Prevalence and distribution of MRI abnormalities in patients with psychogenic nonepileptic events

Neuroimaging studies in patients with psychogenic non-epileptic seizures: A systematic meta-review

“…A link between a common abnormality in the temporal lobe and patients with PNES would be in keeping with the results of the studies by Bolen et al (2016) and Reuber et al (2002) which identified higher prevalence rates of pathological brain abnormalities in this part of the brain (22% and 40% respectively). However, it is notable that this analysis was only based on three studies, and it is important to take account of the fact that no other convergent brain areas where found when we examined all of the nine studies together or when we examined six studies reporting functional connectivity patterns in PNES patients compared to controls.…”

“…While Reuber et al (2002) also found evidence of brain disease in PNES only patients (27%) compared to patients with PNES plus epilepsy (78%), in contrast to Devinsky et al (2001) , Reuber et al (2002) observed no significant difference in lateralization between PNES only patients and patients with PNES plus epilepsy and both groups showed abnormalities in frontal (PNES only = 5%; PNES plus epilepsy = 18.9%) as well as temporal brain regions (PNES only = 40%; PNES plus epilepsy = 54.1%). A more recent study by Bolen et al (2016) reported similar prevalence rates, with 33.8% of patients with PNES only compared to 57.7% of patients with epilepsy showing structural brain abnormalities. They also noted significantly more multifocal abnormalities in frontal, temporal, parietal, occipital, cerebellar and brainstem brain regions in the PNES only patients (47.8%) compared to the epilepsy group (21.9%), in which significantly more temporal abnormalities were detected for those with epilepsy only (57.8% vs 21.7%).…”

“…Secondly, given the high levels of psychiatric comorbidity in patients with PNES ( Diprose et al, 2016 ), it is impossible to infer that these brain abnormalities are specifically associated with this seizure disorder and not with other co-existing psychopathologies. While Bolen et al (2016) suggest that the significant trend toward multifocal abnormalities in their PNES sample may be directly related to the underlying co-existing psychopathology, this is not clear because instances of concurrent psychopathology was not reported in their sample. In addition, there may also be other psychological reasons why an individual with structural brain abnormalities may develop PNES and this again is unclear.…”

“…In addition, there may also be other psychological reasons why an individual with structural brain abnormalities may develop PNES and this again is unclear. Thirdly, the hypothesis put forward by Devinsky et al (2001) that the prevalence of right-sided abnormalities might facilitate conversion due to non-dominant hemispheric injury or damage is not supported by either Reuber et al (2002) nor Bolen et al (2016) . In addition, it is unclear how the emotion dysregulation hypothesis that they put forward for PNES is directly associated with seizure like episodes because emotional processing was not directly measured in their study.…”

“…The use of SPECT in PNES is important because it supports the proposition that PNES is indeed different from epilepsy in the majority of PNES cases. However, like structural MRI studies which have observed instances of brain disease or injury in a sub-population of PNES patients ranging from 25% to 34% ( Bolen et al, 2016 , Devinsky et al, 2001 , Reuber et al, 2002 ), the SPECT studies outlined below have observed similar prevalence rates of abnormal regional cerebral blood flow in a subset of patients with confirmed PNES diagnosis (range 15%–30%).…”