A single high dose of dexamethasone affects the phosphorylation state of glutamate AMPA receptors in the human limbic system.

Glucocorticoids (GC) released during stress response exert feedforward effects in the whole brain, but particularly in the limbic circuits that modulates cognition, emotion and behavior. GC are the most commonly prescribed anti-inflammatory and immunosuppressant medication worldwide and pharmacological GC treatment has been paralleled by the high incidence of acute and chronic neuropsychiatric side effects, which reinforces the brain sensitivity for GC. Synapses can be bi-directionally modifiable via potentiation (long-term potentiation, LTP) or depotentiation (long-term depression, LTD) of synaptic transmission efficacy, and the phosphorylation state of Ser831 and Ser845 sites, in the GluA1 subunit of the glutamate AMPA receptors, are a critical event for these synaptic neuroplasticity events. Through a quasi-randomized controlled study, we show that a single high dexamethasone dose significantly reduces in a dose-dependent manner the levels of GluA1-Ser831 phosphorylation in the amygdala resected during surgery for temporal lobe epilepsy. This is the first report demonstrating GC effects on key markers of synaptic neuroplasticity in the human limbic system. The results contribute to understanding how GC affects the human brain under physiologic and pharmacologic conditions.

Prevalence of headache in patients with Parkinson's disease and its association with the side of motor symptom onset.

We compared the lifetime prevalence and the prevalence of headache during the previous year in patients with Parkinson's disease (PD) and control subjects. We also investigated the association between the side of PD symptom onset and the side of the headache. We interviewed 98 consecutive patients with an established diagnosis of PD between December 2010 and January 2012. The control group consisted of the 98 oldest sex-matched individuals from the nationwide Brazilian headache database. PD patients showed a significantly lower prevalence (40.8%) of headache in the previous year than controls (69.4%) (adjusted OR 0.5, CI 95% 0.2-0.9, p = 0.03). PD patients also showed a lower prevalence of headache throughout life (74.5%) than controls (93.9%) (adjusted OR 0.2, CI 95% 0.1-0.6, p = 0.01). Considering only patients who presented headache during the previous year, PD patients showed a higher association with occurrence of migraine than tension-type headache compared with controls (adjusted OR 3.3, CI 95% 1.2-8.9, p = 0.02). The headache side was ipsilateral to the side of PD onset in 21 patients (84%), with a concordance of 85.7% on the left side and 81.8% on the right side (p < 0.01). The prevalence of primary headache was significantly lower in patients with PD than controls. The predominant side of headache was ipsilateral to the side of initial motor signs of PD.

Multiple brain abscesses caused by Salmonella typhi: case report.

BACKGROUND: Focal intracranial infections caused by Salmonella species are uncommon. The authors report a case of multiple brain abscesses caused by Salmonella typhi. CASE DESCRIPTION: A 2-month-old girl was admitted to the hospital because of diarrhea, vomiting, fever, and poor feeding. Neurological examination revealed cervical hyperextension and absence of sucking and Moro reflexes. During the next 20 hours she developed complex partial seizures with secondary generalization and alternated irritability with drowsiness. Investigation showed hemoglobin 6.3 g/dl; white blood cell count of 19500/mm3 with a marked shift to the left. The analysis of the cerebrospinal fluid revealed white cell count of 1695/mm3, lymphocytes 61%, protein 300 mg/dl and glucose 6 mg/dl. The patient was treated for acute gastroenterocolitis, sepsis, and meningitis. Blood culture taken on the day of admission showed gram-negative bacilli, later identified as S. typhi. Computed tomography scan demonstrated a lesion in the right parietal lobe compatible with a brain abscess. Follow-up computed tomography after 7 days showed several other lesions with the same features. Surgical drainage of the right parietal lesion was performed on the 13th day, through a burr hole. The patient was discharged 5 weeks after admission without neurological deficit. CONCLUSION: Bacteremia, sepsis, and meningitis are relatively common in children with Salmonella infection but intracranial abscesses are very rare. Surgical drainage combined with prolonged antibiotic therapy (drug of choice: chloramphenicol) is the best treatment for Salmonella brain abscesses. The possibility of intracranial infection should be considered in patients with Salmonellosis and neurological dysfunction.

Microelectrode-guided thalamotomy for Parkinson's disease.

OBJECTIVE: To describe the outcomes in our first 40 microelectrode-guided thalamotomies for parkinsonian tremor. METHODS: Twenty-four left-sided and 16 right-sided thalamotomies were performed between October 1984 and January 1996; the mean follow-up period was 35.8 months (range, 1-152 mo). The results were evaluated retrospectively and semiquantitatively by a disinterested observer (MNL) and correlated with the quality of the microelectrode recording and the number and size of radiofrequency lesions made. The first 20 and second 20 procedures were evaluated separately. RESULTS: At the last follow-up, the Unified Parkinson's Disease Rating Scale showed no or virtually no tremor in the upper limb in 75% of patients or in the lower limb in 73% of patients. No significant persistent complications were found. These results were achieved at the expense of having to repeat the procedure on 11 sides (in 5 because of technical problems and in 6 for no obvious reason). Total or nearly total abolition of tremor occurred after the first procedure in 40% of the first 20 operations and in 65% of the second 20. Eight of the first 20 procedures and 2 of the second 20 failed for technical reasons. Lesions were made larger in the second 20 procedures than in the first 20. With the use of an electrode with a 1.1 x 3-mm bare tip for 60 seconds, it seems that lesions had to be created at 60 degrees C or more to produce a successful result. CONCLUSION: Thalamotomy with microelectrode recording is an effective procedure with which to treat tremor in patients with Parkinson's disease and may involve fewer complications than conventional techniques. The procedure appears to involve a learning curve.