The patient was employed as an assistant restaurant manager. She was married with a 1 year-old daughter. She had received an associates degree in culinary arts. There was no family history of psychiatric illness or cardiovascular disease or syncope or sudden death. No history of substance abuse.
At the initial evaluation, the patient was prescribed the following medications: Metoprolol 25 mg BID, Phenytoin 300 mg qHS and KCL 10mEq daily.
After undergoing a structured clinical interview utilizing MINI International Neuropsychiatric Interview, the patient met DSM IV-TR diagnostic criteria for an adjustment disorder with mixed anxiety and depressed mood. We assessed the degree of severity of the patient's symptoms using several quantitative clinical measures. These indicated "severe" levels of general anxiety (via BAI) and borderline clinical depression (via Beck Depression Inventory, BDI) (Beck and Steer,) (Table 3).
The patient underwent a neurology consultation including EEG, to evaluate the possibility of a seizure disorder. The EEG was conducted with the patient in the awake and asleep states. Hyperventilation and photic stimulation were not performed as activating maneuvers, and no sedation was given. While maximally awake, the posterior dominant rhythm was 9-10 Hz, which was symmetric, synchronous and reactive to eye opening and eye closure. Three brief periods of high amplitude theta activity (4-7 Hz) were captured and reported as paroxysmal in nature. They appeared generalized, without a focal cortical distribution, lasting approximately 1-2 s. These slowings occurred in the wakeful and/or drowsy state, with no evidence of epileptiform behaviors at the time. They were interpreted as potentially consistent with physiological drowsiness. In one instance the slowing appeared notched, which could indicate possible epileptiform activity. However, as a fast alpha variant was present at the same time, it was considered suggestive against an epileptic etiology. Vertex waves signifying drowsiness were noted later in the recording, but not at the time of the paroxysmal slowing. This was also considered suggestive against an ictal semiology. Overall, the EEG was judged to be normal in wakefulness and stage II sleep, without any clear electrographic features of seizure. No epileptiform behaviors were identified during clinical observation.
Despite the lack of clear electrographic evidence of a seizure disorder the periods of high amplitude generalized slowing and the reported phenomenology of her episodes were felt to be possibly consistent with a seizure disorder. Seizure prophylaxis was continued, but switched from Phenytoin to Levetiracetam 1000 mg BID.
After further consultation, the patient elected to undergo BCSD. The resection covered the lower half of the stellate ganglion and the bodies of sympathetic chain from T2 through T4. Discharge medications included Levetiracetam 1000 mg BID and Propranolol 40 mg TID. Evaluation of the patient's symptom scores at 1 month post-BCSD revealed clinically significant decreases in depression (via BDI), anxiety (via BAI) and shock catastrophizing (via SCS) (Figure 4). Clinical evaluation at 1 month post-BCSD, revealed that she had not experienced any further shocks, and no further ICD events had been detected. The patient the patient reported her mood and anxiety symptoms were much improved. She declined the recommendation to seek further psychiatric follow up, and as she was subsequently lost to follow-up no further psychometric data are available.
Continuous measures of skin conductance level (SCL), systolic blood pressure (SBP), and diastolic blood presssure (DBP) were recorded during psychophysiological assessment using Biopac MP150 hardware and Acqknowledge 4.3 software (Biopac, Santa Barbara, CA). Two isotonic 1-cm diameter gel electrodes were attached to the thenar and hypothenar eminence of the subject's nondominant hand to assess SCL. This tonic measure of galvanic skin resistance was selected as a measure of sympathetic arousal due the prolonged time intervals examined (Naqvi and Bechara,). Blood pressure was continuously assessed using the CNAP 500 Monitor (CN Systems, Graz, Austria) with finger cuffs, which were placed between the proximal and distal interphalangeal joints of the third and fourth digits of the subject's nondominant hand. Heart rate was not examined due to the presence of atrial pacing in both patients, which kept the heart rate constant.
The psychophysiological assessment began with a 5-min resting baseline during which the subject was seated in a chair and instructed to remain at rest and minimize movement. Psychophysiological measures (SCL, SBP, and DBP) were assessed during the 5-min baseline. As the pre-BCSD testing occurred in an inpatient setting, the first 2 min of the 5-min baseline period were discarded in order to account for possible environment-related influences on autonomic tone. Data for each measure for the final 3 min was averaged to provide a baseline value for that session. Additional interventions to reduce outside distraction included closing the door of the patient's single occupancy room, and silencing the alarms of monitoring equipment. The resting baseline period was followed by 3 tasks in the following order: a valsalva task, a handgrip task, and a mental arithmetic task.
The valsalva task involved performing two sustained valsalva maneuvers while in a seated position. The subject was given the following instructions, "During this task, I will place my hand on your abdomen. The goal is to push my hand away as far as you can by protruding your abdomen. Hold this position for as long as you can. Remember to keep breathing while bearing down." The procedure was demonstrated by the assessor, practiced once by the subject, and then performed twice by the subject. Each trial period lasted approximately 15-25 s. Psychophysiological measures were assessed during the two valsalva trials, and scores on SCL, SBP, and DBP were averaged across the two trials.
The isometric handgrip task involved a hand dynamometer held by the subject's dominant hand. The following instructions were provided before performing the task, "During this task you will squeeze a hand dynamometer for 2 min at a specific grip strength level with your dominant hand. I will first determine your maximum grip strength level by asking you to squeeze the dynamometer with as much force as possible." Following determination of subject's maximum grip strength, the dial on the dynamometer was placed at 30% of the maximum grip strength, and the subject was instructed to squeeze the grip at that level for 2 minutes. Values on SCL, SBP, and DBP were averaged across this 2-min period.
The mental arithmetic task was selected as a cognitive stressor and adapted from the Trier Social Stress Task (Kirschbaum et al.,). This modified protocol consisted of a 5-min period during which the subject was instructed to consecutively subtract by 13's starting at 1022, in front of two experimenters. The subject was told to perform this task aloud as quickly and accurately as possible, was corrected each time an error was committed, and then told to start over at 1022. Mean SCL, SBP, and DBP were assessed across the 5-min period.
Acqknowledge software, version 4.3, was used to process all data collected during the psychophysiological assessment sessions. Using Acqknowledge, SCL was averaged across the pre-specified 2 min resting baseline and specified periods during each task described above. The Acqknowledge blood pressure classifier analysis feature was used to identify SBP and DBP at each heartbeat. Means for SBP and DBP were determined for resting baseline and for specified periods during each task. This study was approved by the Unversity of California Los Angeles Institutional Review Board, and all participants provided informed consent prior to participation.
Mean values of the autonomic testing in Case 2 are displayed in Table 4. Figures 5-7 show changes in each measure from the resting baseline value pre- and post-BCSD. Compared with before BCSD, the patient demonstrated clear declines in baseline adjusted systolic and diastolic blood pressure response for the valsalva and handgrip tasks, but less so with the mental arithmetic stressor, which did not show robust changes at either time point. Comparing pre- vs. post-BCSD, the patient demonstrated prominent declines in baseline adjusted SCL for all tasks (Figure 7).