Differential Diagnosis
The patient presents with acute onset of paralysis of both legs, progressive numbness, and a sensory level at T7, which suggests a spinal cord lesion. The following differential diagnoses are considered:
- Single most likely diagnosis
- A) Epidural abscess: This is the most likely diagnosis given the patient's history of intravenous drug use, which increases the risk of bacterial infections, including epidural abscess. The patient's symptoms of low back pain, progressive numbness, and paralysis of both legs are consistent with an epidural abscess compressing the spinal cord.
- Other Likely diagnoses
- B) HIV myelitis: Although the patient has a history of untreated hepatitis C and intravenous drug use, which may increase the risk of HIV infection, there is no clear indication of HIV infection in the provided history.
- E) Vitamin B12 (cobalamin) deficiency: This condition can cause subacute combined degeneration of the spinal cord, leading to numbness, weakness, and paralysis. However, the acute onset of symptoms in this patient makes this diagnosis less likely.
- Do Not Miss
- Spinal cord compression due to metastatic disease or hematoma: Although not listed among the options, spinal cord compression due to metastatic disease (e.g., from liver cancer related to hepatitis C) or hematoma (e.g., from bleeding disorders or anticoagulation) is a critical diagnosis that should not be missed, as prompt treatment can prevent permanent damage.
- Spinal epidural hematoma: This is another critical diagnosis that should not be missed, as it can cause rapid progression of neurological deficits and requires urgent intervention.
- Rare diagnoses
- C) Human T-cell lymphoma virus type 1 (HTLV-1): This virus can cause tropical spastic paraparesis, a rare condition characterized by progressive weakness and spasticity of the legs. However, the acute onset of symptoms in this patient makes this diagnosis less likely.
- D) Multiple sclerosis: Although multiple sclerosis can cause spinal cord lesions, the acute onset of paralysis and sensory level in this patient, combined with the lack of other typical multiple sclerosis symptoms (e.g., optic neuritis, brainstem symptoms), makes this diagnosis less likely.