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Biomedical subjects

A Hopkins

Publications and source records attributed to A Hopkins.

At least 109 records · Page 6Linked to original sources
PubMed1977

How doctors deal with epilepsy.

All of those adults with epilepsy on the lists of 17 general practitioners in Metropolitan London were identified. 87% of these agreed to be separately interviewed in their homes by a neurologist and a sociologist. The vast majority had been referred to hospital for investigation, and their hospital notes were inspected. The pattern of care suggests unnecessary referral, unnecessary electroencephalography, inadequate communication of the diagnosis, inadequate medication, and follow-up supervision not related to patient need.

Adolescent↗
PubMed1977

Monosynaptic reflexes in falling man.

We have examined peripheral proprioceptive input during fall in man. The first 80 ms of unexpected free fall, both in a parachute harness and while seated, has been studied using the monosynaptic Hoffman (H) and Achilles tendon (T) reflexes. Facilitation of the H reflex begins about 30 to 40 ms after release, representing the onset of motor neurone facilitation before the electromyographic activity which begins about 80 ms after release. Earlier facilitation of the T reflex may represent spindle excitation due to change in muscle shape as suggested by Matthews and Whiteside (1960), but the T reflex inhibition described by these authors after 50 ms of seated fall is probably a purely mechanical phenomenon.

Achilles Tendon↗
PubMed1976

Landing from an unexpected fall and a voluntary step.

The electromyographic (EMG) response of soleus to a sudden fall has previously been shown to consist of two peaks of activity, the first a response to release, and the second in relation to landing (Greenwood and Hopkins, 1976). We have now examined activity in soleus during falls at various reduced accelerations. The amplitude of the first peak is proportional to acceleration and is not present during falls at accelerations of less than about 2-0 ms-2. The timing of the second peak is related to the timing of landing whether the duration of the fall depends upon the height or upon the acceleration of the fall. Its timing depends upon knowledge of the height of the fall, rather than to ongoing visual information, and upon labyrinthine function. EMG activity in soleus was also examined during voluntary downward steps which could be unexpectedly increased in height. The moment of landing is preceded by an increase of EMG activity and is followed by a number of peaks of activity. These peaks were not seen after the moment of expected landing during unexpectedly lengthened steps and thus probably represent reflex activity due to the mechanical event of landing.

Acceleration↗
PubMed1976

Muscle responses during sudden falls in man.

1. E.m.g. activity in soleus during an unexpected fall is found to be more complex than that described by Melvill Jones & Watt (1971b). After a silent period of about 80 msec an initial peak of activity lasts until about 100 msec after release. In falls from sufficient heights a second peak of activity occurs before landing. 2. The initial peak of activity is found in muscles throughout the body and is absent during falls in which the subject releases himself. It is suggested that this initial peak is a startle response to release and on landing during the initial peak any deceleration due to tension in the leg muscles is in part coincidental. 3. The second peak of activity is found in muscles of the lower limbs. Its timing is related to the timing of landing. It is suggested that this is the activity concerned in thhe voluntary control of landing. 4. No initial peak of activity could be recorded in two patients with absent labyrinthine function.

Acceleration↗
PubMed1974

Tuberculous meningitis as a complication of sarcoidosis.

In two patients with well established sarcoidosis, the acute onset of meningitis proved to be due to tuberculosis rather than to an extension of sarcoid granulomata to the meninges. The cerebrospinal fluid changes are very similar, and the differential diagnosis rests on a search for Mycobacterium tuberculosis.

Adult↗
PubMed1974

Clark P. Read.

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History, 20th Century↗
PubMed1973

Hyperpathia in the central cervical cord syndrome.

Seven patients are described with hyperextension or flexion injury to the cervical cord. They illustrate the symptoms and signs previously associated with damage to the centre of the cord, in that weakness is greater in the upper limbs than the lower. We do not believe that the relative sparing of the legs can be accounted for on the basis that corticospinal fibres passing to the lumbar anterior horn cells lie laterally in the pyramidal tract, as has previously been suggested by Schneider, Cherry, and Pantek (1954) as there is no evidence that there is such lamination in man. Severe pain in the shoulders and arms was a major symptom in six of the patients, even in those with relatively minor injuries. The nature of this pain was initially often not recognized.

Adult↗
PubMed1970

The effect of acrylamide on the peripheral nervous system of the baboon.

In the baboon, acrylamide produces a clinical illness characterized by weakness and ataxia of the limbs, weakness of bulbar muscles, and finally tetraplegia. Histological examination shows extensive involvement of peripheral nerves, the main histological change being a Wallerian type of degeneration affecting the distal ends of the largest diameter nerve fibres. The phenomenon of `dying back' has been demonstrated in single teased fibres. Changes also occur in the paranodal myelin; these are not necessarily associated with degeneration of the axon, since intercalated segments and extension of myelin from neighbouring internodes are present in recovering animals. Demyelination of whole internodes is rare. Paranodal changes may be found a few millimetres proximal to complete degeneration, but may also occur on fibres which are otherwise normal in the length examined. The mechanism of the paranodal changes is uncertain, but they may indicate a secondary response of the Schwann cell to a primary change in the axon.

Acrylic Resins↗