Objectives To determine:

The term transcranial route means the brain targeted transfer of drug molecules across the cranium through the layers of the skin and skin appendages of the head, arteries and veins of the skin of the head, the cranial bones along with the diploe, the cranial bone sutures, the meninges and specifically through the emissary veins. The administration of drugs through the scalp in ayurvedic system for the diseases associated with the brain was evaluated with a view to develop a novel targeted route for central nervous system drugs. It is expected to circumvent the systemic side effects of oral route. Diazepam was dissolved in an oil medium and applied on scalp as practiced in the ayurvedic system. Thirty rats were tested on the rotating rotarod for muscle relaxant effect of diazepam. Five groups of rats tested were the control, diazepam i.v. injected (280 µg/0.1 ml) group, two groups treated with transcranial diazepam oil solution (1.5 mg/0.2 ml) and the transcranial blank vehicle treated groups. Holding time in triplicate for each rat on the rotating rotarod was measured. The holding times following each treatment was statistically compared (one-way ANOVA). The pooled average times for the control, diazepam i.v. injected, diazepam oil solution transcranial treated two groups and the blank vehicle treated groups were 35.45, 4.73, 16.5, 15.39 and 33.23 seconds respectively. The two groups subjected to the brain targeted transcranial route showed a statistically significant decrease (50% drop) in the holding time against the control group indicating the centrally acting muscle relaxant effect due to absorption of diazepam into the brain through the proposed route.

Objectives To identify presentations of children with learning difficulties attending Child Psychiatry and Guidance Clinic (CPGC) at Lady Ridgeway Hospital (LRH) and describe their socio-demographic characteristics, health-seeking behaviour and modes of referral.Design Descriptive cross sectional study.Method Children diagnosed to have learning difficulties or attention deficit hyperactive disorder (ADHD), presenting to CPGC at LRH from 27 May to 10 June 2003, were included in study. Learning difficulties were diagnosed by a child psychiatrist using DSM IV criteria. A pre-tested, interviewer administered questionnaire (IAQ) was used to collect socio-demographic data, details on health-seeking behaviour and modes of referral from parents/ guardians. A checklist was used to identify presentations.Results 52 children with learning difficulties were identified and all participated in study. Presentations were with difficulties in reading (70%), mathematics (60%), writing (55%), communication (45%) and motor skills (50%). ADHD was found in 60% cases. 85% were males. Mean age was 9 years. 31% had deficit of schooling. 54% were urban dwellers. Caretaker was mother in 83% cases. Monthly income was greater than 3000 rupees in 92% cases. 89% children were identified by mother or teacher. Initial visits were made to a specialist unit (62%) or a primary health care service (31%).

The response to methylphenidate was assessed in children diagnosed as having attention-deficit hyperactivity disorder (ADHD) in 2000 at the Lady Ridgeway Tertiary Hospital for Children in Sri Lanka. They were managed in outpatient child psychiatry clinics. ADHD was diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV). The severity of the symptoms was determined with a validated Sinhala assessment form based on DSM-IV criteria. The data on problems experienced by the diagnosed children and their families were obtained using an interviewer-administered questionnaire. The severity of the symptoms and problems experienced by the children and their families were reassessed at 6 weeks and 6 months of methylphenidate therapy. Thirty-seven new subjects were diagnosed as having ADHD in 2000, and 36 of them were treated with methylphenidate. The severity of the symptoms and the number of subjects receiving frequent complaints from school were significantly lower 6 weeks after methylphenidate treatment. At 6 months of treatment, the severity of the symptoms was not significantly reduced when compared with the severity assessed 6 weeks after treatment. Methylphenidate did help with school-related problems in the short term, but the long-term effects of methylphenidate were not convincing in this group of subjects and showed poor long-term compliance, probably owing to inadequate improvement seen in symptoms.

Quinolinic acid, a metabolite of tryptophan in the kynurenine pathway, inhibited the 5-HT(2A/2C) direct agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-amino propane hydrochloride (DOI) induced head shakes in mice in a dose-dependent manner. This effect was observed 10 min after intracerebroventricular (i.c.v.) administration of 0.0625-1 microg/mouse. 3-Hydroxyanthranilic acid, which is the immediate stable precursor of quinolinic acid in the kynurenine pathway, showed a similar effect 60-120 min after subcutaneous (s.c.) administration, without showing any effect 10 min after i.c.v. administration or 20-40 min after s.c. administration. These observations suggest that quinolinic acid can alter central effects mediated via 5-HT2A receptors.