Francesco Deleo

Type I focal cortical dysplasia: surgical outcome is related to histopathology

Pre-surgical and post-surgical data were examined and compared from 215 consecutive patients undergoing surgery for intractable epilepsy. Patients were selected on the basis of a proven histopathological diagnosis of type I focal cortical dysplasia (FCD I), alone or associated with other lesions. The patients were divided into five sub-groups: i) 66 with isolated FCD I, ii) 76 with FCD I and hippocampal sclerosis, iii) 49 with FCD I and tumours, iv) 16 with FCD I and other malformations of cortical development and v) eight with FCD I and anoxic-ischaemic or inflammatory diseases. The duration of epilepsy was greatest in patients with FCD I associated with hippocampal sclerosis, and those with isolated FCD I showed the highest seizure frequency at the time of surgery. Hippocampal sclerosis and tumours were the most frequent pathological lesions associated with FCD I in temporal lobe epilepsy. Febrile seizures significantly correlated with the presence of hippocampal sclerosis and FCD I. Isolated FCD I was observed in 31% of the patients, characterized by frequent seizures, negative magnetic resonance imaging, and frequent frontal or multilobar involvement. In comparison to patients with FCD I associated with hippocampal sclerosis, MCD or tumours, the patients with isolated FCD I had a worse post-surgical outcome (46% in class I). Our findings indicate that there is a high incidence of FCD I associated with other apparently distinct pathologies, particularly those affecting the temporal lobe, and highlight the need for a comprehensive clinicopathological approach for the classification of FCD I.

Temporal lobe epilepsy: neuropathological and clinical correlations in 243 surgically treated patients

The present study included analysis of data from 243 patients surgically treated for Temporal Lobe Epilepsy (TLE). Resection was confined to the temporal lobe, with at least two years of follow-up, and specimens sufficiently preserved to allow a precise evaluation of both lateral neocortex and hippocampus. The frequency of different types of lesion and hippocampal sclerosis (HS), isolated or associated with neocortical lesions, risk factors and surgical outcomes in relation to neuropathological findings were evaluated. We found tumours in 33% of patients, malformations of cortical development (MCD) in 45%, isolated HS in 14%, no lesion in 5% and less common lesions in 3%. HS was present in 8% of tumour cases and 70% of MCD. Statistical analysis of antecedents was significantly associated only with febrile seizures (FS). In MCD patients with no history of FS, a strong association between HS and duration of epilepsy was revealed. A Class I outcome was identified in 87% of cases with tumours and 79% in cases with MCD. In 93 patients the antiepileptic drug therapy was withdrawn. Our findings show that MCD, which is significantly associated with HS, is the most common lesion in TLE and support the concept that an optimal outcome is obtained when mesial and neocortical structures are removed. FS are particularly relevant in patients with focal cortical dysplasia and HS.

Electroclinical, MRI and surgical outcomes in 100 epileptic patients with type II FCD

Focal cortical dysplasias (FCDs) are highly epileptogenic malformations associated with drug-resistant epilepsy, susceptible to surgical treatment. Among the different types of FCD, the type II includes two subgroups based on the absence (IIa) or presence (IIb) of balloon cells. The aim of this retrospective study was to investigate possible differences in electroclinical presentations and surgical outcomes between the two subgroups in 100 consecutive surgically treated patients with type II FCDs. All patients underwent a comprehensive presurgical assessment including stereo-EEG (SEEG) when necessary. No significant differences in gender, age at epilepsy onset, duration of epilepsy, age at surgery or seizure frequency were found between the two subgroups. Patients with type IIb FCD frequently showed sleep-related epilepsy. Their peculiar electrographic pattern was characterised by localised rhythmic or pseudo-rhythmic spikes or polyspikes (“brushes”) enhanced during non-REM sleep and also associated with well-localised, brief, low-voltage fast activity. The incidence and frequency of short bursts of fast discharges, interrupted by activity suppression, increased during slow-wave sleep and often recurred pseudo-periodically. The occurrence of “brushes”, present in 76% of the patients with type IIb FCD, was significantly associated (p<0.001) with the presence of balloon cells. We discuss the possible pathogenetic mechanisms underlying this activity. MRI diagnosis of type II FCD was made in 93% of the patients with balloon cells (BCs), suggesting that the presence of balloon cells might be, at least partially, responsible for the MRI features. Patients had very good postsurgical outcomes (83% in Engel class I) even after a long period of follow-up.

Short- and long-term surgical outcomes of temporal lobe epilepsy associated with hippocampal sclerosis: Relationships with neuropathology

Hippocampal sclerosis (HS) is the most frequent neuropathologic finding in patients undergoing surgery for intractable temporal lobe epilepsy (TLE). The International League Against Epilepsy (ILAE) has recently proposed a new classification of HS based on specific patterns of cell loss. The aim of this study was to investigate the relationships between HS types, their etiologic factors, and the short‐ and long‐term postsurgical outcomes of patients undergoing surgery because of drug‐resistant TLE with HS.

Sleep breathing disorders in 40 Italian patients with Myotonic dystrophy type 1

The aim of this study was to estimate the prevalence and nature of sleep breathing disorders in Myotonic dystrophy type 1 (DM1). We wanted to determine whether there is a relationship between sleep breathing disorders and clinical parameters such as pulmonary function, degree of neuromuscular impairment, daytime sleepiness, and fatigue. This will help assess the prevalence of DM1 patients requiring nocturnal ventilatory treatments. We studied a random sample of 40 unrelated patients and found that 22/40 patients had obstructive sleep apnoea. Of these 22 patients, five showed also periodic breathing and four showed sleep hypoventilation. Nine patients were put on nocturnal ventilation following clinical and instrumental evaluations. Our study reveals that obstructive sleep apnoea is very common in these patients, but cannot be predicted on the basis of clinical-neurological features and diurnal functional respiratory tests. Our data emphasize that a periodical evaluation by polysomnography should be mandatory to ascertain, and treat if necessary, the presence of obstructive sleep apnoea, periodic breathing or nocturnal hypoventilation.

Refractory epilepsy and encephalocele: Lesionectomy or tailored surgery?

We read with great interest the paper entitled ‘‘Tailored surgery for drug-resistant epilepsy due to temporal pole encephalocele and microdysgenesis’’ by Giulioni et al. The authors describe two cases of encephalocele associated with cortical microdysgenesis and assert the necessity to consider an extensive surgical resection in subjects with small encephaloceles, due to the possible concomitance of malformations of cortical development. We recently observed two patients that may represent two opposite situations of patients. The first subject is a woman who experienced a tonic– clonic seizure during sleep at age 14 years, and was started with carbamazepine (CBZ) up to 1200 mg/day. No seizures appeared for 8 years. At age 22, she started to experience brief, weekly complex partial seizures, described as loss of consciousness, gestural and bipedal automatisms, followed by confusional status. Seizures persisted despite treatment with numerous antiepileptic drugs in various combinations. At age 35, when she came to our observation, physical and neurologic examinations were normal. Video-EEG monitoring allowed recording a nocturnal seizure originating from wide area of the right frontal lobe. MRI showed a small encephalocele associated with a linear cortical hyperintensity in T2-weighted sequences, localized in right anterior frontal region (Fig. 1A). Neuropsychological examination showed impairment in visuospatial memory, constructive apraxia and difficulties in planning actions, consistent with a right frontotemporal impairment. At age 36, she underwent lesionectomy and resection of adjacent cortex (Fig. 1B). Histologic examination showed encephalocele and an associated type IB focal cortical dysplasia (FCD), extending beyond the resection margin. Surgery was uncomplicated, without any additional post-operative neurologic or neuropsychological deficits, but seizure frequency was not modified (Engel class IV) at 5 years of follow-up. Patient refused further surgical interventions. The second patient is a 20-year-old man who came to our observation at age 14 for rare seizures characterized by déjà-vu, dreaming state and sometimes oral automatisms. Treatment with carbamazepine resulted in seizure freedom for 14 months, then he started experiencing weekly complex partial seizures with cephalic aura, loss of consciousness, oral and gestural automatisms, dystonia and clonic movements of right upper limb, followed by confusion state. Adjunctive treatment with topiramate and, subsequently, lacosamide did not modify seizure frequency. Standard brain MRI was deemed normal. At age 20 he was evaluated for epilepsy surgery. Prolonged video-EEG monitoring allowed detecting three seizures originating from left temporal lobe. High-resolution CT scan (Fig. 1B) showed a small bony defect in left mesial portion of middle cranial fossa. MRI targeted at temporal pole (Fig. 1C) evidenced a tiny encephalocele

Hemispherotomy in Rasmussen encephalitis: Long-term outcome in an Italian series of 16 patients

Surgical disconnection of the affected hemisphere is considered the treatment of choice for Rasmussen encephalitis (RE), however few data on long-term outcomes after disconnective surgery are available. We report on long-term seizure, cognitive and motor outcomes after disconnective surgery in 16 (8 M, 8 F) RE patients. Pre- and post-operative evaluations included long-term video-EEG monitoring, MRI, assessment of motor function, and cognitive evaluation. Hemispherotomy, by various techniques was used to obtain functional disconnection of the affected hemisphere. The patients, of median current age 23.5 years, range 12-33, were operated on between 1993 and 2009. Median age at disease onset was 5.8 years (range 3-11.4). Median time from seizure onset to surgery was 3.8 years, range 8 months to 21 years. Post-surgical follow-up was a median of 9.5 years, range 3-20. At surgery all patients were receiving two or more antiepileptic drugs (AEDs). All but three patients were seizure-free at latest follow-up. AEDs had been stopped in ten patients; in the remaining six AEDs were markedly reduced. Postural control improved in all patients. Gain in cognitive functioning was significantly (p=0.002) related to disease duration. The long-term outcomes, in terms of seizure control, motor improvement, and cognitive improvement provide important support for disconnective surgery as first choice treatment for RE.

Long-term outcome after limited cortical resections in two cases of adult-onset Rasmussen encephalitis.

Rasmussen encephalitis (RE) is a progressive inflammatory disorder characterized by brain hemiatrophy, unilateral focal deficits, and drug‐refractory focal epilepsy. Epilepsia partialis continua (EPC) is a hallmark of the disease. Several immunomodulatory treatments may slow but not halt the disease progression. The treatment of choice still relies on surgical hemispheric disconnection, which is burdened by heavy neurologic morbidity. More limited cortical resections, although more tolerable, are usually considered to be, at best, only transiently effective in RE. Hemispheric disconnections may be not feasible when neurologic functions are preserved and the dominant hemisphere is affected. Adult patients with a milder RE course that preserves neurologic function for a long period are particularly at risk of developing severe deficits after surgery. In this study we present the histories of two patients with adult‐onset RE who have undergone selective cortical resections to control EPC, avoiding, at the same time, the severe postsurgical deficits that may be induced by hemispheric disconnective surgery. The good result obtained on EPC has been stable over a prolonged period; however, this result was not paralleled by the stop of neurologic progression in one of the two cases.

Different parvalbumin and GABA expression in human epileptogenic focal cortical dysplasia

Several studies have reported that inhibitory networks are altered in dysplastic tissue obtained from epilepsy surgery specimens. A consistent decrease in the number of inhibitory interneuronal subpopulation that expresses parvalbumin (PV) was reported in postsurgical tissue from patients with focal cortical dysplasia (FCD). We tested if the decrease in PV protein expression observed in epileptic tissue corresponds to a parallel impairment in the γ‐aminobutyric acid (GABA)ergic compartment.

Bitemporal epilepsy: A specific anatomo-electro-clinical phenotype in the temporal lobe epilepsy spectrum

PURPOSE Temporal lobe epilepsy (TLE) with bilateral ictal involvement (bitemporal epilepsy, BTLE) is an intriguing form of TLE whose characteristics need to be carefully identified as BTLE patients are not good surgical candidates. The purpose of this study was to define the anatomo-electro-clinical features differentiating BTLE from unilateral TLE (UTLE). METHODS Forty-eight BTLE patients underwent long-term video-EEG monitoring (VEEG) and experienced seizures with bilateral temporal lobe involvement. Their main electro-clinical (demographics, interictal and ictal EEG, ictal signs) and neuro-imaging [brain magnetic resonance imaging (MRI)] data were compared with those of a group of 38 UTLE patients. RESULTS In comparison with the UTLE patients, the BTLE cohort was significantly older at the time of epilepsy onset (p = 0.023), more frequently experienced bilateral asynchronous interictal epileptiform discharges during wakefulness (p = 0.001) and sleep (p < 0.001), bilateral upper limb dystonia (p = 0.005), and auditory auras (p = 0.027), and less frequently showed a recognisable initial ictal EEG pattern of focal flattening or low-voltage fast activity (p < 0.001), post-ictal memory of seizures (p = 0.001), staring (p < 0.001), head deviation (p = 0.004), oro-alimentary automatisms (p = 0.006), and positive brain MRI (p < 0.001). MRI revealed neoplastic lesions (p = 0.007) or alterations other than hippocampal sclerosis (p = 0.028) only in the UTLE patients. CONCLUSION The possibility of recognising BTLE patients during pre-surgical evaluation or being able to suspect bitemporal seizures before VEEG by identifying particular anatomo-electro-clinical patterns is diagnostically important for epileptologists and can help to prevent possible surgical failures.