Presentation
Presented with seizures and worsening of his baseline aphasia and right hemiparesis. History of left frontoparietal anaplastic astrocytoma treated with surgery, chemotherapy, and radiotherapy ten years ago.
Patient Data
Left frontoparietal encephalomalacia and ex-vacuo dilatation of the left lateral ventricle. Nodular calcification in the left periventricular area.
Subtle sulcal effacement in the left frontoparietal region can be noted.
FLAIR and DWI sequences show linear cortical hyperintensity. T1 weighted images after venous contrast administration demonstrates cortical thickening and gyriform enhancement on the left hemisphere, predominantly on the insular and temporoparietal lobes. The perfusion slices reveal slightly augmented cerebral brain volume (CVB) on the left temporoparietal regions.
Near-complete resolution of the FLAIR and DWI left cortical hyperintensity, with complete resolution of the left gyral enhancement.
Case Discussion
In this case, the gyral enhancement pattern on postcontrast MRI together with the seizures and the worsening neurological impairment raises a differential diagnosis between several conditions:
- tumor recurrence
- meningoencephalitis
- subacute infarction
- radiotherapy effects
- other less common diseases (e.g. vasculitis, PRES)
Blood tests and CSF analysis were normal. Therefore, the history of brain irradiation and the complete resolution of the gyral enhancement one month afterwards, were nearly diagnostic of SMART (stroke-like migraine attacks after radiation rherapy) syndrome.
SMART syndrome is a very rare condition that can be summarized in these key learning points:
- Typically reversible and beginning years after cranial irradiation.
- MRI shows a unilateral gyriform enhancement predominantly on the temporoparietal and occipital lobes.
- The pathophysiology is relatively unknown, but is thought to be due to cerebral hyperexcitability along with endothelial damage from radiation therapy.
This case is submitted in collaboration with Dr. Briggith Beltran.