BACKGROUND Myasthenia gravis and the Lambert-Eaton myasthenic syndrome (LEMS) may have a similar distribution of muscle weakness. Deciding on a diagnosis of myasthenia gravis or LEMS on clinical grounds may therefore be difficult. OBJECTIVE To compare the localisation of initial muscle weakness and the distribution of weakness at the time of maximum severity in patients with myasthenia gravis...

In heterophoria there is a relative deviation of the visual axes held in check by the fusion mechanism, whereas in heterotropia there is a manifest deviation of the visual axes. The relative position of the visual axes is determined by the equilibrium or disequilibrium of forces that keep the eyes properly aligned and of forces that disrupt this alignment. Clearly, the fusion mechanism and its ...

Studies were performed on the levator palpebrae superioris muscle, isolated from foetuses aged 17 to 30 weeks. The number of muscle spindles varied from 2 in the 17th week to 7 in the 30th week. The length of the muscle spindles ranged from 20 to 500 microm, and the diameter varied from 10 to 70 microm. These observations show that the number of muscle spindles in levator palpebrae superioris m...

We report a case of focal orbital amyloidosis involving rectus muscles, which is an extremely rare clinical condition. CT scans showed rectus muscle enlargement with punctate calcifications. Heterogeneous hypointensity was present on T2-weighted MR images, and homogeneous enhancement was seen on fat-saturated contrast-enhanced images of the muscles. These imaging findings seem to be suggestive ...

An experiment was designed to determine whether or not the human organism possessed "outflow" information derived from monitoring nerve impulses in motor pathways. The experiment focused on the extraocular muscles since proprioceptive input to the central nervous system from these muscles is poor. The results show that in the absence of good proprioceptive information, the presence or absence o...

Recent studies have implicated exotropia as a risk factor for schizophrenia. We determined whether schizophrenia biomarkers have abnormal levels of expression in extraocular muscles from patients with strabismus and explored whether differences in gene expression between medial and lateral rectus muscles may explain the specific association of schizophrenia with exotropia but not esotropia. Sam...

Ophthalmoplegia or the paralysis of nerves supplying extraocular muscles can be due to numerous etiologies. In alcohol users, ophthalmoplegia might Wernicke's encephalopathy. A high dose thiamine should used with a index suspicion in such cases, but at same time, other life-threatening conditions not missed. Careful history taking, clinical features and neuro imaging guide identifying likely ae...

Hyperplasia or hypoplasia of muscles gradually leads to strabismus. Myogenesis-related genes are involved in extraocular muscle development, including myogenic differentiation 1 (MYOD1), myogenin (MYOG), retinoblastoma 1 (RB1), cyclin-dependent kinase inhibitor 1A (P21), cyclin‑dependent kinase inhibitor 1C (P57), insulin-like growth factor 1 (IGF1) and muscle creatine kinase (MCK). This study ...

PURPOSE Ricin-mAb35 is an immunotoxin targeted against skeletal muscle. Previously, we have shown that injection of ricin-mAb35 into rabbit extraocular muscle results in long-term muscle loss, and we have proposed this as a potential treatment for strabismus. In this study, we assessed the effects of ricin-mAb35 injection on extraocular muscle force generation. METHODS Ricin-mAb35, 0.2 microg...

Purpose of review Although the vestibular evoked myogenic potential (VEMP) measured from the cervical muscles (cVEMP, cervical VEMP) is well described and has documented clinical utility, its analogue recorded from the extraocular muscles (oVEMP, ocular VEMP) has been described only recently and is currently emerging as an additional test of otolith function. This review will, therefore, summar...