A simple method for estimating conduction velocity of the spinothalamic tract in healthy humans

OBJECTIVES: The object of this study was to establish a method for estimating the conduction velocity (CV) of the spinothalamic tract (STT) in relation to clinical application. METHODS: The CV of the STT was estimated by an indirect method based on that reported by Kakigi and Shibasaki in 1991 (Kakigi R, Shibasaki H. Electroenceph clin Neurophysiol 80 (1991) 39). Laser-evoked potentials (LEP) were measured in 8 subjects following hand (LEPH) and foot (LEPF) laser stimulation. The conduction times recorded at the scalp (P340, P400 and N150 potentials) were considered as the summation of peripheral and central components. The peripheral conduction times were calculated by measuring the latency of the electrical cutaneous silent period (from the same stimulus site of LEPs), corrected for F- and M-wave latency values. RESULTS: The CV of the STT ranged between 8.3 and 11.01 m/s and its mean value was found to be approximately 9.87+/-1.24 m/s. The CV of the STT obtained by the N150 latencies overlapped that obtained by the P340/P400 latencies. CONCLUSIONS: Our data suggest that our method appears appropriate and useful for practical clinical purposes, furnishing an additional tool for investigating the physiological function of small-fiber pathways

Sporadic Creutzfeldt-Jakob disease without dementia at onset: clinical features, laboratory tests and sequential diffusion MRI (in an autopsy-proven case)

Abstract A rapidly progressing dementia, followed by focal neurological signs, and evidence of periodic sharp wave complexes (PSWC) in the EEG may lead to the clinical suspicion of Creutzfeldt-Jakob disease (CJD). Different clinical variants of CJD have been described in the past, with prominent extrapyramidal or occipital lobe involvement, all included in the sporadic form of CJD (sCJD). Familiar and iatrogenic forms of CJD are also known. More recently a new variant has been described, vCJD, casually linked to bovine spongiform encephalopathy (BSE) and it has attracted increasing attention toward each form of rapidly progressing dementia; likewise the differential diagnosis between sCJD vs. vCJD is not always easy. Magnetic resonance imaging (MRI) too seems to have a peculiar role in differentiating sCJD from vCJD, even if the role of MRI in the diagnosis of CJD is still debated. Diffusion MRI is expected to play an important role in the clinical setting of CJD, contributing to formulation of an early diagnosis, especially in cases with unusual clinical presentation. In fact, the sensitivity of diffusion MRI is superior to that of conventional MRI (T1, T2, FLAIR) in detecting specific basal ganglia and cortical abnormalities early in the course of CJD and these abnormalities correlate well with areas of the most severe and characteristic neuropathological changes. We describe a case of autopsy-proven sCJD, with an unusual clinical course without dementia as a presenting symptom and discuss the role of diffusion MRI and laboratory tests in making an early diagnosis