Reduced electrode arrays for the automated detection of rhythmic and periodic patterns in the intensive care unit: Frequently tried, frequently failed?

OBJECTIVE

To investigate the effect of systematic electrode reduction from a common 10-20 EEG system on pattern detection sensitivity (SEN).

METHODS

Two reviewers rated 17130 one-minute segments of 83 prospectively recorded cEEGs according to the ACNS standardized critical care EEG terminology (CCET), including burst suppression patterns (BS) and unequivocal electrographic seizures. Consensus annotations between reviewers were used as a gold standard to determine pattern detection SEN and specificity (SPE) of a computational algorithm (baseline, 19 electrodes). Electrodes were than reduced one by one in four different variations. SENs and SPEs were calculated to determine the most beneficial assembly with respect to the number and location of electrodes.

RESULTS

High automated baseline SENs (84.99-93.39%) and SPEs (90.05-95.6%) were achieved for all patterns. Best overall results in detecting BS and CCET patterns were found using the "hairline+vertex" montage. While the "forehead+behind ear" montage showed an advantage in detecting ictal patterns, reaching a 15% drop of SEN with 10 electrodes, all montages could detect BS sufficiently if at least nine electrodes were available.

CONCLUSION

For the first time an automated approach was used to systematically evaluate the effect of electrode reduction on pattern detection SEN in cEEG.

SIGNIFICANCE

Prediction of the expected detection SEN of specific EEG patterns with reduced EEG montages in ICU patients.

Applicability of NeuroTrend as a bedside monitor in the neuro ICU

OBJECTIVE

To assess whether ICU caregivers can correctly read and interpret continuous EEG (cEEG) data displayed with the computer algorithm NeuroTrend (NT) with the main attention on seizure detection and determination of sedation depth.

METHODS

120 screenshots of NT (480h of cEEG) were rated by 18 briefly trained nurses and biomedical analysts. Multirater agreements (MRA) as well as interrater agreements (IRA) compared to an expert opinion (EXO) were calculated for items such as pattern type, pattern location, interruption of recording, seizure suspicion, consistency of frequency, seizure tendency and level of sedation.

RESULTS

MRA as well as IRA were almost perfect (80-100%) for interruption of recording, spike-and-waves, rhythmic delta activity and burst suppression. A substantial agreement (60-80%) was found for electrographic seizure patterns, periodic discharges and seizure suspicion. Except for pattern localization (70.83-92.26%), items requiring a precondition and especially those who needed interpretation like consistency of frequency (47.47-79.15%) or level of sedation (41.10%) showed lower agreements.

CONCLUSIONS

The present study demonstrates that NT might be a useful bedside monitor in cases of subclinical seizures. Determination of correct sedation depth by ICU caregivers requires a more detailed training.

SIGNIFICANCE

Computer algorithms may reduce the workload of cEEG analysis in ICU patients.

Prospective assessment and validation of rhythmic and periodic pattern detection in NeuroTrend: A new approach for screening continuous EEG in the intensive care unit

BACKGROUND

NeuroTrend is a computational method that analyzes long-term scalp EEGs in the ICU according to ACNS standardized critical care EEG terminology (CCET) including electrographic seizures. At present, it attempts to become a screening aid for continuous EEG (cEEG) recordings in the ICU to facilitate the review process and optimize resources.

METHODS

A prospective multicenter study was performed in two neurological ICUs including 68 patients who were subjected to video-cEEG. Two reviewers independently annotated the first minute of each hour in the cEEG according to CCET. These segments were also screened for faster patterns with frequencies higher than 4 Hz. The matching annotations (2911 segments) were then used as gold standard condition to test sensitivity and specificity of the rhythmic and periodic pattern detection of NeuroTrend.

RESULTS

Interrater agreement showed substantial agreement for localization (main term 1) and pattern type (main term 2) of the CCET. The overall detection sensitivity of NeuroTrend was 94% with high detection rates for periodic discharges (PD = 80%) and rhythmic delta activity (RDA = 82%). Overall specificity was moderate (67%) mainly because of false positive detections of RDA in cases of general slowing. In contrast, a detection specificity of 88% for PDs was reached. Localization revealed only a slight agreement between reviewers and NeuroTrend.

CONCLUSIONS

NeuroTrend might be a suitable screening tool for cEEG in the ICU and has the potential to raise efficiency of long-term EEG monitoring in the ICU. At this stage, pattern localization and differentiation between RDA and general slowing need improvement. This article is part of a Special Issue entitled "Status Epilepticus".

Prediction of rhythmic and periodic EEG patterns and seizures on continuous EEG with early epileptiform discharges

BACKGROUND

Continuous EEG (cEEG) is necessary to document nonconvulsive seizures (NCS), nonconvulsive status epilepticus (NCSE), as well as rhythmic and periodic EEG patterns of 'ictal-interictal uncertainty' (RPPIIU) including periodic discharges, rhythmic delta activity, and spike-and-wave complexes in neurological intensive care patients. However, cEEG is associated with significant recording and analysis efforts. Therefore, predictors from short-term routine EEG with a reasonably high yield are urgently needed in order to select patients for evaluation with cEEG.

OBJECTIVE

The aim of this study was to assess the prognostic significance of early epileptiform discharges (i.e., within the first 30 min of EEG recording) on the following: (1) incidence of ictal EEG patterns and RPPIIU on subsequent cEEG, (2) occurrence of acute convulsive seizures during the ICU stay, and (3) functional outcome after 6 months of follow-up.

METHODS

We conducted a separate analysis of the first 30 min and the remaining segments of prospective cEEG recordings according to the ACNS Standardized Critical Care EEG Terminology as well as NCS criteria and review of clinical data of 32 neurological critical care patients.

RESULTS

In 17 patients with epileptiform discharges within the first 30 min of EEG (group 1), electrographic seizures were observed in 23.5% (n = 4), rhythmic or periodic EEG patterns of 'ictal-interictal uncertainty' in 64.7% (n = 11), and neither electrographic seizures nor RPPIIU in 11.8% (n = 2). In 15 patients with no epileptiform discharges in the first 30 min of EEG (group 2), no electrographic seizures were recorded on subsequent cEEG, RPPIIU were seen in 26.7% (n = 4), and neither electrographic seizures nor RPPIIU in 73.3% (n = 11). The incidence of EEG patterns on cEEG was significantly different between the two groups (p = 0.008). Patients with early epileptiform discharges developed acute seizures more frequently than patients without early epileptiform discharges (p = 0.009). Finally, functional outcome six months after discharge was significantly worse in patients with early epileptiform discharges (p=0.01).

CONCLUSIONS

Epileptiform discharges within the first 30 min of EEG recording are predictive for the occurrence of ictal EEG patterns and for RPPIIU on subsequent cEEG, for acute convulsive seizures during the ICU stay, and for a worse functional outcome after 6 months of follow-up. This article is part of a Special Issue entitled Status Epilepticus.

Mediastinal foregut duplication cyst of enteric type containing a persistent thymus, imitating a pericardial cyst

Mediastinal foregut duplication cysts are rare congenital masses caused by developmental disorders of the anterior part of the embryonic primitive gut. In adults they can be discovered as an incidental finding on chest radiograph. They can mimic other intrathoracic pathologies as it was initially the case in our patient. A 51-year-old woman was incidentally found to have homogenous mass at the right cardiophrenic angle on the chest radiograph. Based on that finding and echocardiography a pericardial cyst was suspected. Computed tomography demonstrated a simple anterior mediastinal cyst. Because of the growth with a mild progression of the compression of the right atrium, the cyst was resected. Histology and immunohistochemistry revealed the mass to be a mediastinal foregut duplicatory cyst of enteric type containing persistent thymus. To our knowledge, this is the first report in which a mediastinal foregut cyst contained both enteric mucosa and ectopic persistent thymus (Fig. 9, Ref. 13).

KEYWORDS

foregut cyst, mediastinal cyst, thymus, enteric cyst, pericardial cyst.

[The outcome of whole-body FDG-PET examination predicts the future of patients with diffuse large-cell lymphoma in the use of both intermediary staging and at the end of standard chemotherapy]

AIM

Response to the therapy is one of the most valuable prognostic factors. The response evaluation is performed by computer tomography as a standard tool. The introduction of FDG-PET whole body imaging allows to discriminate viable tumor and fibrotic changes in structural abnormalities.

METHODS

We have performed retrospective analysis of 96 patients with diagnosis of diffuse large B-cell lymphoma (1999-2004) who were treated by anthracyclin based chemotherapy and FDG-PET was performed as a part of intermediate restaging (after 2nd-4th cycle, 69 patients) or/and at the end of standard chemotherapy (68 patients).

RESULTS

The progression free survival (PFS) and overall survival (OS) at 3 years were the endpoints. Median follow up was 30 months. The PFS and OS resp. for PET negative pts at intermediate restaging was 80.7% and 97.6% compared to the 50.5% and 71.5 % resp. for PET positive patients. The relapse risk and death risk for PET positive patients was 4.8 and 6.4 resp. The PFS and OS resp. for PET negative pts at the end of chemotherapy was 81.7% and 94.7% resp. compared to the 29.4% (p < 0.0001) and 57.5% (p < 0.0001) resp. for PET positive patients. The relapse risk and death risk for PET positive patients was 7.0 and 12.9 resp. Predictive value of PET at intermediate as well at the end restaging was observed in IPI low group as well IPI high risk subgroups for both PFS and OS, except OS in high risk subgroup at intermediate restaging.

CONCLUSION

The current analysis confirms predictive PET value for patients with DLBCL at intermediate as well at the end restaging. The question if and how to use the PET findings for tailoreing of therapy remains to be answered in prospective trials.

Prediction of outcome using positron emission tomography (PET) compared to standard response criteria and potential role in treatment decisions in diffuse large B-cell lymphoma (DLBCL) patients

7565

Background: PET has been demonstrated to give valid information about viable tumor residua. There are however only limited data regarding the combination of classical response criteria with PET and there is a lack of information on the impact of additional therapy (add-Th) on the outcome of PET neg. or PET pos. pts. Methods: One hundred thirty-nine pts (median age 50y) with newly diagnosed DLBCL who were examined by PET during (after 2–4 cycles CHT - ‘early PET’) or/and at the end of therapy (‘end PET’) were analyzed retrospectively. IPI risk distribution were as follows: L 28%, LI 24%, IH 33% and H 15% pts. All pts were treated with anthracyclin based CHT. “Early PET” was performed in 84 pts. and “end PET” in 103 pts before add-Th, PET at both time points was performed in 48 pts. Add-Th (HDT with ASCT or/and radiotherapy), was given as planned or as a result of response evaluation (conventional methods - CT, trephine biopsy). No treatment modification was made on PET result only, except for 2 cases when planned RT was skipped because of PET neg. RT was performed in 59 pts (42.4%) and HDT with ASCT as consolidation in 54 pts (38.8%). Median follow up was 30 m. Results: CR or CRu was achieved after CHT in 102 (74%) pts, PR in 24 (17%) pts, stable or progress dis. in 13 (9%). ‘Early PET’ was neg. in 60% pts and ‘end PET’ was neg in 67% pts. PET neg. was achieved at least once in 97 (70%) pts, and PET pos. at least once was found in 50 pts (36%). The PFS at 30 m according to the combination of conventional and PET response was as follows: for CR PET-neg. pts 89%, for PR PET-neg. pts 90%, for CR PET-pos. pts 45% and for PR PET-pos. pts 64% (p=0.0001). OS was 93%, 63%, 90% and 83%, respect.(p=0.004). The analysis of impact of add-Th showed PFS at 30 m: for PET-neg pts with Add-Th 96%, for PET-neg. pts without Add-Th 82%. PET-pos. pts without Add-Th had a PFS of only 10% and PET-pos. pts with add-Th had PFS 58% (p=0.0001). The OS was 92%, 98%, 38% and 74% respect. (p=0.0001). Conclusions: Our data demonstrate that PET give more powerful information than standard response criteria. The second analysis support the the idea that pts with DLBCL in CR who remain PET pos. should undergo the additional therapy. Partial support: Grant MSM 0021620808

No significant financial relationships to disclose.

[Adenomatoid tumor of the right adrenal gland: a case report]

Adenomatoid tumor of adrenal gland is a very rare primary tumor with favourable prognosis. The mesothelial origin of this tumor was confirmed by multiple studies of various authors. This origin was proven by immunohistochemical and ultrastructural examinations. In our case report, we present an interesting case of the adenomatoid tumor of the right adrenal gland in a 55-year-old woman. Our case is the second well-documented case of this tumor occurring in a female adult patient. We emphasize the presence of an intraluminal thread-like bridging strands, generally considered to be a characteristic histologic feature of this tumor, which have not yet been reported in literature in adenomatoid tumor located in adrenal glands.

[Columnar cell carcinoma of the thyroid gland--case report]

Columnar cell carcinoma of the thyroid gland is a very rare malignant tumour with characteristic histological features. The tumour is characterized by typical aggressive behaviour and unfavourable prognosis. We describe a case of this carcinoma in 69-year-old man. We present clinical and histological features of this tumour. In addition, we present features of this tumour in fine-needle aspirates, which were described only in a few cases in literature so far.

[Pseudomalignant changes in benign phyllodes breast tumor]

Phylloides tumor of the breast is well known entity in pathology for a long time. It includes fibroepithelial tumors of the different biological character. They are generally divided into three groups: benign, low-grade malignant (borderline) and high-grade malignant. Adenoses of the breast are a group of the benign lesions, the main feature of which is the proliferation of the glandular component of the breast. More frequent adenoses occurring in practice are: blunt duct adenosis, sclerosing adenosis, nodular adenosis, adenosis tumor and florid adenosis. The less frequent adenoses are: microglandular adenosis, tubular adenosis, apocrine adenosis, and myoepithelial (adenomyoepithelial) adenosis. In this article two histologically unusual lesions of the breast in middle-aged women are presented, consisting of the benign variants of the phylloides tumor, modified distinctly by various types of adenoses, which can cause, together with intensive myoepithelial proliferation, great diagnostic problems, especially on frozen sections. They may be mistaken with invasive ductal or lobular cancer. Reliable differentiation between these entities is possible only by using of the immunohistochemical methods.

Susceptibility and reactivity of sheep to Trichinella spiralis infection

Susceptibility and reactive manifestation to Trichinella spiralis infection were studied in atypical hosts (sheep) for the period of 247 days. Sheep produced anti-Trichinella antibodies as early on Day 11 (low titer 1:200), with maximum reached at Day 35 (titer 1:800). From Day 42 the antibody level was declining with a negative result of examination on Day 70. Mice exhibited anti-Trichinella antibodies only on Day 32 (titer 1:200). This level was rising, reaching high titer (1:1600) on Day 56. This antibody level persisted until Day 156. In the following period, a rapid decrease in the titer was observed (Graph). On Day 32, T. spiralis larvae in sheep were present in all groups of the muscles examined. The highest larval counts during the entire experiment were detected in the masseter. The initially high counts in the diaphragm and tongue were reduced to only 1/4 or 1/10 at the end of the experiment. In mice, the larvae occurred evenly throughout the entire experiment (Tab. I). The first appearance of a capsule around the T. spiralis larva in muscles was observed on Day 32 p. i. No cell response was detected around the capsule (Fig. 1). Neither was any response observed around necrotizing larvae, even though the surrounding myofibrils were caused to die off (Fig. 2). Certain differences in the degree of myofibril degradation by larvae were evident as early as on Day 32. The least damaged myofibrils were those in the masseter, tongue and diaphragm. This finding correlates with the histological recovery of a different number of necrotized larvae from the individual muscle groups examined. Fresh blood extravassations around larvae were observed on Day 59 (Fig. 3). They could be caused by the migration of larvae to a parasitation site. Live uncapsulated larvae were also found on Day 115 p. i. (Fig. 4). An increased cellular presence around some larvae was observed on Day 84. The larvae surrounded by lymphocytes consequently died off, those without lymphocytic responses formed capsules and survived (Fig. 5). The necrotizing larvae were subject to a powerful phagocytic process, presented by histiocytes, forming multinuclear symplasms (Fig. 6). On Day 11 p. i., larvae inside a capsule were dying off as well. The initial stage of larval necrosis in a capsule is also accompanied by an increased lymphocytic response (Fig. 7). The condition of larvae in capsules and the cellular unresponsiveness as late as on Day 247 indicate the long-lasting viability of the larvae. The capsules surrounding T. spiralis larvae in mice were distinctly seen as early as on Day 32 p. i. Lymphocytic aggregations around the capsule were observed throughout the entire experiment (247 days)-Fig. 8.