Increasing striatal dopamine release through repeated bouts of theta burst transcranial magnetic stimulation of the left dorsolateral prefrontal cortex. A 18F-desmethoxyfallypride positron emission tomography study.

Introduction: Transcranial Magnetic Stimulation (TMS) can modulate fronto-striatal connectivity in the human brain. Here Positron Emission Tomography (PET) and neuro-navigated TMS were combined to investigate the dynamics of the fronto-striatal connectivity in the human brain. Employing 18F-DesmethoxyFallypride (DMFP) - a Dopamine receptor-antagonist - the release of endogenous dopamine in the striatum in response to time-spaced repeated bouts of excitatory, intermittent theta burst stimulation (iTBS) of the Left-Dorsolateral Prefrontal Cortex (L-DLPFC) was measured. Methods: 23 healthy participants underwent two PET sessions, each one with four blocks of iTBS separated by 30 minutes: sham (control) and verum (90% of individual resting motor threshold). Receptor Binding Ratios were collected for sham and verum sessions across 37 time frames (about 130 minutes) in striatal sub-regions (Caudate nucleus and Putamen). Results: Verum iTBS increased the dopamine release in striatal sub-regions, relative to sham iTBS. Dopamine levels in the verum session increased progressively across the time frames until frame number 28 (approximately 85 minutes after the start of the session and after three iTBS bouts) and then essentially remained unchanged until the end of the session. Conclusion: Results suggest that the short-timed iTBS protocol performed in time-spaced blocks can effectively induce a dynamic dose dependent increase in dopaminergic fronto-striatal connectivity. This scheme could provide an alternative to unpleasant and distressing, long stimulation protocols in experimental and therapeutic settings. Specifically, it was demonstrated that three repeated bouts of iTBS, spaced by short intervals, achieve larger effects than one single stimulation. This finding has implications for the planning of therapeutic interventions, for example, treatment of major depression.

Morbidity pattern and utilization of a primary health care center in a low socioeconomic area of Karachi.

OBJECTIVE: To identify the morbidity pattern according to age, gender and seasonal variation using the ICD coding and the utilization of Primary Health Care (PHC) center services in a demographically defined community. METHODS: The data collected from 2001-2003 was analyzed using the International Classification of Diseases-10 (ICD-10) coding for identifying the morbidity patterns presenting at the PHC Center. The age and gender distribution of the patients and the seasonal variation of few diseases were noted. Only the residents of the area visiting the center for preventive or curative services were included. A structured performa was designed to enter the age, gender, disease and ICD codes. The faculty was trained for using the coding system. RESULTS: A total of 13,519 patients visited the PHC during three-year period. On an average, 376 patients were seen during a month with male to female ratio of 1:2. The most common diseases presented belong to the respiratory system, followed by infections or parasitic infestations and diseases of the reproductive system. The women presented for first visit of antenatal check up were 960 out of 4614 women of reproductive age group. Among the adult population, 391 (6%) presented with hypertension, 64 (1%) were Type 2 diabetics and 86 (1.3%) were asthmatics. The paediatric population analysis showed that 918 (13%) had upper respiratory infections and 1339 (19%) had diarrhoea. CONCLUSION: Problem oriented medical records from health centers, computerized in a uniform standardized way, can give extensive information about the content and burden of health problems in family practice and presumably public health.

Risk factors assessment for hypertension in a squatter settlement of Karachi.

OBJECTIVE: To assess the risk factors for hypertension in adults (age more than 15 years) in a squatter settlement of Karachi. METHODS: Cross-sectional survey of adults more than 15 years old in a squatter settlement of Karachi through random sampling method. RESULTS: A total of 327 adults were approached, 165 (50.5%) were males and 162 (49.5%) females. Blood pressure was measured in 63 (38%) males and 135 (83%) females. Out of which, 11 (17.5%) males and 19 (14%) females were screened hypertensive. Hypertensives were older as compared to normotensives (p < 0.001). The mean BMI of hypertensives (25.6 +/- 4.5 kg/m2) was significantly higher (p = 0.008) than normotensives (22.9 +/- 5.0 kg/m2). Hypertensives were 9.7 times more likely to be diabetic as compared to normotensives in this study (p < 0.001). On analyzing the relationship of hypertension with other variables, no significant difference was noticed for education (p = 0.68), smoking status (p = 0.46), family history (p = 0.31) and occupation (p = 0.27). CONCLUSION: Prevention and control of hypertension is essential as the life expectancy is increasing in developing countries as well. The main emphasis according to this study, should be on controlling the BMI through weight reduction and regular exercise. Awareness about the risk factors for hypertension among the population is required to decrease the double burden on the society.