David Edwin

Prognostic Value of Psychological Testing in Patients Undergoing Spinal Cord Stimulation: A Prospective Study

OBJECTIVE : Associations between psychological and physical states are understood to exist, and the development of standardized psychological tests has allowed quantitative evaluation of this relationship. We tested whether associations exist between psychological test instruments and patients selected for therapeutic trials of spinal cord stimulation (SCS) for chronic, intractable pain. METHODS : Fifty-eight patients selected for SCS were tested prospectively with a battery of standardized psychological tests : Minnesota Multiphasic Personality Inventory with Wiggins content scales, Symptom Check List-90, and Derogatis Affects Balance Scale. Associations between treatment outcomes and preoperative test scores and clinical variables were tested by univariate and multivariate statistical analyses, in which the dependent variables were as follows : 1) the outcome of a therapeutic trial of stimulation (whether the patient derived sufficient reported pain relief with a temporary electrode to proceed with a permanent implant), and 2) long-term outcome of treatment with the permanent implant, as determined by disinterested third-party interview. RESULTS : Significant associations (P ≤ 0.01) were observed between the outcome of the therapeutic trial of stimulation and psychological test results ; patients with low anxiety scores on the Derogatis Affects Balance Scale and with high organic symptoms scores on the Wiggins test were significantly more likely to proceed to permanent implants, as determined by multivariate statistical models. There was an elevation in the Minnesota Multiphasic Personality Inventory hypochondriasis scale in these patients by univariate (P = 0.02), but not by multivariate, models. The multivariate model also identified young age, reproduction of leg pain by straight leg raising, and bilateral leg pain as favorable prognostic factors. The only association with favorable long-term outcome of implantation of a permanent device, by univariate analysis, was an elevated joy score on the Derogatis Affects Balance Scale. Multivariate analysis revealed no statistically significant predictors of long-term outcome. CONCLUSION : Because our study population was selected on the basis of recognized prognostic factors and long clinical experience, it may not be possible to generalize our findings to the overall pain clinic referral population. In the subpopulation we have chosen for SCS trials, psychological testing is of modest value and explains little of the observed variance in outcome. We find little evidence for selecting patients for SCS on the basis of psychological testing. Because self-reported outcome measures may themselves reflect the patients psychological state, these findings should be considered carefully, in overall clinical context. A prospective study with additional objective outcome measures is underway, which will address some of these issues.

Relationship of the model for end-stage liver disease (MELD) scale to hepatic encephalopathy, as defined by electroencephalography and neuropsychometric testing, and ascites.

OBJECTIVE:It has recently been suggested that the Model for End-Stage Liver Disease (MELD) is a better and a more objective predictor of mortality in patients with end-stage liver disease. The aim of our study was to determine the relationship of the MELD score to hepatic encephalopathy (HE), as determined by electroencephalography (EEG) and clinical and neuropsychometric examination, and ascites.METHODS:A total of 66 patients underwent EEG, a neuropsychometric screening by Mini-Mental State Examination, Trails Making Tests, Rey-Osterreith Complex Figure, and Hopkins Verbal Learning Tests, and a clinical assessment for HE. The MELD score was calculated as previously described by using serum creatinine, bilirubin, and international normalized ratio. Subclinical HE was diagnosed if clinical examination did not detect HE but neuropsychometric tests and EEG were abnormal.RESULTS:Sixteen patients had no HE, 28 had subclinical HE, and 22 had clinical HE. Age, sex, race, and cause of liver disease were similar in all three groups. Child-Turcotte-Pugh score was significantly higher in patients with clinical HE compared with the other two groups. There was only a modest correlation (r = 0.5) between Child-Turcotte-Pugh and the MELD scores. The distribution and mean MELD scores were similar in patients with or without HE as determined by clinical or neuropsychometric examination and EEG. Approximately 90% of patients with clinical HE or abnormal EEG and neuropsychometric tests had a MELD score less than 25. Similarly, the MELD score was not affected by the severity of ascites.CONCLUSION:The MELD score does not correlate well with severity of HE or ascites. Patients with HE and ascites might not receive liver transplantation in a timely manner if MELD scores were to be used exclusively for organ allocation.

Outcome prediction by MMPI in subtypes of anorexia nervosa.

Sixty-seven discharged, chronically anorectic inpatients were followed eight to 60 months after discharge at normal weight: 39 with anorexia nervosa, restricting subtype (ANR), and 27 with anorexia nervosa, bulimic subtype (ANB). The groups did not differ demographically. ANB patients produced more elevated MMPI profiles; they were distinguished by profile type as well as by discriminant function analysis, which identified ANB patients as higher in both depression and impulsivity. Outcome criteria, i.e., follow-up weight, bulimic behavior, social functioning, revealed that 39% of all patients maintained treatment gains while 61% relapsed. Forty-nine percent of ANR patients maintained improvement, compared with only 22% of ANB. Minnesota Multiphasic Personality Inventory (MMPI) profiles did not predict outcome across all patients, but did within each subtype. Successful ANR patients were more distressed and dramatic, while greater distress and impulsivity predicted failure among ANB. Prediction of ability to maintain improvement after inpatient treatment was markedly enhanced by first classifying anorectics into clinical subtypes. Higher subjective distress predicted negative outcome in one group and positive outcome in the other. These results may clarify apparent contradictions in the literature and contribute to more focused treatment.

Cognitive impairment in adult-onset adrenoleukodystrophy.

Adrenoleukodystrophy (ALD) is a progressive X-linked disorder that produces pathological changes, mainly in the adrenal cortex and the white matter of the central nervous system. The main biochemical abnormality is the accumulation of saturated unbranched fatty acids with a chain length of 24 or more, referred to as very-long-chain fatty acids (VLCFA). Affected children develop large zones of demyelination associated with perivascular lymphoctyic infiltrations resembling those seen in multiple sclerosis. Adults show a more chronic form of the disease, referred to as adrenomyeloneuropathy (AMN). AMN mainly involves the spinal cord ad peripheral nerves, although the cerebral hemispheres may also be affected. Approximately 15% of female carriers have nervous-system involvement that resembles AMN. It is well known that ALD may initially appear as a psychiatric disorder. In the present study, we have assessed the prevalence of cognitive impairment in a group of AMN patients and neurologically symptomatic ALD heterozygotes initially presenting primarily physical complaints. Sixty percent of these patients demonstrated significant neuropsychological impairment, most commonly a pattern of spared and impaired functions typical of a subcortical dementia. We suggest that this progressive cognitive impairment may underlie other behavioral deficits, affirming the significance of the psychological features of this genetically determined disorder.

Altered cortical brain activity in end stage liver disease assessed by multi-channel near-infrared spectroscopy: Associations with delirium

Delirium is a common and serious psychiatric syndrome caused by an underlying medical condition. It is associated with significant mortality and increased healthcare resource utilization. There are few biological markers of delirium, perhaps related to the etiologic heterogeneity of the syndrome. Functional near-infrared spectroscopy (fNIRS) is an optical topography system to measure changes in the concentration of oxygenated hemoglobin ([oxy-Hb]) in the cerebral cortex. We examined whether altered cortical brain activity in delirious patients with end stage liver disease (ESLD) is detected by fNIRS. We found that the [oxy-Hb] change during the verbal fluency task (VFT) was reduced in patients with ESLD compared with healthy controls (HC) in the prefrontal and bi-temporal regions. The [oxy-Hb] change during the sustained attention task (SAT) was elevated in patients with ESLD compared to HC in the prefrontal and left temporal regions. Notably, [oxy-Hb] change in the left dorsolateral prefrontal cortex during SAT showed a positive correlation with the severity of delirium. Our results suggest that [oxy-Hb] change in the prefrontal cortex during the sustained attention task measured with fNIRS might serve as a biological marker associated with delirium in ESLD patients.