Dementia pugilistica with clinical features of Alzheimer's disease.

A 61-year-old ex-boxer presented with a three-year history of progressive memory decline. During a seven-year follow-up period, there was a continuous cognitive decline, very similar to that usually observed in Alzheimer's disease. Parkinsonian, pyramidal or cerebellar signs were conspicuously absent. Neuropathological examination revealed the typical features of dementia pugilistica: cavum septi pellucidi with multiple fenestrations, numerous neurofibrillary tangles in the cerebral isocortex and hippocampus (and rare senile plaques). Immunohistochemistry disclosed a high number of tau protein deposits and scarce beta-amyloid staining. This case shows that dementia pugilistica may present with clinical features practically undistinguishable from Alzheimer's disease.

[Asymmetric cortical high signal on diffusion weighted-MRI in a case of Creutzfeldt-Jakob disease].

High signal in the cerebral cortex and/or basal ganglia on diffusion-weighted magnetic resonance imaging (DW-MRI) has been described as a good diagnostic marker for sporadic Creutzfeldt-Jakob disease (sCJD). We report a case of sCJD with atypical clinical evolution and unusual DW-MRI findings. A 53-year-old man was seen with a 2-year history of a rapidly progressive dementia and cerebellar ataxia. Cerebrospinal fluid analysis, including the test for 14-3-3 protein, was normal. EEG did not show periodic activity. However, DW-MRI showed gyriform hyperintensity involving practically the entire cortical ribbon of the left hemisphere, whilst being limited to the posterior cingulate gyrus in the right hemisphere. DNA analysis showed no mutations or insertions in the prion protein gene, and homozigozity for methionine in codon 129. A subsequent brain biopsy confirmed the diagnosis of CJD. Thus, high signal on DW-MRI may be limited to the cerebral cortex and may present a very asymmetric distribution in sCJD.

High capacity and low cost detection of prion protein gene variant alleles by denaturing HPLC.

Mutations in the human prion protein gene (PRNP) are responsible for hereditary diseases called transmissible spongiform encephalopathies (TSE) and a polymorphic site at codon 129 determines sensitivity to infectious forms of these maladies. More recently, codon 129 has been related to cognition performance in the elderly, in Alzheimer disease (AD) and in Down syndrome. Furthermore, a rare polymorphism at codon 171 was described in 23% of patients with mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS), the most common form of surgically remediable epileptic syndrome. Thus, a method that permits fast and efficient screening of PRNP mutations and polymorphisms in patients, in high risk populations, and in family members is desirable. In the present study, we established the conditions for analysis of the PRNP open reading frame using denaturing high-performance liquid chromatography (DHPLC), whereby unpurified PCR products were subjected to denaturing and reannealing steps leading to heteroduplex formation. We described specific profiles for the PRNP polymorphisms at codons 129 (M/V), 117 (A/A silent), 219 (E/K), 171 (N/S), and the octarepeat deletion using amplified DNA from 562 samples. The chromatograms for TSE-associated mutations at codons 102 (P/L), 183 (T/A), and 210 (V/I) were also determined. Specificity of the DHPLC profile for each PRNP variant allele was confirmed in 100% of the samples by direct and cloned DNA sequencing in addition to endonuclease digestion when applicable. Therefore, the present study shows that DHPLC is a rapid, highly accurate and efficient technique for the detection of PRNP genetic variants.

Cellular prion protein: implications in seizures and epilepsy.

1. Cellular prion (PrPc) is a plasma membrane protein involved with copper uptake, protection against oxidative stress, cell adhesion, differentiation, signaling, and survival in the central nervous system. 2. Deletion of PrPc gene (Pmp) in mice enhances sensitivity to seizures in vivo and neuronal excitability in vitro which can be related to: (i) disrupted Ca(+2)-activated K+ currents, with loss of IHAP conductance in hippocampus; (ii) abnormal GABA-A inhibition in the hippocampus; (iii) mossy fiber reorganization in the hippocampus; (iv) changes in ectonucleotidases in both hippocampus and neocortex; and (v) higher levels of neocortical and subcortical oxidative stress. Moreover, postnatal Prnp knockout mice showed a significant reduction of after hyperpolarization potentials in hippocampal CA1 cells. 3. Taken together, these findings suggest that loss of PrPc function contributes to the hyperexcitable and synchronized activities underlying epileptic seizures generated in neocortex and hippocampus. Hence, the role of PrPc on human symptomatic, cryptogenic or idiopathic epileptic syndromes deserves further investigation.

Dementia Pugilistica with clinical features of Alzheimer's disease

A 61-year-old ex-boxer presented with a three-year history of progressive memory decline. During a seven-year follow-up period, there was a continuous cognitive decline, very similar to that usually observed in Alzheimer's disease. Parkinsonian, pyramidal or cerebellar signs were conspicuously absent. Neuropathological examination revealed the typical features of dementia pugilistica: cavum septi pellucidi with multiple fenestrations, numerous neurofibrillary tangles in the cerebral isocortex and hippocampus (and rare senile plaques). Immunohistochemistry disclosed a high number of tau protein deposits and scarce beta-amyloid staining. This case shows that dementia pugilistica may present with clinical features practically undistinguishable from Alzheimer's disease.

Um ex-boxeador de 61 anos apresentou-se com história de três anos de perda progressiva de memória e evoluiu com declínio cognitivo lentamente progressivo, sugestivo de doença de Alzheimer, durante seguimento de sete anos. Sinais parkinsonianos, piramidais ou cerebelares estiveram ausentes durante toda a evolução. Exame neuropatológico evidenciou características típicas de dementia pugilistica: cavum do septo pelúcido com múltiplas fenestrações, numerosos emaranhados neurofibrilares no isocórtex cerebral e hipocampo (e raras placas senis). Imuno-histoquímica confirmou número elevado de depósitos de proteína tau e raros de beta-amilóide. Este caso demonstra que dementia pugilistica pode apresentar quadro clínico indistinguível daquele da doença de Alzheimer.

Asymmetric cortical high signal on diffusion weighted-MRI in a case of Creutzfeldt-Jakob disease

Hipersinal no cortex cerebral e/ou nos gânglios da base observado com a técnica de difusão da ressonância magnética (RM-DIF) tem sido descrito como bom marcador diagnóstico da doença de Creutzfeldt-Jakob esporádica (DCJe). Relatamos caso de DCJe com evolução clínica atípica e achados incomuns na RM-DIF. Homem de 53 anos foi examinado com história de dois anos de demência rapidamente progressiva e ataxia cerebelar. Exame do líquido cefalorraqueano, incluindo pesquisa da proteína 14-3-3, foi normal; EEG não revelou atividade periódica; RM-DIF mostrou hiperintensidade nos giros que afetava quase inteiramente o manto cortical do hemisfério cerebral esquerdo e que no hemisfério direito se limitava à parte posterior do giro cíngulo. Análise do DNA revelou ausência de mutação ou de inserção no gene da proteína priônica e a presença de homozigose para metionina no códon 129. Biópsia cerebral confirmou o diagnóstico de DCJ. Hipersinal na RM-DIF pode ser limitado ao córtex cerebral e pode distribuir-se de modo muito assimétrico na DCJe.