Frequent involvement of the optic radiation in patients with acute isolated optic neuritis.

Magnetic resonance imaging revealed asymptomatic lesions in white matter regions corresponding with the optic radiations in 20 of 28 patients (71%) with clinically isolated optic neuritis. In contrast to the findings with symptomatic lesions, there was no relationship between the latency of the visual evoked potential and the presence of these asymptomatic posterior visual pathway lesions.     

Spinal cord MRI in clinically isolated optic neuritis

BACKGROUND/METHODS: One hundred and fifteen patients with clinically isolated optic neuritis underwent magnetic resonance imaging (MRI) of the brain and spinal cord within 3 months of the onset of symptoms. RESULTS: Eighty one (70%) patients had brain lesions and 31 (27%) had cord lesions. Cord lesions were seen in 12% with a normal brain MRI, 21% with between one and eight brain lesions, and 45% with nine or more brain lesions. When the new diagnostic criteria for MS were applied, MRI cord imaging used for evidence of dissemination in time and space allowed a diagnosis of MS in only one additional asymptomatic patient at 1 year, two additional asymptomatic patients at 3 years. CONCLUSIONS: Using existing criteria, spinal cord imaging rarely contributes to the diagnosis in patients with clinically isolated optic neuritis.     

The prognosis of idiopathic optic neuritis

We evaluated the risk of developing clinically definite multiple sclerosis (CDMS) after acute isolated optic neuritis in 102 patients in a follow-up study (duration 6.5±2.0 years). The probability of CDMS was 13% after 2 years, 30% after 4 years, 38% after 6 years, and 49% after 8 and 10 years. CDMS occurred in 42 (59%) of 71 patients with brain lesions detected with magnetic resonance imaging (MRI). No patient with normal MRI exam developed the disease. Patients with 3 or more MRI-detected lesions presented a shorter first interattack interval and a higher relapse rate compared to subjects with only 1 or 2 lesions. The predictive value of CSF examination and of evoked potentials was poor.     

Occurrence of MRI abnormalities in patients with isolated optic neuritis

24 patients with clinically isolated optic neuritis (ON) were examined with MRI. Only 5 patients (22.9%) had a normal MRI scan. The number of detected clinically silent lesions ranged from 0 to 38. They were mainly located in the frontal and parietal white matter. All patients with more than 3 lesions on MRI had pathological findings in CSF. There was no correlation between the number and location of lesions and age at onset of ON.     

Magnetic resonance imaging in multiple sclerosis: investigation of brain and spinal cord lesions

Magnetic resonance imaging (MRI) of the brain was performed on forty-five patients with multiple sclerosis (MS), using T1-weighted inversion recovery and T2-weighted spin echo images, and the results were compared with X-ray computed tomography (CT). Some of the 45 MS patients were also examined by neurophysiological studies (visual evoked potentials and auditory brainstem responses) to compare with the brain MRI findings. MRI showed demyelinating plaques of the brain in 20 (74%) of 27 patients with brain symptoms, 11 (61%) of 18 patients without symptoms and 31 (69%) of all 45 patients. In 27 patients with brain symptoms, MRI was able to detect brain lesions in 6 (86%) of 7 acute stage patients and 14 (70%) of 20 non-acute stage patients. Furthermore, MRI was able to detect brain lesions in 21 (70%) of 30 clinically definite MS patients and 10 (67%) of 15 clinically probable MS patients. X-ray CT was performed on all 45 patients and was able to detect brain lesions in 9 (33%) of 27 patients with brain symptoms and 1 (6%) of 18 patients without symptoms. Visual evoked potentials were evaluated in 31 patients, and showed abnormalities in 1 (11%) of 9 patients without symptoms of optic neuritis and 100% of 22 patients with symptoms. Auditory brainstem responses were evaluated in 19 patients, and showed abnormalities in 1 (11%) of 9 patients without brainstem symptoms and 3 (30%) of 10 patients with symptoms. MRI of the brain was markedly superior to X-ray CT, visual evoked potentials and auditory brainstem responses in detecting clinically unsuspected lesions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Correlation of clinical,magnetic resonance imaging,and cerebrospinal fluid findings in optic neuritis

We found 42 of 74 patients (57%) with isolated monosymptomatic optic neuritis to have 1 to 20 brain lesions, by magnetic resonance imaging (MRI). All of the brain lesions were clinically silent and had characteristics consistent with multiple sclerosis (MS). None of the patients had ever experienced neurologic symptoms prior to the episode of optic neuritis. During 5.6 years of follow-up, 21 patients (28%) developed definite MS on clinical grounds. Sixteen of the 21 converting patients (76%) had abnormal MRIs; the other 5 (24%) had MRIs that were normal initially (when they had optic neuritis only) and when repeated after they had developed clinical MS in 4 of the 5. Of the 53 patients who have not developed clinically definite MS, 26 (49%) have abnormal MRIs and 27 (51%) have normal MRIs. The finding of an abnormal MRI at the time of optic neuritis was significantly related to the subsequent development of MS on clinical grounds, but interpretation of the strength of that relationship must be tempered by the fact that some of the converting patients had normal MRIs and approximately half of the patients who did not develop clinical MS had abnormal MRIs. We found that abnormal IgG levels in the cerebrospinal fluid correlated more strongly than abnormal MRIs with the subsequent development of clinically definite MS.     

Magnetic resonance imaging of the optic nerve in optic neuritis

Magnetic resonance imaging (MRI) of the optic nerves using the STIR (short inversion time inversion recovery) sequence was performed in 37 adult patients with a recent or past attack of optic neuritis. MRI revealed high-signal regions in 84% of symptomatic and 20% of asymptomatic nerves. The mean longitudinal extent of lesions was 1 cm. Slow or poor visual recovery was associated with more extensive lesions, or lesions within the optic canal. Disk swelling was usually associated with anterior lesions but also occurred with lesions in the canal. Visual evoked potentials were even more sensitive than MRI in detecting lesions and are still the investigation of choice in suspected demyelinating disease involving the optic nerve.     

Evaluation of central nervous system involvement in uncomplicated optic neuritis after prolonged follow-up

Magnetic resonance imaging (MRI), multimodal evoked responses (ER) and HLA antigens were examined in 10 patients with idiopathic acute optic neuritis (ON) without any clinical symptoms or signs of multiple sclerosis (MS) during 9-14 years. In MRI, abnormalities compatible with MS were seen in 4 patients. In spite of clinically unilateral ON, a bilateral abnormality in visual evoked responses (VER) was seen in 3 of 9 cases. Brain stem auditory evoked responses (BAER) were normal in all cases, short latency somatosensory evoked response (SER) in all but one. The cerebrospinal fluid at time of ON showed signs of demyelination in one case only. The frequency of HLA antigens DR2 (78%) and B18 (40%) was significantly increased in comparison to healthy controls. MRI seems to be the most sensitive method in the detection of cerebral lesions of MS, especially in mild or asymptomatic forms of the disease. The present techniques are, however, mostly unable to demonstrate optic nerve lesions which more reliably can be evaluated by VERs. The question whether idiopathic ON represents a form of MS solely, cannot be resolved.     

Magnetic resonance imaging in optic nerve lesions with multiple sclerosis

Magnetic resonance imaging (MRI) of the optic nerves was performed in 10 patients with multiple sclerosis (MS) using short inversion time inversion recovery (STIR) pulse sequences, and the results were compared with the visual evoked potentials (VEP). The 10 patients had optic neuritis in the chronic or remitting phase together with additional symptoms or signs allowing a diagnosis of clinically definite or probable MS. Sixteen optic nerves were clinically affected and 4 were unaffected. MRI was performed using a 0.5 tesla superconducting unit, and multiple continuous 5 mm coronal and axial STIR images were obtained. A lesion was judged to be present if a focal or diffuse area of increased signal intensity was detected in the optic nerve. In VEP, a delay in peak latency or no P 100 component was judged to be abnormal. With regard to the clinically affected optic nerves, MRI revealed a region of increased signal intensity in 14/16 (88%) and the VEP was abnormal in 16/16 (100%). In the clinically unaffected optic nerves, MRI revealed an increased signal intensity in 2/4 (50%). One of these nerves had an abnormal VEP and the other had a VEP latency at the upper limit of normal. The VEP was abnormal in 1/4 (25%). In the clinically affected optic nerves, the degree of loss of visual acuity was not associated with the longitudinal extent of the lesions shown by MRI. The mean length was 17.5 mm in optic nerves with a slight disturbance of visual acuity and 15.0 mm in nerves with severe visual loss.(ABSTRACT TRUNCATED AT 250 WORDS)     

Paraclinical tests in acute-onset optic neuritis: basal data and results of a short follow-up

Up to now it is still doubtful whether there is a real risk of developing multiple sclerosis (MS) after initial monosymptomatic optic neuritis (ON). In this study we evaluated 43 patients with isolated acute-onset ON, in order to demonstrate the presence of oligoclonal bands (OBs) in the cerebrospinal fluid (CSF) and any additional clinically silent central nervous system (CNS) lesions. All examinations were performed from 5 days to 4 months (mean 43 days), from the onset of visual disturbances. Brain magnetic resonance imaging (MRI) detected white matter areas with increased signal in 21 patients (49%), while somatosensory and brainstem auditory evoked potentials revealed CNS abnormalities in only 5 patients (12%). OBs were present in the CSF of 20 patients (46%). Visual evoked potentials were abnormal in 39 patients (91%). Seven out of the 37 patients (19%) with at least one year follow-up, (mean duration of the follow-up = 32 months, range = 12-74), developed clinically definite MS (CDMS). All 7 patients had positive brain MRI and 6 had positive CSF examination at the basal evaluation. Our data suggest that MRI and CSF-OBs are the most reliable means of identifying patients with isolated ON who subsequently develop CDMS. They may therefore have a predictive value in defining MS risk.     

Evoked potentials in suspected multiple sclerosis: diagnostic value and prediction of clinical course

Pattern visual, somatosensory and brainstem auditory evoked potentials (EPs) of 14 patients with definite multiple sclerosis, 222 patients suspected of having multiple sclerosis, 26 patients with isolated optic neuritis and 40 patients with a chronic not diagnosed neurologic disorder, were compared with their clinical diagnoses on 2 1/2-year follow-up. In the MS suspects, an EP abnormality demonstrating a clinically silent lesion in any modality (65 patients) was associated with a 71% chance of clinical deterioration (48% chance of definite MS within the follow-up period). Normal EPs (121 patients) were associated with a 16% chance of deterioration (4% chance of definite MS). EPs in patients in whom the only abnormalities confirmed known lesions (36 patients) did not predict follow-up status. Visual EPs demonstrated clinically silent lesions more frequently than somatosensory and auditory EPs (22%, 12% and 5% of patients). Only one of the patients with optic neuritis and 3 of the chronic not diagnosed group had EPs demonstrating clinically silent lesions. CSF and NMR studies also correlated with follow-up in subseries of the patients.     

Cognitive dysfunction 24-31 years after isolated optic neuritis

OBJECTIVE: Cognitive dysfunction is common in multiple sclerosis (MS), but long-term data on cognition in patients with clinically isolated syndromes are sparse. METHODS: We determined cognitive functions in 22 patients 44-75 years old diagnosed with optic neuritis 24-31 years earlier but had no further clinical bouts and had not progressed clinically to MS. We used a neuropsychological test battery covering nine cognitive domains. Magnetic resonance imaging (MRI) of the brain had been performed earlier and was normal in six patients and showed two or more white matter abnormalities compatible with demyelinating lesions in 16 patients. RESULTS: On neuropsychological testing, one patient was within normal range on all tests, six subjects showed borderline results, and 15 patients (68%) showed significantly impaired performance in at least one cognitive domain. Seven patients showed significant impairment in two or more domains. Executive function, visuo-spatial ability, and information processing speed were the most frequently affected domains. There was no apparent correlation between MRI findings and cognitive function. CONCLUSIONS: We conclude that cognitive dysfunction is common in patients many years after clinically isolated optic neuritis. Cognitive dysfunction was found even in patients who had no apparent demyelinating lesions on follow-up MRI.     

Visual evoked potentials and quantitative perimetry in multiple sclerosis

The visual evoked potential (VEP) to a flash stimulus proved to be more effective than quantitative perimetry in detecting evidence of previous optic neuritis (97 vs 56%) or asymptomatic lesions in the visual pathways (56 vs 14%) of 49 patients with multiple sclerosis. The characteristic VEP abnormality, increased latency, was also found in 8 of 15 eyes with visual field defects related to ischemic optic neuropathy. This abnormality therefore is not specific for demyelinative disease, but it is highly suggestive in the presence of normal visual function determined psychophysically. The VEP disclosed a high incidence (81%) of asymptomatic lesions in optic nerves opposite previously affected eyes. Neither the presence nor the magnitude of the latency abnormality correlated with the degree of visual impairment. Prolonged latency may not be present at the onset of acute optic neuritis.     

Is optic neuritis more benign than other first attacks in multiple sclerosis?

Optic neuritis presentations are thought to have a better prognosis. The aim of our study was to compare conversion to multiple sclerosis on the different topographies of CISs. We prospectively evaluated 320 patients with CISs (123 with optic neuritis, 78 with brainstem syndromes, 89 with spinal cord syndromes, and 30 with other topographies) who were observed for a median of 39 months. Patients underwent brain MRI within 3 months of their first attack and again 12 months later. Conversion to multiple sclerosis determined either clinically or by MRI was evaluated according to topography. Baseline MRI was normal in 49.2% of patients with optic neuritis compared with 24% in brainstem syndromes, 24% in spinal cord syndromes, and 18.5% in other syndromes. Optic neuritis behaved differently from the other CISs for lower conversion to clinically definite multiple sclerosis and smaller proportion of patients fulfilling MRI dissemination in space, time, or both. Nevertheless, when only patients with abnormal cranial MRI results at baseline were selected, no differences for clinical or MRI conversion were found. Optic neuritis has a smaller risk for conversion to multiple sclerosis. Nevertheless, MRI at baseline, not CIS topography, appears to be the crucial issue at multiple sclerosis presentation.     

Multifocal visual evoked potential latency analysis: predicting progression to multiple sclerosis

OBJECTIVE: To monitor the difference in conversion rates to multiple sclerosis (MS) in 46 patients with optic neuritis between patients with multifocal visual evoked potential latency delay and those with normal latency. DESIGN: Prospective case series. SETTING: Metropolitan neuro-ophthalmology clinic. PARTICIPANTS: Forty-six patients with optic neuritis who did not have a diagnosis of MS on enrollment in the study. MAIN OUTCOME MEASURES: Conversion to MS according to the McDonald criteria. RESULTS: Analysis revealed that only 22 subjects had multifocal visual evoked potential latency delay. Over 1 year, 36.4% of patients with optic neuritis with latency delays progressed clinically to MS compared with 0% of those with normal latencies (P = .03, chi2). CONCLUSION: This may indicate that multifocal visual evoked potential latency delay can assist in predicting progression to future MS.     

Clinically isolated syndromes suggestive of multiple sclerosis, part I: natural history, pathogenesis, diagnosis, and prognosis

In 85% of young adults with multiple sclerosis (MS), onset is a subacute clinically isolated syndrome (CIS) of the optic nerves, brainstem, or spinal cord. Methods of assessing the prognosis for patients who present with a CIS have been sought, because only 30-70% of patients with a CIS develop MS. When clinically silent brain lesions are seen on MRI, the likelihood of developing MS is high. MS can be diagnosed within 3 months of CIS presentation with certain MRI and CSF criteria. Disability from MS is less likely in patients with a CIS of optic neuritis or sensory symptoms only, few or no MRI lesions, a long period to the first relapse, and no disability after the first 5 years. Development of more reliable prognostic markers will enable new treatments to be targeted for those who are most likely to benefit. We encourage continued clinical and laboratory assessment of patients with a CIS.     

Central nervous system involvement in optic neuritis.

Thirty patients with clinically uncomplicated optic neuritis were subjected to a battery of electrophysiological tests, including visual evoked response (VER), auditory brainstem evoked response (ABER) and somatosensory evoked response (SSER). Blink reflex, electronystagmography (ENG), and computed tomography examinations were also carried out on all patients. These non-invasive tests indicated that in 11 of the 30 patients (37%), the optic neuritis was a symptom of subclinical multiple sclerosis, and that another five patients showed signs of mild central nervous system (CNS) involvement which may develop into multiple sclerosis later. This was confirmed by cerebrospinal fluid (CSF) analysis, using isoelectric focusing, showing oligoclonal extra bands in 11 out of these sixteen. A new classification of optic neuritis is proposed on the basis of these findings.     

Cranial MRI in idiopathic retinal vasculitis

Ten patients with clinically isolated idiopathic retinal vasculitis who had a positive family history for multiple sclerosis (MS) or positive typing for HLA B7 underwent magnetic resonance imaging (MRI) of brain and optic nerves in order to establish the frequency of clinically silent lesions. Brain MRI was normal in seven and abnormal in three: one had a single small white matter lesion, two had extensive white matter abnormalities resembling those seen in MS. In two patients a lesion was shown in the optic nerve. These findings suggest that a minority of patients with idiopathic retinal vasculitis have disseminated central nervous system lesions characteristic of MS, the frequency of such changes being less than in patients with isolated optic neuritis.     

The early risk of multiple sclerosis after optic neuritis.

Serial brain MRI was performed in 53 patients with clinically isolated optic neuritis. Using clinical and imaging evidence for relapse, multiple sclerosis developed within a mean of 12 months in 19 of 34 cases (56%) with brain lesions at presentation, and in only 3 of 19 cases (16%) without (Relative Risk = 6.8, p less than 0.005).     

Delayed and pseudodelayed visual evoked potentials in optic neuritis compared with long time echo-short tau inversion recovery magnetic resonance imaging of optic nerve

Twenty patients affected by optic neuritis (ON) underwent serial visual evoked potential (VEP) recordings, performed with multiple electrode arrays, and with stimuli of 1 and 3 cycles per degree (cpd) for 1 year. VEP findings were correlated with long time echo-short tau inversion recovery (LTE-STIR) magnetic resonance imaging (MRI) of optic nerves and with visual field tests. MRI showed lesions in 95.2% of acute ON and in 66.6% of the 1 year follow-up. VEPs were classified into really 'delayed' VEPs and 'pseudodelayed' VEPs, based on their scalp distribution. Furthermore, VEPs to 1 or 3 cpd could be 'delayed' or 'pseudodelayed' in the same patient. Real delays could be recorded at onset or shortly after ON, and indicated the possibility of recovery of visual functions and good functional prognosis. Pseudodelays, to 3 cpd, corresponded to prominent central scotomata and indicated poor prognosis for the recovery of visual function, unless a breakthrough of normal or delayed components appeared in the first 4 months following acute ON. Pseudodelayed VEPs clustered in patients with longer demyelinating lesions, as shown by LTE-STIR MRI. There was no correlation between latency of VEPs and length of plaques. Our study addresses some reconsiderations of the pathophysiology of conduction delay in acute optic neuritis.