Rapid discontinuation of sodium channel–blocking antiseizure drugs evokes focal edema in the splenium corporis callosi: A matched case‐control study

Altitude-related features and prognosis in patients with reversible splenial lesion syndrome

INTRODUCTION

RESLES (Reversible splenial lesion syndrome) can be observed secondary to various diseases, and intramyelinic edema may play a crucial role in the pathogenesis of SCC (Splenium of the corpus callosum). Some studies have suggested that hypoxic-ischaemic encephalopathy may constitute a risk factor for SCC lesions. However, the potential impact of high-altitude environments on SCC, especially during chronic exposure, remain obscure.

METHODS

Our study included 19 patients who satisfied the diagnostic criteria of RESLES at high altitudes. Ten low-altitude patients with RESLES were included as controls. All participants received MRI (Magnetic resonance imaging) scans twice. Routine blood tests, liver, kidney and thyroid function, coagulation function, electrolytes and vitamins were detected during hospitalization and before discharge. In addition, the patients were followed up in May 2023.

RESULTS

Hypoxic environments at high altitudes may increase the risk of RESLES. The two groups showed different clinical symptoms. High-altitude patients had significantly higher CRP levels than low-altitude patients. The lesion size in high-altitude patients showed a positive correlation with SaO2 levels. However, the patients at low altitudes had positive correlation trends between lesion size and several inflammatory markers (WBC, NEU and CRP). All patients had a benign prognosis that may not be affected by the use of prednisone acetate.

CONCLUSIONS

Hypoxic environments at high altitudes may play a role in the aetiology of RESLES. Additionally, RESLES is a reversible disease and the administration of glucocorticoids may be dispensable for its treatment.

[Febrile ciguatera with corpus callosum involvment]

INTRODUCTION

Ciguatera is a food poisoning caused by marine organisms and has a polymoprhic clinic. Differential diagnoses need to be eliminated.

OBSERVATION

A patient was hospitalized for a febrile syndrome a few days after the appearance of clinical signs suggestive of ciguatera after consuming lagoon fish. He also presented with central neurological signs and brain MRI revealed a lesion of the corpus callosum. A skin infection linked to the scratching lesions was the cause of this febrile state and a diagnosis of CLOCCS was made based on the lesions on MRI.

CONCLUSION

A central neurological involvement in ciguatera is possible but rare, CLOCCS may be one of them. On the other hand, a febrile syndrome should lead to consider an differential diagnosis or a complication.

Association between retinal thickness and disease characteristics in adult epilepsy: A cross-sectional OCT evaluation

OBJECTIVE

Thinning of the peripapillary retinal nerve fiber layer (p-RNFL), as measured by optical coherence tomography (OCT), was recently introduced as a promising marker for cerebral neuronal loss in people with epilepsy (PwE). However, its clinical implication remains to be elucidated. We thus aimed to (1) systematically characterize the extent of the retinal neuroaxonal loss in a broad spectrum of unselected PwE and (2) to evaluate the main clinical determinants.

METHODS

In this prospective study, a spectral-domain OCT evaluation was performed on 98 well-characterized PwE and 85 healthy controls (HCs) (18-55 years of age). All inner retinal layers and the total macula volume were assessed. Group comparisons and linear regression analyses with stepwise backward selection were performed to identify relevant clinical and demographic modulators of the retinal neuroaxonal integrity.

RESULTS

PwE (age: 33.7 ± 10.6 years; 58.2% female) revealed a significant neuroaxonal loss across all assessed retinal layers (global pRNFL, P = 0.001, Δ = 4.24 μm; macular RNFL, P < 0.001, Δ = 0.05 mm3 ; ganglion cell inner plexiform layer, P < 0.001, Δ = 0.11 mm3 ; inner nuclear layer, INL, P = 0.03, Δ = 0.02 mm3 ) as well as significantly reduced total macula volumes (TMV, P < 0.001, Δ = 0.18 mm3 ) compared to HCs (age: 31.2 ± 9.0 years; 57.6% female). The extent of retinal neuroaxonal loss was associated with the occurrence and frequency of tonic-clonic seizures and the number of antiseizure medications, and was most pronounced in male patients.

SIGNIFICANCE

PwE presented an extensive retinal neuroaxonal loss, affecting not only the peripapillary but also macular structures. The noninvasive and economic measurement via OCT bears the potential to establish as a practical tool to inform patient management, as the extent of the retinal neuroaxonal loss reflects aspects of disease severity and sex-specific vulnerability.

PLAIN LANGUAGE SUMMARY

The retina is an extension of the brain and closely connected to it. Thus, cerebral alterations like atrophy reflect also on the retinal level. This is advantageous, as the retina is easily accessible and measureable with help of the optical coherence tomography. Here we report that adults with epilepsy have a significantly thinner retina than healthy persons. Especially people with many big seizures and a lot of medications have a thinner retina. We propose that measurement of the retina can be useful as a marker of disease severity and to inform patient management.

Valproate but not levetiracetam slows the EEG alpha peak frequency - A pharmaco-EEG study

OBJECTIVE

Studies of the effect of valproate (VPA) on the background EEG have shown varying results. Therefore, we compared the effect of VPA and levetiracetam (LEV) on the EEG alpha peak frequency (APF).

METHODS

We retrospectively examined the APF in resting-state EEG of patients undergoing inpatient video-EEG monitoring (VEM) during withdrawal of VPA or LEV. We assessed APF trends by computing linear fits across individual patients' APF as a function of consecutive days, and correlated the APF and daily antiseizure medication (ASM) doses on a single-patient and group level.

RESULTS

The APF in the VPA-group significantly increased over days with falling VPA doses (p = 0.005, n = 13), but did not change significantly in the LEV-group (p = 0.47, n = 18). APF correlated negatively with daily ASM doses in the VPA-group (average of r = -0.74 ± 0.12 across patients, p = 0.0039), but not in the LEV-group (average of r = -0.17 ± 0.18 across patients, p = 0.4072).

CONCLUSIONS

Our results suggest that VPA treatment slows the APF. This APF reduction correlates with the daily dose of VPA and is not present in LEV treatment.

SIGNIFICANCE

Our study identifies a VPA-related slowing of the APF even in patients without electroencephalographic or overt clinical signs of encephalopathy.