Differential Diagnosis for the Presented Case

The patient's history and symptoms suggest a neurological condition related to the fall. Given the information, here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Chronic Subdural Haematoma (B): This is the most likely diagnosis given the patient's age, history of a recent fall, gradual onset of symptoms such as general weakness, and the presence of hypodense brain lesions on the CT scan. Chronic subdural hematomas often present with non-specific symptoms and can occur after minor trauma in the elderly, with symptoms sometimes delayed.

• Other Likely Diagnoses

  • Subacute Subdural Haematoma (C): This could be considered if the symptoms and CT findings align more closely with a subacute timeline (typically between acute and chronic phases). However, the two-week timeline and the nature of the symptoms make chronic subdural hematoma more likely.
  • Acute Subdural Haematoma (A): Less likely given the timeline and the nature of the symptoms. Acute subdural hematomas usually present immediately or shortly after the injury with more severe symptoms.

• Do Not Miss Diagnoses

  • Extradural Haemorrhage (D): Although less likely given the timeline and the description of the CT findings, extradural (epidural) hemorrhage is a critical diagnosis that must be considered, especially in the context of head trauma. It can present with a loss of consciousness and severe headache, but the patient's symptoms do not strongly suggest this.
  • Other Intracranial Pathologies: Conditions like intracerebral hemorrhage, cerebral infarction, or even tumors could present with similar symptoms and must be considered, especially if the CT scan is not definitive or if there are other clinical findings.

• Rare Diagnoses

  • Traumatic Subarachnoid Haemorrhage: This could be a consideration but is less likely given the CT description focusing on hypodense lesions suggestive of hematoma rather than the diffuse pattern often seen in subarachnoid hemorrhage.
  • Cerebral Vasculitis or Other Vascular Pathologies: These are rare and would be unusual presentations but could be considered if other diagnoses are ruled out and there are suggestive clinical or imaging findings.

Each of these diagnoses should be considered in the context of the patient's full clinical picture, including any additional history, physical examination findings, and diagnostic test results.