Posterior fossa malformations and epilepsy

The association between Chiari-like malformation, ventriculomegaly and seizures in cavalier King Charles spaniels

Cavalier King Charles spaniels (CKCSs) with Chiari-like malformation (CM) and associated seizures are frequently diagnosed with idiopathic epilepsy. There could be an association between ventriculomegaly (V) or caudal fossa overcrowding (CCFP) and seizures. A retrospective case-control study was performed using MRI to investigate the possible association between these morphological abnormalities and seizures. Seizure semiology and, where possible, electroencephalographic (EEG) abnormalities were documented. Eighty-five CKCS with CM were included, 27 with seizures. There was no association between V or CCFP and seizures (P=0.10 and 0.71, respectively). Seizures were classified as having partial onset in 61% of individuals in the study population (95% CI 42.41-76.43%). Another cause of recurrent seizures in CKCS (such as familial epilepsy) is suspected, as previously reported.

Cerebellar hypoplasia, continuous spike-waves during sleep, and neuropsychological and behavioral disorders

We describe 3 patients with different degrees of cerebellar hypoplasia and continuous spike-waves during sleep: the more extensive the cerebellar hypoplasia, the more compromised the neuropsychological abilities and behavior. Cerebellar hypoplasia is a risk factor for epilepsy and/or neuropsychological and psychiatric disorders. Epilepsy is also strongly associated with familial antecedents for seizures, as previously reported. The cerebellum is implicated in controlling epileptic seizures and in regulating motor, cognitive, and emotional functions with a topographic organization. The association between cerebellar hypoplasia and continuous spike-waves during sleep has never been reported. We suggest that continuous spike-waves during sleep may further compromise neuropsychological and behavioral features that are associated with cerebellar hypoplasia.

Clinical features of epilepsy in patients with cerebellar structural abnormalities in a referral center

PURPOSE

The objective of this study was to describe epilepsy localization, clinical features and surgery outcome in patients with epilepsy and cerebellar structural abnormalities.

METHODS

We identified 10 patients with cerebellar lesions and epilepsy from our epilepsy database. Patients with only cerebellar atrophy were excluded. Medical records were reviewed for demographic data, seizure history, examination findings, EEG findings, epilepsy treatment and course. We reviewed imaging data for cerebellar structural findings, as well as cerebral abnormalities.

RESULTS

Out of 2288 epilepsy patients in the database, 10 had epilepsy and cerebellar structural abnormalities other than atrophy. Their ages ranged from 26 to 52 years. The most common cerebellar malformations included Dandy-Walker malformation, cerebellar tumors and posterior fossa arachnoid cyst. Epilepsy was classified as generalized in one patient. Nine patients had focal epilepsy: the localization was temporal in five, frontal in one, occipital in one, and unclassified in two. A cerebral structural abnormality considered responsible for epilepsy was identified in six patients; four had hippocampal sclerosis, one had a hippocampal malformation, and one had a temporal pole cortical malformation. Presurgical evaluation was done in six patients. Surgery was performed in five, with excellent outcome in four.

CONCLUSION

In this small series, epilepsy associated with cerebellar malformations was usually focal, most often with a temporal lobe focus. The cerebellar lesions did not adversely affect surgical success.

Mental retardation and epilepsy in patients with isolated cerebellar hypoplasia

Congenital nonprogressive cerebellar ataxia includes a complex group of disorders with heterogeneous phenotypic and etiopathogenetic characteristics. Despite recent advances in the understanding of the role of the cerebellum in cognition and behavior, the opinion that the clinical presentation of congenital cerebellar diseases is principally linked to motor dysfunction is common. This is largely due to the lack of well-organized epidemiologic studies on the prevalence of nonmotor disturbances in cerebellar disease. The association between congenital cerebellar disease and epilepsy has rarely been described. We report clinical, neurophysiologic, neuroimaging, and neuropsychologic features in a group of 14 patients with congenital nonprogressive cerebellar ataxia associated with cerebellar hypoplasia, 5 of whom have familial disease, aiming to further a better knowledge of the prevalence of cognitive and/or emotional impairment and epilepsy. The results confirm that cerebellar hypoplasia predisposes individuals to psychomotor delay (71.4%) and cognitive impairment (85.7%). Moreover, the tendency toward abnormal electroencephalographic (EEG) findings (78.5%), associated in a minor percentage of cases with epilepsy (28.5%), is also evident in our study.

Epilepsy, intelligence, and psychiatric disorders in patients with cerebellar hypoplasia

The cerebellum is involved in motor and cognitive functions and behavior. Its role in controlling epileptic seizures has been demonstrated in the literature. Genetic factors can enhance epilepsy susceptibility when the cerebellum is damaged. We examined the occurrence and features of epilepsy, intelligence, and psychiatric disorders in 28 patients with cerebellar hypoplasia. We compared patients with (10; 35.7%) and without (18; 64.3%) epilepsy. The statistical evaluation showed a significant prevalence of familial antecedents for seizures in patients with epilepsy (P < .01); cerebral associated lesions and type of cerebellar hypoplasia did not influence the occurrence of epilepsy, which was partial in 80% of cases. Profound mental retardation prevailed in patients with epilepsy (P < .05). Both mental retardation (75%) and pervasive developmental disorders (17.8%) prevailed in our cases with respect to the general population (P < .000). Cerebellar hypoplasia in our sample seems to be an important risk factor for the occurrence of epilepsy, mental retardation, and psychiatric disorders.