Falls and Cognitive Decline

🗒️ Question

A 76 year old man with advanced Parkinson’s disease is reviewed in the community palliative care clinic due to worsening mobility, increasing falls and a new onset of confusion. He has a history of recurrent urinary tract infections and uses a catheter intermittently for bladder management. His current medications include levodopa-carbidopa, rotigotine patches and co-careldopa.

On examination, he appears drowsy and disoriented. His blood pressure is 110/70 mmHg, pulse is 92 bpm and regular and his respiratory rate is 18 breaths per minute. There is generalised rigidity, a resting tremor and no focal neurological deficits. His abdomen is soft with mild suprapubic tenderness.

Investigations

• Serum sodium: 138 mmol/L (135–145)

• Serum urea: 6.8 mmol/L (2.5–7.8)

• Serum creatinine: 105 µmol/L (60–120)

• Urine dipstick: Leucocytes ++, Nitrites +

What is the most appropriate investigation?

(A) Abdominal ultrasound

(B) CT brain

(C) Midstream urine culture

(D) Serum ammonia

(E) Thyroid function tests