Katsumi Kurokawa

Diagnostic significance of tau protein in cerebrospinal fluid from patients with corticobasal degeneration or progressive supranuclear palsy

Distinguishing corticobasal degeneration (CBD) from progressive supranuclear palsy (PSP) is clinically and pathologically difficult, and a useful biological marker to discriminative these two diseases has been a subject of clinical interest. In the present study, we assessed tau protein levels in cerebrospinal fluids by sandwich ELISA to distinguish CBD from PSP. The subjects consisted of 27 cases of CBD, 30 cases of PSP, and 36 healthy controls (CTL). The tau values in CBD were significantly higher than those in PSP (P<0.001) and those in CTL (P<0.001). The assay of CSF tau provided diagnostic sensitivity of 81.5% and specificity of 80.0% between CBD and PSP according to receiver-operating characteristic (ROC) curve analysis. When values were compared separately with respect to stage of the disease, differences in the values for moderate CBD vs. moderate PSP had the greatest significance (P<0.001 sensitivity 92.3%, specificity 100.0%), followed by cases of mild CBD and PSP (P<0.005, sensitivity 100.0%, specificity 87.5%). The values in severe CBD and PSP were not significantly different (P=0.07, sensitivity 100%, specificity 75.0%). Using data obtained from a larger number of disease cases, we confirmed our previous findings that tau protein levels in cerebrospinal fluids in patients with CBD are significantly higher than those in patients with PSP. Because tau protein levels in cerebrospinal fluids are significantly higher in early CBD cases than in early PSP cases, measurement of tau protein levels in cerberospinal fluids may be useful for the differential diagnosis of early CBD from early PSP.

Objective evaluation of fatigue by event-related potentials

The purpose of this study was to assess the relationship between mental fatigue and event-related potentials (ERPs). Six healthy men (mean age: 22 years old) performed a simple calculation for 6 h. Auditory ERPs were recorded before and after the calculating task. The scores of subjective fatigue symptoms were significantly increased, and P300 latency of auditory ERPs was significantly prolonged by the calculating task (P<0.05). We suggest that the recording of ERPs may be useful for the objective evaluation of mental fatigue.

Age-Related Change in Peripheral Nerve Conduction: Compound Muscle Action Potential Duration and Dispersion

Background: We investigated the effect of age on nerve conduction parameters with special reference to the compound muscle action potential (CMAP) duration and duration ratio. Method: We examined 295 subjects (aged 15–85 years old) with no previous history or present signs of peripheral neuropathy. The subjects were divided into 3 groups: young (15–34 years old); intermediate (35–64 years old), and old (65–85 years old). Results: CMAP amplitude was lower in the old group than in the young group; however, the CMAP ratio (proximal CMAP/distal CMAP) did not change with age. The CMAP duration and duration ratio did not differ among the 3 groups. The CMAP area was smaller in the old group, but the area ratio was almost constant among the 3 groups. Conclusion: We suggest that age-related changes in CMAP amplitude, duration or area may occur uniformly, at least in the forearm and the calf segment, in routine nerve conduction studies. The present findings also provide useful and reliable information, regardless of age, in diagnosing peripheral neuropathy.

A case of pandysautonomia with associated sensory ganglionopathy

Since Young et al 1described a patient with acute loss of sympathetic and parasympathetic functions in 1969, many similar cases have been reported as being acute idiopathic autonomic neuropathy.2 Apart from acute cholinergic neuropathy, there are four types of acute idiopathic autonomic neuropathy, classified according to somatic nerve involvement: acute pandysautonomia, which has minimal or no motor or sensory dysfunctions3;acute autonomic and sensory neuropathy in which sensation is seriously involved4-6; Guillain-Barre syndrome with prominent dysautonomia, manifesting autonomic and somatic motor dysfunctions; and acute autonomic sensory and motor neuropathy, characterised by prominent dysautonomia and severe motor and sensory impairment. Despite minimal or no sensory disturbance, reduction of myelinated fibres in biopsied sural nerve has been found in several cases with acute pandysautonomia.3However, the exact site of pathological involvement in the sensory system remains unknown, because postmortem examinations have seldom been performed. We report a case of acute pandysautonomia with no evidence of significant somatic nerve involvement, accompanied by dorsal root ganglionopathy shown by postmortem examinations. An 18 year old male student experienced low grade fever, vomiting, and tingling pain in the limbs on 26 February 1987. Orthostatic syncopy occurred three times on the next day. Difficulty in emptying the bladder, alternate diarrhoea and constipation, and lack of sweating over the whole body developed rapidly. He was admitted to the Third Department of Internal Medicine, Medical College of Oita on 24 April 1987. On physical examination, he weighed 46 kg, with a recent weight loss of 14 kg. Blood pressure was 108/78 mm Hg in the supine position and heart rate was 88/min. When changing from the supine to theupright position, he …

QTc interval, and autonomic and somatic nerve function in diabetic neuropathy.

QTc intervals were measured using an electrocardiogram and other autonomic function tests, in 66 neuropathy patients with non-insulin-dependent diabetes mellitus (59.0±12.5 years; mean ± SD). The change in R-R interval did not influence the QTc interval, as calculated by the equation: QTc =QT+(1000-R-R)/7 (ms), compared with the conventional Bazetts equation which appeared to overcompensate in the case of a small R-R interval. The QTc interval in the diabetic patients was significantly longer than that in age-matched controls. The QTc interval showed an inverse correlation with the coefficient of variation of the R-R interval and skin blood flow at rest. However, no correlation was found between QTc interval and blood pressure change, change in heart rate on standing, or results of the sympathetic skin response. The QTc interval did not correlate significantly with motor or sensory nerve conduction parameters. We conclude that the QTc interval can be a simple and useful autonomic indicator for diabetic neuropathy relatively independent of other abnormalities of autonomic and somatic nervous system function. Clin Auton Res 8:139–143