts were due to microscopic embolic metal fragments, most likely from a mechanical heart valve prosthesis. Potential sources of metal emboli should be considered in patients with MRI abnormalities compatible with ferromagnetic artifact.

Genetic variation in the tumor necrosis factor alpha gene and the outcome of multiple sclerosis

The objective of this study was to determine whether sequence variation in the tumor necrosis factor alpha (TNF alpha) gene is associated with MS course and severity in Olmsted County, MN. The severity and temporal course of MS are heterogeneous. Genetic factors may play a role in determining the course of MS. TNF alpha expression is temporally associated with exacerbations of MS and is increased in individuals with progressive disease. The entire TNF alpha gene was amplified by polymerase chain reaction in 78 MS patients and in 39 patients with schizophrenia. Denaturation finger-printing, a modification of direct sequencing that detects virtually all genetic polymorphisms, was performed for four regions spanning the functionally significant portions of the gene, including the promoter region. Polymorphisms were confirmed by complete sequencing. The severity and temporal course of MS were compared in those with wild-type versus variant alleles. Four sequence changes were detected, three of which occurred in MS patients. None occurred in a protein-encoding sequence. Neither of the two most common sequence variants were associated with disease severity or temporal course. Genetic variation of the TNF alpha gene is not associated with variation in the course or long-term outcome of MS in this population-based sample.

The effects of monoamine oxidase B inhibition on dopamine metabolism in rats with nigro-striatal lesions

The purpose of this study was to examine whether monoamine oxidase type B (MAO-B) has a role in striatal dopamine metabolism in animals with a unilateral lesion of the medial forebrain bundle, and whether 2-phenylethylamine (PE) could have a role in amplification of dopamine (DA) responses in DA depleted striatum. Inhibition of MAO-B did not alter DA metabolism in lesioned striata. PE accumulation decreased with loss of DA as long as there was no DA dysfunction. In lesioned striata with dysfunction of DA transmission at the synaptic level, PE accumulation increased, suggesting a compensatory increase in PE synthesis. This increase in PE levels does not appear to be mediated by an increase in the total striatal aromatic L-amino acid decarboxylase (AADC) activity. We conclude that inhibition of MAO-B has no effect on DA metabolism in the hemi-parkinsonian rat striatum and that PE could be involved in the antiparkinsonian action of MAO-B inhibitors.