8.1 Introduction The action potential, initiated by the depolarization of the axonal membrane, has classically been described as having periods of both hypo- and hyperexcitability . Historically, most investigations related to axonal excitability use paired stimuli by first applying a…
7.1 Introduction Language and cognitive mapping is recommended in patients with intrinsic tumors involving language or cognitive pathways. Traditionally, this type of mapping was limited to patients harboring lesions in the so-called dominant hemisphere, where language was thought to be…
6.1 Introduction The functions involving the genitourinary and the anorectal systems are uniquely controlled by the complex interaction of the autonomic and the somatic nervous systems. Insofar as it is the sacral parasympathetic and somatic systems that comprise the most…
5.1 The auditory nerve Introduction of intraoperative monitoring of the hearing function in the 1980s has reduced the incidences of hearing loss as a complication to surgical operations that affect the auditory nerve considerably. The auditory nerve was one of…
4.1 Introduction Neurosurgical procedures for treatment of tumors or vascular lesions along the visual pathways carry a risk of damage to the visual pathways. These procedures include parasellar tumors, pituitary adenomas, craniopharyngiomas, and tuberculum sellae meningiomas. Risk of visual impairment…
3.1 Introduction Intraoperative somatosensory evoked potential (SEP) monitoring selectively helps reduce the risk of injuring the dorsal somatosensory system for proprioception, vibration sense, and discriminative touch . It also complements motor evoked potential (MEP) monitoring of surgeries mainly risking corticospinal…
2.1 Intraoperative monitoring of the motor system: a brief history 2.1.1 Penfield’s time When discussing the use of intraoperative electrical stimulation of the upper motoneurons in humans, it is essential to mention Wilder Penfield (1891–1976). His publication with Edwin Boldrey…
1.1 Introduction The uses of monitoring motor responses for stimulating the human cerebral cortex have clearly expanded beyond the clinical mapping studies of the exposed brain at operation . The discovery that transcranial electrical stimulation (TES) of human motor cortex…
History of Functional Magnetic Resonance Imaging While conventional MRI (magnetic resonance imaging) and CAT (computerized axial tomogram) scan image the structural anatomy of the brain (and pathology) to a high degree of spatial resolution, functional imaging has carried this imaging…
The hardest thing of all is to find a black cat in the dark room especially if there is no cat. Kung Fu Tzu Cognitive function is an intellectual process by which one becomes aware of, perceives, or comprehends ideas.…