To the Editor:-Syndrome:“A group of symptoms that collectively characterize a disease….”(American Heritage Dictionary, 1996). After visions of a modern-day Woolley and Roe catastrophe ("Cauda Equina Syndrome following Single [dose] Spinal … Hyperbaric Lidocaine …") it was a relief to learn that the patient fared no worse than having residual perineal hypesthesia, constipation, and difficulty voiding. [1]He was spared, fortunately, the duo of paraparesis and incontinence that collectively shape the syndrome's symptom triad.
Although the report's title [1]trumpets yet another catastrophe linked to intrathecal hyperbaric lidocaine, the actual case description paints an altogether different (albeit no less unfortunate) picture of persistent bilateral midsacral dorsal radiculopathy. The case made for neurologic sphincter muscle incompetence is tenuous; difficulty voiding more probably is caused by inability to sense bladder fullness (or to injury of preganglionic sacral parasympathetic axons) than by incontinence from bladder sphincter paralysis. Attributing laxative-responsive constipation in a 74-yr-old patient-with a clearly functional anal sphincter-to neurologic dysfunction smacks of denying Mother Nature.
We need to be explicit: cauda equina syndrome proper is the triad of bilateral paraparesis or paraplegia of leg and buttock muscles, saddle anesthesia plus sensory deficits below the groin, and incompetence of bladder and rectal sphincters causing incontinence of urine and feces. [3,4]Scattered below that ultimate asymptote of the drug-exposure/toxicodynamic cumulative probability curve lies a continuum of cauda equinopathies that range from transient radicular irritation or radiculopathy through lumbosacral sensory deficits, monoparesis, and sphincter incompetence, culminating in full-blown chronic cauda equina syndrome. [5]
The impact of hot-button trigger words on public and press all too easily could cripple spinal anesthesia in North America. Intrathecal hyperbaric lidocaine already is under a cloud. Let us present the clinical facts dispassionately, and so, offer spinal lidocaine an impartial hearing.
Rudolph H. de Jong, M.D.
Professor; University of South Carolina School of Medicine; Columbia, South Carolina;rudejong@compuserve.com
(Accepted for publication March 20, 1998.)
