Seizure-related contrast enhancement of a ganglioglioma

An exploration of the spectrum of peri-ictal MRI change; a comprehensive literature review

PURPOSE

The aim of this review was to identify published studies in the literature relating to ictal induced MRI change and to identify certain common themes, practical points for clinicians and areas for future research.

METHODS

We identified 96 articles that satisfied our inclusion criteria yielding 575 cases. All articles were analysed; number of subjects, spectrum of MRI and EEG change, aetiology, and follow-up (both clinical and imaging) were noted.

RESULTS

The most frequent imaging changes were restricted diffusion, T2-hyperintensity and reduced ADC values. The mesial temporal structures and neocortex were most commonly affected locations though subcortical structures like the thalamus and pulvinar were also described. Practical clinical points included; the development of PLEDS concordant with ictal imaging change was associated with worse clinical prognosis, patients with seizures due to symptomatic aetiology may be more likely to develop ictal related imaging change and follow up is vitally important to ensure that ictal related oedema is not misidentified as a mass lesion or conversely that a mass lesion is not misidentified as ictal related change.

CONCLUSION

Qualitative MRI studies have provided clinicians with useful in-vivo insights into the dynamic ictal neuronal environment. Changes are not only localised to the ictal focus but can be remote and irreversible. Small patient numbers varying study design and high numbers of symptomatic seizures makes comparison between studies problematic. Also there is possible microstructural quantitative MRI changes that are missed on qualitative MRI. There is a need for prospective quantitative MRI studies in patients with epilepsy peri-icatlly with a uniform period of follow up and comparison to control data.

Peri-ictal pseudoprogression in patients with brain tumor

Recent advances in the treatment of malignant gliomas have highlighted the fact that the appearance of new contrast-enhancing lesions on magnetic resonance imaging (MRI) is not always indicative of tumor recurrence. It has been suggested that transient seizure-related MRI changes could mimic disease progression (peri-ictal pseudoprogression [PIPG]). However, the clinical and MRI features associated with this situation have not been well described. Here, we consulted the databases of 6 institutions to identify patients with brain tumor who presented during the follow-up period transient MRI lesions wrongly suggesting tumor progression in a context of epileptic seizures. Ten patients were identified. All patients but 1 were long-term survivors who had initially been treated with radiotherapy. The PIPG episode occurred after a median interval of 11 years after radiotherapy. MRI features were highly similar across patients and consisted of transient focal cortical and/or leptomeningeal enhancing lesions that erroneously suggested tumor progression. All patients improved after adjustment of their antiepileptic drugs and transient oral corticosteroids, and MRI findings were normalized 3 months after the PIPG episode. Two patients demonstrated several seizure relapses with the same clinicoradiological pattern. After a median follow-up period of 3.5 years after the initial PIPG episode, only 1 patient presented with a tumor recurrence. In conclusion, in patients with brain tumor, especially in long-term survivors of radiotherapy, the appearance of new cortical and/or leptomeningeal contrast-enhancing lesions in a context of frequent seizures should raise the suspicion of PIPG. This phenomenon is important to recognize in order to avoid futile therapeutic escalation.

Transient postictal MRI changes in patients with brain tumors may mimic disease progression

BACKGROUND

Transient postictal imaging abnormalities in patients with non-tumor-related seizures are well documented and include fluid-attenuated inversion recovery/T2 hyperintensity and parenchymal and meningeal contrast enhancement. In contrast, transient postictal imaging abnormalities in patients with tumor-related seizures have been poorly described. Fifty percent of patients with brain tumors have a seizure during the course of their illness and are often imaged after a seizure or after a change in seizure character or frequency. Interval changes on repeat imaging can mimic disease progression or other pathologic processes.

METHODS

We describe 3 patients with brain tumors and transient postictal MRI changes that mimicked disease progression and infection.

RESULTS

Our patients demonstrated fluid-attenuated inversion recovery/T2 hyperintensity and gadolinium enhancement on MRI studies performed shortly after ictal events. These changes were suspicious for tumor progression in 2 cases and for recurrent infection in the third. Control of seizure activity resulted in resolution of these changes on scans obtained 10 to 21 days later.

CONCLUSIONS

Imaging shortly after an ictal event can potentially mislead the clinician to interpret changes as tumor or pathologic progression. Unnecessary intervention in these patients with new and suspicious imaging findings should be avoided. We recommend repeat imaging be performed in patients with brain tumors and seizures several weeks after seizure control if clinically feasible. Further research is needed to delineate the time course of seizure-induced MRI changes.

Supportive Therapie und Palliativmedizin bei Patienten mit malignen Gliomen

The primary aim of supportive care in patients with malignant gliomas is accurate symptom control in order to optimize quality of life. The palliative approach should be considered from the beginning of treatment, due to the intractable and incurable character of the disease. Neurological signs and symptoms have to be investigated clinically, as well as neuroradiologically in order to evaluate treatment response and to provide adequate supportive care.