The flocculus in computed tomography.
The flocculus may simulate a cerebellopontine angle mass in computed tomography (CT). The CT appearance of the flocculus was compared with acoustic neuroma. Normal internal auditory canals, symmetric cerebellopontine angle cisterns, modest contrast enhancement, and a location posterior to the porus acousticus distinguish the flocculus from an acoustic neuroma.
Does cerebellar flocculus size affect subjective outcomes in pediatric auditory brainstem implantation.
OBJECTIVES
The objectives of study was to 1) Describe relevant surgical anatomy in defining and accessing the lateral recess for placement of electrode, 2) Propose a working classification for grades of Flocculus; 3) To determine if different grades of cerebellar flocculus effects placement of ABI electrode and subjective outcomes in implantees.


METHODS
Our study was a prospective study, and comprised of cohort of 12 patients who underwent ABI surgery via retrosigmoid approach between 1 Jan 2012 to 31 Dec 2014. All children with congenital profound sensorineural hearing loss with either absent cochlea or cochlear nerve were included in the study. Relevant anatomy was noted. We also noted down the difficulty encountered during the placement of ABI electrode. Auditory perception and speech intelligibility was scored post operatively for 1 year.


RESULTS
Cerebellar flocculus was divided into 4 grades depending on the morphology of cerebellar flocculus. It was noted that Grade 3 & 4 flocculus (Group B) had difficult ABI electrode placement in comparison to Grade 1 & 2 flocculus (Group A). The subjective outcomes of Group A was better than Group B. However the p value was not statistically significant.


CONCLUSION
Cerebellar flocculus can be graded depending on morphology and size. Flocculus of higher grades can make the placement of ABI electrodes difficult and adversely effects the postoperative subjective outcomes.
Line Arrester Energy Discharge Duties
Surge arresters could practically eliminate lightning flashovers on distribution lines, if they are properly deployed in large enough numbers, and if they could survive the current and energy discharge duties imposed by high-magnitude lightning strokes. The discharge duty depends on complex interactions between the arrester locations, grounding, shielding from nearby objects, and the local lightning environment. But many factors of traditional concern with distribution arrester application, such as the lead length, surge front time, and protective margin, play little or no role in the discharge duty. Probabilistic methods determine the expected arrester failure rate. This should be much lower than the original flashover rate on the line insulation, otherwise the design is not acceptable. A transient program such as EMTP/ATP provides the best tool for calculating the discharge duty, but simplified methods are also available