Retinal architecture and mfERG: Optic nerve head component response characteristics in MS

OBJECTIVE

To describe a novel neurophysiologic signature of the retinal ganglion cell and to elucidate its relationship to abnormalities in validated structural and functional measures of the visual system.

METHODS

We used multifocal electroretinogram-generated optic nerve head component (ONHC) responses from normal subjects (n = 18), patients with multiple sclerosis (MS) (n = 18), and those with glaucoma (n = 3). We then characterized the relationship between ONHC response abnormalities and performance on low-contrast visual acuity, multifocal visual-evoked potential-induced cortical responses, and average and quadrant retinal nerve fiber layer (RNFL) thicknesses, as measured by spectral-domain optical coherence tomography.

RESULTS

Compared with the eyes of normal subjects, the eyes of patients with MS exhibited an increased number of abnormal or absent ONHC responses (p < 0.0001). For every 7-letter reduction in low-contrast letter acuity, there were corresponding 4.6 abnormal ONHC responses at 2.5% contrast (p < 0.0001) and 6.6 abnormalities at the 1.25% contrast level (p < 0.0001). Regarding average RNFL thickness, for each 10-μm thickness reduction, we correspondingly observed 6.8 abnormal ONHC responses (p = 0.0002). The most robust association was between RNFL thinning in the temporal quadrant and ONHC response abnormalities (p < 0.0001).

CONCLUSION

Further characterization of ONHC abnormalities (those that are reversible and irreversible) may contribute to the development of novel neurotherapeutic strategies aimed at achieving neuroprotective, and perhaps even neurorestorative, effects in disorders that target the CNS in general, and MS in particular.

Freedom from disease activity in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) shares many pathologic features with other immune-mediated inflammatory diseases, such as rheumatoid arthritis, Crohn disease, and psoriasis. The development of effective biologic agents for rheumatoid arthritis has resulted in a treatment paradigm shift such that disease remission is now an explicit goal.

EXPERT CLINICAL OPINION

The traditional immunomodulatory disease-modifying therapies for MS (interferon beta and glatiramer acetate) delay disease progression and reduce activity on brain MRI to varying degrees; however, they have not been demonstrated to induce disease remission. Therefore, the concept of disease remission or freedom from disease activity in MS has received little attention from the neurology community. We discuss some potential definitions of disease remission in MS and whether freedom from disease activity can become an increasingly useful measure of therapeutic response.

FUTURE DIRECTIONS

Future research should be directed at determining the long-term significance of freedom from disease activity during a short-term clinical trial in relapsing-remitting MS.

Neuro-ophthalmic manifestations of hemangiopericytoma

PURPOSE

To describe the neuro-ophthalmic presentations of a rare intracranial tumor, hemangiopericytoma.

METHODS

Retrospective multicenter case series.

RESULTS

The neuro-ophthalmic and radiographic features of hemangiopericytoma are reviewed. The clinical presentation may mimic meningioma and the pre-operative distinction between meningioma and hemangiopericytoma is important because the evaluation, management, treatment, and prognosis differ significantly for the two lesions.

CONCLUSION

We report five cases of intracranial hemangiopericytoma and review the neuro-ophthalmic findings of this uncommon entity.

Supranuclear vertical gaze abnormalities in sporadic Creutzfeldt-Jakob disease

Supranuclear gaze palsies are an uncommon feature of Creutzfeldt-Jakob disease (CJD). Most reported cases of CJD with features of supranuclear gaze palsy are familial. We report 2 patients with supranuclear vertical gaze abnormalities associated with spongiform changes in the midbrain. Both patients were found to have sporadic CJD after genetic testing. Distinguishing familial from sporadic CJD in this setting has important genetic and epidemiological implications.

IM interferon beta-1a delays definite multiple sclerosis 5 years after a first demyelinating event

BACKGROUND

The Controlled High Risk Subjects Avonex Multiple Sclerosis Prevention Study (CHAMPS) showed that IM interferon beta-1a (IFNbeta-1a) significantly slows the rate of development of clinically definite multiple sclerosis (CDMS) over 2 years in high-risk patients who experience a first clinical demyelinating event. This report highlights the primary results of a 5-year, open-label extension of CHAMPS (the Controlled High Risk Avonex Multiple Sclerosis Prevention Study in Ongoing Neurologic Surveillance [CHAMPIONS Study]).

OBJECTIVE

To determine if the benefits of IFNbeta-1a observed in CHAMPS are sustained for up to 5 years.

METHODS

CHAMPS patients at participating CHAMPIONS sites were enrolled in the study. All patients were offered, but not required to take, IFNbeta-1a 30 microg IM once weekly for up to 5 years (from CHAMPS randomization). Patients who received placebo in CHAMPS were considered the delayed treatment (DT) group, and patients who received IFNbeta-1a in CHAMPS were considered the immediate treatment (IT) group. The primary outcome measure was the rate of development of CDMS. Additional outcomes included disease state classification at 5 years, annualized relapse rates, disability level at 5 years (Expanded Disability Status Scale), and MRI measures at 5 years.

RESULTS

Fifty-three percent (203/383) of patients enrolled in CHAMPIONS (n = 100, IT group; n = 103, DT group) and 64% (32/50) of CHAMPS study sites participated in CHAMPIONS. The median time to initiation of IFNbeta-1a therapy in the DT group was 29 months. The cumulative probability of development of CDMS was significantly lower in the IT group compared with the DT group (5-year incidence 36 +/- 9 vs 49 +/- 10%; p = 0.03). Multivariate analysis suggested that the only factors independently associated with an increased rate of development of CDMS were randomization to the DT group and younger age at onset of neurologic symptoms. Few patients in either group developed major disability within 5 years.

CONCLUSIONS

These results support the use of IM interferon beta-1a after a first clinical demyelinating event and indicate that there may be modest beneficial effects of immediate treatment compared with delayed initiation of treatment.

Accuracy of clinical detection of INO in MS: Corroboration with quantitative infrared oculography

The authors compared the accuracy of clinical detection (by 279 physician observers) of internuclear ophthalmoparesis (INO) with that of quantitative infrared oculography. For the patients with mild adduction slowing, INO was not identified by 71%. Intermediate dysconjugacy was not detected by 25% of the evaluators. In the most severe cases, INO was not identified by only 6%. Oculographic techniques significantly enhance the precision of INO detection compared to the clinical exam.

Diagnosis and management of orbital pseudotumor

Orbital pseudotumor, also known as idiopathic orbital inflammatory syndrome (IOIS), may have protean clinical manifestations. Some presentations of IOIS may mimic common conditions such as orbital cellulitis and optic neuritis. IOIS should be considered a diagnosis of exclusion, with evaluation directed toward eliminating other causes of orbital disease. Orbital magnetic resonance imaging is the single most important diagnostic test, but serologic studies are necessary to exclude a systemic cause. Biopsy is usually not performed at presentation, as the risk of producing damage to vital structures within the orbit outweighs the benefits. Patients with multiple recurrences, or those unresponsive to therapy, should have biopsy samples taken. Corticosteroids are the mainstay of therapy and are administered for several months to ensure remission. Radiotherapy may be used in patients who fail to respond to steroids or who have a rapidly progressive course. For those patients who are refractory to both corticosteroids and radiotherapy, anecdotal reports have suggested the use of chemotherapeutic agents such as cyclophosphamide, methotrexate, and cyclosporine.

Serial evoked potential studies and MRI imaging in chronic progressive multiple sclerosis

Measurements of serial evoked potential latencies and plaque burden on MRI scans are often obtained during clinical studies of multiple sclerosis patients to provide additional information to the disability-based primary endpoints. The ideal laboratory-based marker of progression would be expected to significantly change over the time period of study. Serial visual (VEP) and brainstem auditory evoked potentials (BAEP) and MRI scans of 11 chronic progressive MS patients were obtained over a 1.5 year period in a clinical study. Over this period, there was no significant change in disability as measured by the Kurtzke EDSS, Ambulation Index or Neurological Rating Score. The VEP P100 significantly progressed over the period of study. However, the MRI T(2) plaque burden and BAEP I-V intrapeak latency did not significantly progress over the 1.5 years. We conclude that, in chronic progressive MS, serial visual evoked potential tests may complement standard disability-based endpoints to assess disease progression.

A double-blind, placebo-controlled trial of extracorporeal photopheresis in chronic progressive multiple sclerosis

Extracorporeal photopheresis is a safe therapy for cutaneous T-cell lymphoma and may have efficacy in certain autoimmune disorders. We performed a randomized, double-blinded, placebo-controlled trial of monthly photopheresis therapy in 16 patients with clinically definite multiple sclerosis (MS). All patients had progressed during the preceding year with entry Expanded Disability Status Scale (EDSS) scores between 3.0 and 7.0. Patients received photopheresis or sham therapy for 1 year and were followed for an additional 6 to 12 months. Patients were clinically evaluated by three disability scales: (1) EDSS; (2) Ambulation index and (3) Scripp's quantitative neurologic assessment. No serious side effects occurred in either group. There were no differences between the photopheresis and sham therapy groups by the disability measures. Additionally, there were no differences in progression of MRI plaque burden or evoked potential latencies. In this limited study, photopheresis was found to be safe but did not significantly alter the course of chronic progressive MS.

Dementia resulting from dural arteriovenous fistulas: the pathologic findings of venous hypertensive encephalopathy

PURPOSE

Dural arteriovenous fistulas (DAVFs) are acquired arteriovenous shunts located within the dura. The highly variable natural history and symptomatology of DAVFs range from subjective bruit to intracranial hemorrhage and are related to the lesion's pattern of venous drainage and its effect on the drainage of adjacent brain. We examined the prevalence and features of DAVFs in patients with progressive dementia or encephalopathy.

METHODS

The records and radiologic studies of 40 consecutive patients with DAVFs treated at our institution were reviewed.

RESULTS

Five (12.5%) of 40 consecutive patients with DAVFs had encephalopathy or dementia. In each patient, high flow through the arteriovenous shunt combined with venous outflow obstruction caused impairment of cerebral venous drainage. Hemodynamically, the result was widespread venous hypertension causing diffuse ischemia and progressive dysfunction of brain parenchyma. Results of CT or MR imaging revealed abnormalities in each patient, reflecting the impaired parenchymal venous drainage. Pathologic findings in one patient confirmed the mechanism of cerebral dysfunction as venous hypertension. The hemodynamic mechanism and resulting abnormality appeared identical to that seen in progressive chronic myelopathy resulting from a spinal DAVF (Foix-Alajouanine syndrome). Remission of cognitive symptoms occurred in each patient after embolization.

CONCLUSION

Venous hypertensive encephalopathy resulting from a DAVF should be considered a potentially reversible cause of vascular dementia in patients with progressive cognitive deficits.

Object recognition difficulty in visual apperceptive agnosia

Two patients with visual apperceptive agnosia were examined on tasks assessing the appreciation of visual material. Elementary visual functioning was relatively preserved, but they had profound difficulty recognizing and naming line drawings. More detailed evaluation revealed accurate recognition of regular geometric shapes and colors, but performance deteriorated when the shapes were made more complex visually, when multiple-choice arrays contained larger numbers of simple targets and foils, and when a mental manipulation such as a rotation was required. The recognition of letters and words was similarly compromised. Naming, recognition, and anomaly judgments of colored pictures and real objects were more accurate than similar decisions involving black-and-white line drawings. Visual imagery for shapes, letters, and objects appeared to be more accurate than visual perception of the same materials. We hypothesize that object recognition difficulty in visual apperceptive agnosia is due to two related factors: the impaired appreciation of the visual perceptual features that constitute objects, and a limitation in the cognitive resources that are available for processing demanding material within the visual modality.

Cortical blindness secondary to cyclosporine after orthotopic heart transplantation: a case report and review of the literature

Cyclosporine neurotoxicity has been described after liver, kidney, and bone marrow transplantation and has been associated with a number of risk factors, including hypomagnesemia and low serum cholesterol levels. Reports in heart transplant recipients are less common. We present a patient with cortical blindness secondary to cyclosporine after orthotopic heart transplantation. The patient had confusion, focal visual field defects, and bilateral occipital lobe lesions shown on magnetic resonance imaging. Although he had significant clinical improvement with decreasing cyclosporine levels, residual computerized visual field defects and magnetic resonance imaging abnormalities were documented several months later.

Bell's palsy in Moebius syndrome

We report a case of unilateral transient and reversible facial paresis, which was superimposed on a congenital bifacial palsy in a young adult with Moebius syndrome. Our case illustrates the potential for two conditions, both affecting the facial nerve and both of unknown etiology, to be juxtaposed in a single individual. Worsening of facial palsy in the Moebius syndrome may not signify progressive disease.

Echographic correlation of optic nerve sheath size and cerebrospinal fluid pressure

A 23-year-old obese woman presented with papilledema. Computed tomography showed no intracranial mass lesions and lumbar puncture revealed an increased opening pressure, confirming the diagnosis of pseudo-tumor cerebri. Standardized echography of the optic nerves was performed immediately before and after lumbar puncture. A marked reduction of cerebrospinal fluid pressure correlated with a decrease in the subarachnoid fluid of the optic nerve sheath.

Acute sarcoid optic neuropathy with spontaneous recovery

Sarcoid optic neuropathy without fundus lesions is unusual. We present a case of optic neuropathy with spontaneous remission in one eye that paralleled the clinical course of demyelinative acute optic neuritis. The fellow eye had disc swelling with normal visual acuity but with a large blind spot and distended optic nerve sheaths seen on ultrasonography. The diagnosis of sarcoidosis was made by characteristic chest roentgenographic findings and confirmed by skin biopsy.

Oxymorphone-naltrexonazine, a mixed opiate agonist-antagonist

Previous studies from our laboratories have reported the synthesis and pharmacological characteristics of a series of symmetrical opiate azines: naloxonazine, oxymorphonazine and naltrexonazine. We have now synthesized and characterized in binding assays and in vivo two asymmetrical azines: oxymorphone-naltrexonazine and oxymorphone-3-methoxynaltrexonazine. Oxymorphone-naltrexonazine, which theoretically could interact with the receptor as either an agonist or antagonist, displayed antagonist properties in vitro and in vivo. Oxymorphone-3-methoxynaltrexonazine, which theoretically could bind only as an agonist, possessed agonist properties in binding studies and was a potent analgesic in vivo.

Multiple sclerosis disease activity correlates with gadolinium-enhanced magnetic resonance imaging

Magnetic resonance imaging provides a method of visualizing multiple sclerosis plaques, but the age and activity of these plaques cannot be determined with routine magnetic resonance images. Gadolinium DTPA is a paramagnetic contrast agent that does not cross an intact blood-brain barrier. We studied 16 patients with multiple sclerosis, using magnetic resonance imaging, gadolinium-enhanced magnetic resonance imaging, and computed tomographic scans. Gadolinium enhancement of multiple sclerosis plaques correlated with the clinical activity of the disease and corresponded anatomically with the symptoms and signs. We conclude that gadolinium enhancement of magnetic resonance images is a promising tool in the investigation of multiple sclerosis lesions and that it may provide a method for objective follow-up in clinical trails.

Multiple sclerosis: gadolinium enhancement in MR imaging

Magnetic resonance (MR) images--both nonenhanced and enhanced with gadolinium DTPA/dimeglumine (Gd)--were compared with high-iodine (88.1 g I) computed tomographic (HICT) scans in demonstrating lesions in 15 patients known to have multiple sclerosis (MS). T1-weighted, mixed (T1, proton density, and T2), and T2-weighted MR pulse sequences were used. More than 20 lesions in each of 14 patients were demonstrated by pre-Gd mixed images and T2WI. Nine patients had clinical symptoms of active disease. Gd-enhanced T1WI showed at least one lesion that appeared to correspond with newly reported symptoms or signs. In addition, three clinically stable patients showed enhancement. Enhancement was best seen on 3-minute T1WI. HICT scans showed enhancement in four of the nine patients with active disease and in none of five clinically stable patients. Gd-enhanced MR imaging appears to be more sensitive than HICT in the detection of the transient abnormalities of the blood-brain barrier that occur in patients with active MS and appears capable of distinguishing active lesions that may correspond to the anatomic regions responsible for abnormal clinical findings.

Oxymorphazone: a long-acting opiate analgesic

Treating rat brain homogenates in vitro with oxymorphazone, the hydrazone derivative of oxymorphone, selectively inhibited in a long-acting manner the high-affinity (mu 1) binding of a number of 3H-opioids. This inhibition was not affected by extensive wash procedures which did effectively reverse classical opiates such as morphine and naloxone. A similar, persistent inhibition of binding was observed following in vivo administration of the drug. Both systemically and intracerebroventricularly, oxymorphazone produced a dose-dependent analgesia. Acutely, oxymorphazone (ED50, 0.6 mg/kg, sc) was approximately half as potent as oxymorphone (ED50, 0.3 mg/kg, sc) in the tail-flick assay. Administered at their ED50 doses, both compounds had the same durations of action. As the doses of drug were increased, however, the time course of oxymorphazone's analgesia became far more prolonged than that of oxymorphone. Following the administration of oxymorphazone (100 mg/kg), over 50% of the mice remained analgesic for greater than 24 hr, as opposed to none of the mice given oxymorphone (100 mg/kg). Oxymorphazone was far more potent intraventricularly (icv) than systemically. Fifty percent of the mice remained analgesic for greater than 20 hr following the injection of 40 micrograms/mouse (icv), whereas no mice remained analgesic after 20 hr following doses of oxymorphone as high as 50 micrograms/mouse (icv). These long-lasting analgesic actions of oxymorphazone could not be easily explained on pharmacokinetic grounds. Repeated administration of oxymorphazone daily for 3 days resulted in significant tolerance.

Receptor binding and analgesic properties of oxymorphazone

The 14-hydroxydihydromorphinone hydrazones have been quite useful in studying aspects of opiate receptor binding and function. The most extensively studied, naloxazone, effectively and selectively inhibits high affinity (mu1) sites in vitro and morphine analgesia in vivo. We now report on the actions of oxymorphazone on receptor binding in vitro and on analgesia in vivo. Oxymorphazone effectively lowers 3H-opioid binding despite extensive washes with the same selectively for high affinity, or mu1, binding sites as naloxazone. Acutely, oxymorphazone was less potent in vivo than oxymorphone (ED50's of 0.8 and 0.4 mg/kg, respectively). Both quantal dose response curves were parallel. At higher doses (100 mg/kg), 83% of animals given oxymorphazone over 20 hr previously were analgesic whereas none of the oxymorphone animals were (p less than 0.001). Oxymorphazone also produced prolonged analgesia after icv administration. These results, in addition to other studies, suggest that oxymorphazone's actions cannot be adequately explained by pharmacokinetic differences from oxymorphone and supports the hypothesis that the drug works via prolonged receptor binding.