Light Touch Perception Research Articles

Higher frequency of paronychia (nail bed infections) in pediatric and adolescent patients with type 1 diabetes mellitus than in non-diabetic peers.

Paronychia occurs frequently in adolescents, but there are no data about its prevalence in adolescents with type 1 diabetes mellitus (DM1). We investigated the presence and characteristics of nail-bed infections in a group of adolescent patients with DM1 aged 10-20 years. Ninety-three children and adolescents with DM1 and 100 healthy age-matched controls were studied using a structured questionnaire. Frequency, duration and treatment of paronychia and, in the DM1 group, duration of DM, mean HbA1c, frequency of hypoglycemia, footwear and foot care were evaluated. All patients with DM1 underwent a complete neurological examination including vibration perception, thermal perception, and light touch perception. Adolescents with DM1, particularly girls, had a higher frequency of paronychia than controls (34.4% vs 23%; p < 0.01). Diabetic patients with paronychia were older than those without and had a longer duration of DM1, while there was no difference in long-term HbA1c between the groups. Vibration perception was impaired in all regions measured, compared to healthy adolescents. Subclinical neuropathy and microalbuminuria was found to be more frequent in patients with paronychia than in those without. We conclude that foot examination is important and mandatory in adolescents with DM1.

An evaluation of the cutaneous distribution after obturator nerve block.

In 1973, Winnie et al. introduced the inguinal paravascular three-in-one block, which allegedly provides anesthesia of three nerves--the femoral, lateral cutaneous femoral, and obturator nerves--with a single injection. This concept was undisputed until the success of the obturator nerve block was reassessed by using evidence of adductor weakness rather than cutaneous sensory blockade, the latter being variable in its distribution and often absent. We performed this study, therefore, to evaluate the area of sensory loss produced by direct injection of local anesthetic around the obturator nerve. A selective obturator nerve block with 7 mL of 0.75% ropivacaine was performed in 30 patients scheduled for knee surgery. Sensory deficit and adductor strength were evaluated for 30 min by using sensory tests (cold and light-touch perception) and the pressure generated by the patient's squeezing a blood pressure cuff placed between the knees. Subsequently, a three-in-one block was performed, and the sensory deficit was reassessed. The obturator nerve block was successful in 100% of cases. The strength of adductors decreased by 77% +/- 17% (mean +/- SD). In 17 patients (57%), there was no cutaneous contribution of the obturator nerve. The remaining 7 patients (23%) had an area of hypoesthesia (cold sensation was blunt but still present) on the superior part of the popliteal fossa, and the other 6 (20%) had sensory deficit located at the medial aspect of the thigh. The three-in-one block resulted in blockade of the lateral aspect of the thigh in 87% of cases, whereas the anteromedial aspect was always anesthetized. By use of magnetic resonance imaging in eight volunteers, we demonstrated that the obturator nerve has already divided into its two branches at the site of local anesthetic injection. However, the injection of blue dye after having simulated the technique in five cadavers showed that the fluid regularly spread to both branches. We conclude that after three-in-one block, a femoral nerve block may have been assessed as an obturator nerve block in 100% of cases when testing the cutaneous distribution of the obturator nerve on the medial aspect of the thigh. Previous studies reporting an incidence of obturator nerve block after three-in-one block may have mistaken a femoral nerve block for an obturator nerve block in 100% of cases when the cutaneous distribution of the obturator nerve was assessed on the medial aspect of the thigh. The only way to effectively evaluate obturator nerve function is to assess adductor strength.

An Evaluation of the Cutaneous Distribution After Obturator Nerve Block

In 1973, Winnie et al. introduced the inguinal paravascular three-in-one block, which allegedly provides anesthesia of three nerves—the femoral, lateral cutaneous femoral, and obturator nerves—with a single injection. This concept was undisputed until the success of the obturator nerve block was reassessed by using evidence of adductor weakness rather than cutaneous sensory blockade, the latter being variable in its distribution and often absent. We performed this study, therefore, to evaluate the area of sensory loss produced by direct injection of local anesthetic around the obturator nerve. A selective obturator nerve block with 7 mL of 0.75% ropivacaine was performed in 30 patients scheduled for knee surgery. Sensory deficit and adductor strength were evaluated for 30 min by using sensory tests (cold and light-touch perception) and the pressure generated by the patient’s squeezing a blood pressure cuff placed between the knees. Subsequently, a three-in-one block was performed, and the sensory deficit was reassessed. The obturator nerve block was successful in 100% of cases. The strength of adductors decreased by 77% ± 17% (mean ± sd). In 17 patients (57%), there was no cutaneous contribution of the obturator nerve. The remaining 7 patients (23%) had an area of hypoesthesia (cold sensation was blunt but still present) on the superior part of the popliteal fossa, and the other 6 (20%) had sensory deficit located at the medial aspect of the thigh. The three-in-one block resulted in blockade of the lateral aspect of the thigh in 87% of cases, whereas the anteromedial aspect was always anesthetized. By use of magnetic resonance imaging in eight volunteers, we demonstrated that the obturator nerve has already divided into its two branches at the site of local anesthetic injection. However, the injection of blue dye after having simulated the technique in five cadavers showed that the fluid regularly spread to both branches. We conclude that after three-in-one block, a femoral nerve block may have been assessed as an obturator nerve block in 100% of cases when testing the cutaneous distribution of the obturator nerve on the medial aspect of the thigh.

下顎枝逆Ｌ字型骨切りと矢状分割術々後のオトガイ神経知覚異常について

Neurosensory function in the mental nerve region of 24 patients who had undergone intraoral inverted L ramus and sagittal splitting ramus osteotomy was assessed by evaluating light touch perception. Neuropathy was present in 67% of the 48 mental nerves examined. The incidence and recovery period of neuropathy on the side undergoing inverted L ramus osteotomy were similar to those on the side undergoing sagittal splitting ramus osteotomy. Our results suggest that dissection of the periosteum around the mandibular foramen might be a main cause of neurosensory deficits of the mental nerve after mandibular osteotomy.

Rectal compliance, capacity, and rectoanal sensation in fecal incontinence

OBJECTIVE: Assessments of the pathophysiology of fecal incontinence are skewed toward anal sphincter function; however, rectal compliance, rectoanal sensation and capacity may also be relevant. The aim of this study was to evaluate the usual and some novel diagnostic approaches in fecal incontinence. METHODS: In 22 unselected patients with fecal incontinence (21 F, 33–75 yr), we quantified: 1) symptoms, anorectal manometry, and anal ultrasound; 2) anal perception of temperature and light touch; 3) rectal sensitivity and compliance to distension; and 4) rectal reservoir function. Control values were obtained from two groups of 11 (seven F, 32–53 yr), and 32 (18 F, 19–44 yr) volunteers. RESULTS: Patients had urge (14), passive (four), or combined (four) fecal incontinence; symptoms were mild in three, moderate in nine, and severe in 10 patients. Most had low sphincteric pressures and ultrasonic abnormalities. Temperature perception was impaired ( p < 0.05) in incontinent patients, to a greater extent in the proximal anal canal and in patients with passive, as opposed to urge, incontinence. Intraluminal pressures for sensations of rectal distension were lower in incontinent patients ( p = 0.02). Artificial stools elicited sensations of rectal filling at lower volumes than did a barostat bag, and in patients with urge, as opposed to passive, incontinence. In patients and controls, the sensation of urgency was associated ( r 2 = 0.2, p < 0.01) with rectal compliance. CONCLUSIONS: We confirm that temperature sensation is impaired, and perception of rectal distension is not always reduced in fecal incontinence. Artificial stool tended to induce sensations at lower volumes than did balloon inflation. Altered sensory mechanisms may contribute to the pathophysiology of fecal incontinence.

Quantitative sensory testing in gulf war veterans with chronic fatigue syndrome

The study assessed peripheral sensory function and its relation to self-reported wartime exposures to potentially neurotoxic substances in Gulf War veterans with chronic fatigue syndrome (CFS). Male Gulf veterans fulfilling the 1994 CDC diagnostic criteria for CFS were compared with matched controls. Quantitative sensory testing was performed to establish thresholds of perception for the sense of light touch and radiant heat. The Devens survey was used to collect data on self-reported exposures to by-products of combustion and organophosphate compounds. Gulf veterans with CFS had elevated tactile but normal thermal thresholds compared with their controls. Sick veterans had greater rates of self-reported exposures and/or noxious side effects for all assessed toxicants. Interestingly, both Gulf veteran groups, including those reporting no symptoms, had impaired perception of light touch when compared with age-matched samples of non-Gulf war veteran men. The results of this study are consistent with a hypothesis that Gulf veterans with CFS have a subtle neurological deficit that might reflect underlying peripheral neuropathy. The association between this deficit and self-report of multiple potentially neurotoxic exposures suggests that war zone pollutants may be possible contributing factors. Copyright © 1999 John Wiley & Sons, Ltd.

Inferior alveolar nerve function after mandibular osteotomies

A total of 1034 patients who had undergone orthognathic surgery were examined after 2 years; 818 had been treated with varying types of mandibular osteotomy such as vertical ramus osteotomy, sagittal split ramus osteotomy, and genioplasty. Neurosensory function in the mental nerve region was assessed by evaluating light touch perception. The incidence of neurosensory deficiency was 216/548 (39%) after sagittal split ramus osteotomy, 26/140 (19%) after extraoral vertical ramus osteotomy, 9/78 (12%) after genioplasty and 60/650 (9%) after intraoral vertical ramus osteotomy. Additional genioplasty increased both the incidence and severity of neurosensory disturbance after intraoral vertical ramus osteotomy but did not significantly influence the neurosensory function after sagittal split ramus osteotomy. The incidences of neurosensory disturbance after mandibular osteotomies in this report correspond well with those previously reported, but the incidence of almost 40% after sagittal split ramus osteotomy must be considered a disquieting drawback of the procedure.

Toe to hand transfer in children: Part 2: functional and psychological aspects

Forty children with congenital (85%) or acquired hand disorders underwent transfer of one or two toes to one hand. The children were reviewed with their parents and assessed for functional and psychosocial performance. There was some evidence that the older the child at the time of transfer, the better the range of motion. The passive range of motion was on average 60 degrees more than the active range of motion despite subsequent procedures such as tenolysis. All transfers recovered protective sensibility and the majority recovered good levels of two point discrimination and light touch perception. Almost all transfers were naturally incorporated into the use pattern of the limb for some or most of the time. Most parents and patients reported a very positive effect of this surgery on the child's psychosocial functioning.

Recovery of Sensation in the Radial Forearm Free Flap in Oral Reconstruction

The purpose of this study was to find out to what extent sensory function recovers in a free radial forearm flap used for intraoral reconstruction after surgery for oral cancer. In 40 free radial forearm flaps we investigated the perception of light touch, two-point discrimination, pain, directional sensation, and temperature between 6 months and 11 years after flap transfer to the oral cavity. Four flaps (10 percent) were anesthetic, 21 flaps (52.5 percent) recovered partly, and 15 flaps (37.5 percent) had perception of all sensory modalities tested in at least two-thirds of the flap area. All patients with positive sensation in the surrounding area subsequently had good sensory recovery in the flap. This suggests that recovery of sensation in a nonreinnervated free flap is due to nerve ingrowth from the surrounding mucosa. The present results suggest that sensory function in intraoral free radial forearm flaps returns again. Further study is necessary to define the use of neurofasciocutaneous radial forearm flaps in reconstruction of the oral cavity.

Trigeminal sensory neuropathy in connective tissue disease

Trigeminal sensory neuropathy (TSN) may be a feature of connective tissue disorders and is frequently associated with progressive systemic sclerosis or mixed connective tissue disease (MCTD). [1,2] The pathogenesis of TSN is unknown, and there is limited information on the anatomic site of the pathologic process. Lecky et al [1] proposed lesions of both the Gasserian ganglion and the peripheral portions of the trigeminal nerve. We report a patient with TSN and MCTD where neuroimaging and electrophysiological studies suggested a lesion in the cisternal part of the nerve including the Gasserian ganglion. A 31-year-old man was well until August 1990, when he noticed bilateral burning sensations around his mouth followed by numbness of cheeks, tongue, and oral cavity and loss of taste. Neurologic examination showed a decreased perception of pinprick, light touch, and temperature in the territory of the second and third divisions of the trigeminal nerve on both sides. Taste was impaired. Cranial motor functions and reflexes were intact. Laboratory investigation included normal sedimentation rate, blood count, electrolytes, coagulation tests, and liver and muscle enzymes. The ANA titer was 1:640 with a speckled pattern; antibodies to both extractable nuclear antigens (ENA) and ribonucleoprotein (RNP) were negative. …

Dysaesthesiae induced by physiological and electrical activation of posterior column afferents after stroke.

Six of 48 stroke patients had functionally limiting dysaesthesiae induced by repetitive light touch, joint movement, or neuromuscular electrical stimulation (NMS). Only one of these six patients had a thalamic lesion. Quantitative sensory testing showed substantial impairment of pain and temperature sensation in all six patients, whereas light touch, vibration and position sense, and graphaesthesia were normal (three patients) or relatively spared (three patients). By contrast, none of 15 stroke patients in whom NMS did not evoke dysaesthesiae had clinical evidence of dissociated sensory loss. Conscious perception of joint movement and light touch is mediated mainly by the same population of large myelinated fibres activated preferentially by low intensity electrical stimulation. It is suggested that activation of these non-nociceptive, presumably dorsal column, afferents may contribute to dysaesthesiae in some patients with sensory loss after stroke.

Propofol infusion and the suppression of consciousness: dose requirements to induce loss of consciousness and to suppress response to noxious and non-noxious stimuli

We have defined the infusion dose requirements of propofol to suppress consciousness and response to a variety of graded non-noxious and noxious stimuli in 52 unpremedicated patients aged 16-40 yr and 32 patients aged 41-65 yr. They were allocated to receive one of five loading dose-infusion schemes designed to establish stable conditions covering the range from wakefulness, through sedation, to loss of consciousness and anaesthesia. At 10 and 20 min after the loading dose, each patient's response to a graded series of stimuli was recorded. Probit analysis was used to derive mean values (95% confidence interval) for the ED50 and ED95 (as final infusion rate) for loss of response to verbal command at 4.9 (4.7-5.1) mg kg-1 h-1 and 7.9 (7.3-8.8) mg kg-1 h-1, respectively, in the young group and 4.2 (4.0-4.4) mg kg-1 h-1 and 5.8 (5.4-6.4) mg kg-1 h-1, respectively, in the older group. In both groups the dose-response curves for suppression of proprioception, finger counting and perception of light touch in conscious patients were shifted to the left of the curves for loss of consciousness and eyelash reflex. Dose-response curves for noxious stimuli were shifted to the right of those for loss of consciousness.

The Clinical Diagnosis of Sensory Neuropathy in Elderly People

Minor abnormalities in sensory perception are common in elderly people but the significance of these findings is uncertain. In order to define the most relevant clinical tests for the diagnosis of significant neuropathy in the elderly diabetic patient, quantified perception of vibration, temperature, pain, and light touch was assessed in 200 (100 hospitalized, 100 community) consecutive non-diabetic elderly subjects without apparent neurological disease, using an established scoring system. The changes in sensory perception were similar in the two groups and data were pooled for further analysis. Progressive loss of peripheral sensation was apparent with increasing age (neuropathy deficit score vs age: r = .04, p < 0.0001). Loss of vibration perception was particularly marked; deficit scores for vibration were significantly lower in the < 70 years age group than in all the older age groups (vibration score: < 70 years vs 80-84 years mean (95% CI) 0.89 (0.54) vs 3.02 (0.6), p < 0.0001). In contrast, perception of light touch and pain was relatively preserved in old age. Assessment of vibration perception is of limited value in elderly people since the distinction between 'normal ageing' and significant neuropathy is unclear. Perception of light touch and pain are likely to be the most reliable clinical indicators of significant neuropathy in an elderly diabetic population.

Selective neuropathy and preserved vascular responses in the diabetic Charcot foot.

Charcot arthropathy is a disabling complication of diabetic neuropathy. It is however, unclear why it occurs in only a small number of neuropathic patients. We have studied 12 diabetic patients (10 insulin-dependent) with an acute Charcot arthropathy, and compared their neuropathy and vascular responsiveness with 12 diabetic patients (10 insulin-dependent) with recurrent neuropathic foot ulceration, 12 diabetic control subjects (9 insulin-dependent) and 10 normal non-diabetic subjects. The Charcot arthropathy patients demonstrated a preservation of warm perception, 6 (5.5) degrees C, but complete loss of peripheral cold perception, 10 (0) degrees C, p less than 0.001 (median (interquartile range)). This contrasted with the ulcerated neuropathy patients, who had equally severe impairement of both warm and cold sensory thresholds, 10(0.5) degrees C vs 10(1) degrees C, respectively, the diabetic control subjects who were able to detect a 2 (1.3) degrees C warm stimulus and 3 (3.5) degrees C cold stimulus and the normal subjects, whose warm threshold was 2 (1) degrees C and cold was 2 (1) degrees C. Light touch perception at the foot was preserved in the Charcot patients 4 (4) g vs 100 (50) g, p less than 0.0002, in the ulcerated neuropathy patients. Vibration perception at the great toe and cardiovascular autonomic function tests (heart rate variability, Valsalva ratio and postural systolic blood pressure fall) were abnormal in both the Charcot patients and ulcerated neuropathy group, with no differences seen between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of light touch perception threshold by contingent negative variation

An objective method developed to measure the threshold of light touch perception using contingent negative variation (CNV) is described. The light touch stimulus was a slight indentation of the skin produced through a displacement controlled stimulating probe (tip diameter of 2 mm). It was applied as the conditioning (S1) stimulus of the classical CNV paradigm of S1, S2, and R. To increase the CNV amplitude, the S2 stimulus was either a red or a yellow LED. The subjects were required to respond to only one of two by pressing a button. When the light touch stimulus was perceived, the CNV was recorded in all 19 healthy adult volunteers. In 14 of them, a systematic determination of the threshold of the ball of the thumb and index finger, thenar, hypothenar, face, shoulder, anterior thigh, foot dorsum and great toe ball, have been done. The thresholds of the light touch perception as defined by objective CNV measurement are very close to the results of the subjective psychophysiological determinations in normals. The amplitude of the averaged CNV (12 responses) started to decrease when stimulus intensity was reduced to the point that the subjects were able to perceive only a fraction of the presented touch stimuli. We believe, therefore, that the objective CNV determination of the light touch perception threshold is precise and sensitive enough to be used in research as well as in clinical applications.

Sensory ataxic hemiparesis in thalamic hemorrhage.

Ataxic hemiparesis with cerebellar-like features has been reported following infarction or hemorrhage of the thalamus. We describe five patients with incoordination and corticospinal tract signs in the limbs opposite a dorsolateral thalamic hemorrhage. In four patients the hemorrhage extended superiorly into the lateral ventricle, the adjacent paraventricular region, and the upper and medial parts of the posterior limb of the internal capsule. Instead of cerebellar dysfunction, these patients exhibited directional errors of movement that improved distinctly when performed under visual guidance. We explain the incoordination on the basis of conscious deep sensory loss in the involved limbs. Perception of light touch, painful pinprick, and temperature were preserved in all patients. We use the term "sensory ataxic hemiparesis" to distinguish these patients from those with "classic" ataxic hemiparesis and cerebellar-like features, a distinction that may be important when planning functional rehabilitation.

Objective estimation of the light touch perception threshold by CNV

Objective estimation of the light touch perception threshold by CNV

Neurological manifestations of aging.

A group of 51 socially active, self-declared neurologically normal subjects ranging from 61 to 84 years of age were studied with a battery of clinical neurological examinations and a semiquantitative vibration perception test. None of the subjects showed a consistent pattern of neurological deficit that could be identified as pathological. On review of systems, the most frequent complaints were difficulty remembering names, numbness and tingling of fingers and toes, and headaches. In the neurological examination, the most commonly observed abnormalities were positive palmomental reflex, snout reflex, abnormalities in pursuit eye movements, convergence insufficiency, and minor mistakes in perception of light touch. There was no apparent trend of worsening of symptoms and signs with advancing age. In the semiquantitative testing of vibration perception, there was a slight trend toward worsening of vibration perception in the upper and lower extremities with advancing age. Motor abnormalities were absent, and there were relatively few subjects who showed reflex abnormalities. This study confirms the previously reported diminution of vibration perception with aging. Caution must be exercised before attributing myotatic reflex and motor abnormalities to the aging process alone.

Sexual function among patients with spinal cord injury.

Hundred and fifty spinal cord injury patients were interviewed concerning erections, coitus, ejaculation and orgasm. 123 (82%) were able to attain erections. 115 patients had upper motor neuron lesions (reflex activity present in the sacral segments). Seventy-five of the 115 patients had complete lesions; 9% had psychic erections, 95% had spontaneous erections, 92% had erections from penile stimulation. 44% of the patients made no attempt at coitus. Forty-two patients attempted coitus of which 24 (57%) were successful. One percent could ejaculate and have an orgasm. 40 of the 115 patients had incomplete lesions. 48% had psychic erections, 93% had spontaneous erections and 93% had reflex erections. 27% of the patients made no attempt at coitus. 29 patients attempted coitus of which 25 (86%) were successful. 25% could ejaculate and have an orgasm. Thirty-five patients had lower motor neuron lesions (reflex activity absent in the sacral segments). 33 of the 35 patients had complete lesions; 24% had psychic erections, 12% had spontaneous erections. 36% of the patients made no attempt at coitus. 21 patients attempted coitus of which 7 (33%) were successful. 15% could ejaculate and have an orgasm. Two of the 35 patients had incomplete lesions and one of the two had psychic erections. One patient made no attempt at coitus. One patient who attempted coitus was successful and could ejaculate and have an orgasm. All of the patients with complete or incomplete lower motor neuron lesions experienced psychic erections only then when the lesion was below T-12. The activity or hyperactivity of the isolated sacral segment of patients with complete upper motor neuron lesions appear to have an inhibitory effect on ejaculation. Pinprick perception in the sacral segments of patients with incomplete upper motor neuron lesions seems to be prognostically more significant for erection and ejaculation than the preservation of light touch perception or retained volitional motor function of the pelvic floor muscles. Various observations are reported, such as the relationship of spasticity and sexual function, autonomic dysreflexia during sexual activity, premature aging in regard to sexual function, and some interesting psychosexual attitudes reported by the patients. This study has essentially confirmed the findings noted in the original study from this Center.