DOH Neurodiagnostic Technologist oral exam prep

Knowledge: Photic stimulation can provoke a photoparoxysmal response and seizures in people with photosensitive epilepsy, which is common in juvenile myoclonic epilepsy, a likely diagnosis in a teenager with jerks on waking. The updated European algorithm advises stopping stimulation as soon as a generalised photoparoxysmal response appears, to avoid provoking a seizure. Hyperventilation is another activation procedure with its own contraindications, such as recent stroke, significant heart or lung disease, sickle cell disease and raised intracranial pressure. Most tonic-clonic seizures stop within two to three minutes; under the ILAE definition, status epilepticus treatment should begin when a tonic-clonic seizure lasts five minutes.

Management: I would stop the photic stimulator at once, note the time and call for the nurse and physician using the emergency call. I would keep the recording and video running, because the ictal EEG is valuable. I would ease him to the floor or a safe position, protect his head, loosen tight clothing and put nothing in his mouth. When the jerking stops, I would turn him into the recovery position, check breathing and colour, and give oxygen and suction as the unit protocol allows. If the seizure lasts five minutes or recurs without recovery, rescue medicine is given by the nurse or physician under the protocol. I would test his responsiveness and memory as he recovers and annotate the record carefully.

Ethics and communication: Consent for activation procedures should include the small risk of provoking a seizure, and, because he is under 18, the guardian gives consent for the test. I would inform his mother after he is safe and leave the interpretation to the physician. I would document the event, the stimulation settings and the actions taken, and report it through the incident system if policy requires. Advice on driving and safety belongs to the physician.

Reference: Kasteleijn-Nolst Trenite D et al, Methodology of photic stimulation revisited: updated European algorithm for visual stimulation in the EEG laboratory (Epilepsia 2012); Trinka E et al, A definition and classification of status epilepticus: Report of the ILAE Task Force on Classification of Status Epilepticus (Epilepsia 2015)

Knowledge: Non-convulsive seizures and status epilepticus are common in comatose patients after cardiac arrest, and can only be detected on EEG. The ACNS 2021 terminology defines an electrographic seizure as epileptiform discharges averaging more than 2.5 Hz for at least 10 seconds, or any pattern with definite evolution lasting at least 10 seconds. Electrographic status epilepticus is a seizure lasting at least 10 continuous minutes or for at least 20 percent of any 60-minute period. ICU artefacts, such as ventilator, chest physiotherapy, bed vibration, infusion pumps and patting, can mimic rhythmic activity. My role is to recognise and alert, while interpretation and treatment belong to the physicians.

Management: I would check the patient at the bedside and look at the video to rule out artefact, such as chest percussion or bed movement. I would check electrode impedances and the ECG channel. I would then call the neurophysiologist using the critical alert policy and tell the ICU team at the same time, with clear times and features. I would mark the start and end of each event and note clinical signs, such as eyelid twitching and heart rate changes. I would make sure the recording continues with good quality, and check electrode sites for skin breakdown, which is a risk with long recordings. The ICU physician will decide on treatment.

Ethics and communication: I must work within my scope and not interpret the EEG for the family, but I have a duty to escalate promptly. I would document the alert time, the person informed and the response. The family should be updated by the physicians. Health data from continuous recordings is confidential under Federal Law No. 2 of 2019 and should be accessed only by the team.

Reference: Hirsch LJ et al, American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology: 2021 Version (J Clin Neurophysiol 2021); Herman ST et al, Consensus statement on continuous EEG in critically ill adults and children, Part I: indications (J Clin Neurophysiol 2015)

Knowledge: ACNS Guideline 6 defines electrocerebral inactivity as no non-artefactual electrical activity over 2 microvolts when recording from scalp electrode pairs 10 cm or more apart. It requires a full set of scalp electrodes, impedances between 100 and 10,000 ohms, a sensitivity of 2 microvolts per mm for at least 30 minutes, a low-frequency filter not above 1 Hz and a high-frequency filter not below 30 Hz, testing the integrity of the system, an ECG channel, and testing reactivity to stimuli. Confounders that can suppress the EEG include sedative drugs, hypothermia and metabolic disturbance, and the physician must exclude them. The EEG is an ancillary test and cannot replace the neurological examination.

Management: I would apply the electrodes carefully, with double-distance montages and documented placement, check impedances, and calibrate. I would record at the required sensitivity for at least 30 minutes, with additional monitors such as a hand electrode, and note sources of artefact, such as the ventilator and infusion pumps. I would test integrity by touching each electrode to produce an artefact and perform stimulation according to protocol. I would record the medication and temperature, and report any concerns to the neurologist. The recording goes to the neurophysiologist for interpretation.

Ethics and communication: I would answer the husband gently, explaining that my role is to perform the test and that the doctors will explain the results to him. I would not give hints through my words or body language. I would ensure privacy and dignity during the recording. Determination of death follows national criteria and facility policy, and is done by the physicians. The record must be complete because it may support a legal determination.

Reference: Stecker MM et al, American Clinical Neurophysiology Society Guideline 6: Minimum Technical Standards for EEG Recording in Suspected Cerebral Death (J Clin Neurophysiol 2016); Greer DM et al, Pediatric and Adult Brain Death/Death by Neurologic Criteria Determination: Consensus Guideline (Neurology 2023)

Knowledge: Nerve conduction studies use brief electrical pulses that are safe in most patients. A temporary transvenous pacing wire with an external connection provides a low-resistance path for current to the heart, and stimulation close to the chest or the line could cause an arrhythmia, so this is a high-risk situation and needs the physician's decision. Central lines and electrical devices in the ICU also add risk and interference. Implanted pacemakers and defibrillators are generally managed by stimulating away from the device. Low limb temperature slows conduction velocity and prolongs latency, giving false results; warming the limbs to a standard temperature is needed. Guillain-Barre syndrome can show conduction block, prolonged F-waves and reduced amplitudes.

Management: I would inform the neurophysiologist about the pacing wire and line before starting, and agree on the plan, which may include studying the lower limbs first and avoiding stimulation near the chest and the pacing wire side. I would make sure the equipment is checked and grounded, with the ground electrode on the same limb between stimulator and recording sites, and that the patient is on a cardiac monitor with the ICU nurse present. I would warm the limbs and record the temperature. I would use the lowest stimulus intensity that gives a supramaximal response. I would stop at once if the cardiac rhythm changes, and inform the team.

Ethics and communication: I would explain the test to the patient and obtain verbal consent if he can communicate. If he cannot, the physician decides on the test as part of urgent care, and I would document the reason. I would record the safety checks, temperature and any events. Equipment safety checks are part of my professional duty, and any adverse event is reported.

Reference: Gechev A et al, Potential risks of iatrogenic complications of nerve conduction studies (NCS) and electromyography (EMG) (Clin Neurophysiol Pract 2016); Preston DC, Shapiro BE, Electromyography and Neuromuscular Disorders (4th ed, 2020)

Knowledge: An AHI of 72 is severe obstructive sleep apnoea. The AASM clinical guideline for PAP titration says a split-night study is indicated when the AHI is at least 40 over at least 2 hours of diagnostic recording, so this patient qualifies. Severe desaturation, bradycardia and pauses during apnoeas are common, but a run of wide-complex tachycardia is potentially life-threatening and needs the physician's input. The AASM scoring manual sets the rules for respiratory and cardiac events. CPAP titration starts at a low pressure and increases step by step to eliminate obstructive events, while monitoring for central apnoeas.

Management: I would go to the patient at once to check that he is responsive and breathing, and check the electrodes and ECG lead to make sure the event is real. I would call the on-call physician under the laboratory's critical alert policy and describe the AHI, the saturation and the rhythm. If the physician agrees, I would start CPAP titration under the protocol, increasing the pressure gradually and watching the saturation and rhythm. If he becomes unresponsive or the arrhythmia continues, I would call the emergency team. I would stay with him and annotate the recording.

Ethics and communication: I would explain the CPAP mask and the reason for it to the patient, and obtain his agreement before titration. I would document the events, alerts and actions clearly. If he drives for work, the physician must advise him about driving safety, and I would not discuss his results with his employer. His data is confidential under Federal Law No. 2 of 2019.

Reference: Kushida CA et al, Clinical guidelines for the manual titration of positive airway pressure in patients with obstructive sleep apnea (J Clin Sleep Med 2008); AASM Manual for the Scoring of Sleep and Associated Events (Version 3, 2023)

Knowledge: Health information belongs to the patient and is confidential under Federal Law No. 2 of 2019 on the use of information and communications technology in health fields. A technologist must not release results to third parties, including employers, without proper consent and process. The technologist also does not interpret or diagnose. A blackout in a professional driver raises a public safety concern, but decisions about fitness to drive or work belong to the physician, who follows the licensing rules and facility policy. Confidentiality may have limits when there is a serious risk to others, but that judgement belongs to the physician and the facility, not to me.

Management: I would tell the HR officer politely that I cannot confirm or share any information about any patient, and that she should ask the patient to provide a medical report with his consent. I would note the call. I would tell the patient that I cannot discuss results, which the physician will explain, and that I am not able to give legal advice. I would inform the reporting physician about the call and about the patient's driving and his statement, so the physician can address it. I would make sure the record is secure and not accessible to unauthorised staff.

Ethics and communication: Confidentiality is a core professional duty and protects trust. I must not breach it, but I must also not hide a safety concern from the physician who is responsible for the patient. The physician will decide on advice about driving and any reporting duties. I would document the conversations factually, and report any attempt at unauthorised access under the facility policy.

Reference: Federal Law No. 2 of 2019 (UAE); Sinha SR et al, American Clinical Neurophysiology Society Guideline 1: Minimum Technical Requirements for Performing Clinical Electroencephalography (J Clin Neurophysiol 2016)