PSEN1 mutation carriers present lower cerebrospinal fluid amyoid-β42 levels than sporadic early-onset Alzheimer's disease patients but no differences in neuronal injury biomarkers

Most cases of early-onset Alzheimer's disease (EOAD) are sporadic. A minority of EOAD are caused by specific genetic defects in PSEN1, PSEN2, or AβPP genes. Magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) biomarker comparisons between sporadic and monogenic EOAD are practically inexistent. CSF and MRI data from 14 amnestic-onset sporadic EOAD (sEOAD) subjects were compared with data from 8 symptomatic PSEN1 mutation carriers (PSEN1) and 14 age-matched cognitively-preserved controls. CSF concentrations of amyloid-β (Aβ)(42), total tau (t-tau), and phosphorylated tau (p-tau) were determined. Cortical thickness (CTh) and grey matter loss were compared between groups and correlated with CSF biomarkers. PSEN1 had significantly lower CSF Aβ(42) levels compared to sEOAD (mean 244.8 pg/ml versus 381.4 pg/ml; p = 0.006), but no differences in t-tau or p-tau. Both sEOAD and PSEN1 showed widespread CTh loss in AD target areas when compared with controls. No differences were found in the direct comparison between sEOAD and PSEN1 CTh after adjusting for age and Mini-Mental Status Examination scores. Neither was a correlation found between Aβ(42) levels and CTh. CTh in the left superior parietal and caudal middle frontal areas was negatively correlated with t-tau values. In conclusion, PSEN1 had lower Aβ(42) CSF levels compared with sEOAD, suggesting a greater cerebral deposition of Aβ(42). These differences in Aβ(42) deposition were not significantly reflected in the brain structure, and CTh was only correlated with total tau. The lack of significant differences in relation to t-tau and p-tau levels and to the severity of CTh or grey matter loss suggests a similar level of neuronal injury despite higher Aβ(42) load in PSEN1.

[Giant subarachnoid cysts due to neurocysticercosis: two cases reported fro a rural area in Extremadura]

INTRODUCTION

Neurocysticercosis is the commonest cerebral parasitosis. The most recent cases reported in Spain have occurred in patients from endemic countries. The formation of giant subarachnoid cysts (GSC) is an uncommon complication of neurocysticercosis and its treatment is the subject of debate. We report two cases seen recently in the Valle del Jerte, a rural district in Extremadura.

CLINICAL CASES

Case 1. A 64 year old man had had complex partial crises (CPC) since 1985. In 1987 he was diagnosed as having neurocysticercosis with parenchymatous cysts and treated with praziquantel. In 1996, on CAT and MR a left frontal GSC was diagnosed and also two parenchymatous active cysts. The cyst was removed surgically and he was subsequently treated with albendazol. Case 2. A 72 year old man had generalized crises and CPC since 1970. In 1987 and 1991 on CAT and MR several parenchymatous lesions compatible with neurocysticercosis were seen. In 1997 he presented with headache and subacute cognitive impairment. On CAT and MR a left temporal GSC was seen with several active parenchymatous lesions. The patient was treated with albendazol and dexamethasone. Both patients improved, although radiological resolution of the GSC in case 2 took a year.

CONCLUSIONS

Neurocysticercosis is a condition still present in Spain. GSC respond to treatment with albendazol, whilst surgical treatment is the best option when severe intracranial hypertension occurs.

Acute painful diabetic neuropathy following severe weight loss

A 34-year-old man, recently diagnosed as diabetic, presented an acute painful neuropathy. He reported a profound weight loss during the months preceding onset. There were no motor symptoms, and only mild neurological signs were observed on examination. Improvement was related to a good glycemic control and weight gain. Acute painful diabetic neuropathy is a condition that may affect diabetic patients shortly after development of the disease. The pathogenetic roles played by different factors are reviewed.