Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026838 (spasticity)
 6,471 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spasticity and pain are common disabling sequelae following spinal cord injury (SCI) and are often difficult to manage. The two problems are also not infrequently related. A variety of pharmacological and other approaches have been described for management of these problems in SCI. This case study reports a 32-year-old woman with an established incomplete C5 tetraplegia (anterior cord syndrome) who developed severe, intractable anal spasm following a hemorrhoidectomy, which persisted despite very good healing. This prevented evacuation of her bowels and resulted in severe rectal pain and episodes of autonomic dysreflexia. Attempts to modify the rate and mode of delivery of intrathecal baclofen through an existing programmable infusion pump failed to reduce anal sphincter spasm or improve symptoms. A right-sided pudendal block with lignocaine provided some relief. Clonidine was added to baclofen in the pump reservoir and both drugs were administered intrathecally in combination. This resulted in an immediate improvement in anal sphincter spasm and pain relief, allowing rapid reestablishment of her normal bowel pattern without need for any supplemental analgesia. It appears that intrathecal clonidine may have an important role in the treatment of spasticity, either as a single or an adjuvant agent, when intrathecal baclofen alone is ineffective or there is increasing tolerance to baclofen. Intrathecal clonidine may also prove useful in the management of intractable neuropathic pain.
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PMID:Intrathecal clonidine and baclofen in the management of spasticity and neuropathic pain following spinal cord injury: a case study. 870 79

1. In order to study fusimotor control in reduced preparations, soleus muscle spindle afferents were recorded in premammillary decerebrate cats (n = 15) during crossed extensor reflexes and, after spinalization, during locomotion produced by either clonidine or L-beta-3,4-dihydroxyphenylalanine (L-DOPA). The soleus muscle was oscillated sinusoidally (0.25 mm, 4 Hz) and the afferent mean firing rate and modulation were calculated. An increase in firing rate was assumed to arise from activity in dynamic gamma-motoneurones (dynamic gamma-drive) when associated with an increase in modulation to stretching, and in static gamma-motoneurones (static gamma-drive) when modulation decreased. 2. At rest in all preparations the firing rate and modulation in primary muscle spindle afferents were generally much higher than after de-efferentation (ventral root section), suggesting a predominant dynamic gamma-drive. Clonidine decreased and even eliminated this presumed resting gamma-drive in many afferents, both in the decerebrate (7 of 8) and the spinal (6 of 18) state. This effect on gamma-drive may account, at least in part, for its suppressive effect on spasticity in humans. 3. When locomotion commenced in clonidine-treated spinal cats, primary afferents generally fired with much higher mean rates (+121%) and lower sensitivities (-32%), suggesting a large increase in static gamma-drive (possibly accompanied by a small decrease in dynamic gamma-drive). These high rates were usually maintained tonically throughout the step cycle. However, a third of the afferents were silenced during locomotor contractions, and de-efferentation had no significant effect on their firing rates. Thus, for some spindles alpha-activity can occur without significant gamma-drive. 4. During locomotion in L-DOPA-treated spinal cats the inferred static gamma-drive only occurred phasically, coactivated with the EMG, though it could precede the EMG by 100-500 ms. In the flexion phase both the afferent rate and modulation were lower than before locomotion, suggesting a lack of effective gamma-drive. 5. Crossed extensor reflexes in decerebrate cats also produced a substantial increase in primary afferent firing rate (+187%) and decrease in sensitivity (-37%), again suggesting increased static gamma-drive (n = 18). This gamma-drive was largely independent of EMG activity and often occurred without alpha-activity. The mean firing rate of secondary muscle spindle afferents increased significantly during locomotion (with L-DOPA) and crossed extensor reflexes, again indicating increased static gamma-drive. Clonidine reduced or eliminated the gamma-drive in seven of eight afferents during crossed extensor reflexes. 6. In conclusion, although there are some common features, such as a predominant static gamma-drive in all walking preparations, the pattern of static and dynamic gamma-drive is not closely linked to alpha-activity under the conditions studied. As well as gamma-drive without alpha-activity, we have shown for the first time that alpha-motoneurones can be activated without significant gamma-drive to many spindles during behavioural tasks.
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PMID:Regulation of soleus muscle spindle sensitivity in decerebrate and spinal cats during postural and locomotor activities. 888 86

Clonidine, a noradrenergic agonist, and cyproheptadine, a serotonergic antagonist, have each been associated with improved walking in SCI subjects. Baclofen, a GABA agonist, is frequently prescribed for spasticity but its effects on walking have not been well quantified. The objective of this study was to compare the effects of clonidine, cyproheptadine and baclofen on walking in SCI subjects with incomplete injuries. A motorized treadmill was used and harness support provided when necessary. A repeated single-subject design was employed for the twelve subjects. The greatest effects were found in more severely disabled subjects. Cyproheptadine was associated with greatly reduced need for assistance, increases in maximum treadmill speed (MTS) and reduced clonus. Clonidine was associated with increases in MTS and a generally more upright posture. Baclofen was associated with minor changes in walking. In many cases of drug effects, MTS increases and other changes were retained following washout of drugs. The significance and implications of the drug effects and the retention of effects during washout periods are discussed. It is concluded that clonidine and cyproheptadine have different effects but both appear useful for severely disabled SCI subjects. The effects of baclofen on walking after spinal cord injury remains unclear.
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PMID:Effects of drugs on walking after spinal cord injury. 980 Feb 74

We studied the effect of the intrathecal (i.t.) injection of clonidine (30, 60 and 90 microg) on the polysynaptic spinal reflexes (PSR) elicited by electrical stimulation of flexor reflex afferents (FRA), monosynaptic reflex and gait of 11 subjects with spinal cord injuries. The effect of clonidine administration on gait velocity, stride amplitude and duration was measured in eight subjects who were able to walk. Five subjects were able to walk after intrathecal injection of clonidine and three were not able to stand up. Three subjects improved their gait velocity after clonidine administration; one (S6) increased his stride amplitude; the two others decreased their cycle durations. The tibialis anterior seemed to be more regularly activated during gait. Spasticity was reduced dramatically (P<0.0001) after i.t. clonidine injection, but there was no statistically significant difference in the soleus H reflex (no effect on Hmax/Mmax). Clonidine administration decreased the amplitude of the early PSR (90-120 ms, N=4) and the threshold and maximal integrated EMG corresponding to the late response (140-450 ms, N=7). This effect was dose dependent (30, 60 and 90 microg). Placebo injection (N=4) caused no change. The changes in spinal reflexes, with a large reduction in spasticity, no change in motoneurone excitability and a large decrease in PSR, suggest that clonidine acts at a premotoneuronal level, possibly by presynaptic inhibition of group II fibres. The increase in gait velocity in three subjects could have been due to reduced spasticity or activation of spinal circuitry.
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PMID:Effects of intrathecal clonidine injection on spinal reflexes and human locomotion in incomplete paraplegic subjects. 1059 14

We investigated the possibility that a change in transmission in group II pathways contributes to the spasticity of patients with spinal lesions. Thirteen patients were tested by measuring the quadriceps stretch reflex (Ashworth scale), the threshold of the quadriceps H reflex, and the oligosynaptic facilitation of the quadriceps H reflex elicited by volleys to groups I and II afferents in the common peroneal nerve (CPN). All these tests were performed before and after intrathecal injection of clonidine (60 microg). Early group I CPN-induced excitations occurred in 13 patients, and late group II CPN-induced excitations in 12. Both facilitations were, on average, significantly greater than those reported for normal subjects, but these increases were not correlated with the clinically assessed spasticity. Clonidine caused a constant, prolonged and dramatic decrease in spasticity, but did not alter the threshold of the quadriceps H reflex. CPN-induced group I and group II non-monosynaptic excitations of quadriceps motoneurones were significantly decreased, although they did not return to normal values. These results provide a further indication that group II pathways gives rise to the heteronymous late CPN-induced excitation. The pathophysiological role of a change in transmission in group II pathways in spasticity is discussed.
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PMID:Effect of intrathecal clonidine on group I and group II oligosynaptic excitation in paraplegics. 1258 35

Nociceptive stimuli are modulated at the dorsal horn of the spinal cord. This modulation is performed by various systems working independently complementarily, additively or supra-additively. Non-opioid analgesics relieve pain without a motor blockade. In contrast to spinal opioids a reduced risk of respiratory depression is expected. In the therapy of chronic pain non-opioid analgesics may be an alternative, given alone or in combination with an opioid. Clinically relevant dosages for antinociception mediated by the alphaadrenoceptoragonistclonidine are >/=150 mug epidurally. Clonidine is effective in reducing acute and chronic pain. In combination with opioids the action of the opioids is intensified. Clonidine intensifies and prolongs the action of local anesthetics. If opioid tolerance occurs, epidural clonidine alone or in combination with an opioid has good antinociceptive action.Midazolam, a water-soluble benzodiazepine, was injected spinally for the reduction of pain for various indications (postoperative, malignancy, chronic back pain, spinal spasticity). Spinal benzodiazepine should not be injected into the spine in patients until it has been proven that there are no neurotoxic effects. Intrathecally injectedbaclofen is a well-known means of reducing spinal spasticity. Used in this way, it may have a secondary analgesic effect. No significant direct analgesic effect has so far been demonstrated. Spinalcalcitonin often leads to insufficient pain relief when given alone. Combination with an opioid may reduce the dosage of the opioid. Nausea and vomiting are frequent side effects of spinal calcitonin. Intrathecalsomatostatin produces antinociception. However, in animal studies neurotoxic action has been observed. Administration in man has not yet been proved to be safe. Spinalketamine has procluted controversial results in clinical studies, and has not yet been excluded that the substance is not neurotoxic.Lysine acetylsalicylic acid (L-ASA) has been given intrathecally for the therapy of severe cancer pain and chronic back pain. In most patients good analgesia was observed up to 2 months after a single injection. If neurotoxity can be excluded, L-ASA may be an alternative in the therapy of cancer pain before neurodestructive therapy is done.
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PMID:[Intrathecal and epidural administration of non-opioid analgesics in acute and chronic pain treatment.]. 1841 40

Although Clonidine has recently been described as a useful antispasticity agent, to our knowledge there has not been a previous report of clonidine's antispasticity effect antagonized by baclofen. Using a 0-5 Modified Ashworth Scale to evaluate the right knee extensor tone in a 74-year-old man 5 months following a left middle cerebral artery stroke, tone improved from 3 to 1 on Clonidine 0.6 mg daily in divided doses. The day after addition of baclofen at 15 mg daily in divided doses, tone increased to 4. Baclofen was withdrawn with a decrease in tone to 2. Baclofen alone at the above dose resulted in tone comparable to the clonidine-free baseline. Treatment with Clonidine alone was resumed, and the expected reduction in hypertonicity was again observed. Possible mechanisms of action for baclofen antagonizing the beneficial effect of Clonidine on spasticity after stroke are presented and discussed.
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PMID:Beneficial effect of clonidine on spasticity antagonized by baclofen in a stroke patient. 2648 87


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