Patient 73 yo female KTH alzheimer presented for sudden onset fatigue,malaise an

Differential diagnosis for a 73-year-old female with Alzheimer's disease presenting with sudden onset fatigue, malaise, and bilateral lower limb weakness including inability to stand includes:

• Acute neurological events such as stroke or transient ischemic attack, which can cause sudden weakness.
• Delirium or acute medical illness (e.g., infection such as urinary tract infection or sepsis) precipitating acute decline and weakness, especially common in dementia patients.
• Electrolyte imbalances or metabolic disturbances (e.g., hypokalemia, hypoglycemia) causing weakness and malaise.
• Medication side effects or toxicity, particularly from drugs with anticholinergic burden or sedatives that can worsen cognition and cause weakness.
• Progression or superimposed neurological conditions such as Parkinsonism or vascular dementia contributing to motor symptoms.
• Functional neurological disorder, although new neurological signs should prompt further assessment.

Appropriate management involves:

• Urgent clinical assessment including vital signs, neurological examination, and assessment for delirium.
• Immediate investigations: blood tests (full blood count, electrolytes, glucose, infection markers), ECG, and urgent brain imaging (CT or MRI) to exclude stroke or other acute pathology.
• Assessment for reversible causes of cognitive and physical decline such as infection, dehydration, or medication effects.
• Referral to secondary care or specialist services if acute neurological cause is suspected or if the patient is unable to safely mobilize or care for themselves.
• Supportive care including ensuring safety, hydration, nutrition, and prevention of complications from immobility.
• Review and optimization of dementia management once acute issues are addressed, including consideration of specialist dementia services if cognitive decline worsens.

Given the sudden onset and severity of symptoms, urgent hospital admission is often warranted to ensure safety and comprehensive assessment.

Summary: Sudden bilateral lower limb weakness and inability to stand in a patient with Alzheimer's disease is a medical emergency requiring urgent exclusion of stroke, infection, metabolic causes, and medication effects, followed by supportive care and specialist referral as needed ¹,²,³.