Difference of injury of the corticospinal tract according to surgical or conservative treatment in patients with putaminal hemorrhage.

OBJECTIVE: We investigated difference of injury of the corticospinal tract (CST) according to surgical or conservative treatment in patients with putaminal hemorrhage (PH), using diffusion tensor tractography (DTT). METHODS: Forty-six patients with PH (hematoma volume on the brain CT: 20-40 ml) were recruited. Patients were classified as the surgical treatment group and the conservative treatment group. The hematoma volume on the initial brain CT (median 2 hours after onset; range 1-14 hours) and volumes of the hematoma, the total lesion and the peri-hematomal edema volume on the follow-up brain magnetic resonance imaging (MRI) (median 23.5 days after onset; range 12-46 days) were estimated. Diffusion tensor imaging was performed and we defined the injury of the CST in terms of the configuration or abnormal DTT parameters. RESULTS: In the conservative treatment group, the total lesion volume on the brain MRI was increased compared with the hematoma volume on the initial brain CT (p < 0.05). On brain MRI, the hematoma volume, peri-hematomal edema volume, and total lesion volume were larger in the conservative treatment group than in the surgical treatment group (p < 0.05). Twelve patients (60%) in the surgical treatment group and 24 patients (92%) in the conservative treatment group had injury of the CST. CONCLUSION: Injury of the CST was less prevalent in the surgical treatment group than in the conservative treatment group in patients with PH. Therefore, it appears that surgical treatment could be helpful in prevention of injury of the CST in patients with PH.

Functional MRI finding by proprioceptive input in patients with thalamic hemorrhage.

Little is known about the recovery mechanism of somatosensory function in thalamic hemorrhage. We investigated the recovery mechanism of somatosensory function, using functional MRI (fMRI) findings by proprioceptive input in chronic patients with thalamic hemorrhage. Eleven consecutive chronic patients with thalamic hemorrhage who showed severe proprioceptive dysfunction were recruited. The subscale for kinesthetic sensation of the Nottingham Sensory Assessment (NSA) was used for determination of proprioceptive function. fMRI was performed during passive movements of the metacarpophalangeal joint. From fMRI, the laterality index (LI) was calculated for assessment of the relative activity in the ipsilateral versus the contralateral primary sensori-motor cortex (SM1). The average LI for affected and unaffected hand stimulation was 0.89 and 0.90, respectively, and there was no significant difference between LIs (p> 0.05). In addition, LI of the affected hand stimulation was positively related to NSA scores (r=0.790, p< 0.05). Our results for LI suggest that the cortical activation pattern of SM1 was similar in the affected and unaffected hemispheres. Therefore, it appears that the proprioceptive function of the affected hand likely recovered by the normally existing medial lemniscus and its thalamocortical pathway in our patients.

The prevalence of central poststroke pain according to the integrity of the spino-thalamo-cortical pathway.

OBJECTIVES: Little is known about the prevalence of central poststroke pain (CPSP) according to the integrity of the spino-thalamo-cortical pathway (STP). Using diffusion tensor tractography, we investigated the prevalence of CPSP according to the integrity of the STP in patients with intracerebral hemorrhage. METHODS: We recruited 52 consecutive chronic patients and 10 normal control subjects. Patients were classified into two groups according to preservation of the integrity of the STP. Each group was divided into two subgroups according to the presence of CPSP. RESULTS: The preserved group included 34 patients [CPSP subgroup, 16 (47%) patients; non-CPSP subgroup, 18 (53%) patients], and 18 patients were enrolled into the disrupted group [CPSP subgroup, 3 (17%) patients; non-CPSP subgroup, 15 (83%) patients]. The fractional anisotropy and mean diffusivity values of the CPSP and non-CPSP subgroups of the preserved group were decreased and increased when compared with those of the control group, respectively (p < 0.05). CONCLUSIONS: We found that the prevalence of CPSP in patients with partial injury of the STP was higher than that of patients with complete injury of the STP. Partial injury of the STP appears to be more vulnerable to development of CPSP than complete injury of the STP in patients with intracerebral hemorrhage.

Injury of the spino-thalamo-cortical pathway is necessary for central post-stroke pain.

OBJECTIVES: We investigated the relationship between injury of the spino-thalamo-cortical pathway (STP) and central post-stroke pain (CPSP) in patients with intracerebral hemorrhage, using diffusion tensor tractography (DTT). METHODS: 30 consecutive chronic patients, in whom integrity of the STP and the medial lemnisco-thalamo-cortical pathway (MLP) were spared in both hemispheres, were recruited. We classified the patients into two groups according to the presence of the CPSP. DTTs were obtained using the FMRIB Software Library. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured. A laterality index (LI) was used to determine asymmetry of DTT parameters between the hemispheres. RESULTS: The LI for tract volume of the STP in the CPSP group was lower than that of the non-CPSP group (p = 0.000). However, there were no differences between the CPSP group and non-CPSP group for the LIs of FA or MD of the STP or for the LIs of FA, MD, or tract volume of the MLP (p > 0.05). CONCLUSIONS: Decrease of tract volume without changes in the STP FA or MD values in the CPSP group indicates partial injury of STP. Therefore, injury of the STP seems to be a requirement for the development of CPSP in patients with intracerebral hemorrhage.

Comparison of TMS and DTT for predicting motor outcome in intracerebral hemorrhage.

BACKGROUND: TMS (transcranial magnetic stimulation) and DTT (diffusion tensor tractography) have different advantages in evaluating stroke patients. TMS has good clinical accessibility and economical benefit. On the contrary, DTT has a unique advantage to visualize neural tracts three-dimensionally although it requires an expensive and large MRI machine. Many studies have demonstrated that TMS and DTT have predictive values for motor outcome in stroke patients. However, there has been no study on the comparison of these two evaluation tools. In the current study, we compared the abilities of TMS and DTT to predict upper motor outcome in patients with ICH (intracerebral hemorrhage). METHODS: Fifty-three consecutive patients with severe motor weakness were evaluated by TMS and DTT at the early stage (7-28 days) of ICH. Modified Brunnstrom classification (MBC) and the motricity index of upper extremity (UMI) were evaluated at onset and 6 months after onset. RESULTS: Patients with the presence of a motor evoked potential (MEP) in TMS or a preserved corticospinal tract (CST) in DTT showed better motor outcomes than those without (p=0.000). TMS showed higher positive predictive value than DTT. In contrast, DTT showed higher negative predictive value than TMS. CONCLUSIONS: TMS and DTT had different advantages in predicting motor outcome, and this result could be a reference to predict final neurological deficit at the early stage of ICH.

Demonstration of motor recovery process in a patient with intracerebral hemorrhage.

OBJECTIVES: Little is known about the mechanism of motor recovery for patients with intracerebral hemorrhage (ICH). We attempted to demonstrate the motor recovery mechanism in a hemiparetic patient with ICH using diffusion tensor tractography (DTT), transcranial magnetic stimulation (TMS), and functional MRI (fMRI). SUBJECTS: A 37-year-old female patient and twelve age-matched control subjects were evaluated. The patient presented with complete paralysis of the left extremities, which occurred at the onset of a spontaneous ICH in the left corona radiata and basal ganglia. Over the 16 month period following onset, motor function of the affected extremities slowly recovered to a nearly normal state. Three longitudinal evaluations (at 1 month, 4 months, and 16 months from onset) were conducted for the patient. RESULTS: DTT showed that the origin of the corticospinal tract (CST) had changed from the posterior parietal cortex, primary sensory cortex, and primary motor cortex. Additionally, TMS and fMRI demonstrated the recovery process of the damaged lateral CST. CONCLUSIONS: It seems that, in this patient, the affected motor function was recovered through the normalization process of the damaged lateral CST of the affected hemisphere. We conclude that this may be one of various motor recovery mechanisms for patients with ICH. Process of the damaged lateral CST.

Motor outcome according to diffusion tensor tractography findings in the early stage of intracerebral hemorrhage.

We tried to investigate the motor outcome according to diffusion tensor tractography (DTT) findings for the corticospinal tract (CST) in the early stage for hemiparetic patients with intracerebral hemorrhage (ICH). Forty patients with severe paralysis of the affected side were enrolled. DTT was obtained in the early stage of the stroke (7-30 days) and was classified into four groups: type A, the CST originating from primary motor cortex was preserved around the hematoma; type B, the CST was similar to type A except the fiber originated from the adjacent areas to the primary motor cortex; type C, the CST was interrupted at or around the hematoma; and type D, the CST did not reach the hematoma due to degeneration (Fig. 1). Six months after onset, motor function was measured and the statistical influence of the DTT type was tested. Initially, none of the motor function scales of the affected side differed among the four DTT types. Six months after the onset of ICH, motor functions of the same side were significantly different according to DTT type (p<0.05). All motor scales were highest in the DTT type A group, and were lowest in the DTT type D group (p<0.0003). The early DTT findings for CST may be used to predict the motor outcome of the affected extremities in hemiparetic patients with ICH.