Corticospinal tract compression by hematoma in a patient with intracerebral hemorrhage: a diffusion tensor tractography and functional MRI study

Clinico-radiological factors associated with aphasia outcome in post stroke patients: A prospective follow up study from eastern part of India

BACKGROUND

Aphasia is a language disorder acquired secondary to brain damage. This study aims to evaluate clinical and radiological profile of patients with post stroke aphasia and factors affecting its recovery.

METHODS

We conducted a prospective study of patients with first left Middle or Anterior Cerebral Artery infarct or Intracerebral Hemorrhage (ICH) with aphasia admitted within 14 days of stroke onset. Aphasia Quotient (AQ) was assessed at 2 weeks (AQ1) and 3 months (AQ2) using Western Aphasia Battery-Hindi version. Magnetic Resonance Imaging of brain with Diffusion Tensor Imaging (DTI) of bilateral Arcuate Fasciculus (AF) and Corticospinal Tract was done at admission, and stroke volume, Laterality Indices of Fractional Anisotropy (LI-FA), Mean Diffusivity (LI-MD), Radial Diffusivity (LI-RD), Axial Diffusivity (LI-AD) and Apparent Diffusion Coefficient (LI-ADC) were obtained.

RESULTS

36 patients [8 ICH and 28 Acute Ischemic Stroke (AIS)] were included. AQ1 and AQ2 were significantly higher in subcortical stroke than cortical. AQ2 and increase in AQ scores (including its subscores) were significantly higher in ICH than AIS. National Institutes of Health Stroke Scale score at admission and volume of stroke had significant negative correlation with AQ1 and AQ2. Laterality Index of Fractional Anisotropy of Arcuate Fasciculus [LI-FA (AF)] had significant positive correlation with AQ2 and naming score at 3 months. Laterality Index of Mean Diffusivity of Arcuate Fasciculus [LI-MD (AF)] had significant negative correlation with AQ1, AQ2 and all subcomponents of AQ2. Significant positive correlation was seen between improvements in Modified Rankin Scale score and AQ.

CONCLUSION

The study shows that DTI can be used to predict severity of aphasia at follow up and recovery in language and motor functions occur in parallel.

Clinical and neuroimaging factors associated with aphasia severity in stroke patients: diffusion tensor imaging study

This study investigated factors associated with aphasia severity at both 2 weeks and 3 months after stroke using demographic and clinical variables, brain diffusion tensor imaging (DTI) parameters, and lesion volume measurements. Patients with left hemisphere stroke were assessed at 2 weeks (n = 68) and at 3 months (n = 20) after stroke. Demographic, clinical, and neuroimaging data were collected; language functions were assessed using the Western Aphasia Battery. For neuroimaging, DTI parameters, including the laterality index (LI) of fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity, mean diffusivity and fibre density (FD) of the arcuate fasciculus (AF), and lesion volume, were measured. Lesion volume, cortical involvement, and the National Institutes of Health Stroke Scale score significantly predicted aphasia severity at 2 weeks after stroke, whereas the aphasia quotient and presence of depression during the early subacute stage were significant predictors at 3 months after stroke. According to Pearson correlation, LI-AD and LI-FD were significantly correlated with the aphasia quotient 2 weeks after ischaemic stroke, and the LI-FA was significantly correlated with the aphasia quotient 2 weeks after haemorrhagic stroke, suggesting that the extent and mechanism of AF injuries differ between ischaemic and haemorrhagic strokes. These differences may contribute to aphasia severity.

Demonstration of recovery of a severely damaged corticospinal tract: a diffusion tensor tractography and transcranial magnetic stimulation follow-up study

We demonstrated the recovery of a severely damaged corticospinal tract (CST) in a 45-year-old female patient with intracerebral hemorrhage using diffusion tensor tractography and transcranial magnetic stimulation. Two longitudinal evaluations were conducted. There was no evidence of a CST in the affected hemisphere on the first evaluation. However, we observed evidence of a CST on the second evaluation. It seems that the affected motor function was recovered through the recovery of the damaged CST.

Corticospinal tract restoration: combined study of diffusion tensor tractography, functional MRI, and transcranial magnetic stimulation

We tried to demonstrate the restoration of corticospinal tract in a patient with intracerebral hemorrhage, using diffusion tensor tractography and functional magnetic resonance imaging, and transcranial magnetic stimulation. Transcranial magnetic stimulation demonstrated the corticospinal tract had been spared since subacute stage. Diffusion tensor tractography and functional magnetic resonance imaging showed that the corticospinal tract that was displaced by a hematoma had been restored. These combined modalities would be helpful in elucidating the state and change of corticospinal tract.

Role of diffusion tensor imaging in a patient with spontaneous intracerebral hematoma treated by stereotactic evacuation

BACKGROUND

Diffusion tensor imaging is a newly developed technique used to visualize the white matter fibers in the human brain. In previous reports, DTI has been applied in patients with neoplasms, lacunar infarction, ischemic stroke, degenerative motor disease, and diffuse axonal injury, and has become a powerful tool in predicting clinical outcome. However, the implementation of DTI in patients with spontaneous ICH treated by stereotactic evaluation of hematoma has never been reported.

CASE DESCRIPTION

The authors describe a case of a well-predicted outcome of DTI in a 37-year-old right-handed man who presented with sudden onset of vomiting and weakness of right extremities 2 hours before admission. Computed tomographic head scan revealed 1 hyperdense hematoma measuring about 3.9 x 2.2 x 2.6 cm (about 15 mL in volume) located in the left putamen, compressing the posterior limb of left internal capsule. Preoperative DTI revealed that white matter tracts were compressed by the hematomas. After the patient underwent stereotactic evacuation of hematoma, good recovery of muscle power was noted in the right extremities. Postoperative DTI revealed the restoration of white matter tracts.

CONCLUSION

Diffuse tensor imaging is a useful tool for the visualization of white matter tracts, especially the corticospinal tract, which regulates motor function in human beings. In patients with ICH treated by stereotactic aspiration of hematomas, clinical outcome could be more precisely predicted by preoperative DTI.

Diffusion tensor fiber tractography for arteriovenous malformations: quantitative analyses to evaluate the corticospinal tract and optic radiation

BACKGROUND AND PURPOSE

We hypothesized that diffusion tensor fiber tractography would be affected by intracranial arteriovenous malformation (AVM). The purpose of the present study was to evaluate the influence of intracranial AVM on corticospinal tract and optic radiation tractography.

MATERIALS AND METHODS

The subject group comprised 34 patients with untreated intracranial AVM. Hemorrhage was present in 13 patients and absent in 21 patients. Perinidal fractional anisotropy (FA) and number of voxels along the reconstructed corticospinal and optic radiation tracts were measured, and left-to-right asymmetry indices (AIs) for those values were quantified. Patients were assigned to 1 of 3 groups: tracts distant from nidus, tracts close to nidus without neurologic symptoms, and tracts close to nidus associated with neurologic symptoms. One-way analysis of variance was used to compare differences in AI between groups. Hemorrhagic and nonhemorrhagic groups were assessed separately.

RESULTS

In patients without hemorrhage, AI of optic radiation volume (P<.0001), AI of perinidal FA along corticospinal tract (P=.006), and optic radiation (P=.01) differed significantly between groups. In patients associated with hemorrhage, AI of corticospinal tract volume (P=.01), AI of perinidal FA along corticospinal tract (P=.04), and optic radiation (P=.004) differed significantly between groups.

CONCLUSIONS

Corticospinal tract and optic radiation tractography were visualized in patients with AVM. In patients with both hemorrhagic and nonhemorrhagic AVM, the 2 fiber tracts close to the nidus were less visualized in the affected hemisphere than those distant from the nidus. Tracts were less visualized in patients with neurologic symptoms than in asymptomatic patients.