Assessment of the stroke patient
Christos Tziotzios, Jesse Dawson, Matthew Walters, Kennedy R Lees in Stroke in Practice, 2017
Trigeminal (CN V) Test light touch sensation on each side of the patient’s forehead while asking if the two stimuli felt the same on both sides. This should be repeated on the cheek and on the chin. (NB. The superficial cervical plexus is responsible for sensation at the angle of the jaw).The above procedure should be repeated applying light pressure with a pin.Although not done routinely, the corneal reflex may be of value in the unconscious or uncooperative patient.The motor division of the trigeminal nerve should be tested by testing jaw opening and jaw closing.
Brain death and ethical issues
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Essentials of Anesthesia for Neurotrauma, 2018
The corneal reflex assesses the pathway arising from the trigeminal nerve—from small unmyelinated pain fibers in the cornea—and the dorsal parts of facial nuclei in the pons, which determines contraction of the orbicularis oculi muscles when either cornea is touched. The corneal reflex is tested by gently touching the edge of the cornea with a cotton or tissue swab and observing the absence of a responsive blink.
Brain death and ethical issues: Death by neurological criteria
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Essentials of Geriatric Neuroanesthesia, 2019
After confirming a comatose state, the physician can move on to cranial nerve testing. All cranial nerve reflexes must be absent for the diagnosis of brain death. Pupillary response to a bright light must be absent in both eyes. The pupils are typically fixed in mid-position (4–9 mm) due to sympathetic and parasympathetic denervation (4). Pinpoint pupils should alert the provider to possible drug effect. A magnifying glass or pupilometer may be used to detect small changes in pupil size. In a patient with proper spinal integrity, oculocephalic reflexes should be tested by rapidly turning the patient's head from side to side and vertically with the eyes held open. There should be no eye movement in the brain-dead patient. Vestibuloocular reflexes should be tested using maximal ice water caloric stimulation. First, otoscopic examination is performed to ensure that tympanic membrane is intact and external auditory canals are patent. The head of the bed should be at 30°. Fifty mL of ice water is infused into one ear through a flexible, dull-ended tube, such as a butterfly catheter with the needle removed. The infusion occurs over 1 minute, while an assistant holds open the patient's eyes. A patient who is brain dead will display no response to this test, including no grimace, eye movements, or motor response. An interval of 5 minutes should exist before testing the other ear (17). The corneal reflex should be tested with a cotton swab applicator pressed carefully on the cornea bilaterally. Facial muscle response to noxious stimuli should be assessed by applying deep pressure to the temporomandibular joint and the supraorbital ridge. No grimace should be seen. Gag and cough reflexes can be tested by suctioning the patient's endotracheal tube or by stimulating the posterior pharynx with a tongue depressor. A jaw jerk reflex should be absent. Again, all cranial nerve reflexes must be absent bilaterally in order to diagnose brain death and to proceed with further testing.
Effect of the use of dexmedetomidine as an adjuvant in peribulbar anesthesia in patients presented for vitreoretinal surgeries
Published in Egyptian Journal of Anaesthesia, 2018
Sameh Abdelkhalik Ahmed, Mohamad Gamal Elmawy, Amr Ahmed Magdy
Sensory block was assessed by the abolishment of corneal reflex to instillation of physiological drops on the cornea or conjunctiva. The onset of anesthesia was determined by the time interval from local anesthetics injection and loss of corneal reflex. The motor block was evaluated by asking the patient to open, close, and squeeze his eye (Lid Akinesia) and to move his eye globe in the four directions of the gaze (globe akinesia). The quality of akinesia was assessed through the use of akinesia score where 0=inability to move (total akinesia), 1=partial movement (partial akinesia), and 2=full movements (no akinesia). This score was used to assess both lid akinesia and globe akinesia in the four directions with the overall score of 10 [18]. The onset of lid akinesia was calculated from peribulbar injection to the partial loss of ability to open or squeeze eye lids, while, the onset of globe akinesia was estimated from the injection of the local anesthetic mixture and partial loss of movement of eye globe in the four cardinal directions. The surgery was considered to be optimal to be started when the patient had corneal anesthesia together with partial lid and globe akinesia. The optimal time to start the surgery was considered as the elapsed time between local anesthetics injection and satisfying the goals to start the surgery. The intraocular pressure was measured preoperatively and immediately before initiating the surgery with detection of number of patients with increase in the intraocular tension (increase intraocular pressure more than 25mmHg or by more than 10mmHg than the preoperative value)
The Prevalence of Refractive Errors and Visual Impairment among School Children in Brčko District, Bosnia and Herzegovina
Published in Seminars in Ophthalmology, 2018
Allen Popović-Beganović, Jasmin Zvorničanin, Vera Vrbljanac, Edita Zvorničanin
Ocular motility was evaluated by ophthalmologist with cover testing and observation of the corneal reflex at 0.5 and 4.0 meters. Tropias were categorized as exotropia, esotropia or vertical, with the degree of tropia measured using the corneal reflex (Hirschberg´s method). Pupils in both eyes were dilated with two drops of 1% cyclopentolate with an interval of 5 min. If a pupillary light reflex was still present after 20 min, a third drop was administered. Light reflex and pupil dilation were evaluated after additional 15 min. Cycloplegia was considered complete if the pupil was dilated to 6 mm or more and light reflex was absent. Refraction was performed in all children after cycloplegia by ophthalmologist, regardless of their visual acuity, using first streak retinoscopy (Heine Beta® 200 Retinoscope, HEINE Optotechnik Germany). Cycloplegic autorefraction was performed by optometrist using the autorefractor (Humphrey Zeiss ARK 599 Autorefractor Keratometer, Carl Zeiss Meditec AG), with calibration made at the beginning of each day using an eye model. At least eight representative values from the autorefractor were acquired for data analysis. Unreliable measurements were rejected and remeasured. The ophthalmologist evaluated the external eye and anterior segment (eyelid, conjunctiva, cornea, iris and pupil) using a slit lamp while the media and fundus were evaluated with direct and indirect ophthalmoscopic examination.
The effects of pulsed electromagnetic field on experimentally induced sciatic nerve injury in rats
Published in Electromagnetic Biology and Medicine, 2021
Gülten Bademoğlu, Nurten Erdal, Coşar Uzun, Bahar Taşdelen
Operative procedures were performed under sterile conditions with general anesthesia in the Experimental Animal Research Laboratory. Rats were deeply anesthetized using a mixture of 80 mg/kg ketamine HCl (Ketalar, EWL Eczacıbası Warner-Lambert Istanbul, Turkey) and 10 mg/kg xylazine (Rompun, Bayer AG., Istanbul, Turkey) injected intraperitoneally. The depth of anesthesia was checked continuously by assessing palpebra or corneal reflex. The right lateral thighs of rats along the right femur line were shaved and cleaned with an antiseptic solution. The sciatic nerve was identified by dissecting on the plane separating at the mid-thigh level surrounding tissues. After the surrounding tissue on the visible mainline of the sciatic nerve was removed from the sciatic nerve, axonotmesis was applied approximately 1–1.5 cm distal to the femur bone. The sciatic nerve was crushed with locking stainless-steel fine forceps (5.0, No:15) at its maximum point lock for 30 s (Güven et al. 2005) (Figure 1). In Control group surgery, the sciatic nerve of the right hind limb was exposed under the same surgical conditions, but no crush was made. After the wound was closed with 3–0 non-absorbable silk sutures, waiting to recover from anesthesia for 1 day.