Differential Diagnosis
The patient's presentation of shakiness, palpitations, and headaches while recovering from agranulocytosis and a retropharyngeal abscess, and being treated with daptomycin, piperacillin/tazobactam, with a negative CT of the head, suggests a complex clinical picture. Here's a categorized differential diagnosis:
Single Most Likely Diagnosis
- Medication side effects: The patient is on multiple medications (daptomycin, piperacillin/tazobactam), which can cause side effects such as shakiness (tremors), palpitations, and headaches. Daptomycin, for example, can cause muscle weakness and tremors, while piperacillin/tazobactam can lead to neurological effects, though less commonly.
Other Likely Diagnoses
- Sepsis or systemic infection: Despite the negative CT head and treatment for the retropharyngeal abscess, the patient could still be experiencing systemic effects of infection, including shakiness and palpitations due to cytokine release and potential cardiac effects.
- Electrolyte imbalance: Patients recovering from severe infections and on broad-spectrum antibiotics are at risk for electrolyte imbalances (e.g., hypokalemia, hypomagnesemia), which can cause muscle weakness, tremors, palpitations, and headaches.
- Anemia or other hematologic effects: Given the patient's history of agranulocytosis, there could be other hematologic abnormalities, such as anemia, which might contribute to symptoms like palpitations and headaches.
Do Not Miss Diagnoses
- Endocarditis: Although less likely, endocarditis is a serious condition that can occur in the setting of bacteremia (possible with a retropharyngeal abscess) and can cause systemic symptoms including palpitations and headaches. It's crucial to consider, especially in elderly patients with valvular heart disease or other risk factors.
- CNS vasculitis or cerebral venous sinus thrombosis: These conditions could present with headaches and, less commonly, with shakiness or palpitations if there's significant systemic involvement. A negative CT does not entirely rule out these conditions, especially if the study was not specifically designed to evaluate for them (e.g., lack of contrast or specific sequences).
- Adrenal insufficiency: This could be a consequence of prolonged stress from infection and could lead to a variety of symptoms including hypotension, weakness, and potentially palpitations.
Rare Diagnoses
- Neurosyphilis: In the absence of a clear cause, and given the broad range of symptoms, neurosyphilis could be considered, especially if the patient has risk factors for syphilis. However, this would be less likely without specific risk factors or other suggestive symptoms.
- Wilson's disease: This genetic disorder leads to copper accumulation in the body and can cause neurological symptoms (tremors), psychiatric issues, and liver disease. It's rare and typically presents at a younger age, making it an unlikely diagnosis in an 88-year-old but could be considered if other diagnoses are ruled out and there are suggestive symptoms or family history.