Head, neck and vertebral column
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings in McMinn’s Concise Human Anatomy, 2017
Brainstem - extends down from the central part of the cerebrum (Figs.3.7-3.11) and consists from above downwards of the midbrain, pons and medulla oblongata. In the brainstem are groups of nerve cells (cranial nerve nuclei), which either give rise to the motor (efferent) fibres of cranial nerves (p. 52) or receive sensory (afferent) fibres from cranial nerve ganglia, situated on the nerves outside the brainstem (corresponding to the posterior root ganglia of spinal nerves, p. 59). Among the fibres that pass through the brainstem to and from other parts of the brain and spinal cord are the motor fibres from the cerebral cortex. They become grouped together to form a bulge, the pyramid, on either side of the midline of the medulla; here, most of the fibres cross to the opposite side (motor decussation or decussation of the pyramids) to form the lateral corticospinal tract that continues into the spinal cord (p. 58).
The nervous system and the eye
C. Simon Herrington in Muir's Textbook of Pathology, 2020
The brainstem is divided into the midbrain, pons and medulla. Each region contains cranial nerve nuclei and ascending and descending pathways. The principal structures of the midbrain include the colliculi, cerebral peduncles, third and fourth cranial nerve nuclei and the medial longitudinal fasciculus. Symptoms and signs of a lesion in the midbrain include contralateral spastic hemiplegia, diplopia and impairment of vertical eye movements and convergence. Syndromes due to disease in either the pons or the medulla reflect the involvement of sensory and motor long tracts, cranial nerve nuclei and vital centres involved in respiration and control of the heart; if there are bilateral paramedian lesions the patient may become ‘locked in’.
ENTRIES A–Z
Philip Winn in Dictionary of Biological Psychology, 2003
The medulla oblongata or MYELENCEPHALON is the most caudal part of the BRAINSTEM. It merges with the PONS rostrally and the SPINAL CORD caudally and contains sensory and motor nuclei that contribute to the fifth, seventh, eighth, ninth, tenth, eleventh and twelfth CRANIAL NERVES. The RETICULAR FORMATION forms the core of the medulla. Its neurons receive diverse inputs and, in turn, send ascending, descending and propriobulbar (intramedullary) connections that provide the anatomical substrates for coordinated activity of cranial nerve nuclei and AUTONOMIC integration. The sensory and motor decussations of the MEDIAL LEMNISCUS and PYRAMIDAL TRACT (see DECUSSATION) are located in the caudal medulla oblongata.
Duane Retraction Syndrome: Clinical Features and a Case Group-Specific Surgical Approach
Published in Seminars in Ophthalmology, 2019
Abuzer Gunduz, Ercan Ozsoy, Pamuk Betul Ulucan
Duane retraction syndrome (DRS) is a congenital ocular movement disorder characterized by moderate-to-severe limitation in abduction and/or adduction, as well as narrowing of the palpebral fissure, globe retraction, and vertical deviation of the affected eye on adduction.1 There is often a congenital anomaly of the sixth cranial nerve nuclei, with aberrant innervation supplied from the third cranial nerve.2 DRS is the most common form of congenital cranial dysinnervation disorders .3 It has an incidence of approximately 0.1% of the general population and accounts for 1–5% of all strabismus cases.4,5 DRS is primarily unilateral, although it presents bilaterally in 15% of all DRS patients.6 DRS type I is characterized by limited abduction, type II by limited adduction, and type III by limited abduction and adduction.7
Foix-Chavany-Marie syndrome due to unilateral anterior opercular infarction with leukoaraiosis
Published in Baylor University Medical Center Proceedings, 2021
Katherine Rivas, Jie Pan, Angela Chen, Bailey Gutiérrez, Parunyou Julayanont
The current mapping of the divisions of the operculum has demonstrated that stimulation causes motor and language deficits as well as somatosensory and oropharyngeal symptoms.5 The anterior operculum contains the voluntary motor fibers for the 5th, 7th, 9th, 10th, and 12th cranial nerves, which then travel to the cranial nerve nuclei via the corticobulbar tract.1,2 Injury to this area can cause FCMS bilateral voluntary paralysis of facial, masticatory, pharyngeal, laryngeal, and brachial muscles.6–8 Autonomic-voluntary dissociation in FCMS is explained by the presence of alternative pathways for facial emotional expression and automatic movements, hypothesized to be mediated through the inner forebrain and outer longitudinal bundle that connect the amygdala and hypothalamus to the brainstem.1,2
Can the bending forward test be used to detect a diseased anterior semi-circular canal in patients with chronic vestibular multi-canalicular canalithiasis (BPPV)?
Published in Acta Oto-Laryngologica, 2019
Wenche Iglebekk, Carsten Tjell, Peter Borenstein
In patients with CVMCC, abnormal signals are transmitted from diseased labyrinths to the healthy normally functioning vestibular nuclei complex in the brainstem. From there, the labyrinthine abnormal signals go directly or via different cranial nerve nuclei to their end organs [17]. Thus, frequent symptoms among patients with CVMCC are headache, neck pain, generalized pain, TMJ region pain, fatigue, aggravation by physical exertion, decreased ability to concentrate, nausea, vertigo/dizziness, visual disturbances as well as tinnitus [1,2]. The Bending forward-test is valuable for selecting patients with some of these symptoms, who need further investigation. Because the sensation of disturbed spatial orientation or movement illusion during the test is the most important observation, the test can even be of relevance as a pure clinical test without any equipment. Patients without involvement of the anterior SCC do not have movement illusion.
Related Knowledge Centers
- Axon
- Brainstem
- Nucleus
- Synapse
- Trochlear Nerve
- Spinal Cord
- Neuron
- Grey Matter
- Cranial Nerves
- General Somatic Efferent Fibers