Differential Diagnosis

• Single most likely diagnosis:
  • Chronic small vessel ischemic disease: This is the most likely diagnosis given the presence of confluent and non-confluent hypodensities in the periventricular and subcortical white matter, which are characteristic of chronic small vessel ischemic changes. The presence of focal hypodensity in the left centrum semiovale and pons also supports this diagnosis.
• Other Likely diagnoses:
  • Multi-infarct dementia: The presence of multiple chronic lacunar infarcts could be contributing to cognitive decline, making multi-infarct dementia a possible diagnosis.
  • Normal pressure hydrocephalus: The mild prominence of the lateral ventricles and prominent cortical sulci could be indicative of normal pressure hydrocephalus, although further evaluation would be needed to confirm this diagnosis.
  • Chronic lymphoma: The 9.3 mm isodensity seen in the subcutaneous soft tissue of the right suboccipital region could represent lymphoma, although correlation with clinical examination and further imaging would be necessary to confirm this diagnosis.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Brain tumor: Although the imaging findings do not strongly suggest a brain tumor, it is essential to consider this possibility, especially given the presence of an isodensity in the subcutaneous soft tissue of the right suboccipital region.
  • Vasculitis: Inflammatory diseases such as vasculitis could present with similar imaging findings, and missing this diagnosis could have significant consequences.
  • Infectious diseases: Certain infectious diseases, such as neurosyphilis or Lyme disease, could present with similar imaging findings, and missing these diagnoses could have serious consequences.
• Rare diagnoses:
  • CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy): This rare genetic disorder could present with similar imaging findings, although it is less likely given the patient's age and lack of family history.
  • Mitochondrial disorders: Certain mitochondrial disorders, such as MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes), could present with similar imaging findings, although these are rare and would require further evaluation to confirm.