The optic radiation are axons from the neurons in the lateral geniculate nucleus to the primary visual cortex. The optic radiation receives blood through deep branches of the middle cerebral artery and posterior cerebral artery.
The medial longitudinal fasciculus (MLF) is one of a pair of crossed over tracts, on each side of the brainstem. These bundles of axons are situated near the midline of the brainstem and are made up of both ascending and descending fibers that arise from a number of sources and terminate in different areas. The MLF is the main central connection for the oculomotor nerve, trochlear nerve, and abducens nerve. The vertical gaze center is at the rostral interstitial nucleus (riMLF).
The lateral lemniscus is a tract of axons in the brainstem that carries information about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain. Three distinct, primarily inhibitory, cellular groups are located interspersed within these fibers, and are thus named the nuclei of the lateral lemniscus.
Medial medullary syndrome, also known as inferior alternating syndrome, hypoglossal alternating hemiplegia, lower alternating hemiplegia, or Dejerine syndrome, is a type of alternating hemiplegia characterized by a set of clinical features resulting from occlusion of the anterior spinal artery. This results in the infarction of medial part of the medulla oblongata.
The corticobulbartract is a two-neuron white matter motor pathway connecting the motor cortex in the cerebral cortex to the medullary pyramids, which are part of the brainstem's medulla oblongata region, and are primarily involved in carrying the motor function of the non-oculomotor cranial nerves. The corticobulbar tract is one of the pyramidal tracts, the other being the corticospinal tract.
The red nucleus or nucleus ruber is a structure in the rostral midbrain involved in motor coordination. The red nucleus is pale pink, which is believed to be due to the presence of iron in at least two different forms: hemoglobin and ferritin. The structure is located in the tegmentum of the midbrain next to the substantia nigra and comprises caudal magnocellular and rostral parvocellular components. The red nucleus and substantia nigra are subcortical centers of the extrapyramidal motor system.
The spinocerebellar tract is a nerve tract originating in the spinal cord and terminating in the same side (ipsilateral) of the cerebellum.
The anterior choroidal artery originates from the internal carotid artery. However, it may (rarely) arise from the middle cerebral artery.
Cerebellar peduncles connect the cerebellum to the brain stem. There are six cerebellar peduncles in total, three on each side:
The posterior thoracic nucleus, is a group of interneurons found in the medial part of lamina VII, also known as the intermediate zone, of the spinal cord. It is mainly located from the cervical vertebra C7 to lumbar L3-L4 levels and is an important structure for proprioception of the lower limb.
The mammillothalamic tract arises from cells in both the medial and lateral nuclei of the mammillary body and by fibers that are directly continued from the fornix.
In the human brain, the superior cerebellar peduncle is a paired structure of white matter that connects the cerebellum to the midbrain. It consists mainly of efferent fibers, the cerebellothalamic tract that runs from a cerebellar hemisphere to the contralateral thalamus, and the cerebellorubral tract that runs from a cerebellar hemisphere to the red nucleus. It also contains afferent tracts, most prominent of which is the ventral spinocerebellar tract. Other afferent tracts are the trigeminothalamic fibers, tectocerebellar fibers, and noradrenergic fibers from the locus coeruleus. The superior peduncle emerges from the upper and medial parts of the white matter of each hemisphere and is placed under cover of the upper part of the cerebellum.
Brown-Séquard syndrome is caused by damage to one half of the spinal cord, i.e. hemisection of the spinal cord resulting in paralysis and loss of proprioception on the same side as the injury or lesion, and loss of pain and temperature sensation on the opposite side as the lesion. It is named after physiologist Charles-Édouard Brown-Séquard, who first described the condition in 1850.
The myoclonic triangle is an important feedback circuit of the brainstem and deep cerebellar nuclei which is responsible for modulating spinal cord motor activity.
The trigeminal lemniscus, also called the trigeminothalamic tract, is composed of the ventral trigeminal tract, and the dorsal trigeminal tract – nerve tracts that convey tactile, pain, and temperature impulses from the skin of the face, the mucous membranes of the nasal and oral cavities, and the eye, as well as proprioceptive information from the facial and masticatory muscles.
Benedikt syndrome, also called Benedikt's syndrome or paramedian midbrain syndrome, is a rare type of posterior circulation stroke of the brain, with a range of neurological symptoms affecting the midbrain, cerebellum and other related structures.
The pontocerebellar fibers are the second order neuron fibers of the corticopontocerebellar tracts that cross to the other side of the pons and run within the middle cerebellar peduncles, from the pons to the contralateral cerebellum.
The central tegmental tract is a structure in the midbrain and pons.
The cerebellothalamic tract or the tractus cerebellothalamicus, is part of the superior cerebellar peduncle. It originates in the cerebellar nuclei, crosses completely in the decussation of the superior cerebellar peduncle, bypasses the red nucleus, and terminates in posterior division of ventral lateral nucleus of thalamus. The ventrolateral nucleus has different divisions and distinct connections, mostly with frontal and parietal lobes. The primary motor cortex and premotor cortex get information from the ventrolateral nucleus projections originating in the interposed nucleus and dentate nuclei. Other dentate nucleus projections via thalamic pathway transmit information to prefrontal cortex and posterior parietal cortex. The cerebellum sends thalamocortical projections and in addition may also send connections from the thalamus to association areas serving cognitive and affective functions.
The magnocellular red nucleus is located in the rostral midbrain and is involved in motor coordination. Together with the parvocellular red nucleus, the mRN makes up the red nucleus. Due to the role it plays in motor coordination, the magnocellular red nucleus may be implicated in the characteristic symptom of restless legs syndrome (RLS). The mRN receives most of its signals from the motor cortex and the cerebellum.
