CASE 16395 Published on 27.06.2019

Smart syndrome after glioblastoma treatment

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Louis Flamée, Philippe Demaerel

Patient

53 years, female

Categories
Area of Interest Neuroradiology brain ; Imaging Technique MR
Clinical History

A 53-year-old woman, who had undergone surgery and chemoradiotherapy for a glioblastoma 9 years before, was admitted for sudden right-sided headache with photophobia, left-sided hemianopia and dyspraxia for the past 4 days.
Four months after admission and receiving a steroid tapering schedule her symptoms completely resolved.

Imaging Findings

A non-contrast computed tomography (CT) was requested to exclude acute intracranial pathology. Postoperative changes were seen in the right parietal lobe (Fig. 1).
To exclude tumour recurrence, magnetic resonance imaging (MRI) with intravenous gadolinium was performed. In addition to the known postoperative changes, a gyral enhancement was seen in the right occipital lobe and insular cortex. There was no associated leptomeningeal enhancement, oedema or diffusion restriction (Fig. 2).
There was no evidence of tumour recurrence.
The gyral enhancement disappeared on follow-up MRI 5 months later (Fig. 3).

Discussion

Background:
SMART (stroke-like migraine attacks after radiation therapy) syndrome is a rare condition first described in 1995 [1].
The pathophysiology is still unclear. At present the hypothesis of a delayed radiation neurotoxicity is adopted which combines two pathways. First neuronal dysfunction with cerebral hyperexcitability. Second transient endothelial damage represented by a damaged cortical blood brain barrier and an impaired trigeminovascular system [2-5].

Clinical Perspective:
All patients with SMART syndrome have a history of cranial radiation therapy with an average delay time of up to 20 years after therapy [3].
Typical symptoms are migraine, headache, seizures and focal neurological deficits.
There are no specific laboratory or electroencephalography findings.
Since clinical evaluation is not specific, imaging is needed to exclude tumour recurrence.

Imaging Perspective:
Conventional MRI techniques with intravenous gadolinium administration are sufficient to diagnose SMART syndrome.
The typical imaging finding is unilateral gyral contrast enhancement within the radiation field, not restricted by vascular borders and without white matter damage or mass effect [5]. Occasionally minimal leptomeningeal enhancement is associated. In up to 27% of the patients, cortical laminar necrosis can develop in the area of gyral enhancement [3].
Gyral enhancement can be seen 2-7 days after initiation of neurologic symptoms and usually disappears after 2-5 weeks, exceptionally lasting up to 12 weeks, corresponding to the resolution of symptoms [3].
More advanced MRI techniques can be helpful to exclude tumour recurrence but are not necessary to diagnose SMART syndrome.
Diffusion and SWI imaging are normal, spectroscopy is nonspecific and perfusion may be increased in the affected cortex.

Outcome:
Patients with SMART syndrome have a good prognosis. In 83% symptoms completely resolve within less than 2 months [5].
Therapeutically steroids are used and occasionally anti-epileptic drugs.
Because of the nonspecific clinical findings, imaging is essential to differentiate SMART syndrome from tumour recurrence.

Take Home Message/Teaching Points:
One should think of the possibility of SMART syndrome after brain tumour radiotherapy in order to differentiate the imaging findings from recurrent brain tumour.

Written informed patient consent for publication has been obtained.

Differential Diagnosis List
Posterior Reversible Encephalopathy Syndrome (PRES)
Familial/Sporadic Hemiplegic Migraine (F/SHM)
Postictal changes
SMART syndrome
Encephalitis
Final Diagnosis
SMART syndrome
Case information
URL: https://www.eurorad.org/case/16395
ISSN: 1563-4086