Time filter

Source Type

Isle of Islay, United Kingdom

Matharu M.S.,University College London | Zrinzo L.,Unit of Functional Neurosurgery
Current Pain and Headache Reports | Year: 2010

Functional and structural neuroimaging studies have provided pivotal insights into the pathophysiology of trigeminal autonomic cephalalgias (TACs), particularly cluster headache (CH). Functional imaging studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) in TACs have reported activation of the posterior hypothalamus. A structural neuroimaging study using voxel-based morphometry in CH reported increased volume of the hypothalamic gray, although another larger study failed to reproduce this finding. These studies in CH prompted the use of stereotactic stimulation of the target point identified by functional and structural neuroimaging. The precise anatomical localization of the deep brain stimulation (DBS) target places it at the midbrain tegmentum rather than the posterior hypothalamus. A comparison of the PET and fMRI studies in TACs reveals that the diencephalic/ mesencephalic activation is more posteroinferior in the PET studies, straddling the hypothalamus and midbrain tegmentum, whereas the activation is centered on the hypothalamus in the higher spatial resolution fMRI studies. To optimize the outcomes from DBS, it is likely that patients will need to be studied individually using functional imaging techniques that have high spatial and temporal resolution to enable targeting of the appropriate locus with stereotactic stimulation. © Springer Science+Business Media, LLC 2010. Source

Capozzo A.,University of LAquila | Vitale F.,University of LAquila | Mattei C.,University of LAquila | Mazzone P.,Unit of Functional Neurosurgery | Scarnati E.,University of LAquila
Behavioural Brain Research | Year: 2014

The pedunculopontine tegmental nucleus (PPTg) relays basal ganglia signals to the thalamus, lower brainstem and spinal cord. Using the 6-hydroxydopamine (6-OHDA) rat model of parkinsonism, we investigated whether deep brain stimulation (DBS) of the PPTg (40. Hz, 60. μs, 200-400. μA) may influence the preparative and executive phases in a conditioned behavioural task, and the motor asymmetries induced by apomorphine. In the conditioned task, rats had to press two levers according to a fixed delay paradigm. The 6-OHDA lesion was placed in the right medial forebrain bundle, i.e. contralaterally to the preferred forepaw used by rats to press levers in the adopted task. The stimulating electrode was implanted in the right PPTg, i.e. contralateral to left side, which was expected to be most affected. The lesion significantly reduced correct responses from 63.4% to 16.6%. PPTg-DBS effects were episodic; however, when rats successfully performed in the task (18.9%), reaction time (468.8. ±. 36.5. ms) was significantly increased (589.9. ±. 45.9. ms), but not improved by PPTg-DBS (646.7. ±. 33.8. ms). Movement time was significantly increased following the lesion (649.2. ±. 42.6. ms vs. 810.9. ±. 53.0. ms), but significantly reduced by PPTg-DBS (820.4. ±. 39.4. ms) compared to sham PPTg-DBS (979.8. ±. 47.6. ms). In a second group of lesioned rats, rotations induced by apomorphine were significantly reduced by PPTg-DBS compared to sham PPTg-DBS (12.2. ±. 0.6 vs. 9.5. ±. 0.4 mean turns/min). Thus, it appears that specific aspects of motor deficits in 6-OHDA-lesioned rats may be modulated by PPTg-DBS. © 2014 Elsevier B.V. Source

Messina G.,Unit of Functional Neurosurgery | Rizzi M.,Unit of Functional Neurosurgery | Dones I.,Unit of Functional Neurosurgery | Franzini A.,Unit of Functional Neurosurgery
Neuromodulation | Year: 2014

Objective The study aims to describe a novel cosmetic implantation technique of internal pulse generators (IPGs) for deep brain stimulation (DBS) electrodes. Materials and Methods Thirty Parkinson patients during the interval 2001 to 2012 underwent posterior (cervical, dorsal, and lateral subcostal) subcutaneous implantation of DBS connection cables and IPGs in the prone position. Results No surgical complications occurred in any of the patients who underwent this procedure; all of the patients reported a high level of satisfaction with the cosmetic results due to the excellent concealment of the implanted devices. Conclusions Although this procedure is a little more time consuming compared with the conventional procedure, it is safe and leads to very good cosmetic results in DBS patients, which has significant benefits from the standpoint of social and work activities. © 2014 International Neuromodulation Society. Source

Discover hidden collaborations