From an anatomic point of view, both approaches provide similar exposure to the sellar, suprasellar, and anterior communicating artery areas. The pterional approach provides better exposure of the retrosellar area. The ability to operate in the retrosellar area, as judged by our model, was higher with the pterional than with the lateral supraorbital approach.

Deep brain stimulation (DBS) involves the delivery of precise electrical signals to specific deep anatomical structures of the central nervous system, with the objective of altering or modulating neural functioning and achieving a reversible, adjustable and therapeutic or clinically beneficial effect. The exact mechanism of action of DBS is still the subject of ongoing investigations. However, based on extensive clinical investigations, it has become an established modality for the surgical treatment of advanced and medication intractable movement disorders such as Parkinson's disease, essential tremor and dystonia. DBS is also being investigated for conditions such as intractable epilepsy, neurobehavioral and psychiatric disorders such as treatment resistant depression, obsessive compulsive disorders, addiction, obesity, Alzheimer's disease and traumatic brain injury. The advantage of DBS over older deep brain lesioning procedures is its reversibility and adjustability. The design of the DBS systems allows for dynamic adjustment of the effects of electrical stimulation by altering the contacts at which electrical pulses are delivered to the brain and changing the stimulation parameters of those pulses. The clinical results from studies on DBS show that it has great potential making it one of most promising fields which could be used to address challenging neurological problems.

Object The posterior interhemispheric transprecuneus gyrus approach is one of the surgical routes that has been suggested to reach the atrium of the lateral ventricle. It has the advantage of avoiding the disruption of the optic radiations; however, it has a narrow working area that at times makes the execution of this approach rather challenging. The aim of this study was to test a modification of the approach that might create a better surgical angle and a wider corridor by accessing the atrium from the contralateral side after transection of the falx. The authors named this new approach the “posterior interhemispheric transfalx transprecuneus approach.” Methods The posterior interhemispheic transfalx transprecuneus approach was performed bilaterally on 6 fresh adult cadaveric specimens for a total of 12 procedures. Every head was held in the semisitting position and a parasagittal parietooccipital craniotomy on the contralateral side of the targeted ventricle was executed. The dura mater was opened and reflected based on the sagittal sinus. Then the falx was cut in a triangular fashion based on the inferior sagittal sinus. Using the parietooccipital artery and sulcus as landmarks, the contralateral precuneus gyrus was indentified, and a small area of the gyrus was transected to gain access to the atrium. A neuronavigational system was also used to conduct this approach. The working angle of this approach and other distances were measured Results The authors were able to visualize the ventricular atrium, posterior part of the temporal horn, pulvinar, and choroid plexus in all specimens. The temporal horn could be exposed for a length of 20–30 mm from the atrium. The working angle of the approach was better than that of the classic posterior interhemispheric transprecuneus approach with a mean value of 44.5° as opposed to 25.8°. The distance from the middle point of the corticotomy to the splenium ranged from 11 to 16 mm (mean 13.3 mm); the distance to the torcula, from 34 to 53 mm (mean 41.3 mm); and the distance to the atrium, from 22 to 31 mm (mean 25.7 mm). Conclusions Results of this study suggested that the proposed approach can expose the atrium and the posterior part of the temporal horn of the lateral ventricle with a wider surgical angle compared with the conventional homolateral posterior interhemispheric transprecuneus gyrus approach. Moreover, by minimizing the amount of brain retraction homolateral to the target, this approach could make navigation more accurate.

This study demonstrated the feasibility of the resection of the posterior clinoid process extradurally. This maneuver could be incorporated in multiple cranial base approaches to the retrosellar area and interpeduncular cistern region.