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We present a method of imaging angiographic structures in human extremities, including hands, arms, legs, and feet, using a newly developed photoacoustic computed tomography (PACT) system. The system features deep penetration (1.8 cm in muscular tissues) with high spatial and temporal resolutions. A volumetric image is acquired within 5 to 15 s while each cross sectional image is acquired within 100 μs. Therefore, we see no blurring from motion in the imaging plane. Longitudinal and latitudinal cross-sectional images of a healthy volunteer clearly show the vascular network of each appendage and highlight the system’s ability to image major and minor vasculatures, without the use of an external contrast or ionizing radiation. We also track heartbeat-induced arterial movement at a two-dimensional frame rate of 10 Hz. This work substantiates the idea that PACT could be used as a noninvasive method for imaging human vasculatures.

Objective: To assess the frequency of additional causes of distal sensory polyneuropathy (DSP) in patients with diabetes mellitus (DM). Methods: Retrospective review of patients with DM and DSP during a 5 year period. A quantitative sensory score (QSS) was determined at the initial evaluation and extensive laboratory and EMG studies were performed. Patients with one or more potential causes for DSP were compared to those with DM alone. Results: Fifty five patients (53%) had potential additional causes for DSP. These included: neurotoxic medications (seven), alcohol abuse (six), and B12 deficiency and renal disease (four each). The most common laboratory abnormalities were: abnormally low levels of vitamin B6 (11) or B1 (10), monoclonal gammopathy (eight), and hypertriglyceridaemia (eight). Twenty six (25%) subjects had more than one additional cause. Nine (9%) had three or more demyelinating features on EMG. There was a trend toward a lower QSS score (p = 0.05) and reduced mean amplitude of the sensory potentials in those with additional causes. Those with additional causes more often had upper limb sensory symptoms (p = 0.001) and sensory findings (p = 0.003). Conclusion: There was a high frequency of additional sources of DSP in patients with DM. These patients more often had sensory symptoms and findings in the hands. Tests that may be useful in the evaluation of DSP in diabetic patients include measures of vitamins B1, B6, B12, serum triglycerides, and immunofixation.

Objectives: To use the technique of dermal microdialysis to examine sensitivity of skin vessels to noradrenaline (NA) in patients with familial dysautonomia (FD) and in healthy controls. Methods: In 14 patients with FD and 12 healthy controls, plasma extravasation, local laser Doppler blood flow, and skin blanching were observed before, during, and after application of 10-6 M NA through a microdialysis membrane, located intradermally in the skin of the lower leg. Results: Maximum local vasoconstriction measured by laser Doppler blood flow did not differ between patients with FD and controls. In contrast, patients with FD had an earlier onset of vasoconstriction (p = 0.02). Moreover, reaction to NA was more prominent and prolonged in FD, shown by a larger zone of skin blanching around the microdialysis membrane (p < 0.001) and delayed reduction of the protein content in the dialysate after termination of NA application (p = 0.03). Conclusion: These data support the hypothesis that peripheral blood vessels of patients with FD show a denervation hypersensitivity to catecholamines. This may be one mechanism contributing to the major hypertension that frequently occurs during "dysautonomic crises" in FD.

To assess the prevalence of peripheral neuropathy (PN) and its correlation with cryoglobulinemia (CG) in an unselected, untreated referral hepatitis C virus (HCV) population.Two hundred and thirty four patients (120 women and 114 men) with untreated HCV infection were consecutively enrolled by seven Italian centres. Clinical neuropathy was diagnosed when symptoms and signs of peripheral sensory or motor involvement were present. Median, ulnar, peroneal, and sural nerves were explored in all patients and distal symmetric polyneuropathy was diagnosed when all explored nerves or both lower limb nerves were affected. Mononeuropathy and mononeuropathy multiplex were diagnosed when one nerve or two non-contiguous nerves with asymmetrical distribution were affected. Screening for CG was done in 191 unselected patients.Clinical signs of PN were observed in 25 of the 234 patients (10.6%). Electrophysiological PN was found in 36 (15.3%). CG was present in 56/191 patients (29.3%). The prevalence of CG increased significantly with age (p0.001) and disease duration (p0.05). PN was present in 12/56 (21%) patients with CG and 18/135 (13%) without CG (p=NS). PN increased significantly with age (p0.001) and logistic regression analysis confirmed age as the only independent predictor of PN (OR 1.10 for each year; 95% CI 1.04 to 1.15; p0.001).Electrophysiological examination detected subclinical neuropathy in 11 patients (4.7%). Statistical analysis showed that CG was not a risk factor for PN whereas PN prevalence increased significantly with age.

To investigate the effect of tizanidine (an alpha(2) noradrenergic agonist) on transmission in the interneuronal pathway coactivated by group I and group II afferents in post-stroke patients with spastic hemiplegia.Early and late facilitation of the quadriceps H reflex elicited in the common peroneal nerve--attributed to non-monosynaptic group I and group II excitation, respectively--was investigated in 14 spastic hemiplegic patients. All received a single dose of tizanidine (150 microg/kg) or placebo in randomised order at 10 day intervals. Repeated measurements were made at baseline (T0), 45-90 min, and 120 min after drug intake. Spasticity was assessed by modified Ashworth score in the quadriceps muscle and by a leg tone score calculated by the sum of the modified Ashworth score in five muscle groups.On the spastic side a decrease in late group II and, to a lesser extent, early group I common peroneal nerve induced quadriceps H reflex facilitation occurred with tizanidine (group II, mean (SEM) difference T0-T90: 34.3 (10.2)%, p0.001; group I, T0-T120: 19.8 (9)%, p0.05), but not with placebo (group II, difference T0-T90: 12.5 (8)%, NS; group I, T0-T120: 3.2 (7)%, NS). Tizanidine but not placebo decreased the quadriceps muscle and global lower limb Ashworth scores (2.9 (0.2) to 1.9 (0.3), p0.001; and 12 (0.7) to 9.5 (0.8), p0.0001, respectively).Enhancement of group II-group I facilitation of the quadriceps motor neurones on the spastic side of hemiplegic patients is modulated by alpha(2) noradrenergic agonists. This strengthens the view that late facilitation of quadriceps motor neurones is mediated by group II afferents and suggests that group II pathways may be involved in lower limb spasticity.

To test a new neurological sign, the "abductor sign," which can distinguish between organic and non-organic leg paresis using synergic movements of the bilateral hip abductors.The subjects were 33 patients presenting with paresis of one leg, 17 of organic origin and 16 of non-organic origin (hysteria). To test the abductor sign, the examiner told the patient to abduct each leg, and opposed this movement with his hands placed on the lateral surfaces of the patient's legs. The leg contralateral to the abducted one showed opposite actions for organic paresis and non-organic paresis: for example, when the paretic leg was abducted, the sound leg stayed fixed in organic paresis, but moved in the hyperadducting direction in non-organic paresis. Hoover's sign was used for comparison in the same patients.The abductor sign gave the correct classification for all 33 cases. Hoover's sign was reliable if the results were carefully interpreted, but it was non-diagnostic for 16 patients because of strong hip extensors and in two because of strong hip flexors. Two patients with non-organic paresis succeeded in tricking the examiner by pretending full effort to lift the paretic leg.The abductor sign is a useful test to detect non-organic paresis, because (1) it is difficult for a hysterical patient to deceive the examiner, (2) the hip abductor is one of the most commonly involved muscles in pyramidal weakness, and (3) the results are easily visible as movement or non-movement of the unabducted leg.

Objectives: There has been little research into risk factors for dementia outside Western settings, in particular the importance of early life nutrition as estimated by adult body size. This study investigated the associations of arm and leg length with cognitive impairment and dementia in a community sample of older Korean people. Methods: 746 community residents aged 65 or over were clinically assessed for dementia and cognitive impairment. The following were also measured: arm length (demispan), leg length (iliac crest height), and sitting height (standing height minus iliac crest height). Reproductive history was also ascertained in women. Results: Shorter demispan and leg length were associated with increased age and lower education. They were also associated with dementia and Alzheimer's disease after adjustment for these factors. These associations were only significant in women but were not explained substantially by timing of the menarche or menopause. The association between lower education and dementia was also stronger in women, but was not explained substantially by limb length. Conclusions: Shorter limb length was associated with lower childhood socioeconomic status, as estimated by the presence/duration of formal education. It was also independently associated with dementia and Alzheimer's disease. Sex differences in this association might be explained by gender disadvantage in early life for this cohort or by different associations with health states (for example, cardiovascular disease) later in life.

Aims: To evaluate micturition abnormalities in acute transverse myelitis and correlate these with evoked potentials, magnetic resonance imaging (MRI), and urodynamic findings. Setting: Tertiary care teaching hospital. Patients: 18 patients with acute transverse myelitis, aged 4–50 years; 15 had paraparesis and three quadriparesis. Methods: Patients with acute transverse myelitis had a neurological evaluation and tibial somatosensory and motor evoked potential studies in the lower limbs. Spinal MRI was carried out using a 1.5 T scanner. Urodynamic studies were done using Dantec UD 5500 equipment. Neurological outcome was determined on the basis of Barthel index score at six months as poor, partial, or complete. In some patients, urodynamic studies were repeated at six and 12 months. Results: Spinal MRI in 14 of the 18 patients revealed T2 hyperintense signal changes extending for at least three spinal segments in 13; one patient had normal MRI. In the acute stage, 17 patients had a history of urinary retention and one had urge incontinence. On follow up at six months two patients regained normal voiding, retention persisted in six, and storage symptoms developed in 10, of whom five also had emptying difficulties. Urodynamic studies showed an areflexic or hypocontractile bladder in 10, detrusor hyperreflexia with poor compliance in two, and detrusor sphincter dyssynergia in three. Early abnormal urodynamic findings commonly persisted at the six and 12 months examinations. Persistent abnormalities included detrusor hyperreflexia, dyssynergia, and areflexic bladder. The urodynamic abnormalities correlated with muscle tone and reflex changes but not with sensory or motor evoked potentials, muscle power, MRI signal changes, sensory level, or six months outcome. Conclusions: Bladder dysfunction is common in acute transverse myelitis and may be the only sequel. Urodynamic study is helpful in evaluating the bladder dysfunction and also in its management.