There was a substantial component of tremor with intention. By self-report, the tremor was similar to that prior to thalamotomy,

being worse on moving the arm to eat and drink. An MRI within a month of the ictus (shown in Fig. 5) demonstrated a completed stroke involving the right cerebellar hemisphere. Firing rates in thalamic nuclei Vim and Vop for patient 4 are compared to patients with cerebellar tremor, postural ET and controls with pain in Section 2.1.1. There was no difference in the firing rates, or spike×EMG coherence or phase from this patient find more and the rest of the intention ET group (Mann–Whitney U test, z=1.22, P>0.2 for all comparisons). We have now tested the hypothesis that thalamic neuronal and EMG activities during intention ET are similar to those of cerebellar tremor. The results show that Sunitinib cell line intention ET

was similar to cerebellar tremor in multiple measures of tremor related activity while intention ET was apparently different from postural ET in multiple measures. Overall, the characteristics of intention ET are consistent with a mechanism similar to that of cerebellar tremor but different from that of postural ET (Hua and Lenz, 2005, Lenz et al., 2002 and Vilis and Hore, 1980). This mechanism may be based upon disruption of cerebellar function, as in cerebellar tremor. Specifically, intention ET versus postural ET demonstrated lower firing rates, Baricitinib lower SNR, and smaller phase lead of spike×EMG, all of which are consistent with the deafferentation of the thalamus by a cerebellar lesion, as shown in monkey studies (Lenz et al., 2002, Vilis and Hore, 1977 and Vilis and Hore, 1980). Postural ET had as many differences from intention ET as from cerebellar tremor, which suggests that postural ET is not due to cerebellar disruption. In addition, the higher firing rates, SNR, and phase lead of postural ET may result from excitatory

oscillatory input to the thalamus, consistent with a pacemaker in the olive (Lamarre, 1995 and Llinas, 1984). The cerebellar lesion occurring in patient 4 with intention ET is a critical test of whether intention ET is the result of cerebellar disruption or a cerebellar pacemaker. The lesion should increase tremor due to a cerebellar disruption but decrease tremor due to a pacemaker in the cerebellum and related structures. Patient 4 with intention ET had a cerebellar stroke (Table 1, Fig. 5), which increased his intention tremor. In light of this case, the physiological differences described above strongly suggest that intention ET is the result of disruption of the cerebellum. The frequency of thalamic activity during cerebellar tremor in this series is consistent with the accepted frequency range for cerebellar tremor in the literature (Deuschl et al., 1998 and Elble and Deuschl, 2011).