Ultrasonography in Neuromuscular Disorder

High-resolution (HR) ultrasound, which has been progressing continuously in technology, has improved in aspect of spatial and contrast resolution. The HR ultrasonography is a noninvasive, readily applicable imaging technique, which could get static and dynamic image in real-time for various neuromuscular disorders, especially in entrapment neuropathy. It is also a reliable tool to detect dynamic muscle movements such as fasciculation as well as muscle atrophy in chronic myopathies or neuropathies. Although reliability of the HR ultrasonography has not been investigated in large series of patients, different neuromuscular disorders tend to show specific changes on the ultrasound, which can be helpful in differential diagnosis. The HR ultrasonography is an ideal tool for the clinical and research investigation of neuromuscular system complementary to electrodiagnostic studies. This review briefly describes applicability for various neuromuscular disorders with previous study results and the technical aspects of ultrasound and its physical principles.

Reversible Splenial Lesion in a Patient with Influenza B Virus Infection

No abstract available.

Jerky Seesaw Nystagmus in Isolated Internuclear Ophthalmoplegia

The authors report jerky seesaw nystagmus, extorsional downbeating in the right eye and intorsional upbeating in the left eye, in a patient with right internuclear ophthalmoplegia (INO). This pattern of nystagmus may occur by disrupting pathways from contralateral posterior and anterior semicircular canals by a lesion in the medial longitudinal fasciculus. Depending on damage to the pathways from contralateral vertical canals, various patterns of dissociated torsional-vertical nystagmus may accompany INO.

Possible Mechanism of Seesaw Nystagmus in Internuclear Ophthalmoplegia

The authors report jerky seesaw nystagmus, extorsional downbeating in the ipsilesional eye and intorsional upbeating in the contralesional eye, in a patient with internuclear ophthalmoplegia (INO) from focal pontine lesion. This pattern of nystagmus may occur by disrupting pathways from contralateral posterior and anterior semicircular canals by a lesion in the medial longitudinal fasciculus. Depending on the pathways involved, various patterns of dissociated torsional-vertical nystagmus may accompany INO.