Sleep spindles in bipolar disorder - a comparison to healthy control subjects

OBJECTIVE

Bipolar disorder is a severe mental disorder for which currently no reliable biomarkers exist. It has been shown that patients with schizophrenia but not with unipolar depression have a reduced density of fast sleep spindles during N2 sleep. The aim of this study was to assess fast sleep spindle density in euthymic patients with bipolar disorder.

METHODS

Patients with bipolar disorder (n = 24) and healthy control subjects (n = 25) were assessed using all-night polysomnography. Sleep spindles within stage N2 sleep were identified by visual inspection and subdivided into fast (>13 Hz) and slow (≤13 Hz) spindles. All spindles were subsequently characterised by density, frequency, amplitude, duration and coherence.

RESULTS

Euthymic patients with bipolar disorder were found to have a reduced density and a lower mean frequency of fast spindles. Slow spindle density and frequency did not differ between groups. There were no differences regarding amplitude, duration or coherence.

CONCLUSIONS

A reduction in fast spindle density during N2 sleep points towards thalamic dysfunction as a potential neurobiological mechanism of relevance in bipolar disorder. In addition, a reduced sleep spindle density could be interpreted as a common endophenotype shared with schizophrenia but not unipolar depression and may - if replicated - be of utility in early recognition and risk stratification.

Symptom characteristics of depressive episodes prior to the onset of mania or hypomania

OBJECTIVE

Depressive episodes are typically the initial presentation of bipolar disorder. The evidence as to whether depressive episodes occurring in persons who later convert to bipolar disorder are symptomatically distinct from episodes of unipolar depression remains controversial. As there are crucial differences in the therapeutic management, symptom profiles indicating subsequent bipolar conversion may aid in appropriate treatment.

METHOD

A representative community sample of originally N = 3021 adolescents and young adults aged 14-24 years at baseline was assessed up to four times over 10 years. Assessment of symptoms was conducted by clinically trained interviewers using the standardized M-CIDI. Symptom profiles of depressive episodes were compared via logistic regression between subjects that subsequently developed (hypo-)manic episodes (n = 35) or remained unipolar depressive (n = 659).

RESULTS

Initial depression amongst prospective converters was characterized by significantly increased suicidality (odds ratio, OR = 2.31), higher rates of feelings of worthlessness and excessive guilt (OR = 2.52), complete loss of pleasure (OR = 2.53) and diurnal variation (OR = 4.30). No differences were found for hyperphagia, hypersomnia and psychomotor alterations.

CONCLUSION

Findings suggest that the symptom profile of initial depressive episodes may be useful in the identification of subjects with an elevated risk for the subsequent conversion to bipolar disorder.

[Ketamine as antidepressant: the current study situation]

The treatment of depressive episodes is characterized by a delay in response of antidepressant medications and high rates of therapeutic failure. In recent years several open and five controlled trials have demonstrated the antidepressant efficacy of ketamine for major depression. In addition a recent study established the utility of nasal ketamine which may render the necessity of intravenous administration obsolete. The current state of evidence is reviewed and discussed.

Ability to culture resectable non-small cell lung carcinomas is correlated with recurrence

Present clinicopathologic staging of non-small cell lung cancer is limited in its ability to provide more than a general prognostic estimate in patients with lung cancer who have resectable disease. This study was performed to identify whether the ability to adapt tumor tissue from resectable (stage I to IIIa) non-small cell lung cancer was associated with a poorer prognosis and an increased risk for early tumor recurrence. We attempted to culture a tumor specimen obtained from 90 patients with resectable non-small cell lung cancer. We used a culture medium conditioned by exposure to the lung cancer cell line A549-1, a known producer of autocrine lung cancer growth factors, and provided tumor colony scaffolding using a feeder layer of inactivated fibroblasts, and found these measures improved tumor culture yields. Twenty-two cell lines were obtained, a success rate of 24.4%. Tumor recurrences were more common (79%) among the culture-positive patients than among the culture-negative patients (37.5%; p < 0.002). For all patients, survival at 19 months in the culture-positive patients was 50.0%, compared with 83.6% in the culture-negative patients (p < 0.005). The median survival for the culture-positive patients was 15 months, versus 21.7 months for the culture-negative patients (p < 0.004). The establishment of a culture was a predictor of shortened survival for patients with stage I disease. In patients with stage I disease, survival at 19 months was 54.5% for the culture-positive patients, versus 89% for the culture-negative patients (p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Postoperative pain-related morbidity: video-assisted thoracic surgery versus thoracotomy

One hundred thirty-eight consecutive, nonrandomized patients, with equivalent demographic and preoperative physiologic parameters, underwent either a video-assisted thoracic surgical (VATS) approach (n = 81) or a limited lateral thoracotomy (LLT) approach (n = 57) to accomplish pulmonary resection for peripheral lung lesions (< or = 3 cm in diameter). Wedge resection was done in 74 VATS patients and 19 LLT patients. Seven patients underwent VATS lobectomy and 38 patients had lobectomy performed through an LLT. Pain was quantitated by postoperative narcotic requirements, the need for intercostal/epidural analgesia, and patient perception of pain index scoring. Shoulder and pulmonary function (forced expiratory volume in 1 second) were measured preoperatively, 3 days postoperatively, and at 3 weeks of follow-up. Patients undergoing VATS experienced significantly less postoperative pain. No patients undergoing VATS required intercostal block/epidural analgesia; 31 LLT patients (54%) required this treatment for breakthrough pain (p = 0.001). Narcotic requirements were less (p = 0.05) among VATS patients, which correlated with lower perception of pain index after operation for VATS patients. Shoulder girdle strength was equally impaired at day 3, but function was more improved in VATS patients at 3 weeks (p = 0.01). Patients undergoing wedge resection alone by LLT had greater impairment in early (day 3) pulmonary function (forced expiratory volume in 1 second) (p = 0.002); this difference from VATS was not sustained at 3 weeks. Video-assisted thoracic surgery is associated with reduced pain, shoulder dysfunction, and early pulmonary impairment compared with LLT for select patients requiring pulmonary resection.

Plasma amino acids in liver transplantation: correlation with clinical outcome

The branch chain to aromatic amino acid ratio is depressed in patients with advanced liver disease. Liver transplantation results in three different ratio response patterns: (1) no improvement, (2) transient improvement followed by decline, and (3) sustained improvement. In nine patients who underwent 12 transplantation procedures the ratio rose and remained above 2.5 during 70.0% +/- 14.8% of the postoperative period in survivors compared with 11.8% +/- 3.1% when transplantation was unsuccessful (p less than 0.001). At discharge survivors' ratios had risen from 1.5 +/- 0.1 to 3.2 +/- 0.2 (p less than 0.001). The ratio before death or retransplantation caused by graft failure was unchanged at 1.2 +/- 0.1. A persistently low branch chain to aromatic amino acid ratio after liver transplantation should prompt an aggressive search for reversible causes of liver dysfunction. If the ratio does not respond to appropriate therapy, efforts should be directed toward retransplantation.

Indwelling venous access catheters in patients with acute leukemia

Reliable venous access is often a serious problem in the cancer chemotherapy patient. In one year, the authors of this report have inserted 26 chronic double-lumen silastic Hickman catheters in 25 acute leukemia patients. Each patient received an average 12 courses of combination chemotherapy, 11.5 packed red blood cell units, 48.0 platelet units, 4.2 fresh frozen plasma units, and numerous antibiotic doses via the catheters, which remained in situ 101 +/- 97.4 days. Complications included early hemorrhage in two cases, and catheter occlusion in six. Four catheters were removed for occlusion. Fourteen patients suffered bacteremia, predominantly due to gram-negative organisms; six catheters were removed for persistent sepsis. The remaining catheters remained functional until death or elective removal. Eight patients are currently alive as outpatients with functional catheters. The Hickman catheter effectively achieves reliable venous access in the cancer patient. The risks of catheter sepsis must be considered carefully in the immunosuppressed, leukopenic patient.