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Biomedical subjects

N Biary

Publications and source records attributed to N Biary.

At least 19 recordsLinked to original sources

Baclofen attenuates harmaline induced tremors in rats.

Recent experimental and clinical studies clearly suggest the role of gamma-aminobutyric acid (GABA) in the pathogenesis of tremors. The present study was undertaken to investigate the effect of baclofen, a GABA B receptor agonist on harmaline induced tremors. Four groups of female Wistar rats weighing 100+/-15 g were injected with harmaline (10 mg/kg, intraperitoneally) for inducing experimental tremors. The animals in groups 2, 3 and 4 were given baclofen by gavage at doses of 2.5, 5 and 10 mg/kg, respectively, half an hour before harmaline administration, whereas, the rats in group 1 served as control and received water. The latency of onset, intensity and duration of tremor and electromyographic (EMG) responses were recorded. Treatment with baclofen resulted in a dose dependent decrease in the intensity of tremor. Our EMG study also revealed a significant decrease in the amplitude of tremors in baclofen treated rats. A highly significant increase in latency of onset of tremor was observed in the rats treated with high dose (10 mg/kg) of baclofen only. This study clearly suggests beneficial effects of baclofen in harmaline induced tremors.

Animals↗

Effect of lidocaine on harmaline-induced tremors in the rat.

The present study was undertaken to investigate the effect of lidocaine on harmaline-induced tremors in the rat. Four groups of Wistar rats weighing 45-50 g were injected with harmaline (50 mg/kg i.p.) for inducing experimental tremors. The rats in group 1 served as control, whereas the animals in groups 2, 3, and 4 were also given lidocaine i.p. at doses of 12.5, 25, and 50 mg/kg, respectively, 10 min after the onset of tremors (therapeutic study). In a separate four groups of animals intraperitoneal lidocaine injection was given 10 min before harmaline (prophylactic study) in the same dose regimen as mentioned above. The latency of onset, intensity, and duration of tremor and electromyographic responses were recorded. Lidocaine dose dependently attenuated harmaline-induced tremors in rats. The latency period was increased, and duration and intensity of harmaline-induced tremors was reduced by lidocaine. Our electromyography (EMG) study also revealed a decrease in the amplitude of harmaline-induced tremors in lidocaine-treated rats. In conclusion, the results of this study clearly suggest beneficial effects of lidocaine in harmaline-induced tremors.

Animals↗

Effect of aluminum on neurological recovery in rats following spinal cord injury.

OBJECT: This investigation was undertaken to study the effect of aluminum on neurobehavioral, electrophysiological, structural, and biochemical changes in rats following spinal cord injury (SCI). METHODS: Adult male Sprague-Dawley rats classified into different groups were given aluminum sulfate-dosed drinking water in the concentrations of 0%, 0.25%, 0.5% and 1%, respectively. After 30 days of aluminum treatment, the animals were subjected to spinal cord trauma. Laminectomy was performed at T7-8 in anesthetized rats, followed by placement of a compression plate (2.2 x 5 mm) loaded with a 35-g weight over the exposed spinal cord for 5 minutes. Control animals underwent the same surgical procedure, but the compression injury was not induced (sham). Postoperative neurological function was assessed using the inclined-plane test and by obtaining a modified Tarlov score and vocal/sensory score daily for 10 days. Electrophysiological changes were assessed using corticomotor evoked potentials, whereas pathological changes were assessed by light microscopy. The level of vitamin E in the spinal cord was measured as an index of antioxidant defense. The behavioral, biochemical, and histological analyses were performed in a blinded fashion. CONCLUSIONS: Analysis of results obtained in the behavioral studies revealed that the compression of spinal cord produced transient paraparesis in which a maximum motor deficit occurred at Day 1 following SCI and resolved over a period of 10 days. Administration of aluminum significantly impaired the recovery following SCI. Analysis of the results of the biochemical, electrophysiological, and histopathological studies also confirmed the deleterious effects of aluminum on recovery from SCI in rats.

Aluminum↗

Effect of acrylamide on neurological recovery following spinal cord injury in rats.

Acrylamide (ACR) is a cumulative neurotoxin which causes axonal degeneration in animals and man. Industrial workers exposed to ACR have been reported to suffer from a variety of central and peripheral neuropathological symptoms including numbness of hands and feet, skin peeling and muscular weakness of legs. These reports suggest that the body burden of ACR may be a risk factor in recovery patterns following neurotrauma. The present study was designed to assess the effect of ACR on neurological recovery following spinal cord injury (SCI) in rats. Male Sprague-Dawley rats weighing 200-230 g were anaesthetised with chloral hydrate and laminectomy was performed at T 7-8 level leaving the dura intact. A compression plate (2.2 x 5.0 mm) loaded with a weight of 35 g was placed on the exposed cord for 5 minutes. Animals were divided into seven groups of eight rats each. The animals in Group 1 served as control whereas rats in Group 2 underwent laminectomy alone (sham). The rats in Group 3 to 6 were subjected to SCI as mentioned above. Animals in Groups 4, 5 and 6 also received ACR in the doses of 10 mg/kg, 20 mg/kg and 40 mg/kg, i.p., respectively in addition to SCI, whereas the rats in Group 7 received ACR alone at a dose of 40 mg/kg body weight. The first dose of ACR was given 30 minutes before SCI, followed by daily administration of drug for 7 days. Post traumatic neurological recovery was recorded daily for 10 days using a modified Tarlov score, inclined plane test and sensory and vocal score. Electrophysiological changes were assessed using somatosensory and corticomotor evoked potentials. The animals were sacrificed at different time intervals and the injured site of the spinal cord was analysed for lipid hydroperoxides (LPH), conjugated dienes (CD) and glutathione (GSH). Neuropathological changes in the spinal cord were assessed using light microscopy. The rats exposed to compression injury alone showed a maximum neurological deficit at 24 hr and then a gradual recovery was observed over a period of 10 days. The rats treated with ACR along with SCI showed poor or no recovery over a period of 10 days. Our electrophysiological and histopathological studies also confirmed that concomitant exposure to ACR produces a significant deleterious effect on the recovery from SCI. SCI induced increase in oxidative stress (increase in LPH and CD and decrease in GSH) is also exacerbated by ACR suggesting a role of free radicals. The results of this study suggest that increased body burden of ACR may retard the recovery from neurotrauma or even lead to permanent disability.

Acrylamide↗

Neurological recovery in diabetic rats following spinal cord injury.

This study was designed to assess the effect of spinal cord injury on neurobehavioral, electrophysiological, structural, and biochemical changes in normal and diabetic rats. Experimental diabetes was induced in Sprague-Dawley male rats (weighing 250-280 g) with streptozotocin (50 mg/kg i.p.). Eight weeks after the treatment with streptozotocin the animals were anaesthetized with chloral hydrate and laminectomy was performed at T 7-8 level leaving the dura intact. A compression plate (2.2 x 5.0 mm) loaded with a weight of 35 g was placed on the exposed spinal cord for 5 min. Postoperative neurological function was assessed using inclined plane test, modified Tarlov score, and vocal and sensory score daily for 10 days. Electrophysiological changes were assessed using somatosensory and corticomotor evoked-potentials. The animals were sacrificed at different time intervals and injured site of the spinal cord was analyzed for changes in vitamin E and glutathione levels (as markers of oxidative stress). Pathological changes in spinal cord were also studied using light microscopy. The data on neurobehavioral study clearly indicated that the compression of spinal cord produced highly significant neurological deficit and poor recovery in diabetic rats as compared to nondiabetic rats. Our histopathological and electrophysiological results also confirmed that diabetic animals are more susceptible to compressive spinal cord injury as compared to nondiabetic animals. A higher depletion of antioxidant defense markers (vitamin E and glutathione) was observed in diabetic rats as compared to nondiabetic rats. These results point toward the role of free radicals in poor recovery in diabetic rats following neurotrauma. Further studies are warranted to assess the neuroprotective potential of antioxidants to retard the secondary pathophysiological events following neurotrauma and to enhance the recovery.

Animals↗

Schwartz-Jampel syndrome: evidence of central nervous system dysfunction.

We report four patients with Schwartz-Jampel syndrome showing evidence of central conduction impairment documented by somatosensory evoked potentials. Median nerve somatosensory evoked potential showed normal latencies to Erb's point and N13 in all patients. Interpeak latencies between N13 and N19 were prolonged in five nerves, with complete block in three nerves. Posterior tibial nerve somatosensory evoked potentials were performed in three patients. Peripheral latencies were normal in all patients. Interpeak latencies between lumbar and cervical potentials were prolonged in two patients, with conduction delay between cervical and cortical potentials in five of the six nerves tested. Visually evoked potentials, brainstem auditory evoked potentials, electromyography, and nerve conduction velocity studies were normal in all patients. Parents' median nerve and posterior tibial nerve somatosensory evoked potentials were normal.

Brain↗

Guillain-Barre syndrome: a series observed at Riyadh Armed Forces Hospital January 1984--January 1994.

A consecutive series of 47 hospitalized cases of Guillain-Barre syndrome seen over a 10-year period was analysed with respect to: (1) age and sex; (2) antecedent events and seasonal distribution; (3) patterns of clinical presentation; (4) CSF and neurophysiological findings; (5) results of treatment with plasma exchange; and (6) outcome. Twenty-two were children, 20 middle-aged and 5 aged; 37 were male and 10 were female. The most frequent antecedent event was upper respiratory tract infections; a seasonal peak incidence was found in winter. Clinical, CSF and neurophysiological findings concurred with those in the Western literature; 79% of the cases were severe. Plasma exchange performed within the first 2 weeks of onset benefitted in the short-term outcome, i.e. improvement by 1 grade at 4 weeks, but the long-term benefit, i.e. the ability to regain independent locomotion, was questionable. Plasma exchange helped in curtailing the time to walking unaided but had no benefit on the duration of artificial ventilation. Factors associated with an adverse outcome were: age over 15 years, severity of motor electrodiagnostic findings (especially a decreased distal CMAP amplitude and EMG signs of acute denervation), requirement for ventilation and slow progression (>3 weeks) to maximum deficit. After a mean follow-up of 11 months, 55% of the patients regained independent locomotion, which is a comparatively low proportion.

Adolescent↗

Post-heatstroke parkinsonism and cerebellar dysfunction.

A case is presented of a 45-year-old woman who developed parkinsonism, cerebellar dysfunction, aphasia and flaccid paralysis secondary to heat stroke. Magnetic resonance imaging revealed irregular patchy areas of increased signal intensity in the white matter of both cerebral hemispheres and the left striatum, remaining unchanged over a follow-up period of two years. Cerebellar atrophy, while not seen on initial examination, was present on the follow-up study done one year later and became more marked after two years.

Atrophy↗

Long-term therapy of essential tremor with flunarizine.

We investigated the effect of long-term treatment of essential tremor (ET) with flunarizine (Fz) (10 mg/day) in 17 subjects who had a favorable response to 1 month of treatment. Side effects (dystonia, parkinsonism, weight gain and depression) occurred in 29.4% (5/17) of patients, leading to drug discontinuation. Fz was still effective at the end of 30 months of treatment in 41% (7/17) of patients. Loss of efficacy was observed in 29.4% (5/17) of patients. It is concluded that Fz is an alternative for long-term treatment of patients with ET; however, loss of efficacy and side effects are common.

Adolescent↗

The effect of nimodipine on essential tremor.

We investigated the effect of nimodipine (30 mg qid) in 16 de novo patients with essential tremor in a double-blind placebo-controlled study in which we assessed tremor by clinical scorings, tremorgraphic recordings, and patient self-evaluation. Of the 15 patients who completed the study, eight improved. We conclude that nimodipine is effective in some patients with essential tremor.

Adult↗

Posttraumatic paroxysmal nocturnal hemidystonia.

The term "nocturnal paroxysmal dystonia" has been used to describe patients who display paroxysmal episodes of dystonic-dyskinetic movements arising during nonrapid eye movement sleep, in particular stages 2-3 (Lugaresi E, Cirignotta F. Hypnogenic paroxysmal dystonia: epileptic seizure or a new syndrome. Sleep 1981;4: 129-138). The pathogenesis of these attacks has remained controversial. We describe a patient with posttraumatic paroxysmal nocturnal hemidystonia. Acetazolamide led to improvement.

Acetazolamide↗

Idiopathic long QT syndrome: asking the right question.

Infants and young children cannot describe symptoms of cardiogenic syncope accurately. If the attention in such cases is focused on the seizure activity that may follow, the patient will be treated inappropriately with anticonvulsants. We report such a presentation in 4 infants and young children (ages 6 to 48 months) with idiopathic long QT syndrome. All patients presented with recurrent seizures. All patients had a corrected QT interval (QTc) > or = 0.44 s and none had deafness. The diagnosis was suspected by careful history-taking which revealed episodes of loss of consciousness before convulsions in all patients. All patients were treated successfully with propranolol and remained free of symptoms during the follow-up period of 1-2 years. Screening the other family members revealed a prolonged QTc in 9 out of 16, and a history of 3 sudden and unexplained deaths in two families.

Child, Preschool↗

Choroido-cerebral calcification syndrome with retardation.

We present a sibship with a rare syndrome characterized by mental retardation, dense calcification of the lateral ventricular choroid plexus, and increased CSF protein. Neurophysiologic studies yielded nonspecific results, and endocrine studies, including parathormone levels, were normal. Simultaneous measurements of CSF and serum calcium, magnesium, and other electrolytes were normal, but the CSF/serum ratio of phosphate was low, suggesting a possible role in the pathogenesis of this syndrome.

Brain Diseases↗

Flunarizine in migraine: a double-blind placebo-controlled study (in a Saudi population).

We evaluated the effect of flunarizine (Fz) (10 mg/d) on migraine in a double-blind placebo-controlled design. The attacks' frequency, duration, severity and associated symptoms were compared before and after treatment. Forty-two patients completed a three-month trial period; 21 patients received Fz and 21 placebo. Statistical analysis showed no significant difference between Fz and placebo (p > 0.05). In this study Fz was not more efficient than placebo in migraine.

Adolescent↗

Intractable hiccup induced by brainstem lesion.

Four patients with brainstem lesions presented with intractable hiccup and mild to moderate neurological signs. Two of the patients had been initially diagnosed as having a psychogenic cause for their hiccup. Magnetic resonance imaging (MRI) demonstrated brainstem infarction in one case, tuberculoma at the junction of the medulla oblongata and the cervical spinal cord in two, and a vermian tuberculoma compressing the brainstem in one. The brainstem infarct and one of the medullary tuberculoma were not detected on high resolution enhanced computed tomography. The 3 patients with CNS tuberculoma were free of hiccup 1-5 months after antituberculous chemotherapy. It is proposed that hiccup is not an abnormal reflex, but a myoclonus generated by repetitive activity of the "inspiratory solitary nucleus" due to release of higher nervous system inhibitory/-regulatory control. The neuroanatomical network and the mechanisms underlying the formation of intractable hiccup are outlined. The value of MRI in the initial diagnosis and follow-up of patients with intractable hiccup due to brainstem lesions is emphasised.

Adult↗

The effect of flunarizine on essential tremor.

We investigated the effect of flunarizine treatment (10 mg/d) in 17 subjects with essential tremor in a double-blind placebo-controlled design. Tremor was assessed by clinical scoring, tremographic recordings, and subjective rating by subjects. Of the 15 subjects who completed the study, 13 showed improvement. We conclude that flunarizine is effective treatment for essential tremor.

Adolescent↗

Correlation between essential tremor and migraine headache.

The relationship between essential tremor (ET) and migraine was investigated in a prospective study. In a group of 74 ET patients 36.5% had migraine compared with 17.7% of 102 control subjects without tremor. In a group of 58 patients with migraine 17.2% had ET compared with 1.2% of 85 controls without migraine. The prevalence of ET in migraine controls was greater than controls without migraine (22% compared with 1%; p = 0.002). It is concluded that there is an association between essential tremor and migraine.

Adolescent↗