Discharge Diagnosis for TIA Workup with Negative MRI and Suspected Aphasia
Your discharge diagnosis should be "Transient Ischemic Attack (TIA)" even with a negative MRI, as up to one-third of TIA patients have negative diffusion-weighted imaging, and the clinical presentation (aphasia) is consistent with cerebrovascular etiology requiring secondary stroke prevention. 1, 2
Rationale for TIA as Primary Diagnosis
- Negative MRI does not exclude TIA: Approximately 67% of patients with clinically diagnosed TIA have negative diffusion-weighted imaging (DWI), yet still carry significant stroke risk 1, 3
- Aphasia is a high-risk TIA symptom: Speech disturbance is specifically identified as a highest-risk feature for stroke recurrence, with up to 10% risk of stroke within the first week 1
- Clinical diagnosis takes precedence: When neurology suspects aphasia in the context of transient neurological symptoms, the clinical syndrome meets National Institute of Neurological Disorders and Stroke criteria for TIA even without MRI confirmation 3
Why Not Seizure as Primary Diagnosis
While neurology wants outpatient seizure workup, this should be listed as a secondary or differential diagnosis, not the primary discharge diagnosis, for these reasons:
- Seizure mimics are less common: Epileptic causes of isolated aphasia in adults are rare, whereas aphasia from TIA is much more frequent 4
- Predictors favor stroke over seizure: The absence of altered consciousness, prior epilepsy history, concomitant infection, or electrolyte imbalance makes seizure less likely 4
- Treatment implications: Discharging with TIA as primary diagnosis ensures appropriate secondary stroke prevention (antiplatelet therapy, statin, blood pressure control) is initiated immediately 1
Appropriate Discharge Documentation
Primary Diagnosis: Transient Ischemic Attack (TIA) with aphasia
Secondary/Differential Diagnosis: Rule out seizure disorder (pending outpatient EEG and neurology follow-up)
Critical Management Points
- Immediate secondary prevention: Initiate antiplatelet agent, statin, and blood pressure control at discharge regardless of negative MRI 1
- Complete vascular imaging: Ensure noninvasive imaging of cervicocephalic vessels (CTA, MRA, or carotid ultrasound) was performed to identify large artery atherosclerosis 1
- Cardiac evaluation: Verify EKG was done; consider prolonged cardiac monitoring if no clear etiology identified 1
- Urgent follow-up: Arrange neurology follow-up within 2 weeks for both stroke prevention optimization and seizure workup 1
Common Pitfall to Avoid
Do not delay stroke prevention measures while awaiting seizure workup. Even if seizure is ultimately diagnosed, the 18% stroke risk in patients with clinical TIA symptoms warrants immediate preventive therapy 3. The outpatient seizure evaluation can proceed in parallel without compromising stroke prevention.