Evaluation of the management of optic neuritis: audit on the neurological and ophthalmological practice in the north west of England.

The management of acute optic neuritis by neurologists and ophthalmologists in the north west of England was assessed in the light of the Optic Neuritis Treatment Trial (ONTT) recommendations. A questionnaire on a fictitious case of typical unilateral optic neuritis was mailed to all consultant ophthalmologists and neurologists working in the North West and Merseyside Health Authorities. They were then asked to comment on management of the case. Fifty two out of 86 ophthalmologists and 20 out of 28 neurologists replied. The overall response rate was 63%. Sixty five per cent of neurologists and 46% of ophthalmologists would investigate a typical case of acute optic neuritis further. Forty six per cent of neurologists and 36% of ophthalmologists were likely to arrange MRI of the brain or orbit. Significantly more neurologists (55%) than ophthalmologists (9%) chose to treat with intravenous methylprednisolone (p<0.005). Significantly more ophthalmologists (64%) than neurologists (32%) chose not to give steroids (p<0.025). Oral prednisolone alone was rarely selected for treatment. Respondents were more likely to discuss multiple sclerosis with the referring doctor than with the patient. Only 32% of ophthalmologists and 20% of neurologists would clearly mention the possibility of improvement to the patient. Clear differences in practice between ophthalmologists and neurologists remain. A consensus on practice guidelines on the issues raised might be useful.

Wernicke's encephalopathy after vertical banded gastroplasty for morbid obesity.

Thiamine deficiency is known to lead to certain neurological sequelae including Wernicke- Korsakoff encephalopathy. Signs attributable to this condition include ataxia, ophthalmoplegia, nystagmus, and mental confusion. Recognised predisposing conditions include alcoholism gastric carcinoma, pyloric obstruction, hyperemesis gravidarum, and prolonged intravenous feeding. We have recently encountered two cases of Wernicke's encephalopathy after vertical banded gastroplasty for morbid obesity . Other neurological sequelae are recognised after vertical banded gastroplasty, including Guillain-Barre syndrome, psychosis, and pseudoathetosis, but the causes are multifactorial.

The long-term outcome of head injury: implications for service planning.

As most of those experiencing traumatic brain injury tend to be young, disabled survivors will be gradually accruing in each locality as each year passes. How many need continuing care a decade after injury? How many need day care, or need help with finding work, or continuing support for carers? 190 patients who had been admitted to two UK regional neurosurgical units on average some 7 years earlier were followed up. With an average age of 29 years these patients stayed in hospital for an average 33 days. At follow-up 23% were classified as having moderate disability or worse on the Glasgow Outcome Scale, including 7.4% who had died subsequent to discharge. Survivors were given a neuropsychological assessment and a socioeconomic interview. Of the survivors, 17% had failed to make a good recovery, but 36% were failing to occupy their time in a meaningful way. Age over 30 at time of injury, not occupied before injury, and above-average length of stay were some of the predictors for failing to occupy time. Quality of life was severely curtailed for those who could not occupy their time, as was the case for their carers. Appropriate counselling, vocational evaluation and family support in the early years following injury may help to improve quality of life for both the head-injured person and their carers.

On the choice of muscle in the electrophysiological assessment of myasthenia gravis.

We performed repetitive nerve stimulation on 38 adult patients with generalised myasthenia to compare the relative diagnostic yield from deltoid and trapezius. The decrement was consistently greater in deltoid, both before and after maximum voluntary contraction. In 12 patients the test was negative in trapezius but diagnostic in deltoid, whereas the converse occurred in only one. The yield from facial muscles was comparable to that from trapezius while that from hand muscles was very low. Post-tetanic exhaustion often enhanced the decrement but the use of stimulus frequencies greater than 2-3 Hz did not. We conclude that deltoid provides the highest diagnostic yield in myasthenia when doing decremental studies.

Observations on the reflex effects seen in Parkinson's disease on terminating a period of tendon vibration.

Vibration was applied to the tendon of flexor carpi radialis while recording the EMG of the wrist flexors in 29 Parkinsonian patients. Cessation of the vibration led to a small short-latency (approximately 25 ms) reduction in the level of activity which did not differ in magnitude from the normal. Moreover, there was no sign of any subsequent long-latency reduction of activity. Thus the maintained tonic activity of Parkinsonian muscles seems unlikely to be due to an enhancement of the tonic reflex actions of the Ia afferents, especially via the short-latency pathway. In addition, the findings argue against reduction of either Ia or Ib firing being responsible for the delayed excitatory "Westphal" (or "shortening") response that may occur in parkinsonism on allowing a muscle to shorten; this was never found on terminating vibration, even when present on muscle release.

Frontal lobe dementia and motor neuron disease.

Four patients are described, in whom a profound and rapidly progressive dementia occurred in association with clinical features of motor neuron disease. The pattern of dementia indicated impaired frontal lobe function, confirmed by reduced tracer uptake in the frontal lobes on single photon emission computed tomography (SPECT). Pathological examination of the brains of two patients revealed frontal-lobe atrophy, with mild gliosis and spongiform change. The spinal cord changes were consistent with motor neuron disease. The clinical picture and pathological findings resembled those of dementia of frontal-lobe type and were distinct from those of Alzheimer's disease. The findings have implications for the understanding of the spectrum of non-Alzheimer forms of primary degenerative dementia.

Convulsion following intravenous fluorescein angiography.

Tonic-clonic seizures followed intravenous fluorescein injection for fundus angiography in a 47-year-old male. Despite precautions this adverse reaction recurred on re-exposure to intravenous fluorescein.

Single photon emission tomography using 99mTc-HM-PAO in the investigation of dementia.

Single photon emission tomographic imaging of the brain using 99mTc HM-PAO was carried out in patients with a clinical diagnosis of Alzheimer's disease, non-Alzheimer frontal-lobe dementia, and progressive supranuclear palsy. Independent assessment of reductions in uptake revealed posterior hemisphere abnormalities in the majority of the Alzheimer group, and selective anterior hemisphere abnormalities in both other groups. The findings were consistent with observed patterns of mental impairment. The imaging technique has potential value in the differential diagnosis of primary cerebral atrophy.

Stretch and vibration reflexes of wrist flexor muscles in spasticity.

The surface electromyographic (EMG) reflex responses of the voluntarily contracting flexor carpi radialis evoked by 'stretch' and by tendon vibration have been compared in patients with spasticity of the upper limb, arising from upper motor neuron lesions, and normal subjects. Reflex responses to 'stretch' comprised increases in EMG activity lasting up to 100 ms which were often divided into 'short' and 'long'-latency peaks. The short-latency responses of spastic patients were increased in size compared with those of normal subjects whereas later activity was commonly reduced or absent. In both groups vibration elicited short-latency, essentially phasic responses with activity falling back to or below the background level within 50 ms despite continuing stimulation. These initial reflex responses were exaggerated in the spastics as compared with the normals. In the relaxed state 'stretch' and vibration either failed to elicit reflex responses in normal subjects or reflexes were of small amplitude; in spastic patients both modes of stimulation regularly evoked well developed responses. These findings with 'stretch' and vibration, both of which forms of stimulation powerfully excite primary endings of muscle spindles, support the view that group Ia afferent-mediated reflex action is enhanced in spasticity. The observation that the normal long-latency responses evoked by stretch, which have been attributed to the action of spindle group II afferents (Matthews, 1984a) additionally excited with this stimulus, are depressed in many spastic patients is consistent with reduced group II effects. Observed abnormalities of stretch reflex behaviour did not readily explain the severity of accompanying spasticity of individual patients.

Restless red legs: an association of the restless legs syndrome with arborizing telangiectasia of the lower limbs.

Two patients are reported with Ekbom's syndrome of "restless legs" occurring in association with arborizing telangiectasia of the lower limbs. Sensory complaints have previously been reported in this skin condition but not described in detail. The co-existence of the two conditions is discussed in the context of previous explanations of the restless legs syndrome.

Observations on the genesis of the stretch reflex in Parkinson's disease.

Using surface electromyography the reflex response of flexor carpi radialis elicited by forcibly dorsiflexing the wrist was compared with that elicited by applying vibration percutaneously to its tendon. This was done both in patients with Parkinson's disease and in normal subjects. The reflexes were elicited on top of a pre-existing voluntary contraction of the muscle of about 20 per cent maximum. The responses in parkinsonism were qualitatively similar to the normal, but differed quantitatively in certain respects. The response to 'stretch' of the muscle by wrist dorsiflexion normally continued at a high level up to at least 80 ms from the beginning of the movement, commonly with an apparent separation into 'short' and 'long' latency responses. On average, the later components of the response were enhanced in parkinsonian patients in comparison with the normals, confirming other workers' findings; they were also prolonged. The short-latency responses were unchanged. Vibration, in contrast, elicited solely a short-latency response with the initial reflexly-evoked augmentation of EMG activity coming to an end 40 to 50 ms from the beginning of the stimulation, even though the vibration was continuing. Such an absence of the later components that were so prominent with stretch was found whatever the size of the initial short-latency response evoked by vibration, including when it was comparable to that evoked by stretch in the same subject. This purely short-latency vibration response was on average unchanged in parkinsonism. The findings support the hypothesis, already advanced for the long flexor of the thumb, that the long-latency components of response are largely attributable to a spinal excitatory action of the spindle group II afferents with the delay arising from the slowness of their conduction. They are not readily compatible with either of the two major alternative hypotheses, namely the 'long-loop' (or transcortical) hypothesis and the 'resonance' hypothesis, both of which attribute the late response, as well as the initial response, to the spindle Ia afferents. The enhancement of the later components of response in parkinsonism thus now seems likely to be due to an increase in the postulated spindle group II excitatory action, possibly related to a reduction in opposing inhibition, rather than to any change in the reflex excitability of the higher centres on Ia activation. However, the rigidity of parkinsonism cannot be uniquely ascribed to an enhancement of group II action, because over the population as a whole clinically similar degrees of rigidity could be accompanied by quite different long-latency responses, and vice versa.