China
Africa
Explore chapters and articles related to this topic
Neurologic Diagnosis
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
A brainstem medial longitudinal fasciculus lesion in the paramedian midbrain or pons will impair adduction of the ipsilateral eye associated with abducting nystagmus of the opposite eye on horizontal gaze. The INO may be unilateral or bilateral, subtle or obvious. Rapid horizontal eye movements may be needed to bring out an adduction slowing. The patient may or may not be aware of diplopia to one side. The INO may be an isolated sign or accompany other brainstem signs and is most commonly seen in brainstem lesions caused by MS and stroke.
Anatomy for neurotrauma
Published in Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor, Essentials of Anesthesia for Neurotrauma, 2018
Vasudha Singhal, Sarabpreet Singh
Trauma to the midbrain may result in contralateral weakness (corticospinal tract), contralateral loss of proprioception and vibration (medial lemniscus), involuntary movements (corticobulbar tract), upward gaze palsy and ipsilateral ophthalmoplegia (medial longitudinal fasciculus), and loss of pupillary light reflex (CN III). Impairment of reticular activating system may lead to progressive loss of consciousness. Raised ICP in the setting of an intracranial hematoma or cerebral edema due to diffuse axonal injury, may lead to uncal herniation through the tentorial notch, leading to direct midbrain compression leading to a progressive oculomotor palsy (ophthalmoplegia, pupillary dilatation, and ptosis), contralateral limb weakness and falling level of consciousness.
Non-Synonyms (Similar-Sounding)
Published in Terence R. Anthoney, Neuroanatomy and the Neurologic Exam, 2017
Medial longitudinal bundle (M&M, p. 33, 37): The “medial longitudinal fasciculus”—a set of fibers running through much of the brain stem and into the spinal cord. Its function involves coordination of eye movements with head movements.
Effect of an oculomotor rehabilitation program for subacute brain injury patients with ophthalmoplegia: a case-control study
Published in Disability and Rehabilitation, 2022
Takayuki Watabe, Hisayoshi Suzuki, Rikitaro Sako, Marina Abe, Keiichiro Aoki, Mitsumasa Yoda
The main neural mechanism involved in eye movement is located on the dorsal side of the brain stem, running vertically through the midbrain, pons, and medulla oblongata [16,17]. Eye movement in the horizontal direction is controlled by the paramedian pontine reticular formation and medial longitudinal fasciculus [18]. Damage to these systems caused by brain injury can result in oculomotor disturbances. In the present study, these systems were directly damaged in case-group patients C, E, F, and H, while the horizontal oculomotor control system was thought to be affected by compression from a hematoma, edema, or circulatory disturbance in patients A, B, D, I, L, M, N and O. Patients G, J, and K had head injuries, where a diffuse injury probably led to oculomotor disturbance by damaging the oculomotor system, which includes these ocular motility centers. Previous research has indicated that this is a highly probable occurrence [5,8].
Horizontal Gaze Palsy and Progressive Scoliosis in Dizygotic Twins
Published in Journal of Binocular Vision and Ocular Motility, 2022
Catarina Xavier, Miguel Vieira, Ana Filipa Duarte, Ana Xavier, Eduardo D. Silva
As it has been hypothesized in literature, the maldevelopment of the tegmentum plays a crucial role in the pathogenesis of HGPPS. Pathways that cross the midline such as the medial longitudinal fasciculus are affected and so communication from the abducens to the contralateral oculomotor nucleus is deficient, preventing a normal horizontal gaze.2,12 Contrary to what is described in the literature,14 we believe that the synergistic divergence in our patients is not due to miswiring of nerve fibers between the IIIrd and VIth nerves. Instead, we speculate that our patients’ ocular movements are due to supranuclear and internuclear abnormalities. Such as happens in internuclear ophthalmoplegia, our patients have a normal convergence of the eyes due to intact medial rectus innervation.
Disorders of vision in multiple sclerosis
Published in Clinical and Experimental Optometry, 2022
Roshan Dhanapalaratnam, Maria Markoulli, Arun V Krishnan
Hering’s law dictates that conjugate movements of the eyes require yoked coordination of the extraocular muscles, via the supranuclear communication of ipsilateral and contralateral signalling pathways.81 For example on looking to the left, the left lateral rectus muscle works in tandem with the right medial rectus muscle, and this communication all occurs via pathways involving the brainstem nuclei. The midbrain comprises vertical gaze centres, the rostral interstitial nucleus of the medial longitudinal fasiculus (MLF), trochlear and oculomotor nucleus. Lesions in these areas can result in vertical gaze palsy, superior oblique palsy, third nerve palsy and convergence-retraction nystagmus. The pons contains the abducens nucleus, paramedian pontine reticular formation and the MLF, and lesions can result in an internuclear opthalmoplegia, horizontal gaze palsies, sixth nerve palsies and skew deviation.