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Biomedical subjects

D D Barwick

Publications and source records attributed to D D Barwick.

18 recordsLinked to original sources
PubMed1995

Vigabatrin monotherapy in resistant neonatal seizures.

Seizures in a term infant with Ohtahara syndrome, associated with polymicrogyria, and a pre-term neonate with similar clinical features, failed to respond to conventional anticonvulsants, but were controlled with vigabatrin monotherapy. Another infant with Aicardi syndrome improved with vigabatrin. Autopsy in the first infant showed no evidence of intramyelinic oedema. The developmental outcome in the two survivors was better than expected for their condition.

Agenesis of Corpus Callosum↗
PubMed1987

F-response frequency in motor neuron disease and cervical spondylosis.

During a train of 200 stimuli, F-response frequency, frequency of identical responses, and F-response shape were studied in the ulnar nerve of 17 patients with motor neuron disease (MND) and 16 patients with cervical spondylosis (CS). In MND patients, F-response frequency varied between 5% and 96% with a median of 39% which was significantly lower than controls (p less than 0.001), and showed a significant rank correlation with the M-response amplitude (r = 0.62, p less than 0.004). Identical responses occurred more frequently than in controls (median 30.8%, p less than 0.001). F-response frequency was normal in CS patients (median 76.3%, range 35% to 97%), but the frequency of identical responses (median 6.3%) was higher than normal (p less than 0.01). Reduced F-response frequency in MND was thought to reflect loss of lower motor neurons, while the presence of spasticity was probably the major factor underlying the increased frequency of identical responses in both disorders. F-response shape tended to be simpler in MND and rather more complex in CS patients than controls.

Adult↗
PubMed1986

F-responses in syringomyelia.

Motor and sensory nerve conduction and various F-response parameters have been examined in the median and ulnar nerves bilaterally in 22 patients with syringomyelia. Excluding those nerves with isolated peripheral lesions, motor and sensory conduction was normal in the distal nerve segments, except for one subject in whom severe wasting of the muscles was associated with slowed motor velocities. Minimum and/or maximum F-response latencies were increased in one or more nerves in 16 of the 22 cases, which was attributed to disturbed function of anterior horn cells and the intraspinal segment of the motor fibres, or mild subclinical nerve trauma. There was a tendency for F-response amplitude and duration to be increased, probably reflecting the combined effects of spasticity and enlargement of motor units due to reinnervation.

Adult↗
PubMed1986

Multiple intracranial enterogenous cysts.

The case of a 40-year-old woman with increasing ataxia is described. Although the clinical presentation and evoked response studies raised the possibility of multiple sclerosis, further investigation revealed multiple cystic intracranial lesions. Surgical excision of one of the lesions relieved the patient's symptoms. Histological examination revealed that this was an enterogenous cyst. Although single cysts of this type have rarely been reported occurring in the posterior cranial fossa, the occurrence of multiple lesions, some in the supratentorial compartment, appears to be unique.

Adult↗
PubMed1985

F-response behaviour in a control population.

Various parameters of the F-response including minimal and maximal latency, chronodispersion, amplitude (absolute and F%M) and duration have been determined for a sample of 20 responses in the median and ulnar nerves bilaterally in normal healthy subjects of both sexes aged between 12 to 81 years. Side to side comparisons revealed no significant differences in any of the parameters except for slightly longer minimum F latencies in the right median nerve. Strong correlations were found between minimal and maximal F latencies and height, while much weaker relationships were found between these parameters and age. There was a slight but significant relationship between F%M and age, but no age or sex related changes were noted for any of the remaining F-response parameters.

Adolescent↗
PubMed1985

F-responses: a study of frequency, shape and amplitude characteristics in healthy control subjects.

Characteristics of the surface recorded F-response, including frequency, occurrence of identical responses, shape and amplitude have been investigated in the ulnar nerve of control subjects. During a train of 200 stimuli, F-response frequency varied between 50% and 93% in different subjects with a mean of 79%. The vast majority of responses (96.6%) occurred only once; of those responses which repeated, 89.5% occurred between 2-5 times, 9% between 6-10 times and only 1.5% 11 or more times. F-response shape was variable, the majority containing two or more negative peaks. F-response amplitudes tended to be a relatively small proportion of the compound M-response, with median F%M values ranging from 0.8% to 4%. The data suggest that a large proportion of surface recorded F-responses following supramaximal stimulation are composed of recurrent discharges derived from more than one motor unit.

Adult↗
PubMed1982

Exploratory electromyography in the study of vibration-induced white finger in rock drillers.

Electrophysiological observations made in the hands of a group of 16 rock-drillers were compared with 15 controls. Motor and sensory conduction velocities in the median and ulnar nerves together with the latency, duration, and amplitude of the evoked action potentials were measured. The differences between the groups were statistically significant mainly in latency, duration, and amplitude, especially of the sensory action potentials. Measurement of the conduction velocities, in general, proved to be less sensitive, and the only significant change observed was in the sensory conduction velocity in the median nerve when the first digit in the right hand was stimulated. The most interesting result was evidence of an increased prevalence of possible carpal tunnel syndrome in the exposed (44% compared with 7% in the control group). A similar set of data, but exclusively sensory and not standardised for age and sex, was obtained from 25 university students for comparison with the assigned groups. The results showed that apart from sensory duration the control group had values that were closest to the students while the vibration group had values furthest away.

Adult↗
PubMed1976

Unusual manifestations of herpes zoster. A clinical and electrophysiological study.

The literature on complicated herpes zoster is summarized in this paper. The case histories of 18 patients with herpes zoster are presented. Two patients had encephalitis, 2 had myelitis and the other 14 patients had various types of lower motor neurone disturbance. Both patients with encephalitis--one of who developed choreo-athetosis during the illness--recovered fully. Only 1 of the 2 patients with myelitis recovered fully; the other remains severely paraparetic and the reason for her incomplete recovery may be related to the presence of generalized arteriolar disease associated with seronegative rheumatoid disease. One patient developed a Guillain-Barre syndrome 3 weeks after the onset of herpes zoster. Recovery in the 15 patients with lower motor neurone involvement has been slow butcomplete--or almost complete--in all but 1, a patient with persistent facial weakness as part of the Ramsay Hunt syndrome and who also had weakness of one upper limb. Seven other patients had lower limb weakness. In 2 patients the weakness was confined to abdominal myotomes and 2 other patients had urinary retention. Electromyographic abnormalities were found in the muscles which were weak and frequently also in muscles which appeared strong. It is emphasized that neurological disturbances other than sensory abnormalities may be found in patients with herpes zoster. Motor complications of various types are not uncommon.

Adult↗
PubMed1974

Three patients with intracranial tuberculomas with unusual features.

Three patients with verified intracranial tuberculomas are reported. One patient presented with attacks of hydrocephalus initially diagnosed erroneously as migraine, another had multiple tuberculomas and a fourth tuberculoma became apparent during treatment with antituberculous therapy. The third patient presented with a frontal lobe syndrome and the postoperative recovery was complicated by the development of hyperosmolar non-ketotic, non-acidotic diabetic pre-coma. Although there are no pathognomonic symptoms, signs, or radiological appearances of intracranial tuberculomas, a high index of suspicion should always be entertained during the investigation of non-European immigrants.

Adolescent↗
PubMed1974

Jakob-Creutzfeldt disease. Modification of clinical and electroencephalographic activity with methylphenidate and diazepam.

The electroencephalogram in three patients with Jakob-Creutzfeldt disease showed two separate abnormalities-namely, progressive background suppression and periodic generalized synchronous triphasic sharp wave complexes which evolve to a uniform morphology and periodicity. The abnormalities, when found in the EEG of a patient in middle-age with a dementing illness, should not be confused with other periodic electroencephalographic phenomena. Since the neuropathological abnormalities of Jakob-Creutzfeldt disease are non-specific, the electroencephalogram is essential for the recognition of this disorder, although serial recordings may be necessary to establish the diagnosis. Modification of the electroencephalographic abnormalities occurs with afferent stimuli and with methylphenidate or diazepam, suggesting that the phenomenon of background suppression is independent of the presence of the periodic complexes. Modification of clinical activity with methylphenidate suggests that some degree of reversibility of function exists in this inexorably fatal disorder. Further detailed studies of the electroencephalogram in cases of Jakob-Creutzfeldt disease are indicated.

Cerebral Cortex↗