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P Cariga

Publications and source records attributed to P Cariga.

6 recordsLinked to original sources
PubMed2004

Associative recognition in a patient with selective hippocampal lesions and relatively normal item recognition.

Previous work (Mayes et al., Hippocampus 12:325-340, 2002) found that patient YR, who suffered a selective bilateral lesion to the hippocampus in 1986, showed relatively preserved verbal and visual item recognition memory in the face of clearly impaired verbal and visual recall. In this study, we found that YR's Yes/No as well as forced-choice recognition of both intra-item associations and associations between items of the same kind was as well preserved as her item recognition memory. In contrast, YR was clearly impaired, and more so than she was on the above kinds of recognition, at recognition of associations between different kinds of information. Thus, her recognition memory for associations between objects and their locations, words and their temporal positions, abstract visual items or words and their temporal order, animal pictures and names of professions, faces and voices, faces and spoken names, words and definitions, and pictures and sounds, was clearly impaired. Several of the different information associative recognition tests at which YR was impaired could be compared with related item or inter-item association recognition tests of similar difficulty that she performed relatively normally around the same time. It is suggested that YR's familiarity memory for items, intra-item associations, and associations between items of the same kind was mediated by her intact medial temporal lobe cortices and was preserved, whereas her hippocampally mediated recall/recollection of these kinds of information was impaired. It is also suggested that the components of associations between different kinds of information are represented in distinct neocortical regions and that initially they only converge for memory processing within the hippocampus. No familiarity memory may exist in normal subjects for such associations, and, if so, YR's often chance recognition occurred because of her severe recall/recollection deficit. Conflicting data and views are discussed, and the way in which recall as well as item and associative recognition need to be systematically explored in patients with apparently selective hippocampal lesions, in order to resolve existing conflicts, is outlined.

Aged↗
PubMed2002

The prevalence and association of neck (coat-hanger) pain and orthostatic (postural) hypotension in human spinal cord injury.

OBJECTIVE: To investigate the prevalence of orthostatic (postural) hypotension (OH) and neck pain in a 'coat-hanger' occipito-cervical distribution in subjects with spinal cord injury (SCI), and their association. METHOD: Blood pressure was measured during head-up tilt to 60 degrees (to determine OH) and neck pain was assessed in 28 subjects with SCI (cervical, thoracic and lumbar level) with McGill Pain Questionnaire, visual analogue scale for pain intensity and Orthostatic Intolerance Symptoms Questionnaire for pain frequency. RESULTS: Neck pain was reported by 53.6% of subjects. Orthostatic hypotension was present in 57.1% of subjects. Neck pain was reported by 75% of subjects with OH and 25% of subjects without OH (P<0.03, Chi-square). Features of such pain included positive correlation to upright posture and exercise, and relief when lying flat. CONCLUSION: There is a high prevalence of neck pain and OH in SCI, with a positive association similar to that reported in primary autonomic failure with OH.

Adolescent↗
PubMed2002

Organisation of the sympathetic skin response in spinal cord injury.

OBJECTIVES: The sympathetic skin response (SSR) is a technique to assess the sympathetic cholinergic pathways, and it can be used to study the central sympathetic pathways in spinal cord injury (SCI). This study investigated the capacity of the isolated spinal cord to generate an SSR, and determined the relation between SSR, levels of spinal cord lesion, and supraspinal connections. METHODS: Palmar and plantar SSR to peripheral nerve electrical stimulation (median or supraorbital nerve above the lesion, and peroneal nerve below the lesion) were recorded in 29 patients with SCI at various neurological levels and in 10 healthy control subjects. RESULTS: In complete SCI at any neurological level, SSR was absent below the lesion. Palmar SSR to median nerve stimuli was absent in complete SCI with level of lesion above T6. Plantar SSR was absent in all patients with complete SCI at the cervical and thoracic level. In incomplete SCI, the occurrence of SSR was dependent on the preservation of supraspinal connections. For all stimulated nerves, there was no difference between recording from ipsilateral and contralateral limbs. CONCLUSIONS: No evidence was found to support the hypothesis that the spinal cord isolated from the brain stem could generate an SSR. The results indicate that supraspinal connections are necessary for the SSR, together with integrity of central sympathetic pathways of the upper thoracic segments for palmar SSR, and possibly all thoracic segments for plantar SSR.

Adult↗
PubMed2001

Characteristics of habituation of the sympathetic skin response to repeated electrical stimuli in man.

OBJECTIVES: To study the effect of repeating electrical peripheral nerve stimulation on latency, duration and amplitude of the sympathetic skin response (SSR). METHODS: SSRs were elicited in all limbs by median and peroneal nerves stimuli. In 10 subjects, 20 stimuli were applied at random time intervals (15-20 s). Another test was performed in 7 subjects using the same protocol, but switching the stimulation site every 5 or 10 stimuli without warning. RESULTS: The mean amplitude of right palmar response to right peroneal nerve stimulation decreased from 5.05+/-0.76 (SEM) mV at the first stimulus to 1.23+/-0.42 mV at the 20th stimulus (P<0.001). The latency did not change significantly (1473+/-82 to 1550+/-90 ms, P>0.1), while the duration increased (1872+/-356 to 3170+/-681 ms, P<0.001). Stimulation and recording at other sites showed similar trends. Changing the stimulation site failed to alter the adaptation process in terms of amplitude, latency or duration. CONCLUSIONS: Changes in amplitude and duration of the SSRs to repeated electrical stimuli can occur in presence of constant latency and appear to be independent of the source of sensory input. Peripheral sweat gland mechanisms may be involved in the loss of amplitude and increase in duration of the SSR during habituation.

Adult↗
PubMed2001

Haemodynamics of the pressor effect of oral water in human sympathetic denervation due to autonomic failure.

Oral water ingestion increases blood pressure in normal elderly subjects and in patients suffering from autonomic failure, but the time course of the haemodynamic changes is not known. We therefore studied 14 subjects with documented sympathetic denervation due to pure autonomic failure, with continuous haemodynamic recordings obtained before and after ingestion of 500 ml of distilled water at room temperature. The time course of changes in values of systolic and diastolic beat-by-beat finger blood pressure, heart rate, stroke volume, cardiac output, ejection fraction and total peripheral resistance were analysed. Systolic blood pressure rose from 115+/-8 mmHg (mean+/-S.E.M.) to 133+/-8 mmHg (P<0.001), and diastolic blood pressure from 64+/-4 to 73+/-4 mmHg (P<0.001), with the pressor response beginning a few minutes after water ingestion, plateauing between 10 and 35 min (peak at 14 min), and returning to baseline at 50 min. Heart rate fell from 71+/-2.5 to 67+/-2 beats/min (P<0.001), and total peripheral resistance increased from 1.31+/-0.19 to 1.61+/-0.24 m-units (P<0.001). There were no significant changes in ejection fraction, stroke volume or cardiac output. This study confirmed a pressor response to oral water in subjects with sympathetic denervation. The temporal profile of the response did not favour reflexly mediated sympathetic activation. As subjects with autonomic failure are prone to salt and water depletion, and since blood pressure is exquisitely sensitive to such changes, it may be that the observed response is due to repletion or restoration of intravascular and extravascular fluid volume.

Adult↗