Alice in wonderland syndrome "through the looking-glass" in a rare presentation of non-convulsive status epilepticus in cerebral venous sinus thrombosis and COVID-19

Alice in Wonderland Syndrome (AIWS) is a rare perceptual disorder, rarely associated with epileptic etiology. We report the case of a 23-year-old man with subacute onset of right peri-orbital headache and visual misperceptions consistent with AIWS Type B, who underwent laboratory tests, brain CT with venography, ophthalmic examination, and neurological assessment that turned out to be normal except for visuospatial difficulties and constructional apraxia. A nasopharyngeal SARS-CoV2 swab taken as screening protocol was positive. The EEG performed because of the persistence of AIWS showed a focal right temporo-occipital non-convulsive status epilepticus; a slow resolution of clinical and EEG alterations was achieved with anti-seizure medications. Brain MRI showed right cortical temporo-occipital signal abnormalities consistent with peri-ictal changes and post-contrast T1 revealed a superior sagittal sinus thrombosis, thus anticoagulant therapy was initiated. AIWS is associated with temporo-parieto-occipital carrefour abnormalities, where visual and somatosensory inputs are integrated to generate the representation of body schema. In this patient, AIWS is caused by temporo-occipital status epilepticus without anatomical and electroencephalographic involvement of the parietal region, consistent with the absence of somatosensory symptoms of the syndrome. Status epilepticus can be the presenting symptom of cerebral venous sinus thrombosis (CVST) which, in this case, is possibly due to the hypercoagulable state associated with COVID-19.

Changes in Local and Network Brain Activity After Stereotactic Thermocoagulation in Patients with Drug-Resistant Epilepsy

OBJECTIVE

Stereoelectroencephalography-guided radiofrequency thermocoagulation (SEEG-guided RF-TC) aims to reduce seizure frequency by modifying epileptogenic networks through local thermocoagulative lesions. Although RF-TC is hypothesized to functionally modify brain networks, reports of changes in functional connectivity (FC) following the procedure are missing. We evaluated, by means of SEEG recordings, whether variation in brain activity after RF-TC is related to clinical outcome.

METHODS

Interictal SEEG recordings from 33 DRE patients were analyzed. Therapeutic response was defined as more than 50% reduction in seizure frequency for at least one month following RF-TC. Local (power spectral density, PSD) and FC changes were evaluated in three-minute segments recorded shortly before (baseline), shortly after and 15 minutes after RF-TC. The PSD and FC strength values after thermocoagulation were compared with baseline as well as between the responder and non-responder groups.

RESULTS

In responders, we found a significant reduction in PSD after RF-TC in channels that were thermocoagulated (TC) for all frequency bands (p-value =0.007 for broad, delta and theta, p-value <0.001 for alpha and beta bands). However, we did not observe such PSD decrease in non-responders. At the network level, non-responders displayed a significant FC increase in all frequency bands except theta (broad, delta, beta band: p-value < 0.001; alpha band: p-value < 0.01), while responders showed a significant FC decrease in delta (p-value<0.001) and alpha bands (p-value<0.05). Non-responders showed stronger FC changes with respect to responders exclusively in TC channels (broad, alpha, theta, beta: p-value>0.05; delta: p= 0.001).

SIGNIFICANCE

Thermocoagulation induces both local and network-related (FC) changes in electrical brain activity of patients with DRE lasting for at least 15 minutes. This study demonstrates that the observed short-term modifications in brain network and local activity significantly differ between responders and non-responders and opens new perspectives for studying the longer-lasting functional connectivity changes after RF-TC.