The mechanics of the extraocular muscles and orbital tissue ('oculomotor plant') can be approximated by a small number of viscoelastic (Voigt) elements in series. Recent analysis of the eye's return from displacement in lightly anaesthetised rhesus monkeys has suggested a 4 element plant model, with time constants (TCs) of about 0.01, 0.1, 1 and 10 s. To demonstrate directly the presence of lon...

The human motor system and muscles are subject to fluctuations in the short and long term. Motor adaptation is classically thought of as a low-level process that compensates for the error between predicted and executed movements in order to maintain movement accuracy. Contrary to a low-level account, accurate movements might be only a means to support high-level behavioral and perceptual goals....

When we applied a single pulse of transcranial magnetic stimulation (TMS) to any part of the human head during a saccadic eye movement, the ongoing eye velocity was reduced as early as 45 ms after the TMS, and lasted ∼32 ms. The perturbation to the saccade trajectory was not due to a mechanical effect of the lid on the eye (e.g., from blinks). When the saccade involved coordinated movements of ...

The mechanics of the extraocular muscles and orbital tissue ("oculomotor plant") can be approximated by a small number of viscoelastic (Voigt) elements in series. Recent analysis of the eye's return from displacement in lightly anesthetized rhesus monkeys has suggested a four-element plant model with time constants (TCs) of approximately 0.01, 0.1, 1, and 10 s. To demonstrate directly the prese...

Oculomotor nerve palsy frequently occurs because of external compression by an internal carotid-posterior communicating artery aneurysm and diabetes mellitus. In addition, pontine infarction, cavernous sinus tumors, demyelinating disease, and autoimmune disorder are well-known causes of oculomotor nerve palsy. However, cases of complete oculomotor nerve palsy by neurovascular conflicts presente...

PURPOSE To compare the MR characteristics of the oculomotor nucleus with its appearance on anatomic images. METHODS Specimens of cadaveric brains were imaged in a 3.0-T MR imager equipped with a 3.0-cm solenoid coil. The specimens were sectioned, stained, and examined histologically. On anatomic sections, the oculomotor nuclei, medial longitudinal fasciculus, red nuclei, and oculomotor nerve ...

Neuroanatomical Organization of the Anuran Mesencephalon and Brainstem Pathways Related to Oculomotor Function May 1984 Neil M. Montgomery, B.A., University of Massachusetts M.S., University of Massachusetts Ph.D., University of Massachusetts Directed by: Dr. Katherine V. Fite The neuroanatomical organization of the anuran oculomotor system was investigated using the Golgi and horseradish perox...

Although oculomotor nerve palsy, which is common in diabetes, is considered an ischemic mononeuropathy, the susceptibility of the oculomotor nerve to ischemic insult is not well understood. We analyzed the density of endoneurial microvessels of the oculomotor nerve and compared it with that of the sural nerve in non-diabetic patients. The mean vascular density of the oculomotor nerve (23 ± 8.4/...