Quantitative MR neurography of brachial plexus lesions based on diffusivity measurements

Diffusion tensor imaging in patients with diabetic peripheral neuropathy: Fractional anisotropy and apparent diffusion coefficient dataset of posterior tibial nerve

The data in this article described quantitative values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) for 23 (46 extremities) normal healthy males and females, for 46 patients with bilateral diabetic peripheral neuropathy. 1.5 Tesla (T) MR System Multiva – Philips magnets (Baltimore, Netherland, Holland) imaging with axial T1WSE, sagittal T2WSE and STIR sequences by means of diffusion weighted neurography b values of 0 and 800 s/mm². The data obtained as FA and ADC values in healthy adults and patient population can be referred by researchers, clinicians for early diagnosis, to determine intervention effectiveness and patient management.

Role of diffusion tensor imaging in the evaluation of ulnar nerve involvement in leprosy

OBJECTIVE

Early detection of peripheral neuropathy is extremely important as leprosy is one of the treatable causes of peripheral neuropathy. The study was undertaken to assess the role of diffusion tensor imaging (DTI) in ulnar neuropathy in leprosy patients.

METHODS

This was a case-control study including 38 patients (72 nerves) and 5 controls (10 nerves) done between January 2017 and June 2019. Skin biopsy proven cases of leprosy, having symptoms of ulnar neuropathy (proven on nerve conduction study) were included. MRI was performed on a 3 T MR system. Mean cross-sectional area, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of ulnar nerve at cubital tunnel were calculated. Additional ancillary findings and appearance of base sequences were evaluated.

RESULTS

Ulnar nerve showed thickening with altered T₂W signal in all the affected nerves, having an average cross-sectional area of 0.26 cm². Low FA with mean of 0.397 ± 0.19 and high ADC with mean of 1.28 ± 0.427 x 10 ^-3 mm²/s of ulnar nerve in retrocondylar groove was obtained. In the control group, mean cross-sectional area was 0.71cm² with mean FA and ADC of 0.53 ± 0.088 and 1.03 ± 0.24 x 10 ^-3 mm²/s respectively. Statistically no significant difference was seen in diseased and control group. Cut-off to detect neuropathy for FA and ADC is 0.4835 and 1.1020 × 10 ^-3 mm²/s respectively.

CONCLUSION

DTI though is challenging in peripheral nerves, however, is proving to be a powerful complementary tool for assessment of peripheral neuropathy. Our study validates its utility in infective neuropathies.

ADVANCES IN KNOWLEDGE

1. DTI is a potential complementary tool for detection of peripheral neuropathies and can be incorporated in standard MR neurography protocol.2. In leprosy-related ulnar neuropathy, altered signal intensity with thickening or abscess of the nerve is appreciated along with locoregional nodes and secondary denervation changes along with reduction of FA and rise in ADC value.3. Best cut-offs obtained in our study for FA and ADC are 0.4835 and 1.1020 × 10 ^-3 mm²/s respectively.

Additive value of magnetic resonance neurography in diagnosis of brachial plexopathy: a cross-section descriptive study

Background

Management of brachial plexopathy requires proper localization of the site and nature of nerve injury. Nerve conduction studies and electrophysiological studies (ED) are crucial when diagnosing brachial neuropathy but these do not determine the actual site of the lesion. Conventional MRI has been used to evaluate the brachial plexus. Still, it carried the disadvantage of the inability to provide multi-planar images that depict the entire length of the neural plexus .It might be difficult to differentiate the brachial plexus nerves from adjacent vascular structures. Magnetic resonance neurography (MRN) is an innovative imaging technique for direct imaging of the spinal nerves. Our study aims to detect the additive role of MRN in the diagnosis of brachial plexopathy over ED. Forty cases of clinically suspected and proved by clinical examination and ED—traumatic (N = 30) and non-traumatic (N = 10)—were included in our study. We compared MRN finding with results of clinical examination and ED.

Results

MRN findings showed that the root was involved in 80% of cases, trunks in 70% of cases affecting the middle trunk in 40% of cases, the middle and posterior cord in 25%, lateral cord in 50%, and terminal branches on 10% of cases. Ten percent of cases were normal according to MRN, and 90% had abnormal findings in the form of preganglionic nerve root avulsion in 30% of cases, mild perineural edema surrounding C6/7 nerve roots in 20%, lower brachial trunk high signal in 10%, complicated with pseudo meningocele in 20%, and with increased shoulder muscle T2 signal intensity with muscle atrophy in 10%. There were minimal differences between clinical examination finding and MRN findings, with very good agreement between electromyography and nerve conduction (p value < 0.05, with sensitivity and specificity values of 94.44% and 100%, respectively).

Conclusion

MRN is important in differentiating different types of nerve injuries, nerve root avulsion, and nerve edema, playing an important role in differentiating the site of nerve injury, both preganglionic or postganglionic and planning for treatment of the cause of nerve injury, either medical or surgical.

Effect of massage, passive neural mobilization and transcutaneous electrical nerve stimulation on magnetic resonance diffusion tensor imaging (MR-DTI) of the tibial nerve in a patient with type 2 diabetes mellitus induced neuropathy: a case report

BACKGROUND

MR-DTI parameters namely fractional anisotropy (FA) and apparent diffusion coefficient values (ADC) of diffusion imaging demonstrate the directional preference and speed of diffusion of water molecules. The purpose of this case report is to explore the effect of massage, passive neural mobilization and transcutaneous electrical nerve stimulation on MR-DTI of the tibial nerve in a patient with type 2 diabetes mellitus having chronic distal symmetrical sensorimotor neuropathy.

CASE DESCRIPTION

A 63-year-old male with type 2 diabetes mellitus diagnosed with chronic symmetrical sensorimotor diabetic peripheral neuropathy on the basis of medical examination and electrophysiological testing. Altered mechanosensitivity of the tibial nerve was confirmed through neurodynamic testing. MR-DTI revealed severe damage of the tibial nerve as shown by chaotic diffusion of water molecules and damaged microstructural integrity.

INTERVENTION

A total six sessions over 3 weeks including nerve massage in a longitudinal and transverse direction; passive neural mobilization consisting of sliders and tensioners of the tibial nerve; and followed by 15 minutes of continuous transcutaneous electrical nerve stimulation directed along the nerve course.

OUTCOME

FA and ADC values, pain,neuropathy quality of life and range of motion data were collected pre and post intervention. Analysis revealed clinical improvement in all the outcome measures.

CONCLUSION

This case report identified improvement in radiological MR-DTI outcomes following rehabilitation in a patient with diabetic peripheral neuropathy.

A study protocol on nerve mobilization induced diffusion tensor imaging values in posterior tibial nerve in healthy controls and in patients with diabetic neuropathy-multigroup pretest posttest design

Background

Diabetic neuropathy is the commonest chronic disabling complication of diabetes which may lead to amputation and compromising patient’s quality of life. It is characterized by pain, sensation loss associated with neural edema. Diffusion tensor imaging parameter i.e. fraction anisotropy determines the free water proton diffusion in the healthy nerve. Since the diabetes leads to altered mechanosensitivity of the posterior tibial nerve thereby, might interferes with the water molecules movement. Therefore the present clinical trial will provide the evidence of improving the diffusion tensor imaging in the diabetic neuropathy directly by targeting the nerve through nerve mobilization treatment.

Methods

Participants with Type II Diabetes Mellitus induced peripheral neuropathy will be selected randomly on the basis of eligibility criteria and informed consent will be taken. Participants will be recruited into three groups. Group A (experimental group A) will receive neural mobilization technique, Group B (experimental group B) will receive conventional therapy and Group C (control group) will receive sham treatment for 3 weeks. MRI technique, Visual analogue scale and neuropathy specific quality of life questionnaire will be used as assessment tools. Assessment will be taken at baseline and post intervention.

Conclusion

this clinical trial will provide the evidence of efficacy of nerve mobilization in determining the diffusion tensor imaging (DTI) changes in the posterior tibial nerve in patients with diabetic neuropathy. This trial will also be the first one in itself to look at the treatment induced DTI changes in the peripheral nerve.

Trial Registration

Clinical Trial Registry of India (CTRI/2019/06/019552).