Background
Superior temporal cortices include brain regions dedicated to auditory processing and several lines of evidence suggest structural and functional abnormalities in both schizophrenia and bipolar disorder within this brain region. However, possible glutamatergic dysfunction within this region has not been investigated in adult patients.
Methods
Thirty patients with schizophrenia (38.67 ± 12.46 years of age), 28 euthymic patients with bipolar I disorder (35.32 ± 9.12 years of age), and 30 age-, gender- and education- matched healthy controls were enrolled. Proton Magnetic Resonance Spectroscopy data were acquired using a 3.0T Siemens MAGNETOM TIM Trio MR system and single voxel Point REsolved Spectroscopy Sequence (PRESS) in order to quantify brain metabolites within the left and right Heschl's Gyrus and Planum Temporale of superior temporal cortices.
Results
There were significant abnormalities in Glutamate (Glu) (F(2,78)=8.52, p<0.0001), n-Acetyl Aspartate (tNAA) (F(2,81)=5.73, p=0.005), Creatine (tCr) (F(2,83)=5.91, p=0.004) and Inositol (Ins) (F(2,82)=8.49, p<0.0001) concentrations in the left superior temporal cortex. In general, metabolite levels were lower for bipolar disorder patients when compared to healthy participants. Moreover, patients with bipolar disorder exhibited significantly lower tCr and Ins concentrations when compared to schizophrenia patients. In addition, we have found significant correlations between the superior temporal cortex metabolites and clinical measures.
Conclusion
As the left auditory cortices are associated with language and speech, left hemisphere specific abnormalities may have clinical significance. Our findings are suggestive of shared glutamatergic abnormalities in schizophrenia and bipolar disorder.
Neurochemical levels, in the superior temporal cortices, measured with H-MRS discriminated between BD-II and BD-I. Although further studies are needed, one may speculate that the superior temporal cortices (particularly left hemispheric) play a critical role, whose pathology may be related to subtyping bipolar disorder.
Urinary incontinence, although rarely reported, is one of the most important adverse effects of antipsychotic medication. It can be an embarrassing, distressing, and potentially treatment-limiting. Several antipsychotics, including both typical and atypical varieties, are known to induce urinary incontinence. Many antipsychotic drugs target the neural pathways controlling continence by binding to receptors of some neurotransmitters such as serotonin, dopamine, acetylcholine, and adrenaline. Pharmacological management of incontinence should be considered if there is a risk of cessation of the antipsychotic therapy or any decline in patients’ compliance. Amitriptyline, desmopressin, ephedrine, and anticholinergics such as oxybutynin and trihexyphenidyl are the most frequently used agents to treat incontinence. We think that the frequency of incontinence is higher than reported in the literature, and that follow-up routines should include a form of standardized screening for all possible adverse effects, including incontinence, of any given antipsychotic. In this article, we report a case of urinary incontinence as an adverse effect of paliperidone palmitate use during maintenance therapy in a patient with schizophrenia.
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