Efficacy of Gaze Photographs in Diagnosing Ocular Myasthenia Gravis

Clinical Features and Differences of Miller Fisher Syndrome in Southern China: Retrospective Analysis of 72 Patients in 13 Provinces of Southern China

BACKGROUND AND PURPOSE

We aimed to determine the clinical features of Miller Fisher syndrome (MFS) in southern China and compare them with those presenting in other countries.

METHODS

We collected the medical records of patients diagnosed with MFS during 2013-2016. We analyzed the age, sex, onset season, precursor events, clinical symptoms and signs, findings of nerve conduction studies (NCS), cerebrospinal fluid (CSF), therapeutic remedies, nadir time, and length of hospital stay of patients with MFS in southern China. We concurrently compared the differences between urban and rural areas and between patients with incomplete ophthalmoplegia (IO) and complete ophthalmoplegia (CO).

RESULTS

The study enrolled 72 patients: 36 from rural areas and 36 from urban areas, and 50 males and 22 females. The mean age at onset was 47.72 years, and 30 (41.7%) and 21 (29.2%) patients developed MFS in spring and winter, respectively. The typical triad of ophthalmoplegia, ataxia, and areflexia was observed in 50 (69.4%) patients. A history of upper respiratory tract infection 1 week before onset was found in 52.8% of the patients, while 5.6% experienced gastrointestinal infections and 48 (73.8%) exhibited albuminocytological dissociation in the CSF study. Only 26 (36.1%) patients presented abnormalities in NCS. Moreover, restricted outward eyeball movement presented in 83.5% of the patients with classic MFS and acute ophthalmoplegia, and bilateral symmetrical ophthalmoplegia presented in 64.2%. With the exception of the higher proportion of NCS abnormalities in urban areas (47.2% vs. 25.0%), urban and rural differences were insignificant regarding sex ratio, age at onset, high-incidence season, precursor events, disease characteristics, and albuminocytological dissociation in the CSF. Furthermore, patients with CO were older than those with IO (64.53±7.69 vs. 43.19±14.40 years [mean±standard deviation], p<0.001).

CONCLUSIONS

The patients with MFS were mostly male and middle-aged, and most presented in winter and (especially) spring. More than half of the patients had clear precursor events, most of which were classic MFS with the typical triad. More than 70% of the patients presented albuminocytological dissociation in the CSF. NCS abnormalities were uncommon in MFS. The age at onset was lower in patients with IO than in patients with CO; bilateral symmetrical extraocular muscle paralysis was the most common symptom, and the external rectus was the most frequently involved muscle.

The Icepack Test in the Diagnosis of Myasthenia Gravis with Ocular Features: A Systematic Review of Diagnostic Accuracy, Technique, and Economic Utility

BACKGROUND

The diagnosis of myasthenia gravis (MG) may be challenging and require multiple specialised testing modalities. Accessing these investigations can involve significant waiting time and costs. The bedside icepack test (IPT) has been proposed to assist with the diagnosis of MG with ocular features, and may prove an economically viable; however, there have been there is heterogeneity in the literature evaluating the IPT.

OBJECTIVES

A systematic review was performed examining the accuracy, described techniques, and economic implications of the IPT for the diagnosis of MG with ocular features.

METHOD

The databases EMBASE, PubMed, and the Cochrane Library were searched from inception to July 2022. The systematic review adhered to PRISMA guidelines. Eligibility determination was undertaken with a standardised form using appropriate inclusion criteria. The Cochrane risk of bias assessment tool for diagnostic test accuracy was employed to evaluate studies that presented the diagnostic performance of the IPT. The Johanna Briggs Institute Critical Appraisal Checklist for Economic Evaluations was used for the assessment of studies presenting economic evaluations of the IPT.

RESULTS

20 articles met the specified criteria and included a total of 1264 participants. The IPT had a sensitivity ranging from 38.5% to 100%. Specificity was found to be > 95% in six studies. Excluding two outlier results of 25% and 31.3%, the lowest specificity recorded was 62.5%. The most commonly described method of evaluating the IPT involved applying ice to both eyelids and using a >2 mm change as a threshold for a positive test (evaluated with a ruler). There were no adverse effects described with the IPT. There were no studies that formally examined the economic implications of the IPT.

CONCLUSIONS

The IPT is a well-tolerated and readily available diagnostic tool that has an important role in the evaluation of possible MG with ocular features in specific contexts. Despite limited economic evaluation of this test, it is likely the use of the IPT may result in significant financial and time savings.

Strabismus in chronic progressive external ophthalmoplegia

PURPOSE

To elucidate the patterns of strabismus and ophthalmoplegia associated with chronic progressive external ophthalmoplegia (CPEO) confirmed by mitochondrial DNA (mtDNA) deletions in Asians.

METHODS

A total of 10 patients confirmed to have mtDNA deletion associated with CPEO were included. Long-range PCR encompassing the entire mtDNA was carried out. In the cases with mtDNA deletion, the exact deletion ranges of mtDNA were identified by sequencing. A full ophthalmologic examination including prism and alternate cover test in the primary position, evaluation of ductions and versions, and binocularity was performed in 10 patients with confirmed mtDNA deletions associated with CPEO.

RESULTS

All of the patients showed ophthalmoplegia as well as ptosis, even after eyelid surgeries. Ophthalmoplegia was symmetric between both eyes in nine patients (90%) while one patient (10%) showed asymmetric ophthalmoplegia with esotropia and left hypotropia. Among the nine patients with symmetric involvement, four patients (44%) showed exotropia, three (33%) had exotropia with vertical deviation, and the remaining two patients (22%) showed orthotropia. Five out of 10 patients (50%) complained of diplopia associated with strabismus, four of whom (80%) had vertical deviation. Three out of five patients (60%) without diplopia showed exotropia of 20 prism diopters (PD) to 50 PD.

CONCLUSIONS

Exotropia with/without vertical deviation is the most common form of strabismus in Asian patients with CPEO and only one of them showed a small angle of esotropia. Ophthalmoplegia could be asymmetric in 10% of CPEO patients.

Pattern of Extraocular Muscle Involvements in Miller Fisher Syndrome

Background and Purpose

The most-common initial manifestation of Miller Fisher syndrome (MFS) is diplopia due to acute ophthalmoplegia. However, few studies have focused on ocular motility findings in MFS. This study aimed to determine the pattern of extraocular muscle (EOM) paresis in MFS patients.

Methods

We consecutively recruited MFS patients who presented with ophthalmoplegia between 2010 and 2015. The involved EOMs and the strabismus pattern in the primary position were analyzed. Antecedent infections, other involved cranial nerves, and laboratory findings were also reviewed. We compared the characteristics of the patients according to the severity of ophthalmoplegia between complete ophthalmoplegia (CO) and incomplete ophthalmoplegia (IO).

Results

Twenty-five patients (15 males and 10 females) with bilateral ophthalmoplegia were included in the study. The most-involved and last-to-recover EOM was the lateral rectus muscle. CO and IO were observed in 11 and 14 patients, respectively. The patients were aged 59.0±18.4 years (mean±SD) in the CO group and 24.9±7.4 years in the IO group (p<0.01), and comprised 63.6% and 21.4% females, respectively (p=0.049). Elevated cerebrospinal fluid protein was identified in 60.0% of patients with CO and 7.7% of patients with IO (p=0.019) for a mean follow-up time from the initial symptom onset of 3.7 days.

Conclusions

The lateral rectus muscle is the most-involved and last-to-recover EOM in ophthalmoplegia. The CO patients were much older and were more likely to be female and have an elevation of cerebrospinal fluid protein than the IO patients.