Differential Diagnosis for 59 y/o with Altered Mental Status (AMS) and Bilateral Extremities Weakness
- Single Most Likely Diagnosis
- Valproic Acid (VPA) toxicity or subtherapeutic level: The patient has a history of focal epilepsy and is on VPA, but the level is low (38), which may indicate inadequate seizure control or toxicity due to other factors like renal impairment. The patient's symptoms of AMS and bilateral extremities weakness could be related to VPA toxicity or inadequate seizure control.
- Other Likely Diagnoses
- Seizure or status epilepticus: Given the patient's history of focal epilepsy, a seizure or status epilepticus could explain the AMS and bilateral extremities weakness, especially with a low VPA level.
- Acute on chronic kidney disease exacerbation: The patient has worsening acute on chronic kidney disease, which could contribute to AMS and weakness due to electrolyte imbalances, uremia, or other complications.
- Hypertensive emergency: Poorly controlled hypertension could lead to a hypertensive emergency, presenting with AMS and weakness, among other symptoms.
- Diabetic emergency (e.g., diabetic ketoacidosis or hyperosmolar hyperglycemic state): The patient's diabetes, if poorly managed, could lead to a diabetic emergency, causing AMS and weakness.
- Do Not Miss Diagnoses
- Cerebral vasculitis or other vasculopathies: Although the CT scan was negative for acute stroke, cerebral vasculitis or other vasculopathies could present with similar symptoms and would be critical to diagnose due to their potential for severe outcomes.
- Infections (e.g., meningitis, encephalitis): Infections affecting the central nervous system could present with AMS and weakness and are crucial to identify promptly due to their high morbidity and mortality if untreated.
- Metabolic disorders (e.g., hyponatremia, hypernatremia): Significant electrolyte imbalances could cause AMS and weakness and are potentially life-threatening if not addressed.
- Rare Diagnoses
- Mitochondrial disorders: Given the patient's history of epilepsy, strokes, and kidney disease, a mitochondrial disorder could be a rare but unifying diagnosis, although this would be less likely and require specific diagnostic testing.
- Porphyrias: Acute intermittent porphyria could present with neurological symptoms like weakness and AMS, although this is rare and would require specific diagnostic tests to confirm.