PubMed Health⌕ Search

Biomedical subjects

R T Watson

Publications and source records attributed to R T Watson.

At least 19 recordsLinked to original sources
PubMed1990

Frontal hypermetabolism and thalamic hypometabolism in a patient with abnormal orienting and retrosplenial amnesia.

A patient with verbal amnesia and a propensity to direct his attention to the right following a retrosplenial area lesion was studied with positron emission tomography using [F-18] fluorodeoxyglucose. These studies showed that the left thalamus was hypometabolic, and the anterior 2/3 of the left hemisphere was hypermetabolic when compared with the right. There were no significant differences seen in the medial temporal lobes. Based on this study, it is posited that interruption of hippocampal input into the anterior thalamus was responsible for the amnesia, and the left frontal hyperactivity was associated with the propensity to attend contralaterally.

Adult↗
PubMed1979

Perilymph fistulae.

A small series of 14 post-stapedectomy fistulae illustrates the varied aetiology. The long-term competence of the oval window seal may be ensured by making a small hole in the footplate. Contraction of ageing fibrous tissue contributes to late stapedectomy failures. Long-term follow-up is important, for any deterioration in hearing after stapedectomy may result from a perilymph leak.

Female↗
PubMed1979

Thalamic neglect.

Three patients with right thalamic hemorrhage showed contralateral neglect and limb akinesia. They also had anosognosia, visuospatial disorders, and emotional flattening. In animals, neglect can be induced by lesions along a cortico-limbic-reticular loop including the intralaminar thalamic nuclei. We propose that an activation defect is responsible not only for the neglect and akinesia, but also for the visuospatial and emotional defects usually associated with right-hemisphere cortical dysfunction.

Aged↗
PubMed1979

TIA, stroke, and mitral valve prolapse.

Eight patients with transient ischemic attacks, and three with partial nonprogressive strokes associated with mitral valve prolapse, are reported. No other etiology for their ischemic events was found. Only one episode of ischemia recurred on aspirin treatment, whereas none recurred on sodium warfarin therapy.

Adult↗
PubMed1978

Changes in the symptoms of neglect induced by changing task strategy.

Six patients with left side unilateral neglect from lesions of the right cerebral hemisphere were tested with verbal and visuospatial crossing-out tasks. The symptoms of neglect were less severe with the visuospatial than with verbal tasks. We hypothesize that changes in the symptoms of neglect were produced because the tasks altered hemispheric arousal.

Aged↗
PubMed1978

Operating table for guinea pig ear surgery.

This communication describes the construction and method of use of an adjustable operating table. The small table was designed especially to immobilize guinea pigs for experimental ear surgery.

Animals↗
PubMed1978

Inhalation anesthesia with methoxyflurane for guinea pig ear surgery.

Anesthesia with methoxyflurane is ideal for long-term middle ear experiments on guinea pigs. This communication describes the use of a conventional pediatric anesthetic circuit that delivers a mixture of methoxyflurane and air by a face mask; it is effective, safe, and simple to use.

Anesthesia, Inhalation↗
PubMed1978

Nonsensory neglect.

Five monkeys trained to perform with the extremity contralateral to a stimulus had unilateral neglect induced by frontal and reticular formation lesions. Postoperatively the performance of the animals was abnormal only on ipsilateral stimulation, which suggests that the mechanism underlying neglect in these subjects is not deafferentation of sensory inattention but a defect of intention.

Animals↗
PubMed1978

Myokymia, muscle hypertrophy and percussion "myotonia" in chronic recurrent polyneuropathy.

Three unusual features were observed in a patient with chronic relapsing polyneuropathy: myokymia, muscle hypertrophy, and prolonged contraction in response to muscle percussion. Low nerve conduction velocity and conduction block were demonstrated in all motor nerves tested, indicating a demyelinating peripheral neuropathy. Myokymia was caused by spontaneous motor unit activity which was shown to originate in peripheral nerves, since it persisted after nerve block and was abolished by regional curarization. Muscle hypertrophy was attributed to increased peripheral nerve activity, and the prolonged contraction of muscle in response to direct percussion was attributed to irritability of intramuscular nerve terminals.

Adult↗
PubMed1978

Hypoarousal in patients with the neglect syndrome and emotional indifference.

Physiologic theories of emotion suggest that activation is important in the experience of emotion; patients exhibiting "neglect" as a consequence of right parietotemporal of dysfunction show flattened affect. We studied arousal in patients with lesions of the right hemisphere who also exhibited emotional indifference, in aphasic patients with lesions of the left hemisphere, and in non-brain-damaged controls, by stimulating the forearm ipsilateral to the side of the brain lesion while recording galvanic skin responses (GSRs) from the fingers on the same side. The group exhibiting neglect had lower GSRs than aphasic patients or non-brain-damaged controls. Aphasic patients had higher GSRs than non-brain-damaged controls. These results suggest that neglect is associated with disturbances in bilateral arousal and that this disorder of arousal may be responsible in part for flattened affect. The heightened GSR in aphasic patients may reflect disinhibition, which might be partly responsible for increased emotionality in these patients.

Affective Symptoms↗
PubMed1977

Evoked potential in neglect.

The evoked potential was studied in Macaca speciosa before and after they received a lesion inducing neglect. Significant evoked potential changes associated with neglect were seen only in late components (N2, P3). These observations support the hypothesis of the arousal-attention mechanism of neglect.

Animals↗
PubMed1977

Retinal degeneration without pigment alterations in progressive external ophthalmoplegia.

A 56-year-old black man had annular visual field defects and retinal electrophysiologic dysfunction with chronic progressive external ophthalmoplegia and no pigmentary abnormalities in the fundus. Because the association of retinal disease with neurodegenerative states has generally been based on the observation of pigmentary changes, the patient's fields were erroneously interpreted as the nerve fiber bundle defects of glaucoma.

Chronic Disease↗
PubMed1977

The electroencephalogram in neglect.

The extent of electroencephalographic (EEG) abnormalities in 23 consecutive patients with unilateral neglect was compared with the extent of EEG abnormalities in 20 matched aphasic controls. In the neglect group, 22 patients showed EEG slowing that extended over the entire hemisphere. In the control group only 8 patients showed similar hemispheric slowing. This study demonstrates that patients with unilateral neglect from discrete lesions may have EEG slowing in regions of the hemisphere that are remote from the lesion. This study also provides support for the hypothesis that neglect is a unilateral arousal defect.

Animals↗
PubMed1977

Discrimination and evocation of affectively intoned speech in patients with right parietal disease.

Patients with right parietal disease have disturbed comprehension of affective speech. Ability to discriminate affective speech (make same/different discriminations) and ability to repeat emotionally bland sentences with affective tones were tested in three groups of subjects--patients with right parietal dysfunction and neglect, conduction aphasics with left hemispheric lesions, and patients without intracranial disease. Patients with right parietal dysfunction performed significantly poorer than did aphasic controls on both a recognition and discrimination task. Patients with right parietal dysfunction also scored poorer on the evocative task than the nonaphasic controls.

Adult↗