Complications of spinal opioid therapy: myoclonus, spastic muscle tone and spinal jerking

Abstract

This study was made in order to define risk factors for patients requiring spinal opioid therapy developing painful spastic muscle tone together with myoclonus and spinal jerking (MSJ). The case histories of 75 patients, all receiving morphine spinally, were retrospectively analysed and, of these, 10 suffered from the MSJ syndrome. The following were taken as evaluation criteria: age, sex, performance status, duration and dosage of previous systemic and current spinal morphine therapy, concomitant analgesic and co-analgesic medication, pretreatment of the dorsal column and neurological dysfunction due to damage either of the nerval plexus or of the medulla spinalis. As a result, high spinal morphine doses in conjunction with pathological changes within the spine were shown to be risk factors for this syndrome. Changing from spinal to systemic morphine application or reduction of spinal doses together with the addition of systemic morphine led to complete recovery from MSJ. As underlying mechanism, an imbalance between the activity of spinal and central opioid receptors and/or toxic morphine effects on the medulla spinalis are discussed. In conclusion, great care should be taken when applying morphine to the spine in patients with neurological dysfunction due to an apparent pathology of the medulla spinalis, especially if large amounts of morphine are likely to be required. Some systemic application of morphine might reduce the risk of patients developing MSJ syndrome.

Transient spinal myoclonus due to epidural levobupivacaine infusion,

“…[9,11,12] Özellikle spinal kord veya nöromüsküler disfonksiyonu olanların risk altında olduğu belirtilmektedir. Dozdan bağımsız olarak opioid ile ilişkili spinal miyoklonus olguları bildirilmiş olmakla birlikte, daha çok yüksek opioid dozunun spinal ve santral opioid reseptörlerinin aktivitelerinde dengesizlik yaratarak miyoklonusa neden olduğu ifade edilmektedir.…”

“…Dozdan bağımsız olarak opioid ile ilişkili spinal miyoklonus olguları bildirilmiş olmakla birlikte, daha çok yüksek opioid dozunun spinal ve santral opioid reseptörlerinin aktivitelerinde dengesizlik yaratarak miyoklonusa neden olduğu ifade edilmektedir. [11] Bizde olgumuzda kullandığımız fentanil infüzyonu sırasında dozun oldukça düşük olması nedeniyle myoklonik aktive gözlemlemediğimizi düşünmekteyiz.…”

Controversies over spinal treatment in advanced cancer patients

“…Hyperalgesia and myoclonus have been described in patients being given high intraspinal doses of morphine, probably due to a disinhibition of glycinergic and GABAergic control systems by morphine or its metabolites at the spinal cord [13,47]. High spinal morphine doses in conjunction with pathological changes within the spine were shown to be risk factors for myoclonus and spinal jerk syndrome [33]. It has been suggested that during intrathecal infusion morphine gets trapped below a spinal block provoked by tumour growth, giving rise to local toxic CSF concentration of morphine provoking seizure-like muscular contractions of the lower limbs [10].…”

“…It has been suggested that during intrathecal infusion morphine gets trapped below a spinal block provoked by tumour growth, giving rise to local toxic CSF concentration of morphine provoking seizure-like muscular contractions of the lower limbs [10]. An imbalance between the activity of spinal and central opioid receptors and toxic morphine effects on the spinal cord have been reported as possible underlying mechanisms [33]. Since patients develop paresis and paralysis of their extremities, some authors have speculated that myoclonic-like spasms might be secondary to intraspinal spread of malignancy [35].…”

Pain and symptom control for cancer patients at the University Hospital in Essen: integration of specialists' knowledge into routine work

“…To evaluate this object, patients' histories were evaluted in several retrospective studies, each including about 100 patients [4][5][6][7][8]. In summary, nearly all patients (except 2%) obtained adequate pain control.…”