COMMON PATHOPHYSIOLOGICAL MECHANISMS OF PRIMARY HEADACHE AND PARKINSON'S DISEASE - A NEUROPHYSIOLOGICAL EVIDENCE

The brainstem seems to account for nociceptive sensory processing and is involved in the pathophysiology of migraine as well as in the neuro degenerative process in Parkinson's disease (PD). Neurophysiological studies on trigeminal reflexes are used for evaluation of the brainstem interneurons activity. Similar abnormalities in both disorders were reported but patients with headache parallel to PD have not been examined. The aim of this study was to investigate the brainstem reflexes with focus on nociception in patients with headache and with PD. We studied 20 migraine patients, 25 patients with tension-type headache, 20 PD patients and 20 healthy subjects, using electromyographic recording of blink reflex, masseter inhibitory reflex (MIR) and trigemino-cervical reflex (TCR). In all patients groups MIR and TCR were abnormal and facilitated, suggesting trigeminal hyperexcitability state. The results suggest possible central pain processing dysfunction and support the concept of primary brainstem trigeminal dysfunction in both disorders.