From the Guidelines
For tremors and memory issues, a brain MRI without IV contrast is the most appropriate initial imaging study to order, as it provides detailed images of brain structures and can help identify potential causes such as neurodegenerative conditions like Parkinson's disease or Alzheimer's disease. This recommendation is based on the American College of Radiology (ACR) Appropriateness Criteria for movement disorders and neurodegenerative diseases 1. The ACR suggests that MRI head without IV contrast is usually appropriate for the initial imaging of patients with Parkinsonian syndromes, which can present with tremors, and for patients with suspected neurodegenerative diseases that may cause memory issues.
The following sequences should be included in the MRI:
- T1-weighted
- T2-weighted
- FLAIR (Fluid-Attenuated Inversion Recovery)
- DWI (Diffusion-Weighted Imaging)
- SWI (Susceptibility-Weighted Imaging) These sequences are particularly useful for detecting subtle structural changes, vascular abnormalities, and iron deposition that may be associated with movement disorders and neurodegenerative diseases 1. For memory issues specifically, thin-slice imaging through the hippocampus and temporal lobes should be requested, as these areas are critical for memory function and are often affected early in dementia.
It is essential to order the MRI with a clinical history clearly stating both the tremor and memory symptoms to guide the radiologist's interpretation. The use of semi-quantitative scales, such as the medial temporal lobe atrophy (MTA) scale, Fazekas scale, and global cortical atrophy (GCA), is also recommended for routine interpretation of MRI scans 1.
In patients with cognitive decline and suspected Alzheimer's disease, MRI head without IV contrast is usually appropriate for the initial imaging, as it can help identify patterns of atrophy and exclude other potential etiologies 1. Similarly, for patients with Parkinsonian syndromes, MRI head without IV contrast is the optimal imaging modality due to its soft-tissue characterization and sensitivity to iron deposition 1.
Overall, a brain MRI without IV contrast is the most appropriate initial imaging study for patients with tremors and memory issues, as it provides valuable information for diagnosing and managing neurodegenerative diseases and movement disorders.
From the Research
MRI Options for Tremors and Memory Issues
To determine the appropriate MRI for tremors and memory issues, it's essential to consider the underlying causes of these symptoms.
- For tremors, the diagnosis is based on clinical information obtained from the history and physical examination, and the most common tremors are enhanced physiologic tremor, essential tremor, and parkinsonian tremor 2.
- For memory issues, Alzheimer's disease (AD) is a major neurocognitive disorder identified by memory loss and significant cognitive decline, and the accuracy of imaging helps to identify the neuropathological features that differentiate AD from its common precursor, mild cognitive impairment (MCI) 3.
Recommended MRI Sequences
- For Alzheimer's disease and mild cognitive impairment, a combination of multiparametric MRI sequences, including structural MRI (sMRI), functional MRI (fMRI), diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (1H-MRS), can provide information on anatomical and functional changes in the brain 3.
- For Parkinson's disease, structural MRI has shown that dementia is related to cortical structural changes, and specific cognitive dysfunctions can be attributed to atrophy in specific structures 4.
- Advanced diffusion magnetic resonance imaging techniques, such as diffusional kurtosis imaging, neurite orientation dispersion and density imaging, and free water imaging, can evaluate brain microstructural complexity and integrity, axonal order, density, and myelination in patients with Alzheimer's and Parkinson's diseases 5.
Specific MRI Recommendations
- For patients with tremors and memory issues, a combination of sMRI, fMRI, DTI, and MRS sequences can provide a comprehensive evaluation of the brain's anatomical and functional changes.
- Single-photon emission computed tomography can be used to visualize the integrity of the dopaminergic pathways in the brain, and transcranial ultrasonography may be useful to diagnose Parkinson's disease 2.