Brainstem and Cranial Nerves: Midbrain

2021 ◽  
pp. 92-98
Author(s):  
Kelly D. Flemming ◽  
Paul W. Brazis
Keyword(s):  
Substantia Nigra ◽  
Red Nucleus ◽  
Cranial Nerves ◽  
Posterior Commissure ◽  
Middle Cerebellar Peduncle ◽  
Mammillary Bodies ◽  
Imaginary Line ◽  
Cerebellar Peduncle ◽  
Trochlear Nucleus ◽  
Inferior Colliculi

The midbrain (or mesencephalon) is the uppermost segment of the brainstem. This chapter reviews the important structures in the midbrain, including cranial nerves III and IV. The midbrain extends from the level of the trochlear nucleus to an imaginary line between the mammillary bodies and the posterior commissure. Important structures at this level include the cerebral peduncles, superior and inferior colliculi, red nucleus, substantia nigra, decussation of the middle cerebellar peduncle, and cranial nerves III and IV.

Brainstem and Cranial Nerves: Pons

2021 ◽  
pp. 82-91
Author(s):  
Kelly D. Flemming ◽  
Paul W. Brazis
Keyword(s):  
Blood Supply ◽  
Basilar Artery ◽  
Cranial Nerve ◽  
Cranial Nerves ◽  
Middle Cerebellar Peduncle ◽  
Corticospinal Tracts ◽  
Imaginary Line ◽  
Cerebellar Peduncles ◽  
Cerebellar Peduncle ◽  
Pontomedullary Junction

The pons extends from the pontomedullary junction to an imaginary line drawn from the exit of cranial nerve IV. Dorsal to the pons lies the cerebellum, which receives information and projects information back to the brainstem through the inferior, middle, and superior cerebellar peduncles. Important structures at this level include the corticospinal tracts, corticopontocerebellar fibers traveling through the middle cerebellar peduncle, the cerebellum, and cranial nerves V through VIII. Blood supply to the pons is from the basilar artery and its perforating vessels.

scholarly journals Relations of aqueduct with some structures of mesencephalon

2009 ◽  
Vol 62 (7-8) ◽  
pp. 352-357
Author(s):  
Gordana Stankovic ◽  
Valentina Nikolic ◽  
Nela Puskas ◽  
Branislav Filipovic ◽  
Laslo Puskas ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Substantia Nigra ◽  
Red Nucleus ◽  
Middle Part ◽  
Ventricular System ◽  
Posterior Commissure ◽  
Superior Colliculi ◽  
The Third ◽  
Topographic Characteristics ◽  
Made In

Introduction. Aqueductus mesencephali is the biggest part of the ventricular system and that is why it is the most common place of intraventricular obstruction of cerebrospinal fluid. This study was done in order to study topographic characteristics of aqueduct more thoroughly. Materials and methods. Transversal sections of mesencephalon were made in three levels. The first section was made caudally immediately from the posterior commissure. The second section was made in the middle part of the superior colliculi, and the third section was made in the rostral parts of the caudal sections of the superior colliculi. Distances of the aqueduct from structures of mesencephalon, obtained on the second section, are: 1. The distance of the aqueduct from the superior colliculi - 6.96 mm; 2. The distance of the aqueduct from the red nucleus - 6.02 mm; 3. The distance of the aqueduct from the substantia nigra - 12.29 mm; 4. The distance of the aqueduct from the interpeduncular fossa - 10.22 mm. Conclusion. Knowledge of the anatomy of the aqueductus mesencephali is very important because of interpretation of patogenesis of hidrocefalus as well as of other syndromes that occure in some pathological processes in the system of ventricles.

Hemangioblastoma of the pons and middle cerebellar peduncle

2019 ◽  
Vol 1 (2) ◽  
pp. V6
Author(s):  
Satoshi Kiyofuji ◽  
Harry J. Cloft ◽  
Colin L. W. Driscoll ◽  
Michael J. Link
Keyword(s):  
Magnetic Resonance Imaging ◽  
Hearing Loss ◽  
Cranial Nerves ◽  
Cystic Mass ◽  
Preoperative Embolization ◽  
Resonance Imaging ◽  
Middle Cerebellar Peduncle ◽  
History Of ◽  
Cerebellar Peduncle ◽  
Magnetic Resonance Imaging Mri

A 60-year-old man with a history of four prior operations for a left cerebellar/middle cerebellar peduncle hemangioblastoma presented with hearing loss, imbalance, and ataxia (de la Monte and Horowitz, 1989). Magnetic resonance imaging (MRI) demonstrated a 3-cm cystic mass with heterogeneous enhancement in the same location. We resected the mass via reopening of the retrosigmoid approach (Lee et al., 2014). Left cranial nerves IV, V, VII, VIII, IX, X, and XI were all well identified and preserved, and feeding arteries from the brainstem were meticulously coagulated and transected without violating the tumor-brainstem interface (Chen et al., 2013). Preoperative embolization greatly aided safe resection of the mass, whose pathology revealed recurrence of hemangioblastoma (Eskridge et al., 1996; Kim et al., 2006; Sakamoto et al., 2012).The video can be found here: https://youtu.be/3mZgY15xOZc.

scholarly journals A Medley of Midbrain Maladies: A Brief Review of Midbrain Anatomy and Syndromology for Radiologists

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Kathleen Ruchalski ◽  
Gasser M. Hathout
Keyword(s):  
White Matter ◽  
Red Nucleus ◽  
Cranial Nerves ◽  
White Matter Tracts ◽  
Nuclear Complex ◽  
Radiologic Findings ◽  
Fiber Tracts ◽  
Clinical Syndromes ◽  
Brachium Conjunctivum ◽  
Trochlear Nucleus

The midbrain represents the uppermost portion of the brainstem, containing numerous important nuclei and white matter tracts, most of which are involved in motor control, as well as the auditory and visual pathways. Notable midbrain nuclei include the superior and inferior colliculus nuclei, red nucleus, substantia nigra, oculomotor nuclear complex, and trochlear nucleus. In addition, white matter tracts include the brachium conjunctivum, medial and lateral lemniscus, spinothalamic tracts, and the fiber tracts within the cerebral peduncles. Although neurologically vital, many of these small midbrain nuclei and white matter tracts are not easily individually identified on neuroimaging. However, given their diverse functions, midbrain pathology often leads to distinct clinical syndromes. A review and understanding of the location and relationships between the different midbrain nuclei and fiber tracts will allow more precise correlation of radiologic findings with patient pathology and symptomatology. Particular syndromes associated with midbrain pathology include the Weber, Claude, Benedikt, Nothnagel, and Parinaud syndromes. The oculomotor and trochlear cranial nerves also reside at this level. An understanding of their functions as well as their projected courses from the midbrain towards the eye allows identification of distinct locations which are particularly vulnerable to pathology.

scholarly journals Developmentally anomalous cerebellar encephalocele arising within the cerebellopontine angle and extending into the adjacent skull base in a pediatric patient

2021 ◽  
Author(s):  
Forrest A. Hamrick ◽  
Michael Karsy ◽  
Carol S. Bruggers ◽  
Angelica R. Putnam ◽  
Gary L. Hedlund ◽  
...  
Keyword(s):  
Skull Base ◽  
Pediatric Patient ◽  
Cerebellopontine Angle ◽  
Resonance Imaging ◽  
Middle Cerebellar Peduncle ◽  
Cerebellar Tissue ◽  
Cerebellar Peduncle ◽  
Histopathologic Analysis ◽  
The Right ◽  
Internal Acoustic Canal

AbstractLesions of the cerebellopontine angle (CPA) in young children are rare, with the most common being arachnoid cysts and epidermoid inclusion cysts. The authors report a case of an encephalocele containing heterotopic cerebellar tissue arising from the right middle cerebellar peduncle and filling the right internal acoustic canal in a 2-year-old female patient. Her initial presentation included a focal left 6th nerve palsy. Magnetic resonance imaging was suggestive of a high-grade tumor of the right CPA. The lesion was removed via a retrosigmoid approach, and histopathologic analysis revealed heterotopic atrophic cerebellar tissue. This report is the first description of a heterotopic cerebellar encephalocele within the CPA and temporal skull base of a pediatric patient.

Isolated Bilateral Middle Cerebellar Peduncle Infarcts

2013 ◽  
Vol 22 (8) ◽  
pp. e645-e646 ◽  
Author(s):  
Seby John ◽  
Mohamed Hegazy ◽  
Esteban Cheng Ching ◽  
Irene Katzan
Keyword(s):  
Middle Cerebellar Peduncle ◽  
Cerebellar Peduncle

Retrosigmoid transhorizontal fissure approach to lateral pontine cavernous malformation: comparison to transpetrosal presigmoid retrolabyrinthine approach

2021 ◽  
pp. 1-10
Author(s):  
Julia R. Schneider ◽  
Amrit K. Chiluwal ◽  
Mohsen Nouri ◽  
Giyarpuram N. Prashant ◽  
Amir R. Dehdashti
Keyword(s):  
Operative Time ◽  
Cavernous Malformation ◽  
Similar Efficacy ◽  
Middle Cerebellar Peduncle ◽  
Entry Zone ◽  
Cadaveric Dissection ◽  
Cerebellar Peduncle ◽  
Retrolabyrinthine Approach ◽  
Brainstem Cavernous Malformation

OBJECTIVE The retrosigmoid (RS) approach is a classic route used to access deep-seated brainstem cavernous malformation (CM). The angle of access is limited, so alternatives such as the transpetrosal presigmoid retrolabyrinthine (TPPR) approach have been used to overcome this limitation. Here, the authors evaluated a modification to the RS approach, horizontal fissure dissection by using the RS transhorizontal (RSTH) approach. METHODS Relevant clinical parameters were evaluated in 9 patients who underwent resection of lateral pontine CM. Cadaveric dissection was performed to compare the TPPR approach and the RSTH approach. RESULTS Five patients underwent the TPPR approach, and 4 underwent the RSTH approach. Dissection of the horizontal fissure allowed for access to the infratrigeminal safe entry zone, with a direct trajectory to the middle cerebellar peduncle similar to that used in TPPR exposure. Operative time was longer in the TPPR group. All patients had a modified Rankin Scale score ≤ 2 at the last follow-up. Cadaveric dissection confirmed increased anteroposterior working angle and middle cerebellar peduncle exposure with the addition of horizontal fissure dissection. CONCLUSIONS The RSTH approach leads to a direct lateral path to lateral pontine CM, with similar efficacy and shorter operative time compared with more extensive skull base exposure. The RSTH approach could be considered a valid alternative for resection of selected pontine CM.

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