Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Single unit activity in spindle afferent nerve fibres from the finger flexors, the anterior tibial muscle, and the calf muscles was recorded intraneurally with tungsten microelectrodes in patients with Parkinsonism with resting tremor and in spastic patients with clonus. During tremor of Parkinsonism, involving the receptor bearing muscles, the Ia afferent fibre discharge patterns were similar to those seen previously in healthy subjects during voluntary fast alternating finger or foot movements: besides the stretch discharges occurring during the relaxation phases, discharges also occurred during the contraction phases. Such contraction discharges, presumed to originate from intrafusal muscle fibre contractions, were not seen in the spastic patients during clonus. During the clonic oscillations each afferent stretch discharge was regularly followed by a stretch reflex contraction which on its falling phase elicited a new volley of impulses in the Ia afferent fibres. The findings are considered to support the notion that, like the contractions in normal voluntary alternating movements, the contractions in tremor of Parkinsonism are organized according to the principle of alpha-gamma coactivation, whereas the contractions in clonus are stretch reflexes causing pure alpha contractions.
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PMID:Muscle spindle activity in alternating tremor of Parkinsonism and in clonus. 12 83

1. Implanted dorsal root electrodes were used to record discharge trains of single spindle primary afferents (Ia's) of the cat's hind limb during different types of movement.2. The length of the ipsilateral ankle extensors was continuously monitored by an implanted length gauge. Length changes occurring during active stepping were subsequently passively reproduced during brief anaesthesia.3. A comparison of the Ia responses in active and simulated step cycles revealed that moderate fusimotor drive to ankle extensor spindles probably occurred mainly, if not exclusively, during the E(1), E(2) and E(3) phases of active stepping.4. A temporal advance in the Ia response to passive stretching in the F-phase was attributed to the after-effects of fusimotor activity in the extension phases.5. Light thrust applied to the animal's back evoked a potent fusimotor response. This load compensation effect may provide an explanation for the apparently higher degree of alpha-gamma co-activation seen in the mesencephalic locomotor preparation.6. Ankle extensor Ia discharge decreased during falls, despite an increase in extensor e.m.g. This is seen as a clear example of independent alpha and gamma control.7. Placing reactions during walking were consistent with the notion that cutaneous inputs dominate over proprioceptive inputs in these movements.8. alpha and Ia discharge during paw-shaking showed many of the characteristics of that in decerebrate and spastic clonus. The present results suggest that movements resembling clonus may be part of the animal's normal repertoire.9. Isometric co-contraction of agonists and antagonists was found to involve alpha-gamma co-activation.10. Hamstring Ia discharge behaviour during stepping further highlighted the increases in firing rate which normally occur during passive muscle stretching in ;pre-programmed' movements.
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PMID:Ia afferent activity during a variety of voluntary movements in the cat. 14 4

1. Low-frequency (3-30 Hz) oscillatory rotation of the ankle joint in plantarflexion-dorsiflexion was generated with a torque motor. Torque, rotation about the ankle and electromyograms (e.m.g.s) for the gastrocnemius-soleus and the anterior tibial muscles were recorded.2. Fourier coefficients at each drive frequency were used to calculate the effective compliance (ratio of rotation and torque). The compliance has a sharp resonance when tonic, voluntary muscle activity is present.3. The resonant frequency of compliance is between 3 and 8 Hz. The location of the resonant frequency and the magnitude of the compliance at resonance depend upon both the degree of tonic muscle activity and the amplitude of the driving torque. The resonant frequency increases with increasing tonic activity.4. With tonic muscle activity, the compliance in the frequency range below resonance increases with increasing amplitudes of driving torque.5. The e.m.g., when evoked by the rhythmic stretch, lags the start of stretching by between 50 and 70 msec.6. When tonic muscle activity is present, the resonant frequency of the stretch reflex is between 5 and 6.5 Hz.7. Following the start of driven oscillation at frequencies near resonance, slowly increasing amplitudes of angular rotation (to a limit) are observed.8. Distortion (from the sinusoidal wave shape) of angular rotation is frequently observed with drive frequencies between 8 and 12 Hz during which there sometimes occur spontaneous recurrences of oscillation at the drive frequency. For the angular rotation, a significant portion of the power may be in subharmonic frequency components of the drive frequency when that frequency is between 8 and 12 Hz.9. Self-sustaining oscillation (clonus) near the resonant frequency of the compliance is sometimes observed after the modulation signal to the motor is turned off. This is most often seen when the gastrocnemius-soleus muscles are fatigued. Clonus may be evoked by driven oscillation at any frequency.10. The hypothesis that physiological tremor, which occurs between 8 and 12 Hz, is a consequence of stretch reflex servo properties seems to be at odds with the observations of resonance in the compliance and of self-generated clonus both occurring in the 5-8 Hz region.
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PMID:Oscillation of the human ankle joint in response to applied sinusoidal torque on the foot. 87 86

We reported a 65-year-old man whose sister was suffering from HTLV-I-associated myelopathy (HAM) and who presented slowly progressive spastic paraparesis, sensory disturbance in the feet, tremors and cerebellar ataxia. He was also positive for serum anti-HTLV-I antibody. He first showed a head tremor at the age of 3 years. He developed a spastic and ataxic gait when aged 15 years, and it became difficult for him to walk at the age of 50 years. Examination at 65 years showed a spastic and ataxic gait and scanning speech. Hyper-reflexia and Bahinski's signs were observed. Sensation in the feet was decreased. The anti-HTLV-I antibody titer in the serum was 1:512 by the PA method, and Western blot analysis revealed bands of P19, P24, P28 and P32. Examination of the cerebrospinal fluid (CSF), including oligoclonal bands, gave normal results. The CSF was negative for anti-HTLV-I antibody. CT and MRI of the head showed cerebellar atrophy. His sister was 60 years old. She had developed a spastic gait at the age of 15 years. Sensory defects and bladder dysfunction developed when aged 35 years. Hyper-reflexia, Babinski's sign and foot clonus were observed. Sensation in the feet was decreased. The urinary residual volume was increased. Ataxia was not observed. The anti-HTLV-I antibody titer in the serum was 1:8,192 by the PA method, and Western blot analysis revealed bands of p24, p28 and p32. Examination of the CSF, including oligoclonal bands, gave only normal results.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Spastic paraparesis and sensory disturbance improved by prednisolone therapy]. 139 32

A Japanese woman, aged 42, was admitted because of paroxysmal attacks consisting of paresthesia of the left face, tremor in the right hand, epigastric pain and urinary incontinence. A year prior to the admission, she noticed some difficulty in writing, dysarthria and unsteadiness of walking. These symptoms had been persistent since then. At the end of March, 1991, these symptoms rapidly worsened, and she fell down frequently. She also experienced pain behind both eyes, numbness in her left fingers and toe, urinary frequency and the above-mentioned attacks. Neurological examination disclosed bilateral internuclear ophthalmoplegia and upbeating nystagmus on upward gaze, titubation in the head, scanning speech, dysmetria in all limbs, exaggerated reflexes in jaw and both legs, bilateral extensor plantar reflexes and ankle clonus. SEP showed delayed cortical response with stimulation of the median nerves bilaterally and of the right posterior tibial nerve. P40 was absent with the left posterior tibial nerve stimulation. VEP was normal. T2-weighted image of MRI showed multiple high intensity areas located around the third ventricle, crus cerebri and the right upper part of the pons. The diagnosis of multiple sclerosis was made. Each paroxysmal attack started with numbness in the left face and burning sensation in the neck. Almost simultaneously tremor in the right hand began. The surface EMG showed the rhythmic contractions in the dorsal hand muscles and wrist extensors at a frequency of 6-7 Hz, and sometimes it revealed synchronized contractions of finger flexors and the dorsal hand muscles. A few seconds later she felt painful sensation in the epigastric region, and the tremor gradually increased in its intensity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A case of multiple sclerosis with paroxysmal attacks of facial paresthesia, unilateral hand tremor, epigastric pain and urinary incontinence]. 162 36

We tested the hypotheses that systemic absorption of epidural lidocaine: (1) contributes to the shivering-like tremor seen during epidural anesthesia by causing central nervous system disinhibition of spinal reflexes, or (2) activates or alters thermoregulatory mechanisms. In a double-blind, placebo, cross-over study, nine healthy volunteers were given intravenous lidocaine (or saline) to approximate the plasma levels of lidocaine achieved during epidural anesthesia for major abdominal surgery. Five volunteers were studied in a warm room (to test for nonthermoregulatory tremor), and four volunteers were studied in a cold room (to test the effects of lidocaine on normal thermoregulation). Central temperatures, peripheral vasoconstriction, tremor and clonus were unaffected by intravenous lidocaine. We conclude that the systemic absorption of epidural lidocaine does not contribute to tremor or shivering by these mechanisms.
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PMID:Intravenous lidocaine does not cause shivering-like tremor or alter thermoregulation. 191 98

To evaluate physiologic responses to mild perianesthetic hypothermia, we measured tympanic membrane and skin-surface temperatures, peripheral vasoconstriction, thermal comfort, and muscular activity in nine healthy male volunteers. Each volunteer participated on three separate days: 1) normothermic isoflurane anesthesia; 2) hypothermic isoflurane anesthesia (1.5 degrees C decrease in central temperature); and 3) hypothermia alone (1.5 degrees C decrease in central temperature) induced by iced saline infusion. Involuntary postanesthetic muscular activity was considered thermoregulatory when preceded by central hypothermia and peripheral cutaneous vasoconstriction. Tremor was considered normal shivering when electromyographic patterns matched those produced by cold exposure in unanesthetized individuals. During postanesthetic recovery, central temperatures in hypothermic volunteers increased rapidly when residual end-tidal isoflurane concentrations were less than or equal to 0.3% but remained 0.5 degree C less than control values throughout 2 h of recovery. All volunteers were vasodilated during isoflurane administration. Peripheral vasoconstriction occurred only during recovery from hypothermic anesthesia, at end-tidal isoflurane concentrations of less than approximately 0.4%. Spontaneous tremor was always preceded by central hypothermia and peripheral vasoconstriction, indicating that muscular activity was thermoregulatory. Maximum tremor intensity during recovery from hypothermic anesthesia occurred when residual end-tidal isoflurane concentrations were less than or equal to 0.4%. Three patterns of postanesthetic muscular activity were identified. The first was a tonic stiffening that occurred in some normothermic and hypothermic volunteers when end-tidal isoflurane concentrations were approximately 0.4-0.2%. This activity appeared to be largely a direct, non-temperature-dependent effect of isoflurane anesthesia. In conjunction with lower residual anesthetic concentrations, stiffening was followed by a synchronous, tonic waxing-and-waning pattern and spontaneous electromyographic clonus, both of which were thermoregulatory. Tonic waxing-and-waning was by far the most common pattern and resembled that produced by cold-induced shivering in unanesthetized volunteers; it appears to be thermoregulatory shivering triggered by hypothermia. Spontaneous clonus resembled flexion-induced clonus and pathologic clonus and did not occur during hypothermia alone; it may represent abnormal shivering or an anesthetic-induced modification of normal shivering. We conclude that among the three patterns of muscular activity, only the synchronous, tonic waxing-and-waning pattern can be attributed to normal thermoregulatory shivering.
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PMID:Physiologic responses to mild perianesthetic hypothermia in humans. 192 69

Direct electrical stimulation of either the dorsal or ventral hippocampal formation elicits wet dog shakes and overt seizures. Destruction of dentate granule cells in the dorsal hippocampal formation does not significantly reduce the number of wet dog shakes elicited by ventral hippocampal stimulation. However, destruction of dentate granule cells in the ventral hippocampus virtually eliminates wet dog shaking elicited by dorsal hippocampal stimulation. Destruction of either dorsal or ventral dentate granule cells lowers the threshold for eliciting forelimb clonus with rearing. These results suggest that dentate granule cells in the ventral hippocampus are essential for wet dog shakes elicited by intrahippocampal stimulation. However, dentate granule cells throughout the hippocampal formation appear to play an important inhibitory role in the spread of seizure activity within the hippocampus.
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PMID:Differential effects of colchicine lesions of dentate granule cells on wet dog shakes and seizures elicited by direct hippocampal stimulation. 223 60

Skin desensitization by topical anesthetic was studied for its effects on the frequency and amplitude of 3 overt involuntary oscillations of the ankle: pathological clonus, physiological clonus, and physiological action tremor. Pathological clonus was studied in two spinal cord patients, physiological clonus in 3 normal subjects following prolonged exercise, and physiological action tremor in 7 normal subjects performing voluntary movements. Topical anesthetic applied to the skin of the leg, ankle and proximal half of the foot resulted in a significant decrease in the amplitude of all 3 oscillations with no significant change in frequency. The effect of topical anesthetic on pathological clonus amplitude was so profound that neither patient could initiate clonus for approximately 30 min, despite repeated attempts to do so. While the mechanism determining the frequencies of these oscillations is a matter of considerable debate, the consistency in their response to topical anesthetic suggests that a common mechanism may exist. A possible clinical application is suggested. Topical anesthetic may be a non-invasive means of attenuating undesirable large amplitude tremors and clonus.
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PMID:A decrease in clonus amplitude by topical anesthesia. 241 26

The effect of the focal injection of N-methyl-D-aspartate (NMDA) and 2-amino-7-phosphonoheptanoate (APH) into the substantia nigra pars reticulata (SNR) and entopeduncular nucleus (EP) on behavioural signs of the high pressure neurological syndrome (HPNS) in rats was studied. Doses of 1, 5 and 10 nmoles of NMDA or APH were injected into the SNR or EP, 10-30 min prior to the exposure of animals to a high pressure. Injection of NMDA into either SNR or EP results in a lowering of the threshold pressure for tremor by about 30%. Injection of NMDA into the SNR has no significant effect on clonic seizures whereas its injection into the EP results in a decrease of threshold pressure for clonic seizures. NMDA also facilitates the occurrence of forelimb clonus when injected into the EP. Injection of the NMDA antagonist, APH, into the SNR or EP significantly increases the threshold pressure of tremor (32.8 and 48.2% respectively). Seizure threshold is also increased by the injection of APH into either area, but nigral injections (especially the higher doses) are more protective against seizures than the EP injections. Comparing the two sites blockade of NMDA receptors within the EP is more protective against tremor, whereas in the SNR NMDA blockade is more protective against seizures.
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PMID:Studies on the role of the NMDA receptor in the substantia nigra pars reticulata and entopeduncular nucleus in the development of the high pressure neurological syndrome in rats. 255 89


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