Neurologic deficits and arachnoiditis following neuroaxial anesthesia

Abstract

Of late, regional anesthesia has enjoyed unprecedented popularity; this increase in cases has brought a higher frequency of instances of neurological deficit and arachnoiditis that may appear as transient nerve root irritation, cauda equina, and conus medullaris syndromes, and later as radiculitis, clumped nerve roots, fibrosis, scarring dural sac deformities, pachymeningitis, pseudomeningocele, and syringomyelia, etc., all associated with arachnoiditis. Arachnoiditis may be caused by infections, myelograms (mostly from oil-based dyes), blood in the intrathecal space, neuroirritant, neurotoxic and/or neurolytic substances, surgical interventions in the spine, intrathecal corticosteroids, and trauma. Regarding regional anesthesia in the neuroaxis, arachnoiditis has resulted from epidural abscesses, traumatic punctures (blood), local anesthetics, detergents, antiseptics or other substances unintentionally injected into the spinal canal. Direct trauma to nerve roots or the spinal cord may be manifested as paraesthesia that has not been considered an injurious event; however, it usually implies dural penetration, as there are no nerve roots in the epidural space posteriorly. Sudden severe headache while or shortly after an epidural block using the loss of resistance to air approach usually suggests pneumocephalus from an intradural injection of air. Burning severe pain in the lower back and lower extremities, dysesthesia and numbness not following the usual dermatome distribution, along with bladder, bowel and/or sexual dysfunction, are the most common symptoms of direct trauma to the spinal cord. Such patients should be subjected to a neurological examination followed by an MRI of the effected area. Further spinal procedures are best avoided and the prompt administration of IV corticosteroids and NSAIDs need to be considered in the hope of preventing the inflammatory response from evolving into the proliferative phase of arachnoiditis.

Severe adhesive arachnoiditis resulting in progressive paraplegia following obstetric spinal anaesthesia: a case report and review

“…Local anaesthetics themselves have been proposed as a cause of adhesive arachnoiditis [1,17], although this suggestion is controversial. Laboratory studies have demonstrated dose-dependent damage to neural elements exposed to supra-clinical concentrations of local anaesthetic [33].…”

“…Obstetric procedures predominate and development of symptoms severe enough to warrant neurosurgical referral is usually in the order of days to weeks following the anaesthetic. The temporal relationship between the neuraxial anaesthetic and the development of adhesive arachnoiditis is compelling in all cases, but the proposed mechanisms of initial injury remain speculative and controversial [1,5,17]. They include an inflammatory response to blood in the subarachnoid space, the action of the local anaesthetics themselves and accidental contamination of the injectate.…”

“…In the modern era, adhesive arachnoiditis is most commonly encountered as a complication of multiple revisions of lumbar spine surgery or disc herniation [15,16], or in patients who underwent contrast myelography in the decades when this was prevalent [1,8,17]. Historically, central nervous system infections were the most significant cause and remain so in some parts of the developing world, particularly as a complication of tuberculosis [8].…”

“…Neurological complications are uncommon and almost invariably temporary [17,18,21]. These can result from direct trauma to neural elements or, more rarely, through introduction of infection, hypoxic cord injury, expanding epidural haematomas or injection of anaesthetic into or adjacent to a canal already critically stenosed by osteophytes, disc protusion or less common abnormalities, such as arteriovenous fistulae [22].…”

“…These can result from direct trauma to neural elements or, more rarely, through introduction of infection, hypoxic cord injury, expanding epidural haematomas or injection of anaesthetic into or adjacent to a canal already critically stenosed by osteophytes, disc protusion or less common abnormalities, such as arteriovenous fistulae [22]. Adhesive arachnoiditis is a rare, but recognised cause of neurological deficit following central neuraxial anaesthesia [5,12,17,[22][23][24][25][26][27][28][29].…”