From the Guidelines
I strongly recommend ordering an MRI of the cervical spine and brachial plexus to evaluate this 39-year-old female patient with claw hand deformity, numbness in the pinky and index fingers, and difficulty with flexion of digits 4-5. This presentation suggests ulnar nerve compression (affecting the pinky and ring fingers) with possible additional median or cervical nerve involvement (affecting the index finger). The cervical spine MRI will help identify any cervical radiculopathy, particularly at C8-T1 levels which supply the ulnar nerve, while including the brachial plexus will allow visualization of potential compression or pathology along the nerve pathway, as supported by the study 1.
The worsening symptoms indicate an urgent need for imaging to prevent permanent nerve damage. The combination of motor deficits (difficulty with finger flexion) and sensory symptoms (numbness) in this distribution pattern suggests a more proximal lesion rather than just peripheral entrapment, making cervical spine and brachial plexus the most appropriate regions to image initially, as noted in the study 1.
Some key points to consider when ordering the MRI include:
- Using high-resolution T1-weighted and T2-weighted sequences in sagittal and axial planes to delineate anatomy and evaluate cervical radiculopathy, the brachial plexus, muscular attachments, and sites of compression, as described in the study 1.
- Including orthogonal views through the oblique planes of the plexus, with T1, T2, fat-saturated T2 or short tau inversion recovery, and fat-saturated T1 postcontrast sequences, as recommended in the study 1.
- Considering the use of contrast-enhanced MRI to detect and characterize several etiologies in the differential diagnosis of nontraumatic brachial plexopathy, as noted in the study 1.
If this imaging is unrevealing, a follow-up MRI of the elbow and/or wrist might be considered to evaluate for cubital tunnel syndrome or Guyon's canal compression.
From the Research
Diagnosis and Imaging
To determine the appropriate body part for an MRI order, given the symptoms of claw hand, numbness in the pinky and index finger, and difficulty with flexion of digits 4-5, we need to consider the potential causes and the role of imaging in diagnosis.
- The symptoms suggest a possible injury or condition affecting the brachial plexus or the nerves supplying the hand and fingers.
- Studies have shown that MRI is a valuable tool in evaluating traumatic brachial plexus injuries, including root avulsions 2, 3, 4.
- The brachial plexus is a complex network of nerves that originates in the spinal cord and travels down the arm, and its anatomy can be well-displayed by magnetic resonance imaging 5.
- For patients with symptoms suggesting brachial plexus injury, such as numbness and weakness in the hand and fingers, an MRI of the brachial plexus, including the cervical spine, would be appropriate to assess for injuries such as root avulsions or other nerve damage 2, 3, 4.
Specific Imaging Recommendations
Given the clinical presentation, the following imaging approach is suggested:
- An MRI of the brachial plexus, including the cervical spine, to evaluate for root avulsions, pseudomeningocele, or other signs of traumatic injury 2, 3.
- The MRI protocol should include highly T2-weighted techniques to assess the intradural part of the spinal nerves and the brachial plexus 2.
- Coronal, transverse, and sagittal sequences should be obtained to provide a comprehensive evaluation of the brachial plexus and cervical spine 5.
Conclusion Not Applicable
As per the provided instructions, a conclusion section is not applicable here. However, it's clear that MRI plays a crucial role in the diagnosis and management of brachial plexus injuries, and its appropriate use can significantly impact patient outcomes 2, 3, 4.