Acta Neurol Scand 1995: 92: 33-40 Printed in Belgium - all rights reserved

Copyright 0 Munksgaard 1995 ACTA NEUROLOGICA

SCANDINAVICA ISSN 0001-6314

Spectrum of epilepsy in neurocysticercosis: a long-term follow-up of 143 patients

Monteiro L, Nunes B, MendonGa D, Lopes J. Spectrum of epilepsy in neurocysticercosis: a long-term follow-up of 143 patients Acta Neurol Scand 1995: 92: 33-40. 0 Munksgaard 1995.

To characterize the clinical profile and the prognostic factors of the epilepsy due to parenchymal neurocysticercosis (NCC) 143 patients were analysed. Patients (62 men, 81 women) had a mean age at epilepsy onset of 29 years (range 2-71), mean epilepsy duration of 16 years (range 1-58) and mean follow-up of 5.2 years. Seizures were generalised tonic-clonic (GTC) in 50 patients (35%), simple partial (SP) in 66 (46%) and complex partial (CP) in 27 (19%). Epilepsy began as a single seizure in 73% and as a cluster of seizures or status epilepticus in 27 %. Seizures were controlled in 64% of patients. Multivariate analysis revealed that significant prognostic factors associated with seizure control were type of seizures and age at epilepsy onset. Control is more likely in GTC and SP seizures and in patients with a higher age at seizures onset. Our analysis establishes that epilepsy due to NCC is a heterogeneous syndrome concerning age and mode of onset, seizure type, duration of epilepsy and pattern of evolution probably related with different pathogenic mechanisms.

Neurocysticercosis (NCC) is the most common par- asitosis of the central nervous system (1). Before the advent of CT-scan, NCC was only sporadically diag- nosed in Portugal. Since 1983, computed tomogra- phy (CT) has been routinely used in Hospital Geral Santo Antonio (HGSA) in the study of epilepsy. In the last years the endemic nature of NCC in the North of Portugal was suspected and confirmed (2), although certainly with a lower prevalence than in other regions.

Seizures are the most frequent clinical manifesta- tion of NCC (2-4) and the main aetiology of late onset epilepsy in endemic areas for Tueniu soliurn taeniasis/cysticercosis (5-8). However, studies deal- ing with the characteristics of this form of symptom- atic epilepsy only recently appeared (9, 10). The aim of the present study is to contribute for a better knowledge of the spectrum of this epileptic disorder. In 143 patients with epilepsy caused by NCC, fac- tors contributing to seizure control were analysed.

Patients and methods

In a period of 10 years (1983-1992), 348 patients with NCC were diagnosed at the HGSA by CT scan, the "gold standard test" for the diagnosis of this cerebral infection (2, 11, 12). HGSA is a cen- tral hospital, being the neurological reference centre

Luis Monteiro I, Belina Nunes *, Denisa Mendonqa 3, JoBo Lopes Departments of ' Neurology, ' Neurophysiology, Hospital Geral Santo Antonio, Population Studies, lnstituto de Cilncias Biomdicas Abel Salazar, Porto, Portugal.

Key words: epilepsy; neurocysticercosis.

Luis Monteiro, Serviqo de Neurologia, Hospital Geral Santo Antonio, 4000 Porto, Portugal.

Accepted for publication October 12, 1994

for a population of 1.7 million inhabitants, both rural and urban, including a part of the district of Oporto and the north inland. Diagnostic CT criteria of pa- renchymal NCC, active or inactive, were detailed elsewhere (2, 13, 14). Briefly, they included charac- teristic lesions, mainly cortical located: i) small (5- 10 mm) round calcifications, single or multiple; ii) rounded areas (5-15 mm) with cerebrospinal fluid density not enhanced by the administration of con- trast medium (cysts); iii) ring or discoid enhancing lesions somounded bay edema (granulomas).

In recent years parenchymal active NCC was con- firmed by the presence of anti-cysticercus antibodies in the cerebrospinal fluid revealed by an ELISA (enzyme-linked imunosorbent assay) test (15). As previously reported (14) 52% of NCC patients were asymptomatic (incidental radiological findings) and the remaining had the symptomatic form of the dis- ease, 28 % of which were active forms, parenchymal or extraparenchymal. The present study was per- formed in symptomatic patients excluding patients with active extraparenchymal form of NCC. A total of 143 patients were studied: 119 with inactive and 24 with an active NCC at the moment of the first CT. At present there are no signs of activity in any of these patients after treatment with cysticidal drugs (praziquantel and/or albendazol). Two single gran- ulomatous lesions of uncertain etiology, were ex-

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Monteiro et al.

rn b e 20 r

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cised. With increasing experience in more recent pa- tients with a single granuloma no treatment was done and the spontaneous resolution of the lesion was documented by CT. There are two arguments for the exclusion of patients with an extraparenchymal form associated with seizures: either the disease remains active or patients have other potential epileptogenic lesions besides parenchymal calcifications (ventric- uloperitoneal shunt or infarction due to cysticercotic arteritis). Data on the 143 patients meeting the se- lection criteria was collected from the medical records and from questionnaires sent to patients in order to minimise missing data and to update the follow up in 70 patients who are regularly followed by their general practitioner. Complete medical information on all seizures’ parameters was collected for the great majority of patients and only in a very small num- ber there were missing data in some of the variables considered in the analyses. Seizures were classified in accordance with the International League Against Epilepsy (16). For classification and control analy- sis only the type of the first seizure was considered. Epilepsy onset was classified as: i) status epilepticus when partial or generalised seizures occurred with- out complete recover of consciousness between sei- zures, ii) cluster of seizures when more than one seizure occurred during the first 48 h but with com- plete recover of consciousness between them; iii) spo- radic seizures when only a single seizure occurred in the first 48 h. The time elapsed between epilepsy onset and 1992 was called duration of epilepsy, re- gardless of the epilepsy pattern, i.e., independently of any period of remission of seizures. Epileptic sei- zures were considered controlled (or in remission) if patients had been free of seizures for more than two years at 1992 with or without antiepileptic drugs (AED) and again regardless of the existence or not of remissions in the past (17). Phenytoin, carbam- azepine, phenobarbital was used in monotherapy and in association in resistant cases. Antiepileptic treatment was started either early, after seizures’ onset or after seizures recurrence. All EEGs were recorded on 16- channel machines with both refer- ential and bipolar recordings by means of the inter- national 10-20 electrode placement system. A stan- dard EEG was made with hyperventilation for 3 min and intermittent photic stimulation. The EEGs were classified as normal or as presenting focal or gener- alised paroxysmal activity; records presented simul- taneously focal and generalised abnormalities were classified in the focal group. EEG focal activity was considered ipsilateral or controlateral when appeared respectively on the same or on the opposite hemi- sphere of a single CT lesion. Paroxysmal activity when present on both sides was named bilateral.

Statistical analysis - Comparisons between groups were made using the Pearson chi-square test for the

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analysis of the categorical variables, and the Stu- dent’s t-test for the continuous variables. The Kappa statistic (K) was used to assess the agreement be- tween EEG focus and the location of CT calcifica- tion. Factors such as sex, age of epilepsy onset, type of epilepsy, duration of epilepsy, and AED treat- ment were compared between the two groups of patients with controlled and non-controlled seizures. To account for the interrelationship between these factors, logistic regression techniques were used. The estimated odds-ratios and 95 % confidence intervals for the relevant factors were obtained from the re- sults of the logistic regression analysis. To be con- sistent with the results of the logistic regression the unadjusted (single factor) 2’ values were also cal- culated using the likelihood ratio criterion. For the logistic regression analysis all explanatory variables were used in categorical form. The variables age at epilepsy onset and duration of epilepsy were classi- fied into categories: age of epilepsy onset was grouped into three categories (< 19 , 19-45 and >45 years) and duration was aggregated in three groups (2-9 , 10-29 and > 29 years). Throughout the analyses, a level of 5 % was used to indicate statistical signifi- cance. SPSS (18) and BMDP (19) statistical soft- ware were used to perform the analyses.

Results

The 143 patients (62 men; 81 women) had a mean age at epilepsy onset of 29 years (range 2-71 years; sd 17.7), illustrated in Fig. 1. The duration of epi- lepsy had a mean value of 16 years (range 1-58). The mean follow-up was 5.2 years (range 1-18) with 51 % of patients regularly followed in our epileptic out- patient clinic.

Seizure type - Seizures were generalised tonic- clonic (GTC) in 50 patients (35%) and had a par- tial onset in 93 cases (65%). In this later group, 66 were simple partial (SP) with secondary generalisa-

[ 11.143 1 301 I I

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Epilepsy in neurocysticercosis

tion in 48 patients and in the remaining 27 seizures were complex partial (CP) with secondary general- isation in 20.

Epilepsy onset - In 132 patients the mode of sei- zure’s onset was known: 9 (7%) as a status epilep- ticus (partial = 7, generalised = 2), 27 (20%) as a cluster of seizures and in the remaining 96 patients (73%) as a single seizure. In this later group there are 24 patients with only a single seizure during follow-up (mean disease duration of 5.8 years, range 1-16, mean age of seizures’ onset of 38 years, range 6-70) and in patients with more than one seizure the interval between seizures’ recurrence was highly variable: < 5 years (n = 63); 5-10 years (n = 4); > 10 years (n = 5).

Control of seizures - Information about the control of seizures was available in 136 patients (95%). Ten cases had a duration of epilepsy less than two years and according to the definition of seizures’ control adopted were not considered for this analysis. Sei- zures were controlled in 64% (81/126) of patients and uncontrolled in 45 patients. The pattern of re- currence was yearly in 17, monthly in 22 and weekly in 6 patients. Of 126 patients, 4 were never medi- cated, 91 are on monotherapy and 29 patients are on polytherapy, mostly on the group without control of seizures. Table 1 summarises the main characteris- tics of these 126 patients. The group with controlled seizures has a significantly higher age of epilepsy onset than the group with uncontrolled seizures (t = 4.16, p < 0.001). Significant differences were also found in relation to seizure type ( x 2 = 24.25, p < 0.00 1) - the percentage of seizure control is high- est in patients with GTC seizures (86%), drops to 27% in patients with CP seizures and presents an intermediate value in patients with SP seizures. Al- though the numbers are too small for a consistent analysis concerning the mode of seizures onset and the control of seizures it can be noticed that all the seven patients with epilepsy starting as status epi- lepticus have seizures controlled. No statistically significant difference in control of seizures was found

Table 1. Control of seizures in patients with duration of epilepsy > 2 years

in terms of sex (x2=0.01, p>O.O5): males and fe- males present similar proportions. The percentage of patients with seizures controlled is significantly higher among those treated early than in patients who started AED treatment only after seizures’ re- currence ( x 2 = 4.6, p < 0.05). It must be emphasised that the majority of patients (68 %) were treated im- mediately after the first seizure. Concerning the du- ration of epilepsy significant differences were found in the percentage of patients with seizures controlled ( x ’ = 9.03, p<O.O5): the group of patients with du- ration x 10 years presents a relatively high percent- age with seizure controlled 76% whilst the group with duration >29 shows the lowest percentage (39%). When the factors were modelled together, the association of type of epilepsy and age of onset with seizure control remained significant at 5% level, whilst duration of epilepsy and AED treatment be- came non-significant. In addition sex remained non- significant. Adjusting each significant factor for the other led to a reduction in the chi-square values: for age x 2 adjusted = 9.64 (unadjusted 15.41) and for type of epilepsy x 2 adjusted = 19.01 (unadjusted 24.78). Using CP seizures as the reference group and controlling for age, the results of the model show that patients who present GTC or SP had a much higher probability of having seizures controlled - odds ratio: 12.8 (95% CI 3.5-46.3) and 5.72 (95% CI 1.9-17.1), respectively. Adjusting for type of sei- zures, in general there was an increase in control of seizures as age of onset increased: patients in the groups 19-45 or > 45 years had a much higher prob- ability of having seizures controlled relative to the reference group of youngest subjects - odds ratio: 3.0 (95% CI 1.2-7.4) and 6.6 (95% CI 1.5-29.8), respectively.

Neuroradiologicalfidings - CT presented a single (n = 51) or multiple (n = 68) parenchymal calcifica- tions. In the 24 active forms, the first CT revealed a combination of cysts and calcifications in 9 cases, a single cysticercotic granuloma in 8, an association of cysts, granulomas and calcifications in 6 and cysts

Sex Age of Epilepsy onset’ Seizure type Treatment onset’ Duration of epilepsy (years) onset

Male Female (mean) E.S. CI. Sz. Sp. Sz. SP CP GTC First Sz Later < 10 10-29 >29

Sz.: seizure; E.S.: epileptic status; CI.: cluster; Sp.: sporadic; SP: simple partial; CP: complex partial; GTC: generalized tonic-clonic; ’ unknown in seven patients; unknown in 13 patients.

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Monteiro et al.

Table 2. Clinical characteristics of patients with single vs multiple calcifications

Epilepsy onset’ Seizure type Control of seizures’

(mean) E.S. CI. sz. sp. sz. SP CP GTC Yes No Age of onset

Single lesion 28 years 3 133%) 8 (30%) 40 (42%) 27 (41%) 8 (30%) 24 (48%) 34 (42%) 18 (40%) (n=59)

Multiple lesions 30 years 6 (67%) 19 (70%) 56 (58%) 39 (59%) 19 (70%) 26 (52%) 47 (58%) 27 (60%) (n = 84)

E.S.: epileptic status; CI.: cluster; Sz.: seizure; Sp.: sporadic; SP: simple partial; CP: complex partial; GTC: generalized tonico-clonic; ’ unknown in eleven patients; unknown in seven patients and ten with duration <2 years.

with granulomas in 1 case. In Table 2, the two groups of patients, with a single lesion and with multiple lesions are compared in relation to some param- eters. No statistical significant difference was found between the two groups in terms of age at onset (t = 0.92, p > 0.05), type of presentation (x’ = 1.40, p > 0.05), seizures’ type ( x 2 = 2.45, p > 0.05) and sei- zures’ control ( x 2 = 0.01, p > 0.05).

EEG findings - At least one EEG record was obtained in 128 patients (90%). Of the patients with known information about control of seizures and duration of epilepsy higher than two years, 116 had EEGs recorded. EEG was normal in 27(23%) and abnormal in 89 (77%). Abnormal slow activity as- sociated or not with paroxysmal events was recorded in 71 cases and in the remainder only paroxysmal activity was present. Normal and abnormal EEG groups presented similar proportions of seizures controlled, 66% and 62%, respectively (x’= 0.05, p> 0.05). Significant association was found between type of seizures and abnormality in EEG (x’ = 6.2, p < 0.05): patients having GTC seizures presented the highest percentage of normal results (35%). The corresponding percentage drops to 8 % and 22% for CP and SP, respectively.

CTIEEG correlation - In 48 of the 5 1 patients with a single calcification on the first CT at least one EEG record was performed and we analysed a possible association between CT location and EEG focal ab- normalities. EEG was normal in 12 patients and presented focal abnormalities in 3 1 and generalised paroxysmal activity in 5. Focal EEG paroxysmal activity was ipsilateral in 14 of the 31 focal EEGs and controlateral or bilateral in the remainder. Within the group of patients with unilateral focal EEG ab- normalities no significant agreement was exhibited between the EEG focus and the location of the cal- cification (k = 0.24; p > 0.05). The relatively small sample size in each subgroup of seizure type pre- cludes any detailed analysis of the association be- tween type of seizures and EEG focus in patients with a single calcification.

Illustrative cases

Although epilepsy due to NCC is similar to other epilepsies in most of its characteristics, there are some features, presumably related with the seizure threshold of each patient the location and staging (transitory acute inflammation vs definitive scar) of lesions resulting in different patterns of epileptic dis- order. In this perspective we present four clinical examples.

Case I - A-7-year old male child, with a single GTC seizure preceded by a visual aura at age 5, with a normal neurologic examination and a first CT showing a contrast-enhanced ring lesion surrounded by white matter edema (Fig. 2a). A concomitant EEG presented focal paroxysmal activity concor- dant with the CT location. Cerebrospinal fluid ex- amination gave normal results including the ELISA test for anti-cysticercus antibodies. Serum enzyme- linked electrotransfer blot assay (20) was positive. He was started on 100 mg per day of phenobarbital, albendazol(300 mg per day) during 8 days and dex- ametasone. One month later there was only a re- sidual lesion (Fig. 2b,c) One year later the MR was normal (Fig. 2d). A second EEG was performed after one year of phenobarbital treatment that gave normal results and phenobarbital was withdrawn without recurrence of seizures in the following two years. Comment - this case represents the most be- nign spectrum of seizure disorder in NCC, with sei- zures appearing only during the acute phase of the cyst degeneration (granuloma) which resolved with- out any radiological or functional sequel.

Case 2 - A-24-year old woman with a single left parasagital calcification who has had simple partial sensitivomotor seizures of the right leg during two years, from age 13 until 15, and is presently free of seizures and not under AED. Comment - this case also represents a benign form of epilepsy with a few number of partial seizures during a brief period, en- tering easily into prolonged remission.

Case 3 - A-54-year old man had a first GTC

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Epilepsy in neurocysticercosis

Fig. 3. MR axial T2 weighted images. Globular hipointense le- sions surrounding by hyperintense halo, corresponding respec- tively to calcified granuloma and likely glial scars.

controlled and she had a partial left motor status epilepticus in 1986. Three years later she started having right partial motor seizures with aphasia and she had three more status epilepticus during the following years. A MR showed multiple calcifica- tions, almost all surrounded by glial scars (Fig. 3). Comment - This case represents the other end of the disease severity with uncontrolled seizures and of different seizure’s types due to several epileptic foci originated by multiple glial scars.

Fig. 2 . a) Contrast enhanced CT. Posterior parietal granuloma surrounding by oedema. b) Contrast enhanced CT, one month later. Only a residual lesion can be seen (arrow). c) MR T2- weighted image contemporary of b), showing a small hyperintense lesion (arrow). d) Normal MR image one year later.

seizure during sleep, at age 22 that recurred only 14 years later, when he was 36; he was never treated and had a third seizure at age 49, again during sleep. He remained untreated until the fourth GTC seizure three months later, when he sought medical care. The diagnosis of NCC was based on multiple cal- cifications on CT and he was put on AED (pheny- toin 200 mg per day). The EEG presents left tem- poral paroxysmal activity. Comment: This patient raises some questions in relation with the concept of remission and pathogenesis of epilepsy, and the need of antiepileptic treatment after the first seizure in NCC cases. Does each seizure represent a granulo- matous transformation of one cyst or the effect of trigger seizures’ factors (sleep deprivation, alcohol ingestion, etc) acting concurrently in a damaged cor- tex?

Case 4 - This 54-year-old woman started epilepsy at age 25, with GTC and CP seizures. At age 44 years she has started with left motor partial seizures maintaining the previous seizuresr types. A CT done in 1984 revealed multiple calcifications, cysts and granulomas and the EEG presented left temporal and generalised paroxysmal activity. She was treated with praziquantel during 15 days. In spite of differ- ent medical approaches the epilepsy remained un-

Discussion

Seizures are the most frequent clinical manifestation of NCC, either as an isolated symptom or as part of a more complex neurological picture (2,3). Reported epilepsy frequency varies with the availability of sen- sitive test (before or after CT), the inclusion criteria and hospital setting. The CT increased fivefold the accuracy of the NCC diagnosis (13,21) and re- vealed this parasitosis to be the main single cause of late-onset epilepsy in endemic areas of Tueniu solium cysticercosis (5-9). Before CT era, Dixon & Lipscomb (4) describe, in military personnel coming from India, the only series of NCC patients in which epilepsy predominates. The diagnosis was easily made due to the presence of subcutaneous cysticerci and/or muscle calcifications seen on X-ray. In the studies of CT era, epilepsy emerged definitively as the most common clinical NCC presentation al- though at variable frequencies (2, 3, 7, 22) due to inclusion criteria. While epilepsy is a constant fea- ture of the symptomatic parenchymal forms, either inactive or active, is much less frequent in the ex- traparenchymal cases (14, 23).

The outcome of this symptomatic epilepsy was the subject of two recent longitudinal studies of adult patients treated with cysticidal drugs, one with ex-

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Monteiro et al.

clusively parenchymal active forms (10) and the other with a large predominance of active forms, parenchymal and extraparenchymal (9). The present series, with 83% of inactive NCC lesions and a longer follow-up provides further insight into the un- derstanding of this symptomatic epilepsy

The NCC affects both sexes indistinguishably and manifests usually in the age group 20-40 years, al- though it is not rare in children (24, 25). In the present series the mean age at epilepsy onset was 29 years. This value is lower than the reported in the two recent studies (9, 10) due to the inclusion of paediatric patients and to the exclusion of extra- parenchymatous forms.

In the seminal paper of Dixon & Lipscomb (4) is stated "On the whole the epileptic attacks were in- distinguishable from those of idiopathic epilepsy [ ...] but appeared to be a greater tendency towards vari- ation in the pattern of the fits....". Before CT, rel- evance was given to the side shifting of simple par- tial seizures as an attribute of NCC (26). However this phenomenon is uncommon, being reported spo- radically (27) and occurring in our series only in one patient (case 4).

Partial seizures, with or without secondary gen- eralisation, occurred in two thirds of cases similarly to what is well established (3-5, 7, 10) and in con- trast to the unexpected high percentage of GTC sei- zures reported in a recent investigation (9), timely criticised (28). The mode of epilepsy onset has been scarcely referred in the literature. Status epilepticus occurred in 7% of our patients, percentage higher than the 2.4% reported for an adult series (9) and significantly lower than the value of 20% found in a paediatric study (25).

In previous studies, follow-up is either nonexist- ent (26) or shorter (9,lO) than the mean value of 5.2 years of the present series. This long follow-up al- lowed to establish different prognostic trends of the NCC epilepsy. It was possible to identify 24 (18%) patients with no recurrence after the first seizure. Within this last group seven patients presented a single seizure and a single granuloma (being Case 1 an example), a particular clinico-radiologic picture that should be individualised given that is the most benign condition within the spectrum of the symp- tomatic NCC (29).

The search for risk predictors of recurrence after a first unprovoked seizure was the subject of impor- tant studies in the last decade and the object of a meta-analysis (30). This quantitative analysis esti- mated an overall risk of 51 % at two years. Etiology, epileptiform dicharges and partial seizure type were reliable predictors of recurrence. In the present study, as in the others (9) EEG was non contribu- tory to assess the likelihood of recurrence. In a com- munity based epileptic study (3 1) where all types and

etiologies of seizures were represented the EEG was also non contributory for prognostic evaluation. Conversely in a recent prospective hospital-based investigation in patients with idiopathic first GTC seizures (32) epileptiform discharges in the EEG were considered predictors of higher risk of recur- rence.

In our series 66% of patients are seizures free. GTC seizures have the best prognosis and CP sei- zures the worst, according to what is common in epileptology (33). All patients with onset by status epilepticus have seizures controlled. Higher age at first seizure was a good prognostic factor for remis- sion. Adjusting for age of onset and type of seizures, duration of epilepsy, sex and AED treatment imme- diately after the first seizure had no predictive value. Furthermore CT findings (single or multiple calcifi- cations) were also not associated with prognosis, similarly to what was reported by others (9)

Nine patients, exemplified by Case 3, had spon- taneous recurrence intervals of more than five years. The possibility of spontaneous long interval between seizures is well known (4) which makes arguable the rationale of chronic antiepileptic treatment. Further- more, inactive parenchymal NCC is frequently an asymptomatic infection (2). Recent epidemiological studies (34) reinforce the notion that in endemic communities a majority of infected subjects are also asymptomatic.

Focal abnormalities were found in 71 % of the EEG records. Furthermore there was also focal ab- normalities in 62% of the EEGs of patients with GTC seizures that seems to demonstrate that seizures clinically classified as generalised are focally origi- nated. An electro-anatomical concordance (EEG focus with single calcification) was only found in two thirds of patients, lower than the figure described by others (35).

The main mechanism involved in epileptogenesis of NCC has been linked to the glial scar around the calcified parasite (28, 35, 36). However, and simi- larly to what occurs in other acute neurological in- sults, there are also acute symptomatic seizures due to inflammatory reaction around the dying larva. Seizures due to acute infectious diseases of the cen- tral nervous system are often self-limited conditions (37). Only remote symptomatic seizures must be considered an epileptic disorder condition (38).

Previously we reported six patients with a single granuloma who had a single seizure during the acute inflammatory episode (29). We hypothesised that in NCC the occurrence of seizures depends on several factors, including the host immune response to the parasite, the location and staging of the lesions, the convulsive threshold of the patient and other life- style dependent epileptogenic factors. In our opinion the individual epileptogenic threshold is of para-

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mount importance as presumed by a high percent- age of asymptomatic cases and the large spectrum of seizure’s behaviour in epileptic patients with similar radiological findings.

This study has clear limitations. First, it is a ret- rospective study without a homogeneous methodol- ogy either from the clinical, therapeutically or ancil- lary examinations. Second, there has been important modifications in clinical practice during the decade under analysis. In the last years patients with a first seizure are rapidly referred to tertiary neurological centres were most of them are immediately submit- ted to CT and antiepileptic treatment

In conclusion, our study confirms the good prog- nosis of epilepsy due to NCC but it also reveals its strong variability in what concerns mode of seizures onset, seizures type, duration of epilepsy and sei- zures’ control. A better prognosis is associated with a late age of onset of epilepsy, GTC seizures and a single granuloma. Epilepsy caused by NCC is a het- erogeneous condition related with multiple patho- genic mechanisms, with a spectrum of behaviour ranging from a single fit to uncontrolled seizures.

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