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Effect of spinal cord transection on N-methyl-D-aspartate receptors in the cord.

Spinal cord injury can lead to an exaggeration of transmission through spinal pathways, resulting in muscle spasticity, chronic pain, and abnormal control of blood pressure and bladder function. These conditions are mediated, in part, by N-methyl-D-aspartate (NMDA) receptors on spinal neurons, but the effects of cord injury on the expression or function of these receptors is unknown. Therefore, antibodies to the NMDA-R1 receptor subunit and binding of [3H]MK-801 were used to assess NMDA receptors in the spinal cord. Receptor density in rats with intact spinal cords was compared to that in rats 1 and 2 weeks after spinal cord transection (SCT) at the mid-thoracic level. At 1 and 2 weeks after SCT, [3H]MK-801 binding was reduced in most laminae in cord segments caudal to the injury, whereas no decrease in amount of R1 subunit immunoreactivity was observed. No significant changes in [3H]MK-801 binding and NMDA-R1 immunoreactivity could be seen rostral to the transection. Since [3H]MK-801 binding requires an open ion channel, the discrepancy between [3H]MK-801 binding and immunocytochemistry may indicate a loss of functional receptors without a consistent change in their total number. Therefore, the exaggerated reflexes that are well established in rats 2 weeks after cord injury must be mediated by a mechanism that withstands attenuation of NMDA receptor function.

Animals↗

The combined effects of clonidine and cyproheptadine with interactive training on the modulation of locomotion in spinal cord injured subjects.

The combined effects of a noradrenergic agonist, clonidine, and a serotonergic antagonist, cyproheptadine, together with an interactive locomotor training program incorporating progressive body weight support and treadmill walking exercise, were investigated in two chronic spinal cord injured subjects. Both subjects had no independent locomotor ability due to severe spasticity. Kinematic, temporal distance and electromyographic (EMG) data were collected during treadmill walking. The EMG activity of the lower limb muscles, initially characterized by tonic discharge and abnormal timing, became more phasic with less clonus following medication, which was related to a change in the kinematic pattern. Further kinematic and functional improvement were gained by training. Previously wheelchair-bound, both patients became functionally ambulatory overground with the aid of Canadian crutches. Thus, a potentially effective strategy for facilitating the expression of the locomotor pattern following spinal cord injury is proposed. This preliminary study showed that such a treatment strategy could possibly lead to a recovery of locomotor function in some chronic, wheelchair-bound spinal cord injured patients who had previously been stabilized on conventional therapies.

Adult↗

Bladder dysfunction in schizophrenia.

In schizophrenic patients with incontinence our previous urodynamic studies showed detrusor hyperreflexia in some cases. Many schizophrenic patients have brain abnormalities similar to those associated with urge incontinence and detrusor hyperreflexia in neurological patients. We therefore propose bladder dysfunction and incontinence as previously unrecognized neurobiological correlates of schizophrenia. To clarify this concept our first step, the present study, was a patient survey for urinary problems. Incontinence was more prevalent in schizophrenic patients than in a comparison group of mood disorder patients at the same hospitals. Urge incontinence and leakage of any type were related closely to psychiatric diagnosis. These data, like our pilot urodynamic studies, suggest that incontinence represents detrusor hyperreflexia in a significant subset of schizophrenic patients. Prospective urodynamic studies will be needed to test our proposal directly.

Adult↗

Human T-cell lymphotropic virus type I (HTLV-I)-related clinical and laboratory findings for HTLV-I-infected blood donors.

Clinical and laboratory findings were examined for 111 human T-cell lymphotropic virus type I (HTLV-I)-infected blood donors. HTLV-I provirus loads in subjects with a family history of adult T-cell leukemia (ATL) or HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) tended to be higher than those in subjects without a family history of these conditions. There were 3 asymptomatic patients with ATL, 4 with a history of uveitis, 7 with hyperreflexia in the lower limbs, and 3 with urinary frequency in the night. The mean CD4 cell/CD8 cell ratio +/- SD was significantly lower (p<.0001) in subjects with hyperreflexia in the lower limbs (1.3 +/- 0.2) than in subjects without any clinical abnormalities (1.7 +/- 0.6), suggesting that subjects with hyperreflexia in the lower limbs already have some immunologic abnormalities. The concordance of HTLV-I infection between husband and wife was lower in this study than in a previous study. HTLV-I-related inflammatory symptoms were more frequent (p =.021, Fisher exact test; OR = 9.5; 95% CI, 1.7-53.5) in HTLV-I tax A-infected donors (3 [50%] of 6 donors) than in HTLV-I tax B-infected donors (10 [9.5%] of 105 donors), suggesting different risks of HTLV-I-related symptoms according to the virus genotype.

Adult↗

Frequency and clinical progression of the vitamin E deficiency neurologic disorder in children with prolonged neonatal cholestasis.

To determine the frequency of biochemical vitamin E deficiency and of the clinical signs of the vitamin E deficiency neurologic syndrome in children with prolonged neonatal cholestatic disorders, we studied 46 children (aged 1 month to 17.0 years) with chronic forms of intrahepatic neonatal cholestasis and 47 children (aged 4 months to 8.0 years) with extrahepatic biliary atresia. Based on serum vitamin E concentrations and the ratios of serum vitamin E concentration to total serum lipid concentration, 64% of the intrahepatic and 77% of the extrahepatic cholestasis groups were vitamin E deficient. Prior to age 1 year, neurologic function was normal in all children. Between ages 1 and 3 years, neurologic abnormalities were present in approximately 50% of the vitamin E-deficient children; after age 3 years, neurologic abnormalities were present in all vitamin E-deficient children. Areflexia was the first abnormality to develop between ages 1 and 4 years; truncal and limb ataxia, peripheral neuropathy, and ophthalmoplegia developed between ages 3 and 6 years. Neurologic dysfunction progressed to a disabling combination of findings by ages 8 to 10 years in the majority of vitamin E-deficient children. Neurologic function was normal in the vitamin E-sufficient children. We conclude that vitamin E status should be evaluated in infants in whom cholestasis is diagnosed, and effective therapy should be initiated to prevent or treat vitamin E deficiency at an early age.

Adolescent↗

A method for neurological evaluation within the first year of life: experience with full-term newborn infants with birth injury.

In a prospective study undertaken at Port-Royal Maternity Hospital, Paris, 1785 deliveries were studied during a 15-month period. Signs of cerebral dysfunction were observed in 57 newborn infants--mild signs in 38 infants, moderate in 17, severe in 2. There was a high incidence of abnormal labour in 28 of these 57 infants (50%) (dysfunctional labour patterns without obvious cephalopelvic disproportion, including false labour, prolonged active-phase dilatation, (prolonged descent, marked caput succedaneum). During the first year of life, 30 of the 57 infants were followed. In 14 of the 30 infants transitory abnormalities were observed. In five infants abnormalities persisted at the end of the first year. Eleven infants were normal throughout the first year. In another study the incidence of cerebral symptoms at birth was compared in full-term infants born in 1974 and those born in 1976. Thirteen infants with moderate and severe symptoms were observed out of 1578 deliveries during 1974 and five out of 1934 deliveries during 1976, the incidence of Caesarean section necessitated by acute fetal distress being the same in both groups. This decreasing percentage of complications appears to be linked with improving care, including more widespread use of fetal monitoring.

Birth Injuries↗

Reduced renal responses to volume expansion in streptozotocin-induced diabetic rats.

To determine whether the volume reflex is defective in the diabetic state, the diuretic and natriuretic responses to acute volume expansion (VE) were measured in streptozotocin (STZ)-induced diabetic (Dia) rats. Urine flow (UV) and sodium excretion (UNaV) were measured before and after VE from innervated and denervated kidneys in anesthetized (Inactin 0.1 g/kg, ip) control and Dia rats (Sprague-Dawley rats injected with vehicle or STZ 65 mg/kg ip, respectively, 2 wk before the experiment). Blood glucose levels were significantly elevated in the Dia group compared with the control group. A VE of 1.2 ml/min for 15 min produced a significantly greater diuresis and natriuresis in control rats compared with Dia rats. In addition, reducing the hyperglycemia in Dia rats (third group) by treatment with insulin reversed the blunted UV and UNaV responses to VE. Ratios of UV (innervated-denervated, I/D) before and after VE indicate significant increases in UV by the innervated kidneys, relative to the denervated kidneys in all three groups. I/D ratios of UNa V were not different between the three groups before VE, but were significantly smaller in the Dia rats compared with both control and STZ plus insulin groups after VE. This study demonstrates that 1) there is an abnormal volume reflex in the STZ-induced Dia rats; 2) the natriuresis due to renal sympatho-inhibition is blunted in response to VE in Dia rats; and 3) restoring the glucose levels to normal by insulin treatment in the Dia rats normalizes the volume reflex.

Animals↗

Effect of dialysis and renal transplantation on autonomic dysfunction in chronic renal failure.

Autonomic functions were evaluated in 25 nondialyzed patients with chronic renal failure and eight controls. Eight patients were reassessed after 6.6 +/- 1.0 weeks of hemodialysis and 12 patients were restudied 24 +/- 4.0 weeks after renal transplantation. In addition, six patients who had been on maintenance hemodialysis for a duration of 21.5 +/- 3.0 weeks were also studied. Autonomic function tests, including blood pressure and heart rate response to sudden loud noise, mental arithmetic, hand immersion in cold water, Valsalva maneuver, change in posture and respiration, were performed using brachial artery cannulation and continuous monitoring by electrocardiogram. Baroreceptor sensitivity slope was determined using bolus injections of phenylephrine. Supine and standing plasma norepinephrine levels were measured. The cold pressor test, response to sudden loud noise and mental arithmetic were normal in nondialyzed patients with chronic renal failure, suggesting an intact efferent sympathetic pathway. The plasma norepinephrine concentration varied widely but the mean value was similar to the control group (P greater than 0.05). Expiration/inspiration ratio, lying/standing ratio, Valsalva ratio and the baroreceptor sensitivity slope were significantly abnormal (P less than 0.001) in nondialyzed patients. This indicates a defective efferent parasympathetic pathway and depressed baroreceptor sensitivity. The blood pressure response to phenylephrine was lower in the uremics, suggesting a reduced end-organ responsiveness to alpha agonists. The presence of hypertension did not affect autonomic function. The heart rate response to standing and the baroreceptor sensitivity were significantly lower (P less than 0.05) in patients who developed hypotension during hemodialysis. Lower baroreflex sensitivity could contribute to hypotension during dialysis. Autonomic functions remained unaltered after short- and long-term dialysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Auditory neuropathy/dys-synchrony: diagnosis and management.

Auditory brainstem responses (ABRs) and otoacoustic emissions (OAEs) are objective measures of auditory function, but are not hearing tests. Normal OAEs reflect normal cochlear outer hair cell function, and an ABR indicates a synchronous neural response. It is quite possible for a patient to have normal OAEs but absent or grossly abnormal ABR and a behavioral audiogram that is inconsistent with either test. These patients, who may constitute as much as 10% of the diagnosed deaf population, have auditory neuropathy/dys-synchrony (AN/AD). To diagnose AN/AD accurately, ABRs are obtained in response to condensation and rarefaction clicks to distinguish cochlear microphonics (CM) from neural responses. Appropriate management is confounded by variation among patients and changes in auditory function in some patients over time. Recommendations for management include visual language exposure through methods such as American Sign Language (ASL), Cued Speech, or baby signs, and closely following patients.

Acoustic Impedance Tests↗

Muscle computed tomography features of motor neuron disease in late-onset GM2 gangliosidosis.

Late-onset GM2 gangliosidosis, a rare inherited neuronal storage disease, is characterized by a variety of clinical manifestations. The common clinical picture comprises neuromuscular, spinocerebellar, extrapyramidal, cognitive, and psychiatric abnormalities. Details of the extent of muscle involvement have never been reported. Eight patients with this syndrome were evaluated for the existence and extent of motor neuron disease using routine electrodiagnosis and systematic evaluation of skeletal musculature by computed tomography. Motor neuron disease was present in each and every patient regardless of the clinical manifestations and to a degree beyond that suspected on neurological examination. Muscle imaging disclosed a diffuse wasting and fatty replacement of muscles with predilection of pelvic and thigh muscles, and especially the quadriceps group. It seems that progressive motor disability in this syndrome is mainly due to motor neuron disease, as manifested by muscle atrophy, which can be easily demonstrated by muscle computed tomography.

Adipose Tissue↗

Sensorimotor gating deficits and hypofrontality in schizophrenia.

Patients with schizophrenia exhibit (a) deficient sensorimotor gating as indexed by impaired prepulse inhibition (PPI) of the startle eyeblink reflex suggesting abnormal automatic information processing and (b) abnormal attentional modulation of PPI suggesting impaired controlled information processing. Here we test the hypothesis of deficient attentional modulation of PPI in schizophrenia as a defect in the interrelationship between frontal lobe functions of planning and executive action and posterior function of processing of sensory stimulation using positron emission tomography (PET). Consistent with the literature, our findings indicate that unmedicated schizophrenia patients exhibit lower frontal/occipital ratios (termed "hypofrontality") compared with healthy controls (n=15 in each group) during a standard tone-length-judgment (attention-to-prepulse) task. Moreover, better attentional modulation of PPI was associated with higher frontal/occipital ratios in the control, but not the patient group. These findings extend animal models to humans by demonstrating the importance of frontal and occipital lobe coordination in the modulation of PPI.

Animals↗

Distal rectoanal excitatory reflex: a reliable index of pudendal neuropathy?

PURPOSE: Denervation of the extrinsic anal sphincter and pudendal neuropathy are confirmed by electrophysiologic or electromyographic testing, techniques that may not be available universally and require special equipment and training. A simple manometric test that is easy to perform and complements existing studies was performed to confirm pudendal neuropathy. METHODS: Fourteen patients with excessive defecatory straining and 30 patients with idiopathic fecal incontinence were studied by electrophysiology and balloon reflex manometry. Pudendal nerve terminal motor latency (PNTML) and rectoanal excitatory reflex were evaluated for abnormalities. Results were compared with 20 controls who had no anorectal complaints and who had similar testing performed. RESULTS: In controls, PNTML was normal in all but one person. Rectoanal excitatory reflex could be elicited in all controls with either 20 or 40 ml of air. Four different types of balloon reflex responses were observed in patient groups: diminutive excitation, delayed excitation, excitation at high volume of distention only, and absent excitation. Ten patients with fecal incontinence had normal PNTML but abnormal distal excitatory reflex, 5 patients had abnormal PNTML but normal distal excitatory reflex, and 15 patients had both PNTML and excitatory reflex that were abnormal. In patients with excessive defecatory straining, results of both tests were abnormal in six patients, and eight patients had abnormal excitatory reflex but normal PNTML. CONCLUSION: Pudendal neuropathy may result in abnormalities of excitatory reflex morphology or other characteristics. Abnormal distal excitatory reflex may complement electrophysiologic findings or may serve as a suitable alternative to confirm pudendal neuropathy in centers where facilities for formal testing are not available.

Adult↗

Acoustic neuroma in an adolescent without neurofibromatosis: case study.

When acoustic neuromas are found in younger age groups, they are typically bilateral and associated with neurofibromatosis (NF). A unilateral acoustic neuroma in a child or adolescent without NF is rare. We report audiometric, auditory brainstem response (ABR) and magnetic resonance imaging (MRI) data for a 15-year-old male with an acoustic neuroma but without associated NF. The patient was seen for audiologic assessment on three separate occasions over a period of 5 years. The first two assessments produced unremarkable audiometric and immittance data. The third assessment, subsequent to a failed school hearing screening, demonstrated a flat unilateral sensorineural hearing loss, unilateral absent acoustic reflexes, and abnormal bilateral ABR recordings. MRI with contrast demonstrated a unilateral mass extending out of the internal auditory meatus. Microscopic examination of the removed tumor confirmed a vestibular schwannoma. An enhanced MRI 3 years post neuroma removal demonstrated no evidence of tumor regrowth and no evidence of other neoplasms. ABR recordings for the uninvolved ear continued to demonstrate neural synchrony as evidenced by normal absolute wave latencies; however, the III-V and I-V interwave latencies remained extended beyond the 99th percentile. Postoperatively, the young man was fitted with a high gain in-the-ear hearing aid in the involved ear, which he has continued to wear on a daily basis for the past 3 years.

Adolescent↗

Abnormal baroreflex control of heart rate in normotensive young subjects with a family history of essential hypertension.

This study was performed to determine whether baroreflex control of heart rate is impaired in young normotensive subjects with hypertensive relatives. Blood pressure, baroreflex function, pressor response to phenylephrine, aortic distensibility (pulse pressure/stroke volume) and minimal forearm vascular resistance (minFVR) were assessed in 13 normotensive subjects with hypertensive relatives (group A) and 11 normotensive subjects with no family history of hypertension (group B). Baroreflex sensitivity was significantly lower in group A than in group B (9.4 +/- 1.7 versus 17.5 +/- 1.7 ms/mmHg, P less than 0.01), although blood pressure, aortic distensibility and minFVR were not different between two groups. Pressor response to phenylephrine was identical for both groups. These results suggest that baroreflex control of heart rate is impaired in normotensive young subjects with hypertensive relatives and this defect may be inherited rather than the result of elevated blood pressure and decrease aortic distensibility.

Adult↗

Neurally mediated syncope detected by carotid sinus massage and head-up tilt test in sick sinus syndrome.

It is generally accepted that a positive response to carotid sinus massage (CSM) or head-up tilt (HUT) in patients affected by syncope suggests a reflex cause of the syncope. To study the role of the autonomic nervous system in causing syncope in the sick sinus syndrome (SSS), CSM and HUT were performed in 35 consecutive patients (20 men, mean age 70 +/- 9 years) with syncope and SSS. Results were compared with those in 35 patients affected by syncope that, despite careful cardiovascular and neurologic examination, were of uncertain origin (21 men; mean age 68 +/- 9 years) and with those of 35 subjects without syncope (20 men; mean age 69 +/- 10). All patients underwent CSM in the supine and standing positions for 10 seconds and HUT to 60 degrees for 60 minutes. In the patients with SSS, the full reproduction of spontaneous symptoms by CSM occurred in 21 (60%) and by HUT, in 19 (54%). At least 1 test was positive in 28 patients (80%): cardioinhibitory or mixed responses in 69%, vasodepressor responses in 11%. The percentages of positive tests in the patients with syncope of uncertain origin were similar to or slightly less than those of patients with SSS (CSM 63%, HUT 26%, overall 74%) with cardioinhibitory or mixed responses in 54% and vasodepressor in 20% (p less than 0.05). In control subjects, syncope was induced by CSM in 1 (3%) and by HUT in 2 (6%); overall positivity was 9%. In conclusion, in most patients affected by syncope and SSS, an abnormal neural reflex probably plays a major role in causing syncope.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Clinical and neurological abnormalities in adult celiac disease.

We assessed the occurrence of neurological signs and symptoms in adult patients with celiac disease and evaluated the correlation between neurological features and diet. A total of 176 patients and 52 age-matched controls underwent a semistructural interview and a neurologic examination. The effect of gluten-free diet was evaluated by comparing the prevalence of signs and symptoms among patients adhering to a gluten-free diet and patients on an unrestricted diet. The occurrence of headache, dysthymia and signs of peripheral neuropathy was significantly higher in patients with celiac disease than in control subjects. Adherence to a strict gluten-free diet was associated with a significant reduction of headache, dysthymia, cramps and weakness, but did not modify the occurrence of paresthesia or hyporeflexia. Neurological signs and symptoms are associated with celiac disease and can be ameliorated by a gluten-free diet.

Adolescent↗

Simultaneous arterial and urinary bladder pressure recordings in multiple system atrophy and in spinal disorders with detrusor hyperreflexia.

Simultaneous arterial and urinary bladder pressure measurements were recorded during bladder filling in 21 patients with urinary bladder symptoms; seven patients had autonomic failure due to multiple system atrophy (MSA), seven had spinal cord disease of different aetiology with detrusor hyperreflexia (DH) and seven had no neurological abnormalities. A significant increase in average systolic blood pressure (BP) was recorded on bladder filling in the neurologically intact patients (from 110 to 137 mmHg) and in the patients with spinal cord disease and DH (from 109 to 129 mmHg). In those with MSA, the BP rose in four and fell in three patients. The vesicopressor response during cold receptor-mediated DH was not significantly higher when compared with room-temperature saline and when compared with the BP response during bladder filling in the neurologically intact patients. Finally, intravesical lignocaine retained in the bladder for 15 min did not influence the BP response to cold receptor stimulation in patients with spinal cord disease and DH. These findings and their pathophysiological and clinical implications are discussed.

Adult↗

Peripheral sympathetic function in patients with a polyneuropathy.

Abnormal peripheral vasoconstrictor responses to inspiration were found in the finger tips of 11 out of 20 patients with a suspected polyneuropathy, most of whom had no clinical evidence of autonomic involvement. Among these 11 patients the neuropathy involved both motor and sensory fibers in 9, sensory fibers alone in 1, and autonomic fibers alone in another; it was accompanied by electrical changes suggestive of axonal degeneration in 9 patients, and by normal findings in 1, while the remaining patient was not investigated electrophysiologically. In addition to conventional electrophysiological tests of somatic motor and sensory function, it is suggested that peripheral vasomotor function be evaluated when patients with a polyneuropathy are being investigated, in order to identify the spectrum of nerve fibers that are involved and thereby characterize the disorder more fully.

Adolescent↗