Distigmine and amitriptyline in the treatment of chronic pain

Sixty-five patients attending a pain relief clinic were randomly allocated to treatment for 5 weeks with amitriptyline alone, distigmine alone, amitriptyline and distigmine started together, or addition of distigmine to preexisting treatment with amitriptyline. Forty-eight patients successfully completed the trial; the most common cause for withdrawal was dry mouth in the amitriptyline-alone group. Two parameters were measured: Pain intensity was measured at the beginning and end of the treatment, and the saliva flow was measured at the beginning and the end of the treatment. At the end of 5 weeks, treatment with a combination of amitriptyline (75 mg/day) and distigmine (10 mg/day) resulted in a 43% reduction of pain and no subjectively noticeable mouth dryness. Distigmine alone also decreased pain and increased saliva flow, sometimes to the point of discomfort, whereas amitriptyline alone, in this particular series, did not significantly reduce pain and produced unpleasant mouth dryness. The addition of distigmine to preexisting (and ineffective) amitriptyline treatment failed to relieve pain. We therefore conclude that a combination of amitriptyline and distigmine (both given ab initio) may be a useful therapy for chronic pain.     

Contralateral mirror-image pain following anterolateral cordotomy

A hypothesis is put forward to explain the occurrence of mirror-image pain following pain relief by anterolateral cordotomy. This depends upon the fact that some nociceptive neurones in the deep spinal grey matter have bilaterally symmetrical receptive fields, one-half of which is normally subject to tonic descending inhibitory control. It is suggested that some cordotomy lesions may damage this descending inhibitory pathway. Experience following naloxone injection in our own cases further suggests that this inhibitory mechanism may normally involve enkephalinergic interneurones.     

The management of central post-stroke pain.

Central post-stroke pain (CPSP) used to be known as ''thalamic syndrome''. Early post-mortem studies showed that many cases had extrathalamic lesions, and modern imaging methods have confirmed and extended these findings. CPSP affects between 2 and 6% of stroke patients, ie, there is an annual incidence in the UK of between 2000 and 6000. Most patients with CPSP appear to be younger than the general stroke population, and usually to have relatively mild motor affliction; thus they may live for many years, giving a prevalence perhaps as high as 20,000. True CPSP, characterised by a partial or total deficit for thermal and/or sharpness sensations, is best treated initially with adrenergically active antidepressants. If these do not work, mexiletine may be added in suitable cases. Recent studies suggest that stimulation of the motor cortex or spinal cord by implanted electrodes may help patients resistant to medical treatment. Positive relaxation, as an adjuvant therapy, should be used in nearly all cases. Considerable or even total relief can be achieved in almost two thirds of patients. There is evidence that the sooner antidepressant treatment is begun, the more likely the patient is to respond; time should not be wasted trying conventional analgesics, which rarely have any significant effect.     

Quantification of blood flow with dynamic MR imaging and presaturation bolus tracking

A technique is described for rapid imaging of blood flow and dynamic measurement of its velocity. The method is a combination of bolus tracking and low-flip-angle gradient-echo cine angiography. This method provides precise determination of velocity with high temporal resolution in a single measurement. Unlike what occurs in phase imaging techniques, flow is displayed directly, eliminating potential errors that result from non-flow-related sources of phase shifts. Manipulation of raw data sets is avoided. Results obtained from a flow phantom, healthy volunteers, and a patient with an aortic aneurysm demonstrate the capability of the technique to track flow at low and high velocities and to differentiate flowing blood from thrombus. Because of its conceptual simplicity, rapidity, and lack of susceptibility to extraneous phase shifts, this technique may prove ideal for in vivo flow measurement and evaluation of flow patterns.     

False aneurysm of the femoral artery: Computed tomographic and ultrasound appearances

Twenty-five patients presenting with pulsating masses in the groin, 1-10 days after diagnostic arterial catheterisation, were investigated by computed tomography (CT), ultrasound (US) or both. False aneurysm was demonstrated in 10, four by CT alone, three by US alone and three by both CT and US. Both methods allowed rapid accurate and non-invasive diagnosis of this uncommon complication of arterial catheterisation.     

Estimation of the age at onset in spinocerebellar ataxia type 2 Cuban patients by survival analysis

Almaguer‐Mederosa LE, Falcón NS, Almira YR, Zaldivar YG, Almarales DC, Góngora EM, Herrera MP, Batallán KE, Armiñán RR, Manresa MV, Cruz GS, Laffita‐Mesa J, Cyuz TM, Chang V, Auburger G, Gispert S, Pérez LV. Estimation of the age at onset in spinocerebellar ataxia type 2 Cuban patients by survival analysis. Previous studies have investigated the close association that exists between CAG repeat number and the age at onset in SCA2 = spinocerebellar ataxia type 2. These studies have focused on affected individuals. To further characterize this association and estimate the risk of a carrier developing SCA2 at a particular age as a function of a specific CAG repeat size, we have analyzed a large group of 924 individuals, including 394 presymptomatic and 530 affected individuals with a CAG repeat length of 32–79 units. Using a Kaplan–Meier survival analysis, we obtained cumulative probability curves for disease manifestation at a particular age for each CAG repeat length in the 34–45 range. These curves were significantly different (p < 0.001) and showed small overlap. All these information may be very valuable in predictive‐testing programs, in the planning of studies for the identification of other genetic and environmental factors as modifiers of age at onset, and in the design of clinical trials for people at enlarged risk for SCA2.     

The cost of treatment for post-herpetic neuralgia in the UK

Post-herpetic neuralgia (PHN) following acute shingles caused by the herpes simplex virus is a painful and often disabling condition. Treatment of the condition can involve a range of drug therapies. In addition, patients with continuing pain may make several visits to general practitioners and hospital outpatient departments. The costs of treatment for these patients may be substantial. The main objective of this study was to estimate the costs and consequences to the UK National Health Service (NHS) of the treatment of PHN following shingles, and the effect of the condition on patients' lives in terms of pain and time off usual activities such as work. The lifetime direct treatment costs of a cohort of people from onset of PHN to resolution of the disease or death were calculated. These costs were estimated from data on the type and quantity of health resources used, and the unit costs or prices of those resources. This study has shown that PHN can be a costly consequence of acute shingles. For patients attending a tertiary referral centre the lifetime cost was 770 British pounds sterling. For a 1-year incidence cohort of people with shingles in the UK, the lifetime costs of treating PHN are between 4.8 million British pounds sterling (incidence of 21 000 people) and 17.9 million British pounds sterling (incidence of 78 200 people). Efforts are needed to reduce the incidence or severity of PHN.(ABSTRACT TRUNCATED AT 250 WORDS)