[Show abstract][Hide abstract] ABSTRACT: The negative symptoms of schizophrenia have been considered to be a psychiatric form of the frontal lobe syndrome. However, no studies have compared these two disorders at the clinical level. In this study, 12 negative symptom schizophrenic patients and 11 patients with behavioural variant frontotemporal dementia (bv-FTD) were rated for negative symptoms and for occurrence of frontal lobe behaviours in everyday life. They were also rated for speech disorder and were given a series of executive tests. Both patient groups showed positive ratings on negative symptoms and frontal lobe behaviours in daily life; however, the schizophrenic patients had higher negative symptom scores and the bv-FTD patients had higher carer ratings on frontal behaviours in daily life. Both groups were impaired on the executive tests, but the bv-FTD patients showed significantly greater impairment on verbal fluency and a test requiring inhibition of prepotent responses. A minority of the bv-FTD patients unexpectedly showed speech abnormalities typically associated with schizophrenia. The findings indicate that the negative syndrome in schizophrenia and the frontal lobe syndrome resemble each other clinically in important respects. Some of the differences may be attributable to the additional presence of disinhibition in the frontal lobe syndrome.
European Archives of Psychiatry and Clinical Neuroscience 02/2011; 261(1):59-67. · 2.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A key neuropsychological proposal in schizophrenia is that negative and disorganization symptoms are associated with different patterns of impairment on executive tasks.
Studies reporting correlations between positive, negative or disorganization symptoms and any type of executive test were meta-analysed. The influence of moderating factors was also examined, including age, treatment and stage of illness and whether symptoms were relapsing or persistent. The magnitudes of the correlations were compared with those for general intellectual impairment.
Pooled correlations between executive impairment and both negative symptoms and disorganization were significant in the small-to-moderate range. That for positive symptoms ('reality distortion'), however, was close to zero. The pattern of correlations among different executive tests differed significantly for negative symptoms and disorganization. Patients with stable clinical pictures showed significantly higher correlations with executive impairment than those with relapsing and remitting illnesses. Both negative symptoms and disorganization also correlated significantly with general intellectual function as indexed by current IQ.
Meta-analysis supports the view that negative symptoms and disorganization are associated with partially dissociable patterns of executive impairment. However, co-existent general intellectual impairment has been an important confounding factor in the studies to date.
Psychological Medicine 07/2008; 39(3):381-92. · 5.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To draw attention to severe presentations of atypical neuroleptic related diabetes and to document that a marked degree of remission can take place after drug withdrawal.
We describe two patients who presented with diabetic ketoacidosis after treatment with quetiapine and risperidone, respectively.
Both patients were negative for islet cell antibodies. They both required treatment with insulin, one in very high dosage, but their insulin requirements fell progressively after the atypical antipsychotic was withdrawn. After several months, neither patient required antidiabetic treatment.
Atypical antipsychotic-induced diabetes does not always take a "type 2" presentation in which weight gain and insulin resistance are implicated. Sometimes the presentation is with diabetic ketoacidosis, requiring insulin treatment, which can nevertheless be reversible.
The International Journal of Psychiatry in Medicine 02/2005; 35(3):307-11. · 1.15 Impact Factor