Autonomic control of heart and vessels in patients with very early stage of Parkinson disease.

Objective. Non-motor symptoms including those reflecting autonomic cardiovascular dysregulation are often present in Parkinson disease. It is unclear whether it is possible to detect cardiovascular autonomic dysregulation in the very early stage of Parkinson disease potentially supporting the concept of the upstream propagation of nervous system damage through autonomic nerves. We hypothesized that cardiovascular dysregulation should precede the motor symptoms and at the time of their occurrence autonomic dysregulation should be clearly demonstrable. Therefore, the aim of this study was to assess the various aspects of autonomic cardiovascular control in the very early stage of Parkinson disease.Approach. We performed prospective case-control study on 19 patients with Parkinson disease (<6 months after motor signs occurrence) and 19 healthy control subjects. For each phase of study protocol (supine, head-up tilt, supine recovery), we calculated a wide array of cardiovascular control related parameters reflecting cardiac chronotropic, cardiac inotropic and vasomotor control and baroreflex mediated cardiovascular response.Main results. We observed the well-preserved heart rate and blood pressure control in patients with early stage of Parkinson disease. However, causal analysis of interactions between heart rate and blood pressure oscillations revealed subtle differences in baroreflex function and baroreflex mediated vasoconstriction response to orthostasis. Furthermore, a tendency towards a decreased contraction strength in Parkinson disease was observed.Significance. Considering only subtle cardiovascular control impairment in our study employing a wide array of sensitive methods at the time when motor signs were clearly expressed, we suggest that motor signs dominated in this stage of Parkinson disease.

Contrast-induced encephalopathy.

Contrast-induced encephalopathy (CIE) is a rare complication of the intravascular application of a contrast agent. CIE can be manifested by headache, cortical blindness, consciousness disorders, seizures, or focal neurological deficit. Neurological symptoms are typically transient with temporary abnormal findings on a brain scan. Urgent neuroimaging is important to obtain the correct diagnosis, especially in cases that require an acute management and treatment. We present a case of CIE after a digital subtraction angiography of the vertebral arteries in the patient with a symptomatic pre-occlusive stenosis of the posterior cerebral artery (Ref. 36). Text in PDF www.elis.sk Keywords: encephalopathy, iodixanol, contrast agent, cortical blindness, cerebral angiography.

Modulation of Cough Reflex by Gaba-Ergic Inhibition in Medullary Raphé of the Cat.

We studied the effects of GABA receptor agonists microinjections in medullary raphé on the mechanically induced tracheobronchial cough response in anesthetized, unparalyzed, spontaneously breathing cats. The results suggest that GABA-ergic inhibition significantly contributes to the regulation of cough reflex by action of both GABA(A) and GABA(B) receptors. The data are consistent with inhomogeneous occurrence of GABA-ergic neurons in medullary raphé and their different involvement in the cough reflex control. Cells within rostral nucleus raphéobscurus with dominant role of GABA(A) receptors and neurons of rostral nucleus raphépallidus and caudal nucleus raphémagnus with dominant role of GABA(B) receptors participate in regulation of cough expiratory efforts. These cough control elements are distinct from cough gating mechanism. GABA-ergic inhibition in the raphé caudal to obex had insignificant effect on cough. Contradictory findings for GABA, muscimol and baclofen administration in medullary raphé suggest involvement of coordinated activity of GABA on multiple receptors affecting raphé neurons and/or the local neuronal circuits in the raphé modulating cough motor drive.