Usefulness of Three Dimensional Proset MR Images for Diagnosis of Symptomatic L5-S1 Foraminal and Extraforaminal Stenosis.

OBJECTIVE: To suggest a new useful diagnostic technique, principles of the selective excitation technique-magnetic resonance images (Proset-MRI), and to know the precise radiologic findings that can prove symptomatic foraminal and extraforaminal stenosis at L5-S1. METHODS: Nineteen patients with symptomatic L5-S1 stenosis were checked by Proset-MRI. Four patients were performed decompressive surgery and 15 patients were performed selective nerve root block (SNRB) at L5. The pain scale of patients was checked by Visual Analogue Scale (VAS) scores at the pre- and post-treatment state. RESULTS: Proset-MRI findings of patients with symptomatic stenosis are root swelling (RS) and indentation. The comparisons with VAS scores had a meaningful statistical result at each RS (p<0.01) and indentation (p<0.01). However, the findings of RS combined with indentation lacked statistical significance (p=0.0249). In addition, according to a comparison with the treatment modalities, reducing of VAS scores had statistical meaningful significance in decompressive surgery cases (p<0.01), and also in SNRB cases (p<0.01) after a 3-month follow-up period. CONCLUSION: The three dimensional Proset-MRI is very useful and sensitive technique to diagnose the symptomatic foraminal and extraforaminal stenosis at L5-S1.

Relation between cingulum injury and cognition in chronic patients with traumatic brain injury; diffusion tensor tractography study.

OBJECTIVES: Many diffusion tensor imaging (DTI) studies have reported an association between cingulum injury and cognition in patients with traumatic brain injury (TBI) using DTI parameters. In this study, we attempted to investigate the relation between cingulum injury and cognition in chronic patients with TBI, using the integrity of the cingulum as well as DTI parameters. METHOD: Thirty five consecutive chronic patients with TBI were recruited. The intelligence quotient (IQ) of the Wechsler Intelligence Scale and Memory Assessment Scale (MAS) was used for assessment of cognition. The patients were classified into three groups, according to continuity to the lower portion of the genu of the corpus callosum: type A-both sides of the cingulum showed intact continuity, type B-either cingulum showed a discontinuation, and, type C-both cingulums showed discontinuation. We measured the fractional anisotropy (FA), apparent diffusion coefficient (ADC), and voxel number of both cingulums. RESULTS: The IQ and MAS scores of type A and B were significantly higher than those of type C, respectively (p < 0.05), however, we did not observe a significant difference between type A and type B (p > 0.05). A positive correlation was observed between the FA value of the cingulum, and IQ and MAS, respectively (IQ r = 0.373, p < 0.05, MAS r = 0.357, p < 0.05), and between the voxel number and MAS (r = 0.500, p < 0.05). By contrast, we observed a negative correlation between the ADC value and IQ (r = -0.353, p < 0.05). CONCLUSION: In terms of integrity to the basal forebrain and DTI parameters of the injured cingulum, DTI findings showed a close association with whole cognition and memory in chronic patients with TBI.

Cingulum injury in patients with diffuse axonal injury: a diffusion tensor imaging study.

Accurate assessment of the cingulum is difficult, because it is a long neural tract that extends from the orbitofrontal cortex to the medial temporal lobe. We divided the cingulum into five parts and investigated changes caused by injury in these regions in patients with diffuse axonal injury (DAI) using diffusion tensor tractography (DTT). Twenty-one patients with DAI and 21 control subjects were recruited. The cingulum was divided into; the anterior, superior (the anterior and posterior portions), posterior, and inferior regions. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and tract number were measured in each region. FA values and tract numbers in the patient group were lower in the anterior superior cingulum than in controls (p<0.05); whereas the ADC values in the patient group were higher in the anterior and posterior superior cingulum than in controls (p<0.05). In the superior cingulum, increases in the ADC values of the anterior portion (Δ8.1%) were higher than those of the posterior portion (Δ5.5%). We found that the superior cingulum was injured in patients with DAI, and that the anterior portion of the superior cingulum was more injured than the posterior portion. Consequently, the superior cingulum appears to be a vulnerable area and the anterior superior cingulum appears more vulnerable than the posterior superior cingulum in DAI.

Diffusion tensor imaging findings of optic radiation in patients with putaminal hemorrhage.

OBJECTIVES: Little is known about optic radiation (OR) injury in intracerebral hemorrhage (ICH). We attempted to investigate OR injury in patients with ICH by diffusion tensor imaging (DTI). METHODS: Forty-three consecutive patients with putaminal hemorrhage and 40 normal healthy control subjects were recruited. DTI data were acquired at the beginning of rehabilitation (average 34 days after onset). DTI-Studio software was used to reconstruct the OR. Fractional anisotropies (FA) and fiber numbers of the ORs were measured. FA values and fiber numbers of affected ORs were described as abnormal when they were more than 2.5 SD lower than those of normal controls. RESULTS: Thirty (70%) of the 43 patients showed an OR abnormality in the affected hemisphere. In 13 (30%) patients, the affected OR was disrupted or nonreconstructable. On the other hand, of the 20 patients with preserved OR integrity, 14 (33%) had a low FA value and 3 (7%) a low FA and fiber number. The other 13 (30%) of the 43 patients had no abnormal OR findings. CONCLUSION: Seventy percent of patients showed any abnormality of OR in the affected hemisphere on DTI. This result suggests that patients with putaminal hemorrhage are at high risk of OR injury.

The effects of hydrocephalus on the periventricular white matter in intracerebral hemorrhage: a diffuser tensor imaging study.

OBJECTIVES: Many diffusion tensor imaging (DTI) studies have described the effects of hydrocephalus on periventricular white matter in patients with normal pressure hydrocephalus. However, little is known about hydrocephalus following stroke. We investigated the effect of hydrocephalus on periventricular white matter in patients with hydrocephalus after an intracerebral hemorrhage (ICH) using DTI. METHODS: Fourteen patients with ICH and hydrocephalus, and 17 age- and sex-matched normal control subjects were recruited. DTI parameters were estimated in six regions of interest (ROIs) in periventricular white matter: the anterior corona radiata, the posterior corona radiata, the genu of the corpus callosum, the splenium of corpus callosum, the anterior limb of the internal capsule, and the posterior limb of the internal capsule. RESULTS: Mean fractional anisotropy of the anterior corona radiata in patients was significantly higher than in controls (p < 0.05), but apparent diffusion coefficient (ADC) was not different in the two groups (p > 0.05). No significant differences between fractional anisotropies and ADCs were observed in the other five ROIs (p > 0.05). CONCLUSIONS: The anterior corona radiata was found to be more compressed by hydrocephalus than the other five regions of periventricular white matter examined in patients with hydrocephalus following ICH. It is believed that the results of the present study will be useful for the diagnosis and management of hydrocephalus following stroke.

Differentiation between symptomatic and asymptomatic extraforaminal stenosis in lumbosacral transitional vertebra: role of three-dimensional magnetic resonance lumbosacral radiculography.

OBJECTIVE: To investigate the role of lumbosacral radiculography using 3-dimentional (3D) magnetic resonance (MR) rendering for diagnostic information of symptomatic extraforaminal stenosis in lumbosacral transitional vertebra. MATERIALS AND METHODS: The study population consisted of 18 patients with symptomatic (n = 10) and asymptomatic extraforaminal stenosis (n = 8) in lumbosacral transitional vertebra. Each patient underwent 3D coronal fast-field echo sequences with selective water excitation using the principles of the selective excitation technique (Proset imaging). Morphologic changes of the L5 nerve roots at the symptomatic and asymptomatic extraforaminal stenosis were evaluated on 3D MR rendered images of the lumbosacral spine. RESULTS: Ten cases with symptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. On 3D MR lumbosacral radiculography, indentation of the L5 nerve roots was found in two cases, while swelling of the nerve roots was seen in eight cases at the exiting nerve root. Eight cases with asymptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. Based on 3D MR lumbosacral radiculography, indentation or swelling of the L5 nerve roots was not found in any cases with asymptomatic extraforaminal stenosis. CONCLUSION: Results from 3D MR lumbosacral radiculography Indicate the indentation or swelling of the L5 nerve root in symptomatic extraforaminal stenosis. Based on these findings, 3D MR radiculography may be helpful in the diagnosis of the symptomatic extraforaminal stenosis with lumbosacral transitional vertebra.

Limb apraxia in a patient with cerebral infarct: diffusion tensor tractography study.

We report on a patient with ideomotor apraxia (IMA) and limb-kinetic apraxia (LKA) following cerebral infarct, which demonstrated neural tract injuries by diffusion tensor tractography (DTT). A 67-year-old male was diagnosed as cerebral infarct in the left frontal cortex (anterior portion of the precentral gyrus and prefrontal cortex) and centrum semiovale. The patient presented with severe paralysis of the right upper extremity and mild weakness of the right lower extremity at onset. At the time of DTT scanning (5 months after onset), the patient was able to move all joint muscles of the right upper extremity against gravity, except for the finger extensors, which he could extend partially against gravity. The patient showed intact ideational plan for motor performance; however, his movements were slow, clumsy, and mutilated when executing grasp-release movements of his affected hand. The patient's score on the ideomotor apraxia test was 20 (cut-off score < 32). DTTs for premotor cortex fibers, supplementary motor area fibers, and superior longitudinal fasciculus of the left hemisphere showed partial injuries, compared with those of the right side, and these injuries appeared to be responsible for IMA and LKA in this patient.

Neural tract injuries by brain herniations after head trauma.

OBJECTIVES: : Little is known about the usefulness and findings of brain herniation on diffusion tensor tractography (DTT). Using DTT, we demonstrated neural tract injuries in 2 patients who showed subfalcine and trasntentorial herniations after subdural hematoma resulting from motor vehicle accident. DESIGN: : Two patients and 6 age- and sex-matched, healthy volunteers were recruited for this study. SETTING: : An inpatient rehabilitation unit. MAIN OUTCOME MEASURES: : Diffusion tensor tractography for the patients was performed 5 weeks after onset. RESULTS: : Diffusion tensor tractography of patient 1 showed complete injury of both cingulums at or around the rostrum of the corpus callosum, the fornix at the anterior and posterior body, and both corticospinal tracts at the pons. In addition, partial injury of both somatosensory tracts at the midbrain was also observed. Patient 2 showed complete injury of both cingulums above the body of the corpus callosum, the fornix at the anterior and posterior body, and right corticospinal tracts at the pons level and partial injury of the right somatosensory tract. We found that the fractional anisotropy values of all neural tracts, except fornix, in both patients and left somatosensory tract in patient 2 and voxel number for left somatosensory tract in patient 2 were decreased 2 SDs below that of normal controls. CONCLUSIONS: : We determined that DTT would be a good technique for use in the detection of underlying lesions in patients with brain herniation.

Neuronal loss in the medial cholinergic pathway from the nucleus basalis of Meynert in patients with traumatic axonal injury: a preliminary diffusion tensor imaging study.

OBJECTIVE: The recent development of diffusion tensor imaging (DTI) allows visualization and estimation of the medial cholinergic pathway (MCP), which originates from the nucleus basalis of Meynert and provides cortical cholinergic innervation to the cerebral cortex. We investigated the injury to the MCP in patients with traumatic axonal injury (TAI), using DTI. DESIGN: Retrospective survey. PARTICIPANTS: Fourteen patients with chronic TAI and 14 age- and sex-matched normal control subjects. MAIN OUTCOME MEASURES: Using the Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (FMRIB analysis group, Oxford University, United Kingdom), diffusion tensor images were acquired by using a sensitivity-encoding head coil at 1.5 T DTIs. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume of the MCP were measured. RESULTS: The FA value and tract volume were significantly decreased in the group with TAI compared with those of the control group (P < .05); in contrast, there was no difference in the MD value between the 2 groups (P > .05). CONCLUSIONS: Changes in DTI parameters of the TAI group appear to be due to neuronal loss of the MCP. We believe that DTI would be useful for the evaluation of the MCP in patients with TAI.

Three-dimensional magnetic resonance rendering imaging of lumbosacral radiculography in the diagnosis of symptomatic extraforaminal disc herniation with or without foraminal extension.

STUDY DESIGN: Retrospective analysis of lumbosacral radiculography using 3-dimensional (3D) magnetic resonance (MR) rendering in patients with extraforaminal disc herniation. OBJECTIVE: To investigate the significance of lumbosacral radiculography as depicted by 3D MR rendering in the diagnosis of symptomatic extraforaminal disc herniation with or without foraminal extension. SUMMARY OF BACKGROUND DATA: Given that accurate evaluation of the extraforaminal zones on routine axial and sagittal images is difficult, extraforaminal disc herniations tend to be sometimes overlooked. In addition, oblique coronal images along intervertebral foramina and MR myelography may not clearly demonstrate a detailed full view of nerve root changes. Furthermore, the detection of the morphologic changes of the nerve root is very important for the diagnosis of symptomatic extraforaminal disc herniation. Thus, a useful method for evaluating the nerve root in order to diagnose symptomatic extraforaminal disc herniation is required. METHODS: Twenty-four patients with extraforaminal and combined (extraforaminal with foraminal) lumbar disc herniations were included in this study. Conventional spin-echo sequence and 3D coronal fast-field echo sequences with selective water excitation by using the principles of the selective excitation technique (Proset imaging) were acquired. Indentation and swelling of the nerve roots and dorsal root ganglion (DRG) in the symptomatic sides and levels were evaluated on the basis of 3D MR rendering images of the lumbar spine. The tilting angle of the nerve root in the symptomatic side was compared with those in the asymptomatic contralateral side again on the basis of the 3D MR rendering images. RESULTS: Dorsal root ganglion indentation without swelling of the nerve roots was found in 7 patients whereas that with swelling of the nerve roots was observed in 6 patients. Swelling of the entire segment of the nerve from nerve root to spinal nerve (n = 9) or only the spinal nerve (n = 2) was observed in 11 patients. Compared with the contralateral nerve root, 7 patients exhibited a tilting angle abnormality of the ipsilateral nerve root. CONCLUSION: Based on lumbosacral radiculography through 3D MR rendering, important findings related to the diagnosis of symptomatic extraforaminal disc herniation include swelling of DRG and/or nerve roots and DRG indentation. Ultimately, 3D MR lumbosacral radiculography is a very useful method in the diagnosis of the symptomatic extraforaminal disc herniation.

Injuries of the cingulum and fornix after rupture of an anterior communicating artery aneurysm: a diffusion tensor tractography study.

BACKGROUND: After rupture of an anterior communicating artery (ACoA) aneurysm, the anterior cingulum and the fornix can be vulnerable to injury. However, very little is known about this topic. OBJECTIVE: To investigate injuries of the cingulum and fornix in patients with an ACoA aneurysm rupture with diffusion tensor tractography. METHODS: Eleven consecutive patients with an ACoA aneurysm rupture and 11 age- and sex-matched normal control subjects were recruited. Diffusion tensor imaging was scanned at an average of 54.1 days (range, 29-97 days) after onset of ACoA aneurysm rupture. RESULTS: We found that 6 (54.5%) and 7 (63.6%) of 11 patients revealed no trajectory of the anterior cingulum and the fornical body on diffusion tensor tractography, respectively. In terms of diffusion tensor imaging parameters, we found that the fractional anisotropy value and tract volume of the cingulum and fornix were decreased (P < .05) and that mean diffusivity values were increased (P < .05), except for those of the left fornix, which showed no difference (P > .05). CONCLUSION: We found injuries of the cingulum and fornix in patients with an ACoA aneurysm rupture. It is our belief that sustained memory impairment of patients with an ACoA aneurysm rupture might be related to injury of the cingulum and fornix. Therefore, we recommend evaluation of the cingulum and fornix with diffusion tensor tractography for patients with an ACoA aneurysm rupture.

Cortical reorganization of hand motor function to face somatotopy in a patient with brain injury: a functional MRI study.

We report on a patient with a meningioma whose hand motor function appeared to be reorganized mainly into the face somatotopy of the primary motor cortex (M1) following meningioma removal, using functional RMI (fMRI). A 76-year-old right-handed woman showed leukomalactic lesions in the left fronto-parietal lobes and subcortical white matter, including the upper portion of the precentral knob after meningioma removal. She recovered motor function to the point that she was able to extend the affected fingers against gravity at 6 weeks and extend the affected fingers against resistance at 12 weeks. The right primary sensori-motor cortex centered on the precentral knob was activated during movement of the unaffected (left) hand. By contrast, the face somatotopy and inferior portion of the precentral knob of the left primary motor cortex were activated during movement of the right hand. Peak activations were present at the left face somatotopy of the primary motor cortex during movement of the right hand and the right precentral knob during movement of the left hand. Motor function of the affected hand appeared to be reorganized mainly into the face somatotopy of the primary motor cortex and partially into the lower portion of the precentral knob after meningioma removal.

Identification of the anterior corticospinal tract in the human brain using diffusion tensor imaging.

The corticospinal tract (CST) is generally classified into the crossed lateral CST and the uncrossed anterior CST. No diffusion tensor imaging study for identification of the anterior CST in the human brain has been conducted. Using diffusion tensor imaging, we attempted to identify the anterior CST and investigate the characteristics of the anterior CST in the normal human brain. We recruited 15 healthy volunteers for this study. Diffusion tensor images were scanned using 1.5T. For the whole CST, two regions of interest were placed on the CST area of the pons and upper medulla. By contrast, for the anterior CST, an additional region of interest was given on the anterior funiculus of the upper cervical cord. The anterior CSTs, which originated from the cerebral cortex descended through the known pathway of the CST, and terminated in the anterior funiculus of the upper cervical cord. Compared with whole CSTs, the anterior CSTs showed decreased fiber number, fractional anisotropy, and apparent diffusion coefficient (P<0.05). The mean fiber number of the anterior CST was 12.4% of the whole CSTs. We identified the anterior CST and found that it has the characteristics of less directionality and fewer fibers in comparison with the whole CST. We believe that the methodology and results of this study would be helpful in research on motor control in the normal human brain and motor recovery mechanisms following brain injury.

Periventricular white matter injury by primary intraventricular hemorrhage: a diffusion tensor imaging study.

OBJECTIVES: Intraventricular hemorrhage (IVH) in adult stroke patients is known to be an independent risk factor for poor functional outcome. Using diffusion tensor imaging (DTI), we attempted to investigate the effect of IVH on the white matter. METHODS: We recruited 10 consecutive patients with IVH and 18 age- and sex-matched control subjects. Using a 1.5-T Philips Gyroscan Intera system, DTI data was acquired at an average of 84 days (range: 38-149) after IVH onset. We measured fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values at the fornix, corpus callosum (CC), corona radiata (CR), and posterior limb of the internal capsule (PL). In addition, integrity and fiber number were measured for the fornix. RESULTS: DTI revealed disruption of the fornix in all patients. FA values showed a decrease in the fornix, CC, and CR; in contrast, the ADC value showed an increase in the CC, without changes in the fornix or CR. Fiber number of the fornix also decreased. However, no change was observed in the PL. CONCLUSIONS: We found periventricular white matter (fornix, CC, and CR) injury following IVH. We think that this result would be helpful in the establishment of management strategies for patients with IVH.

Prognostic factors for motor outcome in patients with compressed corticospinal tract by intracerebral hematoma.

Little is known about prognostic factors associated with motor outcome when the corticospinal tract (CST) was compressed by hematoma. Using diffusion tensor tractography (DTT), we attempted to investigate prognostic factors for motor outcome in patients whose affected CST was compressed by hematoma. The study included 51 consecutive severe hemiparetic patients with a hematoma involving the corona radiata and basal ganglia. Integrities of the affected CSTs were preserved to the cerebral cortex and were found to be compressed by a hematoma on DTT. Patients were classified into four groups according to the region which the CST was originated from the precentral gyrus (type A), postcentral gyrus (type B), posterior parietal cortex (type C), and premotor cortex (type D). We measured the ratios of DTT parameters between affected/unaffected hemispheres.The motor function of the affected extremities at 6-month after onset was better with the following order: DTT type A, type B, type C, and type D patients. The 6-month motor function for DTT type A patients was higher than that of DTT type D patients (p=0.008). The fractional anisotropy ratio between the affected and unaffected CST was positively correlated with the 6-month motor function of the affected extremities (Pearson's correlation coefficient, p=0.025, r=0.313). We found that motor outcome differed according to the originated area of the affected CST and the degree of injury of the affected CST in patients whose affected CST was compressed by hematoma.

The anatomical characteristics of the stria terminalis in the human brain: a diffusion tensor tractography study.

The stria terminalis (ST) connects the amygdale (AM) with the hypothalamus, anterior commissure, preoptic area, and septal region. Many animal studies have reported on the anatomy and function of the ST; in contrast, little is known about its anatomy and function in the human brain. In the current study, we attempted to investigate the anatomical characteristics of the ST in the normal human brain, using diffusion tensor tractography. We recruited 30 healthy volunteers for this study. Diffusion tensor images were scanned using 1.5-T, and the ST was obtained using FMRIB software. Values of fractional anisotropy, mean diffusivity, and tract volume of the ST were measured. STs passed from the AM to the anterior hypothalamus, through the region, around to the anterior margin of the temporal horn of the lateral ventricle, over the posterior and superior margin of the thalamus, behind the anterior commissure. No differences according to the side of the hemisphere and sex in terms of fractional anisotropy, mean diffusivity, and tract volume of the ST (P<0.05) were observed. We identified the ST and observed the anatomical characteristics of the ST in the normal human brain. We believe that the methodology and results reported here would be helpful to researchers and clinicians in this field.

Extensive demyelinating change in cerebrum after a total knee replacement -A case report-.

Demyelination is characterized by the loss of myelin with the preservation of axons. Demyelinating diseases can be classified into several categories: demyelination due to inflammation, viral infection, osmotic derangements and hypoxic ischemia. In particular, osmotic myelinolysis is representative, and is associated with hyperosmolality, hypokalemia or rapid correction of hyponatremia. Osmotic myelinolysis was reported to be associated with underlying conditions, such as alcoholism, diuretics and malnutrition. A 67-year-old woman with hypertension was scheduled to undergo both total knee replacements (TKR). She was observed to be lethargic with dysphagia and quadriplegia after the second TKR. She had been taking diuretics for a long time, and did not have an adequate amount of food intake due to patient controlled analgesia and a gastric ulcer after the first TKR. A laboratory examination revealed hypokalemia but normonatremia. T2 weighted-MRI revealed abnormal high signal intensity in the basal ganglia and periventricular area. This case was diagnosed with osmotic myelinolysis associated with hypokalemia without an apparent sodium imbalance.

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.

Corticospinal tract injury in patients with diffuse axonal injury: a diffusion tensor imaging study.

Diffusion tensor imaging (DTI) can be useful in detecting corticospinal tract (CST) injury at the subcortical white matter level. In the current study, we attempted to investigate the incidence and distribution of CST injury in patients with diffuse axonal injury (DAI), using DTI. Fourteen patients who showed motor weakness without any specific lesion along the CST pathway on conventional brain MRI, and twelve age-matched, normal healthy control subjects were recruited. DTI was performed using 1.5 T with a synergy-L Sensitivity Encoding (SENSE) head coil. Fractional anisotropy was measured using the region of interest method. A CST injury was defined as the FA value of a certain area being decreased two standard deviations below that of normal controls. All 14 patients had more than one lesion at the CST injury, and the mean number of CST injuries was 3.6 (range: 2-7). The CSTs were involved at the following locations: the pons (61%), the cerebral peduncle (39%), the corona radiata (21%), the medulla (14%), and the posterior limb (11%). The pons was the most prevalent area of CST injury in patients with weakness caused by DAI at the subcortical level. We found that DTI is a useful technique for detecting a DAI of the CST at the subcortical level.

The comparison of cortical activation patterns by active exercise, proprioceptive input, and touch stimulation in the human brain: a functional MRI study.

Active execution, proprioception, and touch discrimination are important for the execution of movement. In the current study, we attempted to compare the cortical activation patterns of active exercise, proprioceptive input, and touch stimulation in the normal human brain using functional MRI. Nine subjects were recruited for this study. Functional MRI was performed using 1.5-T with three tasks at a fixed rate. The active exercise and proprioceptive input were performed at the metacarpophalangeal joint using a specially equipped apparatus, and touch stimulation was applied on the dorsum of the hand using a rubber brush. We performed analysis using the region of interest (ROI) method, and calculated the laterality index (LI) to assess the relative activity in the ipsilateral versus the contralateral ROI. When active exercise or proprioceptive input were applied, the LI in the primary sensorimotor cortex (SM1) was significantly higher than that of touch stimulation. The supplementary motor cortex, cerebellum, and contralateral SM1 showed stronger activation during active exercise than during proprioceptive input or touch stimulation, and the opposite pattern was observed in the insula. We found that the LIs of active exercise and proprioceptive input were higher than the LI of touch stimulation. This suggest that touch stimulation may be a less lateralized function than active exercise and proprioceptive input.