Seizure outcome trajectories in a well-defined cohort of newly diagnosed juvenile myoclonic epilepsy patients.

OBJECTIVE: To investigate the temporal course of medication response and associated prognostic factors in a cohort of juvenile myoclonic epilepsy (JME) patients over a long-term follow-up. MATERIALS AND METHODS: Data from 113 JME patients diagnosed according to recently proposed class II criteria were retrospectively reviewed. Early sustained remission was defined as 4-year seizure remission starting within 2 years from the first antiseizure medication (ASM) intake, as opposed to delayed sustained remission. Spontaneous relapse rate (ie, not related to ASM withdrawal) was also investigated, along with factors associated with seizure relapse. RESULTS: Four-year seizure remission was obtained by 76/113 (67.3%) subjects. Early sustained remission was achieved by 45/76 (59.2%) patients. Absence seizures were significantly associated with no-remission at multivariable multinomial logistic regression analysis. Catamenial seizures and earlier age at epilepsy onset significantly predicted delayed sustained remission. Spontaneous seizure relapse after 4-year remission occurred in 15.7% of patients with early sustained remission and in 35.5% of those with delayed sustained remission (p = 0.045). The most common concomitant factors for a spontaneous relapse were irregular lifestyle habits and pregnancy-related switch from valproate to another ASM. Patients with a history of catamenial seizures were more likely to experience a spontaneous generalized tonic-clonic seizure relapse after 4-year remission at univariable analysis. SIGNIFICANCE: Our data support the prognostic relevance of early medication response in JME patients. Furthermore, the prognostic significance of catamenial seizures and the impact of valproate switch on seizure relapse after a prolonged remission account for the challenging therapeutic management of women with childbearing potential.

Myoclonic epilepsy, parkinsonism, schizophrenia and left-handedness as common neuropsychiatric features in 22q11.2 deletion syndrome.

BACKGROUND: 22q11.2 deletion syndrome (22q11.2DS) is considered as the genetic model of schizophrenia. However, its polymorphic nature has led researchers to further investigate its neuropsychiatric manifestations. METHODS: We enrolled 56 adults (38 men, 18 women) diagnosed with 22q11.2DS. All subjects were evaluated by a multidisciplinary team. The neuropsychiatric features were investigated by means of clinical and neurophysiological evaluation (video-EEG). RESULTS: Thirty per cent of our patients were left-handed. Fifty-eight per cent had a low IQ, and 22 of 56 subjects had psychotic disorders (13 of 22 with schizophrenia). Eighteen patients reported at least one seizure in their lifetime, and ten were diagnosed with epilepsy; among them, seven had genetic generalised epilepsy (GGE), and five of seven showed features suggestive of juvenile myoclonic epilepsy (JME). Video-EEG recordings revealed generalised epileptiform abnormalities in 24 of 56 cases. Besides, only one patient with epilepsy had a cardiac malformation. Lastly, 31 of 56 subjects presented with parkinsonism, 16 of whom were taking neuroleptics. None of the 15 patients with parkinsonism not related to neuroleptic therapy was diagnosed with epilepsy, compared with 6 of those taking antipsychotics. CONCLUSIONS: 22q11.2DS is characterised by left-handedness and neuropsychiatric features such as cognitive impairment, schizophrenia, epilepsy and parkinsonism. GGE, mostly the JME phenotype, is the predominant epilepsy type. The significant association between 22q11.2DS and parkinsonian features confirms these patients' genetic susceptibility to parkinsonism. Despite the lack of any conclusive evidence, our study suggests a possible relationship between the analysed clinical variables: (1) an inverse correlation between low IQ/psychosis/epilepsy and major cardiac diseases; (2) a direct association between psychosis and both mental delay and epilepsy; and (3) an inverse correlation between parkinsonism and epilepsy.

Persistent treatment resistance in genetic generalized epilepsy: A long-term outcome study in a tertiary epilepsy center.

OBJECTIVE: To assess prognostic patterns and investigate clinical and electroencephalography (EEG) variables associated with persistent treatment resistance in a population of genetic generalized epilepsy (GGE) patients with a long-term follow-up. METHODS: Data from GGE patients followed from 1975 to 2019 were reviewed retrospectively. Subjects with a follow-up >10 years, starting from epilepsy diagnosis, were included. Persistent treatment resistance was defined as the absence of any period of remission ≥1 year despite treatment with two appropriate and adequate antiepileptic drugs (AEDs). RESULTS: One hundred ninety-nine patients were included. The median age was 39.5 years (interquartile range [IQR] 30-49) and the median follow-up was 27 years (IQR 18-35). The most common syndrome was juvenile myoclonic epilepsy (JME), diagnosed in 44.2% of patients. During follow-up, 163 subjects (81.9%) experienced 3-year remission from any seizure type, whereas 5- and 10-year remission occurred in 141 (70.8%) and 92 (46.2%) cases, respectively. The most common prognostic pattern was a relapsing-remitting course, observed in 80 patients (40.2%), whereas 29 (14.6%) displayed persistent treatment resistance. According to multivariable logistic regression analysis, febrile seizures (FS), specific EEG patterns (namely generalized paroxysmal fast activity, GPFA) and valproate (VPA) resistance were the only variables significantly associated with persistent treatment resistance. JME was the only epilepsy syndrome statistically associated with persistent treatment resistance in univariable logistic regression analysis. SIGNIFICANCE: Persistent treatment resistance was observed in almost 15% of GGE patients followed in a tertiary epilepsy center. A worse outcome was associated with specific clinical variables (JME, FS) and EEG patterns (GPFA).

Doing without valproate in women of childbearing potential with idiopathic generalized epilepsy: Implications on seizure outcome.

OBJECTIVE: Valproate (VPA) use in women with idiopathic generalized epilepsy (IGE) who are of reproductive age has been a matter of concern and debate, which eventually led to the recent restrictions by regulatory agencies. The aim of our study was to investigate the relationship between VPA avoidance/switch and seizure outcome in women of childbearing potential. METHODS: We retrospectively reviewed data from female patients with IGE, 13-50 years of age, followed since 1980. We evaluated the prescription habits, and the rate of VPA switch for other antiepileptic drugs (AEDs) and its prognostic implications. Seizure remission (SR) was defined as the absence of any seizure type more than 18 months before the last medical observation. The main aim of the study was to assess (a) possible changes in seizure outcome related to VPA switch for other AEDs, especially in patients planning a pregnancy; and (b) possible differences in SR based on the presence/absence of VPA at last observation. RESULTS: One hundred ninety-eight patients were included in the study. Overall SR at last medical observation was 62.7%. SR significantly differed between subjects taking and those not taking VPA (P < .001) at last visit. Multiple regression models showed that taking VPA at last medical observation was strongly associated with SR in both the general population (P < .001) and the juvenile myoclonic epilepsy (JME) group (P < .001). Thirty-six (70.6%) of 51 patients who switched from VPA during follow-up experienced a clinical worsening. Switching back to VPA was more frequently associated with SR at last observation (P < .001). In those patients who substituted VPA in view of a pregnancy, SR and drug burden (monotherapy vs polytherapy) differed significantly before and after the switch. SIGNIFICANCE: Our study suggests that VPA avoidance/switch might be associated with unsatisfactory seizure control in women with IGE who are of childbearing potential. Our findings further highlight the complexity of the therapeutic management of female patients of reproductive age.

Anxiety as the only manifestation of focal non-convulsive status epilepticus: case report and review of the literature.

Psychiatric disorders represent common comorbidities in epileptic patients. Sometimes anxiety is part of the ictal semiology, especially during seizures arising from/involving frontal or temporal lobes. We describe a patient with focal epilepsy and recurrent hyperkinetic seizures who also presented prolonged episodes characterized by massive anxiety, alarm and fear. A Video-Electroencephalographic monitoring performed during one of these attacks revealed a continuous epileptiform activity over the right frontal regions, consistent with a focal non-convulsive status epilepticus accounting for the patient's psychiatric symptoms. Our case confirms the complex relationship between epilepsy and anxiety. A review of the literature is also included.

A novel action of lacosamide on GABAA currents sets the ground for a synergic interaction with levetiracetam in treatment of epilepsy.

Epilepsy is one of the most common chronic neurological diseases, and its pharmacological treatment holds great importance for both physicians and national authorities, especially considering the high proportion of drug-resistant patients (about 30%). Lacosamide (LCM) is an effective and well-tolerated new-generation antiepileptic drug (AED), currently licensed as add-on therapy for partial-onset seizures. However, LCM mechanism of action is still a matter of debate, although its effect on the voltage sensitive sodium channels is by far the most recognized. This study aimed to retrospectively analyze a cohort of 157 drug-resistant patients treated with LCM to describe the most common and effective therapeutic combinations and to investigate if the LCM can affect also GABAA-mediated neurotransmission as previously shown for levetiracetam (LEV). In our cohort, LEV resulted the compound most frequently associated with LCM in the responder subgroup. We therefore translated this clinical observation into the laboratory bench by taking advantage of the technique of "membrane micro-transplantation" in Xenopus oocytes and electrophysiological approaches to study human GABAA-evoked currents. In cortical brain tissues from refractory epileptic patients, we found that LCM reduces the use-dependent GABA impairment (i.e., "rundown") that it is considered one of the specific hallmarks of drug-resistant epilepsies. Notably, in line with our clinical observations, we found that the co-treatment with subthreshold concentrations of LCM and LEV, which had no effect on GABAA currents on their own, reduced GABA impairment in drug-resistant epileptic patients, and this effect was blocked by PKC inhibitors. Our findings demonstrate, for the first time, that LCM targets GABAA receptors and that it can act synergistically with LEV, improving the GABAergic function. This novel mechanism might contribute to explain the clinical efficacy of LCM-LEV combination in several refractory epileptic patients.

Ictal EEG/fMRI study of vertiginous seizures.

Vertigo and dizziness are extremely common complaints, related to either peripheral or central nervous system disorders. Among the latter, epilepsy has to be taken into consideration: indeed, vertigo may be part of the initial aura of a focal epileptic seizure in association with other signs/symptoms, or represent the only ictal manifestation, a rare phenomenon known as "vertiginous" or "vestibular" seizure. These ictal symptoms are usually related to a discharge arising from/involving temporal or parietal areas, which are supposed to be a crucial component of the so-called "vestibular cortex". In this paper, we describe three patients suffering from drug-resistant focal epilepsy, symptomatic of malformations of cortical development or perinatal hypoxic/ischemic lesions located in the posterior regions, who presented clusters of vertiginous seizures. The high recurrence rate of such events, recorded during video-EEG monitoring sessions, offered the opportunity to perform an ictal EEG/fMRI study to identify seizure-related hemodynamic changes. The ictal EEG/fMRI revealed the main activation clusters in the temporo-parieto-occipital regions, which are widely recognized to be involved in the processing of vestibular information. Interestingly, ictal deactivation was also detected in the ipsilateral cerebellar hemisphere, suggesting the ictal involvement of cortical-subcortical structures known to be part of the vestibular integration network.

Ictal pain in focal non-convulsive status epilepticus.

We report an adult with acute unilateral pain as isolated manifestation of acute symptomatic focal non-convulsive status epilepticus. Pain is rarely a manifestation of epileptic seizures. Traditionally, painful seizures have been thought to originate in either the parietal or temporal lobes, but their localising value is debatable. Recent functional neuroimaging studies and electrophysiological findings obtained by using intracerebral recordings have shown the involvement of the insular cortex along with several other brain structures in the processing of painful inputs, comprising a more widespread anatomo-functional network. Despite their rarity as a distinct clinical entity, especially in adults, painful somatosensory seizures can be disabling and misdiagnosis or delayed diagnosis is common; it is therefore essential to consider epilepsy as a possible cause of paroxysmal pain to ensure proper assessment and appropriate treatment.

Ictal epileptic headache in adult life: Electroclinical patterns and spectrum of related syndromes.

OBJECTIVES: Both headache and epilepsy are frequent paroxysmal disorders that often co-occur or are related in numerous ways. Although ictal epileptic headache has become the focus of several studies, this remains a very rare and not well-known phenomenon. Electroclinical features, pathophysiology, and syndromic context are heterogeneous. We investigated the electroclinical and neuroimaging findings in a population of adult patients with ictal epileptic headache. METHODS: We retrospectively examined 8800 EEG recordings of almost 4800 patients admitted to our video-EEG laboratory from 2010 to 2013 with a history of well-documented epilepsy. We selected patients who reported headache closely related to a seizure documented by video-EEG or 24-hour ambulatory EEG. We analyzed ictal electroclinical features of headache, and we defined the related epileptic syndromes. RESULTS: We identified five patients with ictal epileptic headache. Two patients described tension headache during an epileptic seizure. In three patients, the headache was accompanied by other "minor" neurological symptoms mimicking a migrainous aura. In all cases, the headache stopped with the end of the epileptic activity. Three patients had a history of partial symptomatic epilepsy with cerebral lesions (low grade glioma, astrocytoma, porencephalic cyst) in the left posterior regions, whereas two patients were affected by idiopathic generalized epilepsy. CONCLUSION: This study confirms the rarity of ictal epileptic headache. To date, well-documented video-EEG cases remain as exceptional reports, especially in cases of idiopathic generalized epilepsies. Moreover, we confirm the main involvement of posterior regions in patients with ictal epileptic headache affected by partial symptomatic epilepsies.

Epilepsy surgery in adult-onset Rasmussen's encephalitis: case series and review of the literature.

Rasmussen's encephalitis (RE) is a rare immune-mediated condition characterized by drug-resistant focal epilepsy, progressive neurological, and cognitive deficits associated to unilateral hemispheric atrophy. The onset is typically reported in childhood, although adult cases (A-RE) have been described. While surgical strategies in childhood RE are well defined, little is known about usefulness of epilepsy surgery in A-RE patients. We describe clinical features, surgical approach, and outcome of five A-RE patients who underwent epilepsy surgery, and we review the literature with regard to surgical A-RE cases. We retrospectively studied five A-RE patients aged 21-38 years (mean age 22.8 years) who were followed after surgery for a period ranging from to 1 to 6 years. Demographic, electroclinical, and neuroimaging data were systematically reviewed. Four out of five subjects underwent invasive EEG monitoring to define epileptogenic zone. Epilepsy outcome was defined according to Engel's classification. Surgery consisted of frontal corticectomy in three patients, temporal lobectomy in one, combined temporal lobectomy plus insular, and frontobasal corticectomy in the remaining case. No permanent neurological deficits were observed after surgery. At the last follow-up observation, one patient was seizure-free, two subjects experienced rare disabling seizures, another had moderate seizure reduction, and one had no clinical improvement. Our experience, although limited to few cases, suggests that resective surgery in A-RE may play a role in the context of multidisciplinary therapeutical approach of this severe condition. Since the lack of specific data about surgical options, this topic seems to deserve further investigations and more targeted studies.

Cryptogenic focal epilepsy and "hidden" celiac disease in adulthood: a causal or accidental link?

PURPOSE: Celiac disease (CD) is an immuno-mediated small bowel disease characterized by chronic inflammation due to a permanent intolerance to gliadin. Several neurological complications have been described, including epilepsy, whose evolution might often improve by adopting gluten-free diet (GFD). We studied a population of adult patients affected by posterior drug-resistant epilepsy of unknown cause by performing an accurate screening for CD. In the selected patients presenting the association of epilepsy and CD, we characterized the related electro-clinical features. MATERIALS AND METHODS: We consecutively identified 211 adult subjects affected by drug-resistant cryptogenic focal epilepsy with posterior seizures. All these patients underwent serological screening for CD. In 10 subjects positive serological tests allowed to perform a CD diagnosis (confirmed by duodenal biopsy). For each patient clinical and EEG data, neuroimaging studies, serological and histological findings were revised, as well as response to GFD, defined as an improvement in seizure outcome. RESULTS: A significant delay between diagnosis of epilepsy and CD was documented. Visual ictal manifestations were reported in half of subjects. In all cases, interictal EEG showed slow and epileptiform abnormalities over parietal-occipital and temporal regions; in three cases, FOS phenomenon was observed. Four patients had familiar history of CD and six cases showed clinical signs/symptoms of malabsorption. GFD led to a reduction of seizure frequency in half of patients. CONCLUSIONS: "Posterior" ictal semiology, peculiar EEG patterns and drug-resistance emerge as the most interesting characteristics. CD screening should be performed in epilepsy patients presenting such features.

Ictal epileptic headache revealing non convulsive status epilepticus in a case of eyelid myoclonia with absences.

Epileptic seizures and headache attacks are two common neurologic phenomena characterized by paroxysmal alteration of brain functions followed by complete restauration of the baseline condition. Headache and epilepsy are related in numerous ways, and they often co-occur. Although the link between these two diseases is not completely clear, several clinical, physiopathological and therapeutic features overlap. Headache is reported in association with epileptic seizures as a pre-ictal, ictal or post-ictal phenomenon. We present the case of a 40 year-old woman affected by eyelid myoclonia with absences (EMA) with a history of prolonged headache attacks. A video-EEG recording performed during one of these episodes showed subcontinuous epileptic activity consisting of generalized spike-and-wave discharges (GSWDs), clinically associated with tensive headache. Our work represents one of the few well EEG-documented cases of ictal epileptic headache in idiopathic generalized epilepsy (IGE).

Clinical experience with intravenous valproate as first-line treatment of status epilepticus and seizure clusters in selected populations.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of intravenous valproate (i.v. VPA) as first-line treatment of status epilepticus (SE) and seizure clusters in selected patient populations. METHODS: We enrolled 23 patients (11 females and 12 males; mean age: 61 years) with SE who received i.v. VPA as first-line therapy (25 mg/kg in 100 mL saline infused over 15 min). ECG tracing was monitored before, during, and after infusion. Liver function and serum ammonia tests were conducted after 24 and 72 h of treatment. We evaluate the response of SE to i.v. therapy and short-term outcome. RESULTS: In 15 out of 23 patients (65%), i.v. VPA was effective. In our population, we retrospectively identified three different subgroups: patients with cardiorespiratory comorbidities discouraging the use of traditional SE first-line drugs, patients with specific epileptic subsyndromes (such as idiopathic generalized epilepsy), and patients affected by psycho-organic syndromes. No significant adverse effects were detected. DISCUSSION: Our study shows the clinical relevance of i.v. VPA as first-line therapy of SE in patients with medical conditions contraindicating the use of traditional first-line antiepileptic drugs for SE, and in those presenting with specific forms of SE.

The spectrum of epileptic syndromes with fixation off sensitivity persisting in adult life.

PURPOSE: The term "fixation off sensitivity" (FOS) was proposed by Panayiotopoulos to describe epilepsy/electroencephalography (EEG) changes evoked by the suppression of central vision and fixation. The EEG pattern usually consists of spike/polyspike and waves localized in occipital regions. FOS occurs mainly in children with idiopathic occipital partial epilepsies and rarely in adults. In this retrospective study we evaluated the clinical data, EEG, and magnetic resonance imaging (MRI) findings of patients with epilepsy and FOS persisting in adult life to better define the spectrum of syndromes. METHODS: We selected 15 consecutive patients (12 female/3 male; age range 19-59 years). The main inclusion criterion was the diagnosis of epilepsy with FOS persisting in adult life. We retrospectively analyzed clinical EEG and neuroimaging data. KEY FINDINGS: We observed a female prevalence (F/M = 12/3). Eight patients presented both simple and complex partial seizures, whereas seven had only complex partial seizures. Partial seizures evolved into generalized seizures/hemiconvulsions in nine cases. The FOS pattern consisted of spike-and-wave and slow-wave abnormalities with posterior localization (bilateral in eight/monolateral in seven). We recorded seizures in 10/15 patients. All showed a posterior onset (bilateral in 2/left in 2/right in 6). FOS was prevalent in symptomatic epilepsy (cortical malformations in 7; celiac disease in 3; calcified vascular malformation in 1). One patient presented cryptogenic epilepsy and only three idiopathic epilepsy (Gastaut syndrome). SIGNIFICANCE: FOS can be observed in adult life in idiopathic epilepsy, representing the "prolongation" of the same phenomenon arisen during childhood. Nevertheless, it often represents the EEG expression of symptomatic epilepsies (cortical malformations/celiac disease).

Extrarolandic electroclinical findings in the evolution of adult-onset Rasmussen's encephalitis.

Rasmussen's encephalitis (RE) is a rare immunomediated disorder characterized by unilateral hemispheric atrophy, drug-resistant focal epilepsy, and progressive neurological deficits. Its onset typically occurs in childhood, though it has also been reported in adult age (A-RE) with atypical clinical features. The aim of this study was to describe the electroclinical features in a group of seven patients with A-RE. We retrospectively studied seven women aged 23-43years (mean: 32.1years) with a diagnosis of RE according to commonly accepted diagnostic criteria. All the patients were clinically evaluated and underwent prolonged video-EEG monitoring, laboratory investigations, and high-resolution MRI follow-up. All the patients displayed an ictal electroclinical pattern whose evolution varied. We identified an early phase characterized by polymorphic ictal electroclinical manifestations (temporal semiology in five cases, frontal in one, and parietal in the remaining case) and a late phase clinically characterized by viscerosensitive phenomena followed by somatosensitive signs, experiential symptoms, and motor signs in all the cases. In the late phase, the ictal EEG pattern was characterized by monomorphic, pseudorhythmic, repetitive slow-wave theta activity over the frontal and central regions, with ipsilateral propagation and/or secondary spreading to contralateral perisylvian structures. Patients were treated with a combination of AEDs and immunotherapy (steroids and IVIg); epilepsy surgery was performed in 3 cases. Our results show that A-RE is characterized by early and late clinical- and EEG-different features which may reflect a progressive involvement of a specific "extrarolandic" network in the advanced phase of the disease and may suggest that the electroclinical expression of RE varies according to the different stages of the pathological process.

Oxcarbazepine-induced myoclonic status epilepticus in juvenile myoclonic epilepsy.

Juvenile myoclonic epilepsy (JME) is a frequent idiopathic generalised epilepsy syndrome with typical clinical and EEG features that can usually be controlled by valproate monotherapy. JME may be underdiagnosed or misdiagnosed; in the latter case, it may be mistaken for partial epilepsy. The incorrect diagnosis of JME is likely to result in inappropriate therapy, which may, in turn, worsen the seizures. While a number of studies have documented that carbamazepine aggravates idiopathic generalised epilepsy, few have shown a worsening of symptoms following the administration of oxcarbazepine (OXC). We report the case of a 44-year-old male affected by JME in which the inappropriate use of OXC precipitated a dramatic worsening of myoclonic seizures. In this case, video-EEG monitoring documented myoclonic status epilepticus with positive and negative myoclonus, correlating with repetitive, continuous, rhythmic, generalised polyspike-and-wave discharges. This is the first case of myoclonic status epilepticus induced by OXC in a patient with JME which is clearly documented by video-EEG. A review of the literature with regards to OXC-induced worsening of seizures is also presented. [Published with video sequences].

Ictal epileptic headache as "subtle" symptom in generalized idiopathic epilepsy.

Epilepsy and migraine are common neurologic chronic disorders with episodic manifestations characterized by recurrent attacks and a return to baseline conditions between attacks. Epilepsy and migraine are frequently observed in comorbidity, with the occurrence of one disorder increasing the probability of the other: Migraine occurs in about one-fourth of patients with epilepsy, whereas epilepsy is present in 8-15% of patients with migraine. The link between headache and seizures is controversial and multifactorial. In epilepsy, headache can be seen as a preictal, ictal, or postictal phenomenon. In this report, we describe a case of a 37-year-old patient, affected by both drug-resistant generalized idiopathic epilepsy and headache, who displayed the sudden onset of a headache attack referred during a 24-h electroencephalography (EEG). The EEG tracing during this event revealed the activation of subcontinuous epileptic activity consisting of generalized spike-wave discharges (GSWDs) and generalized polyspike and wave discharges (GPSWDs) that persisted for 60 min, that is, until the disappearance of the headache. The case we describe appears to be original in that it represents one of the few EEG-documented ictal epileptic headaches in generalized idiopathic epilepsy.

Olfactory impairment in autoimmune encephalitis: another piece of the puzzle.

BACKGROUND: Despite being long neglected, olfaction has recently become a focus of intense research in neuroscience, as smell impairment has been consistently documented in both neurodegenerative and neuroinflammatory diseases. Considering the close anatomo-functional correlations between the limbic system and the central olfactory structures, we investigated olfaction in a population of patients with autoimmune encephalitis (AE). METHODS: Nineteen adult subjects (14 males, median age 64 years) diagnosed with definite (14/19) or possible (5/19) AE and followed for ≥ 6 months were enrolled. The Brief Smell Identification Test (B-SIT), a 12-item, forced-choice, scratch-and-sniff measure, was used to assess the patients' olfactory function in comparison with a group of sex- and age-matched healthy controls (HC). According to the B-SIT score, subjects were classified as anosmic (< 6), hyposmic (6-8) and normal (≥ 9). Electro-clinical, laboratory and neuroimaging findings were reviewed. RESULTS: Smell impairment was revealed in 15/19 patients (9 hyposmic, 6 anosmic), compared with 5/19 HC (p = 0.0029). Age, gender and smoking habits did not affect the participants' performance at B-SIT. Olfactory dysfunction appeared more common among patients with definite AE (p = 0.0374), regardless of autoantibody status. Subjects with higher modified Rankin Scale (mRS) scores at AE onset more likely presented hyposmia/anosmia (p = 0.033), and so did those with bilateral ictal/interictal EEG abnormalities (p = 0.006). CONCLUSIONS: We found olfaction to be impaired in a significantly large proportion of AE cases. Smell deficits appeared more common in subjects with severe AE (as indicated by both definite diagnosis and higher mRS score), and might represent an additional feature of immune-mediated encephalitis.