Pharmacologic agent Effect Modality: electrocochleography Resistant to effects of anesthesia Modality: auditory brainstem response Inhalation anesthetics (enflurane, halothane, isoflurane) Delay of 0.5–1.0 ms prolongation of wave V; I–V interpeak latency…
Fig. 26.1 Coronal SSFP image showing facial nerve anatomy: root exit point (RExP), attached segment (AS), root detachment point (RDP), transition zone (TZ), and cisternal portion (CP) Imaging in HFS…
Fig. 46.1 Blood flow velocity measured by TCD during carotid endarterectomy. Preinduction (a). Internal and external carotid arteries clamped (b). Significant decrease in BFV occurs with loss of pulsatility. With…
Fig. 24.1 MRI of 64-year-old woman that shows a large tumor mass in the right cerebellopontine angle (CPA). The cerebellum is shifted to the left hemisphere and the brainstem is…
Fig. 21.1 Tracing of SSEPs from left upper extremity, with normal responses from Erb’s point and the cervical region, but abnormal from the cortical leads. These abnormal tracing were caused…
Fig. 11.1 Standard 10–20 system for location of EEG scalp electrode placement (i.e., montage). The number 10 indicates distance in percentage (10 %) from nasion and inion to adjacent frontal…
Fig. 33.1 Adolescent in the headrest (ProneView, Dupaco, Oceanside, CA). The potential pressure points include the forehead and chin. It is important to make sure that the weight of the…
Fig. 31.1 Representative of cortical SSEP changes caused by unilateral carotid occlusion due to retractor malposition What are the possible causes for the diminished left-sided SSEP and MEP signals at…
Fig. 7.1 Placement of electrodes for recording EMG responses from the extraocular muscles (CNs III, IV, VI), facial muscles (CN VII), masseter muscle (CN V), trapezius muscle (CN XI), and…
Fig. 42.1 Representative transcranial electric motor-evoked potentials , ulnar nerve somatosensory-evoked potentials (SSEPs) , and posterior tibial nerve SSEPs recorded during neuroendovascular surgery for embolization of carotid artery fistula. The…
