Núria Bargalló, Teresa Lema,Mar Carreño, Antonio Donaire, Javier Aparicio, Iratxe Maestro. Hospital Clínic i Provincial de Barcelona MRI Changes In Status Epilepticus: A Systematic Review In A Tertiary Center.

Background  MRI changes due to status epilepticus (SE) often suggest a combination of cytotoxic and vasogenic edema, but it is unclear why only certain patients have MRI changes.  There are numerous case reports in the literature about these status-associated MRI signal changes; however, more extensive series on this subject are rare.

Objectives  To study the frequency of MRI changes associated to episodes of status epilepticus (SE).  To establish associations with different clinical and imaging features including the location of the epileptogencic zone.  To describe the most common MRI findings

Methods.  We retrospectively reviewed the charts of 112 adult patients who were discharged from Hospital Clínic, Barcelona, with the diagnosis of Status Epilepticus (SE) from 2000 until  Subjects included: 27 patients who had MRI performed during the admission  Clinical and demographical data were examined, including: sex, age, previous history of epilepsy, type and etiology of SE and time between onset of SE and MR performance.

MRI acquisition  MR examination: 1.5 T scan ( GE and Siemens).  Sequences: T1WI, T2WI, FLAIR in all patients – DWI : n=24/27 – T1WI post gadolinium: n= 12/27 – Spectroscopy = 4/27  All MRI data were reviewed by a neuroradiologist with expertise in epilepsy.

Results. Clinical and demographic   14 males and 13 females.   Mean age : 52 years ( range 20-88).   17/27 ( 63%) No previous diagnosis of epilepsy  10/27 (37%) have previous diagnosis of epilepsy. –6/10 with low AED or AED withdrawal. –4/10 for other provoking factors including sleep deprivation or febrile systemic disease. *mean time between SE and MRI exam: 5,11 days ( range 0-17 days)

Types of status  13/27 Complex partial status epilepticus.  7/27. Simple motor focal SE, evolving to generalized convulsive in 4 patients.  7/27 Generalized compulsive status epilepticus

MRI findings   Changes related to SE: n=14; (51,8%) ( 3 also have epileptogenic lesion associated )   Epileptogenic lesion: n=7; ( 25,9%). (Tumor, cysticercosis, ischemic injury)   MRI normal, n=9;( 33,3%)   No correlation between MRI changes and time of MRI exam, etiology of status.   Correlation between MRI changes and EEG findings( p<0.05).

MRI changes related to SE ( n=14)  Diffuse involvement: 8/14 p. (57,14%)  Focal involvement : 6/14 p. ( 42,8%)  Limbic system: 9/14 (64%)  neocortex: 7 /14 p (50%)  neocortex and subcortical structures: =3/14 (21,4%)  neocortex, subcortical white matter and basal ganglia-thalamus: 3/14 (21,4%).  + cerebellum : 1/ 14p.(7,1%)  There is a tend between focal involvement and previous epilepsy p =0,06. p =0,06.  Anoxia ( 3p) and infections (2 p) shows diffuse lesions.

MRI Characteristics:  Diffuse pattern. (8): - T2WI 7/8 and FLAIR 8/8 - DWI 5/8 - DWI 5/8 - ADC 3/8; ADC 2/8; normal 3/8. - ADC 3/8; ADC 2/8; normal 3/8. - Gyral enhancement 0/5. - Gyral enhancement 0/5.  Focal pattern. (6) : - T2WI 6/6 and FLAIR 6/6 - DWI 5/5 - DWI 5/5 - ADC 3/5; ADC 2/5. - ADC 3/5; ADC 2/5. - Gyral enhancement 4/5. - Gyral enhancement 4/5. - MRS lactate 2/2 - MRS lactate 2/2 * Mean time between SE and MRI exam : ADC = 3,78 days ; ADC = 5,25 days; normal ADC = 3,33 days

Focal involvement CPSE. Time 3 days. EEG: Right hemispheric spikes and slow wave discharge. Previous diagnosis of epilepsy. Brain trauma with right malacic changes.

Diffuse involvement CPSE. Time 3 days. EEG: right posterior sharp waves and slow waves, continuous left hemispheric slow waves, BIPLEDs. No previous diagnosis of epilepsy.

Focal involvement CPSE. Time 8 days. EEG: Left frontal-temporal seizures. Intercritical PLEDS. Previous diagnosis of epilepsy,low AED.

Focal Involvement. CPSE. Time 8 days. EEG: Left frontal-temporal seizures. Intercritical PLEDS. Previous diagnosis of epilepsy,low AED.

Diffuse Involvement. CPSE. Time 4 days. EEG: PLEDS. subclinical seizures. No previous diagnosis of epilepsy. Anoxia

Focal Involvement. CPSE. Time 1 day. EEG: Right parietal-occipital continuous spikes.. No previous diagnosis of epilepsy.

Diffuse Involvement. Focal SE secondarily generalized. Time 1 day. EEG: Right fronto-temporal continuous spikes.. No previous diagnosis of epilepsy. Liver transplant

Varicela-zoster encephalopathy

Conclusion  MRI changes in status epilepticus can be observed in about 50% of patients.  Two imaging patterns can be observed: focal or diffuse involvement and in some cases seems to be related with etiology.  Cortical signal abnormalities in T2WI, FLAIR and DWI are the most frequently observed.  Findings related to intra or extracelular edema can be observed in SE