Depression is the most common psychiatric disorder following stroke. Depression is associated with excessive disability, cognitive impairment, and mortality [
The frontal lobes are thought to be involved in the pathogenesis of depression [
A total of 3,219 patients with first-ever or recurrent acute ischemic stroke were admitted to the Acute Stroke Unit of the Prince of Wales Hospital (PWH) between June 2004 and July 2008. The PWH is a university-affiliated general hospital serving a population of 800,000 in Hong Kong. Of the 1,353 patients who received an MRI examination, a convenience sample of 705 (52.1%) was recruited for this study. Compared to the participants, the excluded patients (
The inclusion criteria for the study were (1) Chinese ethnicity, (2) Cantonese as the primary language, (3) aged 18 or above, (4) well-documented (clinical presentation and CT scan of the brain) first or recurrent acute stroke occurring within the seven days prior to admission, and (5) ability and willingness to give consent. The exclusion criteria were (1) transient ischemic attack, cerebral haemorrhage, subdural haematoma, or subarachnoid haemorrhage, (2) history of a central nervous system disease such as tumour, trauma, hydrocephalus, and Parkinson’s disease, (3) aphasia, defined as a score of 2 or more in the best language item of the NIHSS [
The study protocol was approved by the Clinical Research Ethics Committee of the Chinese University of Hong Kong. All participants signed a consent form.
A research nurse, who was blind to the psychiatric diagnoses, collected the demographic data (age, sex, and education level in terms of school years) and assessed stroke severity using the NIHSS within two days of admission. A research assistant evaluated all participants with the MMSE and the Lubben Social Network Scale (LSNS) [
Three months after the onset of the index stroke, a psychiatrist, who was blind to the participants’ radiological data, administered the Chinese version of the Structured Clinical Interview for DSM-IV [
MRI with diffusion-weighted imaging (DWI) and proton density sequences was performed on each participant with a 1.5-T system (Sonata, Siemens Medical, Erlangen, Germany) within seven days of admission.
DWI spin EPI (TR/TE/excitation = 180/122/4, matrix =
A neurologist, who was blind to the psychiatric diagnoses, assessed the MRIs to determine the following.
All statistical tests were performed using SPSS for Windows (Release 14.0, SPSS Inc., Chicago, IL, USA). The demographic and clinical variables (age, sex, education level, and NIHSS and MMSE scores) and radiological characteristics of the participants with DAS were compared with those of the non-DASs group using the
Eighty-five patients were diagnosed with DAS. The participants’ demographic, clinical, and MRI characteristics stratified by DAS status are shown in Table
Univariate and multivariate analyses of the clinical and radiological determinants of DAS.
DAS | No DAS |
|
|
---|---|---|---|
Mean ± SD | Mean ± SD | ||
|
85 | 620 | |
Age | 66.9 ± 11.6 | 66.2 ± 11.6 | 0.632† |
Female | 50 (58.8) | 238 (38.4) | <0.001‡ |
Education (years) | 4.4 ± 4.7 | 5.7 ± 4.7 | 0.005 |
Previous stroke | 23 (27.1) | 123 (19.8) | 0.123‡ |
NIHSS during index admission | 5.1 ± 3.5 | 4.4 ± 3.4 | 0.029 |
MMSE | 24.8 ± 3.6 | 26.1 ± 3.2 | 0.002 |
LSNS | 25.5 ± 8.4 | 30.4 ± 8.2 | <0.001† |
MLES | 2.3 ± 1.2 | 1.7 ± 0.8 | <0.001 |
Past history of depression | 14 (16.5) | 7 (1.1) | <0.001‡ |
Severe brain atrophy | |||
Frontal lobe | 12 (14.1) | 35 (5.6) | 0.003‡ |
Temporal lobe | 6 (7.1) | 76 (12.3) | 0.161‡ |
Parietal lobe | 14 (16.5) | 97 (15.6) | 0.845‡ |
Occipital lobe | 13 (15.3) | 95 (15.3) | 1.000‡ |
Periventricular hyperintensities | 1.2 ± 0.8 | 1.3 ± 0.9 | 0.653 |
Deep white matter hyperintensities | 1.1 ± 0.9 | 1.1 ± 0.8 | 0.726 |
Number of acute infarcts | 1.0 ± 1.4 | 1.3 ± 1.1 | 0.131 |
Acute infarct volume (mm3) | 2.4 ± 5.2 | 2.9 ± 9.1 | 0.772 |
NIHSS: National Institute of Health Stroke Scale; MMSE: Mini-Mental State Examination; LSNS: Lubben Social Network Scale; MLES: Modified Life Event Scale; SD: standard deviation.
*In comparison to the DAS group by means of Mann-Whitney
†In comparison to the DAS group by means of
‡In comparison to the DAS group by means of Chi-square
Severe FLA was more common in the DAS group. Participants with DAS were also more likely to be female and to have a history of depression, a lower level of education, and higher NIHSS and MLES scores but lower MMSE and LSNS scores.
The following variables were entered into the regression model: sex, education, severe FLA, history of depression, and the NIHSS, MMSE, MLES, and LSNS scores. Severe FLA was a significant independent predictor of DAS, with an odds ratio of 2.6 (
Multivariate logistic model of the clinical and radiological determinants of DAS.
Variable | Odds ratio (95% CI) |
|
---|---|---|
Severe frontal lobe atrophy | 2.648 (1.198–5.856) | 0.016 |
History of depression | 11.99 (3.953–36.372) | <0.001 |
MLES | 1.925 (1.490–2.487) | <0.001 |
LSNS | 0.943 (0.915–0.972) | <0.001 |
NIHSS | 1.106 (1.032 –1.185) | 0.004 |
Female | 2.312 (1.370–3.902) | 0.002 |
MMSE | — | NS |
Education | — | NS |
NIHSS: National Institute of Health Stroke Scale; MMSE: Mini-Mental State Examination; LSNS: Lubben Social Network Scale; MLES: Modified Life Event Scale; NS: nonsignificant.
To the best of our knowledge, this is the first MRI study to show that severe FLA is an independent predictor of DAS.
Although a number of studies have examined the relationship between brain atrophy and DAS, none has focused on the frontal lobes. In addition, only broad measures of atrophy, such as global [
FLA in stroke can be the result of degeneration and/or ischemic injuries. Brain atrophy is associated with subcortical white matter lesions both in patients with vascular dementia [
One limitation of this study is that it was conducted in a hospital-based sample, and thus its findings may not be applicable to patients treated in other settings. In addition, the exclusion rate was high which might have resulted in a biased sample. Furthermore, the number of cases of DAS with FLA was small and a large number of possible confounding variables were adjusted in the multivariate analysis; hence the findings should be regarded as tentative and need replication. Finally, FLA was only one of the six significant factors in the final regression model.
In conclusion, the results of this study indicate that there is an association between FLA and DAS. Further investigations are needed to clarify the impact of FLA on the clinical presentation, treatment response, and outcome of DAS in stroke survivors.
The authors report no conflict of interests.
This work was supported by the Research Grant Council of the HKSAR.