High-frequency rTMS using a double cone coil for gait disturbance.

OBJECTIVE: It is difficult to stimulate leg motor areas with magnetic current using a figure-of-eight coil due to the deep anatomical location of the areas. However, a double cone coil is useful for stimulating deep brain regions. We postulated that the use of the same coil may allow repetitive transcranial magnetic stimulation (rTMS) to modulate the neural activity of the same areas. The purpose of this study is to investigate the effect of high-frequency rTMS applied over bilateral leg motor areas with a double cone coil on walking function after stroke. MATERIALS AND METHODS: Eighteen post-stroke hemiparetic patients with gait disturbances attended two experimental sessions with more than 24 h apart, in a cross-over, double-blind paradigm. In one session, high-frequency rTMS of 10 Hz was applied over the leg motor area bilaterally in a 10-s train using a double cone coil for 20 min (total 2,000 pulses). In the other session, sham stimulation was applied for 20 min at the same site. To assess walking function, walking velocity, and Physiological Cost Index (PCI) were evaluated serially before, immediately after, and 10 and 20 min after each stimulation. RESULTS: The walking velocity was significantly higher for 20 min after stimulation in the high-frequency rTMS group than the sham group. PCI was lower in the high-frequency rTMS group than the sham group, but this was significant only immediately after stimulation. CONCLUSIONS: High-frequency rTMS of bilateral leg motor areas using a double cone coil can potentially improve walking function in post-stroke hemiparetic patients.

Effect of low-frequency rTMS on motor neuron excitability after stroke.

OBJECTIVES: The purpose of this study was to test the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) over the non-lesional hemisphere on motor neuron excitability of the paretic upper limb in post-stroke patients by electrophysiological examination. MATERIALS AND METHODS: Thirteen post-stroke patients with spastic upper limb hemiparesis were studied (age, 57.5 ± 11.1 years; time after stroke, 55.2 ± 51.4 months). Low-frequency rTMS of 1 Hz was applied for 20 min to the motor cortex of the non-lesional hemisphere. The M-response amplitude and F-wave parameters were recorded in the abductor pollicis brevis muscle following stimulation of the median nerve in both the affected and unaffected upper limbs. The F-wave frequency, F-max/M ratio (ratio of maximum F-wave amplitude to M-response amplitude), and F-mean/M ratio (the ratio of mean F-wave amplitude to the M-response amplitude) were measured before and after the 20-min rTMS, analyzed for both limbs. RESULTS: Application of low-frequency rTMS did not result in significant changes in the frequency of F-wave and F-max/M ratio in both upper limbs, but significantly decreased F-mean/M ratio in the affected upper limb (P < 0.005), but not in the unaffected limb. CONCLUSIONS: Low-frequency rTMS applied to the non-lesional hemisphere might be potentially useful therapeutically for post-stroke patients with spastic upper limb hemiparesis.

Combined therapeutic application of botulinum toxin type A, low-frequency rTMS, and intensive occupational therapy for post-stroke spastic upper limb hemiparesis.

BACKGROUND: For spastic upper limb hemiparesis after stroke, we developed triple-element protocol of botulinum toxin type A (BoNTA) injection, low-frequency repetitive transcranial magnetic stimulation (LF-rTMS), and intensive occupational therapy (OT). Aim. To investigate the safety and feasibility of the protocol. Design. A preliminary study. Setting. At a university hospital. Population. Fourteen post-stroke patients with spastic upper limb hemiparesis (mean age: 54.9±9.2 years, time after onset: 87.1±48.2 months, ±SD). METHODS: In all patients, BoNTA was injected into spastic muscles of the affected upper limb (maximum total dose: 240 units). Four weeks later, they were hospitalized to receive 22 sessions of 20-min LF-rTMS and 120-min intensive OT daily over 15 days. Motor function of the affected upper limb was evaluated mainly using Fugl-Meyer Assessment (FMA), Wolf Motor Function Test (WMFT), motor activity log (MAL), and the severity of spasticity was measured with modified Ashworth scale (MAS) at BoNTA injection, discharge and four weeks post-discharge. RESULTS: All patients completed the protocol without any adverse effects. The FMA score and MAL scores, but not WMFT performance time, improved significantly at discharge. The MAS score of all examined muscles decreased significantly between BoNTA and discharge. The beneficial effect of the protocol on motor function and spasticity was almost maintained until four weeks after discharge. CONCLUSION: The protocol is safe and feasible, although further larger studies are needed to confirm its efficacy. CLINICAL REHABILITATION IMPACT: The protocol is a potentially useful neurorehabilitative approach for this patient population.

Changes in regional cerebral blood flow in the right cortex homologous to left language areas are directly affected by left hemispheric damage in aphasic stroke patients: evaluation by Tc-ECD SPECT and novel analytic software.

BACKGROUND: The objective of this study was to clarify the influence of regional cerebral blood flow (rCBF) changes in language-relevant areas of the dominant hemisphere on rCBF in each region in the non-dominant hemisphere in post-stroke aphasic patients. METHODS: The study subjects were 27 aphasic patients who suffered their first symptomatic stroke in the left hemisphere. In each subject, we measured rCBF by means of 99mTc-ethylcysteinate dimmer single photon emission computed tomography (SPECT). The SPECT images were analyzed by the statistical imaging analysis programs easy Z-score Imaging System (eZIS) and voxel-based stereotactic extraction estimation (vbSEE). Segmented into Brodmann Area (BA) levels, Regions of Interest (ROIs) were set in language-relevant areas bilaterally, and changes in the relative rCBF as average negative and positive Z-values were computed fully automatically. To assess the relationship between rCBF changes of each ROIs in the left and right hemispheres, the Spearman ranked correlation analysis and stepwise multiple regression analysis were applied. RESULTS: Globally, a negative and asymmetric influence of rCBF changes in the language-relevant areas of the dominant hemisphere on the right hemisphere was found. The rCBF decrease in left BA22 significantly influenced the rCBF increase in right BA39, BA40, BA44 and BA45. CONCLUSIONS: The results suggested that the chronic increase in rCBF in the right language-relevant areas is due at least in part to reduction in the trancallosal inhibitory activity of the language-dominant left hemisphere caused by the stroke lesion itself and that these relationships are not always symmetric.

Clinical importance of microbleeds in patients receiving IV thrombolysis.

BACKGROUND: Cerebral microbleeds (MBs) detected on gradient echo (GRE) imaging may be a risk factor for hemorrhagic complications in patients with stroke treated with IV tissue plasminogen activator (tPA). METHODS: The authors prospectively evaluated patients with acute ischemic stroke treated with IV tPA between 3 and 6 hours of symptom onset. MRI scans, including GRE imaging, were performed prior to tPA treatment, 3 to 6 hours after treatment and at day 30. The authors compared the frequency of hemorrhagic complications after thrombolysis in patients with and without MBs on their baseline GRE imaging. RESULTS: Seventy consecutive patients (mean age, 71 +/- 29 years; 31 men, 39 women) were included. MBs were identified in 11 patients (15.7%) on baseline GRE imaging. There was no significant difference in the frequency of either symptomatic or asymptomatic hemorrhagic complications after thrombolysis between patients with and without MBs at baseline. None of the 11 patients with MBs (0%) at baseline had a symptomatic intracerebral hemorrhage compared with 7 of 59 patients who did not have baseline MBs (11.9%). In addition, no patients with baseline MBs had asymptomatic hemorrhagic transformation observed at the site of any pre-treatment MB. CONCLUSIONS: The presence of cerebral microbleeds on gradient echo imaging does not appear to substantially increase the risk of either symptomatic or asymptomatic brain hemorrhage following IV tissue plasminogen activator administered between 3 and 6 hours after stroke onset.

Rhabdomyolysis lesions showing magnetic resonance contrast enhancement.

Although T2-weighted magnetic resonance imaging (MRI) was reported to be useful for depicting rhabdomyolysis lesions, little is known as to the usefulness of gadolinium-enhanced T1-weighted imaging. The authors performed noncontrast and postcontrast T1-weighted MRI along with T2-weighted MRI in a patient with rhabdomyolysis in the chronic phase. Non-contrast T1-weighted imaging revealed no abnormality, whereas postcontrast T1-weighted imaging demonstrated lesions more definitively than T2-weighted imaging. Gadolinium-enhancement study may contribute to the MRI diagnosis of rhabdomyolysis.