title: Cerebellar changes in partial seizures: clinical correlations of quantitative SPECT and MRI analysis.
abstract: OBJECTIVE
  To determine the frequency and patterns of periictal cerebellar hyperperfusion, whether it is associated with increased cerebellar atrophy, and whether cerebellar hyperperfusion and cerebellar atrophy are associated with predisposing clinical factors or with the outcome of epilepsy surgery.
  
  
  METHODS
  Periictal and interictal SPECT scans and volumetric brain magnetic resonance imaging (MRI) were quantitatively analyzed in 54 consecutive patients with medically refractory partial epilepsy. Their histories were reviewed and their postsurgical outcomes assessed.
  
  
  RESULTS
  Significant periictal cerebellar hyperperfusion was found in 26 (48.1%) patients, of whom 18 had CCH, two had homolateral cerebellar hyperperfusion (HCH), and six had symmetrical bilateral hyperperfusion (BCH). No relation found between the site of the SPECT seizure localization and the presence or type of cerebellar hyperperfusion. CCH was more common when the injected seizure involved unilateral clonic motor activity (p < 0.05). A smaller MRI relative cerebellar volume (cerebellar volume/cerebral volume) was correlated with a greater seizure frequency (Rs = -0.30; p < 0.05) but not with the duration of epilepsy. There was no difference in the cerebellar volumes between the different patterns of cerebellar perfusion (p > 0.05). However, patients without a focal structural MRI lesion had significantly smaller cerebellar volumes (p < 0.05). In patients who underwent epilepsy surgery (n = 31), there was a trend for those without excellent outcomes to have smaller relative cerebellar volumes than did those with excellent outcome (10.6 vs. 11.8%; p = 0.08).
  
  
  CONCLUSIONS
  Periictal changes in cerebellar perfusion, particularly CCH, are common in patients with intractable partial epilepsy. However, periictal hyperperfusion does not appear to be a major contributor to the development of cerebellar atrophy.
authors.affiliation: The Department of Neurology, Mayo Clinic and Mayo Medical School, Rochester, Minnesota 55905, USA.
authors.forename: N I
authors.initials: NI
authors.lastname: Bohnen
authors.forename: T J
authors.initials: TJ
authors.lastname: O'Brien
authors.forename: B P
authors.initials: BP
authors.lastname: Mullan
authors.forename: E L
authors.initials: EL
authors.lastname: So
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001284:Atrophy / Q000209:etiology / Q000473:pathology; D002526:Cerebellar Diseases / Q000209:etiology / Q000473:pathology; D002531:Cerebellum / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D004828:Epilepsies, Partial / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome
chemical_list: D019690:Technetium Tc 99m Exametazime