| Abstract|| |
Objectives : The brain damage associated with schizophrenia has been established beyond doubt; however, what remains unexplored is the biological nature of transcultural variations. An important reason for this was the lack of mid and high field scanners in developing countries like India.
Material and Methods : We undertook a pilot study using a 0.5 Tesla MRI scanner (General Electric Signa Contour) to explore identifiable structural brain lesions in ten randomly selected individuals with schizophrenia.
Results: Nine of the ten participants in the series had structural brain changes. The most common findings were ventricular dilatation and prominent cerebral cortical sulci and cerebellar folia. Additionally non-focal white matter lesions were observed in three patients and small right hippocampus was noted in one participant.
Conclusions : The study discusses that establishing structural brain lesions with mid field scanners is indeed feasible. The small study sample and heterogeneity of schizophrenia however made it difficult to establish any definite associations
Keywords: schizophrenia, MRI, mid field scanners
|How to cite this article:|
Parkar S R, Seethalakshmi R, Shah H. Structural brain lesions in schizophrenia -magnetic resonance imaging on a mid field magnet. Indian J Radiol Imaging 2006;16:299-301
|How to cite this URL:|
Parkar S R, Seethalakshmi R, Shah H. Structural brain lesions in schizophrenia -magnetic resonance imaging on a mid field magnet. Indian J Radiol Imaging [serial online] 2006 [cited 2020 Feb 17];16:299-301. Available from: http://www.ijri.org/text.asp?2006/16/3/299/29000
| Introduction|| |
When Emil Kraepelin first described schizophrenia in 1919, he described it as 'demence precoce' an organic brain disease. Subsequent to this, the organic nature of this illness has remained an enigma for a long time. This 'graveyard of neuropathologists'  started showing signs of life in the past twenty years due to improved methods and newer technologies of studying brain abnormalities. Transcultural variations in symptom profile are however yet explained on a socio-environmental basis with little or no focus on biological issues. Most literature on structural lesions in schizophrenia is from the West with very little Indian contribution to the same, thereby limiting transcultural biological explanations. One important reason for this dearth of Indian literature was the initial lack mid and high field scanners. We would like to discuss a pilot study carried out on a series of ten individuals with schizophrenia using a 0.5 Tesla MRI scanner.
| Method|| |
Ten patients who satisfied DSM-IV  criteria for schizophrenia were randomly selected from the outpatient department of a tertiary care hospital and invited to participate. Only male patients without comorbid Axis I diagnosis, medical or surgical illnesses, mental retardation, substance dependence other than nicotine dependence and capable of giving informed consent were included. Sociodemographic details, details regarding their illness including treatment were obtained and severity of psychosis was rated on the Positive and Negative Syndrome Scale for Schizophrenia (PANSS) . The participants underwent MRI scanner (General Electric, Signa Contour, -0.5 Tesla). 5 mm thick T1 Weighted, T2 Weighted and Proton Density axial images; T1 Weighted sagittal images and FLAIR coronal images were obtained. The subjects were aligned in three planes, coronal, sagittal and axial, in accordance with a topogram. Radiological interpretation of the scans was carried out in a blinded fashion.
| Results|| |
The average age of the participants was 27.8 years; average duration of psychosis was 6.1 years. Only one participant was medication-naive, two participants had not received any antipsychotics in the past one year. The average duration of treatment with antipsychotics prior to imaging in the other seven patients was 8.33 months. Two of the ten participants had been treated with ECTs in the past. All participants had PANSS scores ranging from 80-120 (mean PANSS score- 91), implying active psychosis. Three of the ten patients had predominantly positive symptoms, two had predominantly negative symptoms and the remaining five had a mixed picture .
Only one of the ten participants had a normal brain MRI. The remaining nine participants had either ventricular enlargement or prominent sulci with five of these nine having both. Three subjects had prominent cerebral cortical sulci and cerebellar folia; one had enlarged lateral ventricles (left more than right) [Figure - 1][Figure - 2]. In addition to these, one participant had a hyperintensity in the posterior parietal periventricular white matter; cystic encephalomalacic areas cysts were reported in the cerebellum and right parietal regions in two subjects. Incidentally, these two participants with white matter lesions had been treated with ECTs in the past. A smaller right hippocampus as compared to the left was noted in one participant. However, no specific correlation of these lesions to the symptom profile emerged.
| Discussion|| |
Since the first MRI study in 1982 , studies have consistently reported enlargement of ventricles in individuals with schizophrenia; a recent systematic review reported a median 40% reduction in ventricular size, the left being preferentially affected in men . All but one participant in our series had MRI findings suggestive of ventricular enlargement or prominent sulci, with preferential left-sided affliction in one participant. Lawrie and Abukmeil  reported that ventricular enlargement is accompanied by a loss of brain tissue averaging 3%. Sallet et al  further added that as compared to the right hemisphere, the gyrification index in the left hemisphere is significantly lower in patients with schizophrenia when compared with normals particularly in individuals with disorganized schizophrenia as compared to paranoid and residual types. In our study, we were unable to quantify tissue loss and hence were unable to establish similar relationships. However, it is evident that atrophy was present irrespective of the type of symptoms; positive and negative.
Studies have identified reductions in the volumes of the amygdala and the hippocampus. Though a recent meta-analytical study concluded that the reduction in hippocampal size was bilateral; a median reduction of 7- 8.5 % particularly on the right side has been described in male schizophrenics . Reduction of the right hippocampus as compared to the left was observed in one of our patients. Two regions of the brain which are consistently implicated in schizophrenia are the thalamus and the basal ganglia; these were not studied in this series due to technological limitations.
Three participants in our series had hyperintensities. Non-specific focal degenerative abnormalities such as small infarcts and white matter changes unrelated to the clinical picture have been described in a high proportion (approximately 50%) of schizophrenic brains . This high frequency of lesions probably suggests that the brain of a schizophrenic is vulnerable to neurodegenerative and vascular impairment. Indeed, such vascular hyperintensities have now been postulated as contributory to psychiatric symptoms, particularly in the elderly population. Two of the three participants had been treated with ECTs in the past, suggesting possible ECT-induced structural damage. ECT-induced brain damage has remained a matter of debate. However, in a recent longitudinal study of depressed patients; Coffey et al  reported that structural abnormalities were noted in a number of individuals prior to the ECT. Time-blind measurements of regional brain volumes have also revealed that ECT does not induce brain changes . In our series, there were only two patients who had been treated with ECTs; to assign a causative role to ECTs for these brain lesions however would be presumptuous.
The considerable heterogeneity of schizophrenia has laid a Herculean challenge in the identification and specification of brain lesions. However, what can be declared beyond doubt is that schizophrenia is a brain disease. Moreover, what can also be acknowledged is that these brain lesions can be identified using mid field scanners too. Indeed, if 'psychiatrists and radiologists start talking to each other', it should not be long before the enigma of schizophrenia and the biological explanations for its transcultural variations are unveiled.
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Department of Psychiatry, Seth GS Medical College and KEM Hospital, Parel, Mumbai
Source of Support: None, Conflict of Interest: None
[Figure - 1], [Figure - 2]