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Biomedical subjects

U Lindblom

Publications and source records attributed to U Lindblom.

At least 55 records · Page 3Linked to original sources
PubMed1980

Behavioral and electrophysiological effects of various types of peripheral nerve lesions in the rat: a comparison of possible models for chronic pain.

Three types of nerve lesions involving the brachial plexus were produced in rats: (1) multiple dorsal rhizotomy; (2) spinal nerve section just distal to the dorsal root ganglia (DRG); (3) section of the median, ulnar and radial nerves. The 3 types of lesion caused self-mutilation (autotomy) of the denervated forelimb. Significant differences were found in the time course and severity of this abnormal behavior among the 3 groups. Rats that had undergone spinal nerve lesion (group 2) performed significantly less severe autotomy than rats with dorsal rhizotomy (group 1) or peripheral nerve lesions (group 3). The latency to the onset of autotomy was significantly shorter for group 2 than for groups 1 and 3. Electrophysiological investigation of rats in group 2 revealed neural activity in the dorsal roots. The characteristics of the neural discharge were largely a function of postoperative survival times. The possible role of the various types of nerve lesion in producing chronic pain states is discussed.

Afferent Pathways↗
PubMed1979

Sensory functions in chronic neuralgia.

Eleven patients with sustained neuralgia, in most cases after traumatic nerve lesion, were subjected to quantitative sensory testing with thermal and non-noxious mechanical stimuli. Measurements were made in the pain area and at a homologous site on the contralateral normal side. All patients were hypoaesthetic with raised thresholds for warm and cold or touch, or both. Thermal pain thresholds were also raised in some patients but lowered in others indicating hypersensitivity of the nociceptor system or dysaesthesia for thermal input. In six patients single mechanical stimuli produced a painful response above the touch detection threshold. Reaction time measurements indicated that this painful response to suprathreshold mechanical pulses was measured by magnitude estimation as a function of stimulus amplitude. The results were fitted by power functions, as in normal skin, but with steeper slopes on the abnormal side. Suprathreshold hyperaesthesia (recruitment) may exist in the presence of normal threshold functioning.

Adult↗
PubMed1979

Standardised method of determining vibratory perception thresholds for diagnosis and screening in neurological investigation.

Vibration threshold determinations were made by means of an electromagnetic vibrator at three sites (carpal, tibial, and tarsal), which were primarily selected for examining patients with polyneuropathy. Because of the vast variation demonstrated for both vibrator output and tissue damping, the thresholds were expressed in terms of amplitude of stimulator movement measured by means of an accelerometer, instead of applied voltage which is commonly used. Statistical analysis revealed a higher power of discimination for amplitude measurements at all three stimulus sites. Digital read-out gave the best statistical result and was also most practical. Reference values obtained from 110 healthy males, 10 to 74 years of age, were highly correlated with age for both upper and lower extremities. The variance of the vibration perception threshold was less than that of the disappearance threshold, and determination of the perception threshold alone may be sufficient in most cases.

Adolescent↗
PubMed1976

Method for quantitative estimation of thermal thresholds in patients.

A quantitative method for the examination of thermal sensibility was applied in 26 normal subjects and in patients with various neurological disorders. The stimulation technique resembled Békésy audiometry: the patient reversed the direction of the temperature change of a thermode whenever warm, cold, or thermal pain thresholds were reached. The resulting temperature curve enables a quantitative description of the subject's thermal sensibility and of the degree of impairment displayed by neurological patients.

Abdomen↗
PubMed1975

Influence on touch, vibration and cutaneous pain of dorsal column stimulation in man.

Five patients out of a group of ten who had dorsal column electrodes implanted for the relief of chronic pain were examined for the influence of the stimulation on the spontaneous pain and on the thresholds for touch, vibration and cutaneous pain induced by pinching. Stimulation producing paraesthesias resulted in an almost immediate abolishment of spontaneous pain and was accompanied by significant elevations of both tactile and vibratory thresholds. Elevation of thresholds was confined to segments below the site of implantation and occurred bilaterally also when the paraesthesias were restricted to one side. The changes of thresholds generally persisted for some time after the stimulation but these effects were short lasting in comparison with the effect on spontaneous pain. Elevation of sensory thresholds is presumably not due to blocking of the primary neurones but to central inhibitory mechanisms. The thresholds for induced cutaneous pain were not influenced by dorsal column stimulation except for one case in whom an abnormally low threshold within an hyperaestethic area became normalized.

Adult↗
PubMed1975

Preservation of peripheral nerve function in severe uremia during treatment with low protein high calorie diet and surplus of essential amino acids.

Twelve patients with severe chronic renal failure (serum creatinine 7.0-27 mg %), and marked uremic symptoms on a 40 g protein diet, were treated with a caloric-rich diet containing 16-20 g protein, supplemented with the 8 essential amino acids (1.1-2.2 g N) and histidine (0.23-0.45 g N)in the form of tablets for periods between 3 and 34 months. During the treatment the serum urea-N fell, and the uremic symptoms subsided or diminished without the patient exhibiting signs of malnutrition. The nerve function was followed with quantitative and semiquantitative neurological tests (among others, determination of vibratory perception thresholds and nerve conduction times). Initially all patients but 2 had signs of neuropathy as measured by these methods. During the course of treatment no deterioration of peripheral nerve function was recorded in any of the patients, several of whom had had serum creatinine conceptrations above 15 mg % for long periods. We conclude that conservative treatment with N-poor diet in far advanced chronic renal failure may prevent the further development of peripheral neuropathy provided that adequatecaloried and essential amino acids (2-3 times the minimal requirements) are supplied. The results suggest that, in addition to uremic toxines, malnutrition is a factor of importance for the developments of of uremic neuropathy.

Adult↗