Posterior inferior cerebellar artery aneurysm epidemiology

Posterior inferior cerebellar artery aneurysms constitute 0.5-3% of all intracranial aneurysms ¹⁾ ²⁾ ³⁾.

Of 2169 aneurysms treated between January 1995 and March 2007 in St. Elisabeth Ziekenhuis, Tilburg, the Netherlands, 60 were located on the PICA (incidence, 2.8%).

PICA aneurysms may take origin from one of its six segments and two loops (based on its relationship to the medulla oblongata and the cerebellum including: a) the BA-VA-PICA junction; b) the anterior medullary segment, from VA-PICA origin to the inferior olivary prominence; c) the lateral medullary segment, extending until the origin of IX-X-XIth cranial nerves; d) the tonsillomedullary segment, until the caudal portion of tonsils (including the caudal loop); e) the telovelotonsillar segment, from the midportion of its ascent along the medial surface of tonsil to the cortical cerebellar surface (including the cranial loop); and, f) the cortical segment, extending until the cerebellar vermis and hemisphere ⁴⁾ ⁵⁾ ⁶⁾ ⁷⁾ ⁸⁾.

In general, PICA aneurysms tend to present at an earlier age as compared with other aneurysms. The mean age as reported in many large series is in the fifth decade, with Lewis et al ⁹⁾ reporting 51 years, Lehto et al ¹⁰⁾ as 52 years, and Dernbach et al 10 even lower at 44.7 years. In their series, Lehto et al ¹¹⁾ compared the age of patients with distal PICA aneurysms in eighty cases with those cases who had aneurysms located at other locations during the same study period. They, however, never found a significant difference in the ages, as the mean age of other cases presenting with aneurysms was 49 years. In the series of Deora et al., ¹²⁾ the mean age was 51 years, ratifying with most previous series.

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Hudgins RJ, Day AL, Quisling RG, Rhoton AL, Jr, Sypert GW, Garcia-Bengochea F. Aneuryms of the posterior inferior cerebellar artery.A clinical and anatomical analysis. J Neurosurg. 1983;58:381–7.

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Lister JR, Rhoton AL, Matsushima T, Peace DA. Microsurgical anatomy of the posterior inferior cerebellar artery. Neurosurgery. 1982;10:170–99.

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Weir B. Baltimore: Williams and Wilkins; 1987. Aneurysms affecting the nervous system; pp. 489–91.

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Lewis SB, Chang DJ, Peace DA, Lafrentz PJ, Day AL. Distal posterior inferior cerebellar artery aneurysms: Clinical features and management. J Neurosurg. 2002;97:756–66.

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Drake CG. The treatment of aneurysms of the posterior circulation. Clin Neurosurg. 1979;26:96–144.

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Krayenbuhl N, Guerrero C, Krisht AF. Technical strategies to approach aneurysms of the vertebral and posterior inferior cerebellar arteries. Neurosurg Focus. 2005:19–E4.

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Margolis MT, Newton T. Borderlands of the normal and abnormal posterior inferior cerebellar artery. Acta Diagn (Stockh) 1972;13:163–76.

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Lewis S B, Chang D J, Peace D A, Lafrentz P J, Day A L. Distal posterior inferior cerebellar artery aneurysms: clinical features and management. J Neurosurg. 2002;97(04):756–766.

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Lehto H, Harati A, Niemelä M et al.Distal posterior inferior cerebellar artery aneurysms: clinical features and outcome of 80 patients. World Neurosurg. 2014;82(05):702–713.

¹²⁾

Deora H, Nayak N, Dixit P, Vikas V, Rao KVLN, Pruthi N, Srinivas D, Shukla DP, Bhat DI, Malla BR, Devi BI, Somanna S. Surgical Management and Outcomes of Aneurysms of Posterior Inferior Cerebellar Artery: Location-Based Approaches with Review of Literature. J Neurosci Rural Pract. 2020 Jan;11(1):34-43. doi: 10.1055/s-0039-3399486. Epub 2020 Jan 27. PMID: 32269450; PMCID: PMC7138643.