Differential Diagnosis
- Single most likely diagnosis
- Thalamic pain syndrome (E): The patient's presentation of burning pain and hypersensitivity over the right side of the face, arm, and leg, along with the presence of hyperpathia and allodynia, is consistent with thalamic pain syndrome. The CT scan showing multifocal subcortical hypodensities also supports this diagnosis, as it suggests a lesion in the thalamus or its connections.
- Other Likely diagnoses
- Peripheral neuropathy (B): The patient's long history of smoking and type 2 diabetes mellitus increases her risk for peripheral neuropathy, which could cause burning pain and hypersensitivity. However, the distribution of symptoms over the right side of the face, arm, and leg is less typical for peripheral neuropathy.
- Radiculopathy (C): The patient's symptoms could be consistent with radiculopathy, particularly if the CT scan shows evidence of nerve root compression. However, the presence of hyperpathia and allodynia is more suggestive of thalamic pain syndrome.
- Do Not Miss diagnoses
- Stroke or transient ischemic attack (TIA): Although the CT scan shows multifocal subcortical hypodensities, it is essential to consider the possibility of a stroke or TIA, particularly given the patient's history of hypertension, smoking, and hyperlipidemia. Missing this diagnosis could have severe consequences.
- Multiple sclerosis: The patient's symptoms and the presence of multifocal subcortical hypodensities on the CT scan could also be consistent with multiple sclerosis. Although less likely, this diagnosis should not be missed due to its significant implications for treatment and prognosis.
- Rare diagnoses
- Functional neurologic disorder (A): Although the patient's symptoms are consistent with a functional neurologic disorder, the presence of objective findings such as hyperpathia and allodynia, as well as the CT scan abnormalities, make this diagnosis less likely.
- Spondylosis (D): The patient's symptoms are not typical for spondylosis, and the CT scan does not show evidence of spinal stenosis or nerve root compression. This diagnosis is therefore less likely.