====== Midbrain hemorrhage ======

[[Midbrain]] [[hemorrhage]]s often secondarily result from a superior extension of [[pontine hemorrhage]] or [[cerebellar hemorrhage]] or an inferior extension of [[thalamic hemorrhage]] or [[putaminal hemorrhage]].
(( Han S H, Roh J K, Myung H J. Mesencephalic hemorrhage—a report of 3 cases. J Korean Med Sci. 1989;4(01):1–5.))
((Tuttle P V, Reinmuth O M. Midbrain hemorrhage producing pure sensory stroke. Arch Neurol. 1984;41(07):794–795.))
((Perez F J, Nuñez C T. Scanning dysarthria secondary to spontaneous midbrain hemorrhage: case report and review of literature. Eur Neurol. 2008;60(02):89–91.)).

===== Etiology =====

While the etiologies of nontraumatic primary [[midbrain hemorrhage]]s are largely unidentified, the most frequent ones are [[vascular malformation]]s and bleeding [[diathesis]] with [[hypertension]] occasionally
((Link M J, Bartleson J D, Forbes G, Meyer F B. Spontaneous midbrain hemorrhage: report of seven new cases. Surg Neurol. 1993;39(01):58–65.))

===== Classification =====

[[Primary spontaneous mesencephalic hemorrhage]].

[[Tectal mesencephalic hemorrhage]].

===== Clinical Features =====

Because of the complex anatomy [[midbrain lesion]]s, result in a broad spectrum of clinical signs and symptoms, including [[ataxia,]] [[vertigo]], ocular motility disorders, parkinsonian signs, and [[hydrocephalus]]
((Bhola R, Olson R J. Dorsal midbrain syndrome with bilateral superior oblique palsy following brainstem hemorrhage. Arch Ophthalmol. 2006;124(12):1786–1788.))
((Britt C W, Jr, Raso E, Gerson L P. Spindle coma, secondary to primary traumatic midbrain hemorrhage. Electroencephalogr Clin Neurophysiol. 1980;49(03/04):406–408.))
((Esteban Muñoz J, Tolosa E, Saiz A, Vila N, Martí M J, Blesa R. Upper-limb dystonia secondary to a midbrain hemorrhage. Mov Disord. 1996;11(01):96–99.))
((Galetta S L, Balcer L J. Isolated fourth nerve palsy from midbrain hemorrhage: case report. J Neuroophthalmol. 1998;18(03):204–205.))
((Kremer M, Russell W R, Smyth G E. A mid-brain syndrome following head injury. J Neurol Neurosurg Psychiatry. 1947;10(02):49–60.))
((Ogane K, Suzuki S, Sobata E, Iwabuchi T. [Two cases of well-known syndrome due to midbrain-brain stem hemorrhage—Weber's syndrome and one and a half syndrome] [in Japanese] No To Shinkei. 1993;45(02):163–168.))
((Shuaib A, Israelian G, Lee M A. Mesencephalic hemorrhage and unilateral pupillary deficit. J Clin Neuroophthalmol. 1989;9(01):47–49.))((Shuaib A, Murphy W. Mesencephalic hemorrhage and third nerve palsy. J Comput Tomogr. 1987;11(04):385–388)).
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Among all, eye movement disorders are the most prominent manifestation because the vertical gaze centers and two nuclei of the extraocular muscles are located in the midbrain
((Lee A G, Brown D G, Diaz P J. Dorsal midbrain syndrome due to mesencephalic hemorrhage. Case report with serial imaging. J Neuroophthalmol. 1996;16(04):281–285.))
((Rodríguez-Gómez J, Colás J, Aragón A, Albo M I, Casado F. [Upward and downward gaze palsy with a unilateral mesencephalic hemorrhage] [in Spanish] Rev Neurol. 2000;30(04):324–326.))
((Shintani S, Tsuruoka S, Minato Y, Shiigai T. Radiologic-clinical correlation. Isolated third nerve palsy caused by midbrain hemorrhage. AJNR Am J Neuroradiol. 1994;15(08):1508–1511.))
((Tomecek F J, Morgan J K. Ophthalmoplegia with bilateral ptosis secondary to midbrain hemorrhage. A case with clinical and radiologic correlation. Surg Neurol. 1994;41(02):131–136.)).
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Neuroophthalmological involvement is prominent in most patients. Third nerve dysfunction, skew-deviation, gaze palsy (especially in the vertical axis), and pupillary irregularities are common.

Parinaud syndrome (superior gaze palsy, pupillary dysfunction, and tonic downward and medial deviation of the eyes) is seen with hemorrhages in close proximity to the posterior commissure.

Third nerve involvement may be unilateral or bilateral. With unilateral involvement, there may be partial or complete paralysis of function, and the affected lesion may involve the nucleus or the third nerve fascicle. With fascicular involvement, motor long tracts may be affected in the cerebral peduncle.


Isolated fourth nerve palsy may also be a rare manifestation.

===== Outcome =====

The prognosis is known to be generally favorable, as minute and benign cases have been increasingly recognized with the widespread use of imaging techniques
((Perez F J, Nuñez C T. Scanning dysarthria secondary to spontaneous midbrain hemorrhage: case report and review of literature. Eur Neurol. 2008;60(02):89–91.)).

===== Case reports =====
A 14-year-old boy with a long-standing history of frequent migraine headaches and attention deficit/hyperactivity disorder (ADHD). Neurologic examinations, noncontrast computed tomography (CT) scans, and magnetic resonance imaging (MRI) suggested that the lesion likely affected the dorsal part of the midbrain. The neurologic symptoms improved following endoscopic third ventriculostomy (ETV) with the placement of external ventricular drains (EVDs). In this report, anatomical correlations to the case are discussed and previous reports of midbrain hemorrhages are reviewed
((Nguyen KR, Kim H, Nagy L. Isolated Spontaneous Midbrain Hemorrhage in a 14-Year-Old Boy. J Neurol Surg Rep. 2017 Jan;78(1):e5-e8. doi: 10.1055/s-0036-1597616. PMID: 28180053; PMCID: PMC5283167.)).