Asier Gomez-Ibañez

Hyperammonemic encephalopathy related to valproate, phenobarbital, and topiramate synergism

We present a woman with epilepsy secondary to a lesion in the left frontal lobe. She developed episodes of disorientation and behavioral changes. She was taking valproic acid (1500 mg/day), topiramate (200 mg/day), and phenobarbital (100 mg/day). During an episode, the EEG revealed moderate encephalopathy and ammonia levels were increased (195 μg/dL, reference range: 11-60 μg/dL). Episodes ceased after withdrawal of valproic acid.

Recognition of facial emotions and identity in patients with mesial temporal lobe and idiopathic generalized epilepsy: An eye-tracking study

PURPOSE To describe visual scanning pattern for facial identity recognition (FIR) and emotion recognition (FER) in patients with idiopathic generalized (IGE) and mesial temporal lobe epilepsy (MTLE). Secondary endpoint was to correlate the results with cognitive function. METHODS Benton Facial Recognition Test (BFRT) and Ekman&Friesen series were performed for FIR and FER respectively in 23 controls, 20 IGE and 19 MTLE patients. Eye movements were recorded by a Hi-Speed eye-tracker system. Neuropsychological tools explored cognitive function. RESULTS Correct FIR rate was 78% in controls, 70.7% in IGE and 67.4% (p=0.009) in MTLE patients. FER hits reached 82.7% in controls, 74.3% in IGE (p=0.006) and 73.4% in MTLE (p=0.002) groups. IGE patients failed in disgust (p=0.005) and MTLE ones in fear (p=0.009) and disgust (p=0.03). FER correlated with neuropsychological scores, particularly verbal fluency (r=0.542, p<0.001). Eye-tracking revealed that controls scanned faces more diffusely than IGE and MTLE patients for FIR, who tended to top facial areas. A longer scanning of the top facial area was found in the three groups for FER. Gap between top and bottom facial region fixation time decreased in MTLE patients, with more but shorter fixations in bottom facial region. However, none of these findings were statistically significant. CONCLUSION FIR was impaired in MTLE patients, and FER in both IGE and MTLE, particularly for fear and disgust. Although not statistically significant, those with impaired FER tended to perform more diffuse eye-tracking over the faces and have cognitive dysfunction.

Aberrant Mitochondria in a Bethlem Myopathy Patient with a Homozygous Amino Acid Substitution That Destabilizes the Collagen VI α2(VI) Chain

Background: Collagen VI amino acid substitutions are common, and it is difficult to determine if they are pathogenic. Results: COL6A2 p.D871N chains are abnormal and cannot assemble. Alternatively spliced chains lacking the mutation cannot functionally substitute. Conclusion: COL6A2 p.D871N is a recessive mutation. Significance: Protein studies reveal the consequences of amino acid substitutions in the globular domains of collagen VI. Bethlem myopathy and Ullrich congenital muscular dystrophy (UCMD) sit at opposite ends of a clinical spectrum caused by mutations in the extracellular matrix protein collagen VI. Bethlem myopathy is relatively mild, and patients remain ambulant in adulthood while many UCMD patients lose ambulation by their teenage years and require respiratory interventions. Dominant and recessive mutations are found across the entire clinical spectrum; however, recessive Bethlem myopathy is rare, and our understanding of the molecular pathology is limited. We studied a patient with Bethlem myopathy. Electron microscopy of his muscle biopsy revealed abnormal mitochondria. We identified a homozygous COL6A2 p.D871N amino acid substitution in the C-terminal C2 A-domain. Mutant α2(VI) chains are unable to associate with α1(VI) and α3(VI) and are degraded by the proteasomal pathway. Some collagen VI is assembled, albeit more slowly than normal, and is secreted. These molecules contain the minor α2(VI) C2a splice form that has an alternative C terminus that does include the mutation. Collagen VI tetramers containing the α2(VI) C2a chain do not assemble efficiently into microfibrils and there is a severe collagen VI deficiency in the extracellular matrix. We expressed wild-type and mutant α2(VI) C2 domains in mammalian cells and showed that while wild-type C2 domains are efficiently secreted, the mutant p.D871N domain is retained in the cell. These studies shed new light on the protein domains important for intracellular and extracellular collagen VI assembly and emphasize the importance of molecular investigations for families with collagen VI disorders to ensure accurate diagnosis and genetic counseling.

Clinical phenotypes within non-surgical patients with mesial temporal lobe epilepsy caused by hippocampal sclerosis based on response to antiepileptic drugs

PURPOSE To evaluate evolution and elucidate clinical phenotypes related to prognosis of patients with mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) treated exclusively with antiepileptic drugs (AED). METHODS Forty-seven out of 68 MTLE-HS patients treated between January 2005 and June 2010 were retrospectively studied for demographic, clinical and outcome data. The population was divided into drug-responder and drug-resistant patients; the latter was divided, according to the duration of the seizure-free periods along their evolution, into patients with at least one seizure-free period longer than one year and those with shorter periods. Variables were compared between drug-responders vs drug-resistants and drug-resistants with long seizure-free periods vs drug-resistants without it. RESULTS There were 7 (15%) drug-responders, 39 (83%) drug-resistants and 1 patient (2%) with an undetermined response. Eighteen (46%) drug-resistant individuals had seizure-free periods longer than one year, with mean duration of 46 months (3.8 years). Since no factor was statistically associated with long seizure-free period within drug-resistants, we can clinically distinguish two phenotypes: women with left HS and late onset of seizures, with poor prognosis, and men with right HS and earlier appearance of seizures, attaining a better outcome. Twenty out of 47 (42.5%) patients followed an intermittent pattern of epilepsy. CONCLUSIONS Non-surgical MTLE-HS drug-resistant patients can achieve long seizure-free periods with AED, but relapses are common. Female gender, left or bilateral lesion and later onset of seizures seem to be bad prognosis factors within MTLE-HS drug-resistant patients.

Psychiatric symptoms after temporal epilepsy surgery. A one-year follow-up study

Psychiatric symptoms must be considered in patients with refractory temporal lobe epilepsy after epilepsy surgery. The main objectives of our study were to describe clinical and socio-demographical characteristics of a cohort of patients with pharmacoresistant temporal lobe epilepsy who underwent temporal lobe epilepsy surgery, and moreover, to evaluate possible risk factors for developing psychiatric symptoms. In order to achieve those goals, we conducted a prospective evaluation of psychopathology throughout the first year after surgery in a clinical sample of 72 patients, by means of three clinical rated measures; the Hamilton Anxiety Rating Scale (HARS), the Hamilton Depression Rating Scale (HDRS), and the Brief Psychiatric Rating Scale (BPRS). The psychopathological evaluations were performed by an experienced psychiatrist. A presurgical evaluation was done by a multidisciplinary team (that includes neurologist, psychiatrist, neurosurgeon, neurophysiologist, radiologists, and nuclear medicine specialist) in all patients. The decision to proceed to surgery was taken after a surgical meeting of all members of the Multidisciplinary Epilepsy Unit team. The psychiatrist conducted two postoperative assessments at 6months and 12months after surgery. The main finding was that past history of mental illness (patients who were receiving psychiatric treatment prior to the baseline evaluation) was a risk factor for anxiety, depression, and psychosis after temporal lobe epilepsy surgery.