A 76-year-old man presents with a 2-day history of headaches and blurred vision. He complains of general lethargy and muscle aches over the last 3–4 days.
On further questioning, he reports that when brushing his hair, he experiences pain on the same side of his forehead as the headache. Laboratory investigations Hemoglobin: 13.2 g/dL (Normal range 11.5–16.0 g/dL) Mean cell volume: 86 fL (Normal range 76–96 fL) White cell count: 9 x 10 9 /L (Normal range 4.0–11.0 x 10 9 /L) Platelets: 355 x 10 9 /L (Normal range 150–400 x 10 9 /L) Erythrocyte sedimentation rate: 100 mm/h (Normal range 10–20 mm/h) Sodium: 132 mmol/L (Normal range 135–145 mmol/L) Potassium: 3.9 mmol/L (Normal range 3.5–5.0 mmol/L) Urea: 5.1 mmol/L (Normal range 2.5–6.7 mmmol/L) Creatinine: 69 μmol/L (Normal range 44–80 μmol/L) Glucose: 6 mmol/L (Normal range 3.5–5.5 mmol/L) What is the probable diagnosis?…
