Central sensitization mechanisms in chronic migraine with medication overuse headache: a study of thalamocortical activation and lateral cortical inhibition.

BACKGROUND: It is unclear whether cortical hyperexcitability in chronic migraine with medication overuse headache (CM-MOH) is due to increased thalamocortical drive or aberrant cortical inhibitory mechanisms. METHODS: Somatosensory evoked potentials (SSEP) were performed by electrical stimulation of the median nerve (M), ulnar nerve (U) and simultaneous stimulation of both nerves (MU) in 27 patients with CM-MOH and, for comparison, in 23 healthy volunteers (HVs) of a comparable age distribution. We calculated the degree of cortical lateral inhibition using the formula: 100 - [MU/(M + U) × 100] and the level of thalamocortical activation by analyzing the high frequency oscillations (HFOs) embedded in parietal N20 median SSEPs. RESULTS: Compared to HV, CM-MOH patients showed higher lateral inhibition (CM-MOH 52.2% ± 15.4 vs. HV 40.4% ± 13.3; p = 0.005), which positively correlated with monthly headache days, and greater amplitude of pre-synaptic HFOs (p = 0.010) but normal post-synaptic HFOs (p = 0.122). CONCLUSION: Our findings suggest that central neuronal circuits are highly sensitized in CM-MOH patients, at both thalamocortical and cortical levels. The observed changes could be due to the combination of dysfunctional central pain control mechanisms, hypersensitivity and hyperresponsiveness directly linked to the chronic intake of acute migraine drugs.

End of life issues in brain tumor patients.

Despite aggressive antitumor treatment, the prognosis of brain tumor (BT) patients remains poor. In the last stage of disease, BT patients present severe symptoms due to the growing tumor or to treatment side-effects, which require adequate palliative management and supportive therapy. However, studies specifically addressing palliative care and end-of-life (EoL) issues in BT patients are lacking. This study explores symptoms experienced by BT patients in the last weeks of disease and EoL issues observed in a population of brain tumor patients followed at home until death by a neuro-oncological home care palliative unit set up in our Institution in 2000. From October 2000 to December 2005, 324 patients affected by brain tumor and discharged from our Institution were enrolled in a comprehensive program of neuro-oncological home care supported by the Regional Health System. Out of 324 patients enrolled in the home care program, 260 patients died of which 169 (65%) were assisted at home until the end of life and have been included in this study. Clinical symptoms, palliative treatments and EoL treatment decisions were collected from home clinical records. Among the 169 patients assisted at home until death, the most frequent symptoms observed in the last four weeks of life were: epilepsy 30%, headache 36%, drowsiness 85%, dysphagia 85%, death rattle 12%, agitation and delirium 15%. Palliative management of brain tumor patients requires a multidisciplinary approach performed by a well trained neuro-oncology team. Development of home care models of assistance may represent an alternative to in-hospital care for the management of patients dying of brain tumor and may improve the quality of end-of-life care.