History and evolution of surgical treatment for spasticity: a journey from neurotomy to selective dorsal rhizotomy.

The evolution of neurosurgical approaches to spasticity spans centuries, marked by key milestones and innovative practitioners. Probable ancient descriptions of spasmodic conditions were first classified as spasticity in the 19th century through the interventions of Dr. William John Little on patients with cerebral palsy. The late 19th century witnessed pioneering efforts by surgeons such as Dr. Charles Loomis Dana, who explored neurotomies, and Dr. Charles Sherrington, who proposed dorsal rhizotomy to address spasticity. Dorsal rhizotomy rose to prominence under the expertise of Dr. Otfrid Foerster but saw a decline in the 1920s due to emerging alternative procedures and associated complications. The mid-20th century saw a shift toward myelotomy but the revival of dorsal rhizotomy under Dr. Claude Gros' selective approach and Dr. Marc Sindou's dorsal root entry zone (DREZ) lesioning. In the late 1970s, Dr. Victor Fasano introduced functional dorsal rhizotomy, incorporating electrophysiological evaluations. Dr. Warwick Peacock and Dr. Leila Arens further modified selective dorsal rhizotomy, focusing on approaches at the cauda equina level. Later, baclofen delivered intrathecally via an implanted programmable pump emerged as a promising alternative around the late 1980s, pioneered by Richard Penn and Jeffrey Kroin and then led by A. Leland Albright. Moreover, intraventricular baclofen has also been tried in this matter. The evolution of these neurosurgical interventions highlights the dynamic nature of medical progress, with each era building upon and refining the work of significant individuals, ultimately contributing to successful outcomes in the management of spasticity.

A history of the Jannetta procedure.

Peter Jannetta was a neurosurgery resident when he proposed the neurovascular compression theory. He built upon the astute observations of Dandy, Gardner, and others who, in the era before the operating microscope, had successfully ventured into the posterior fossa. In 1965, Jannetta performed cranial nerve microdissections for dental students and identified the trigeminal portio intermedia. He proposed that preservation of these sensory fibers may avoid complete facial numbness, and together with Robert Rand developed a subtemporal transtentorial approach for selective rhizotomy for trigeminal neuralgia (TN). Such rash surgery, using an operating microscope, was then forbidden at their University of California, Los Angeles center, so they collaborated with John Alksne to perform the first surgery at Harbor General Hospital. Upon visualizing the trigeminal nerve root, Jannetta was surprised to see a pulsating superior cerebellar artery compressing the nerve and said "That's the cause of the tic." He also hypothesized that alleviating the observed vascular cross-compression may be curative.A few months later, while assessing a patient with hemifacial spasm, Jannetta had the epiphany that this was the same disease process as TN, but instead affecting the facial nerve. The patient consented to what would become Jannetta's first microvascular decompression procedure. The senior faculty members who had forbidden such surgery were away, so the supervising neurosurgeon, Paul Crandall, granted the approval to perform the surgery and assisted. Via a retromastoid approach with the patient in the sitting position and using the operating microscope, Jannetta identified and alleviated the culprit neurovascular compression, with a cure resulting.Jannetta presented his neurovascular compression theory and operative findings to the neurosurgical patriarchy of the time. Elders of the field were generally not inclined to accept the bold speculations of an untested neurosurgeon, and were often determined to discredit the new "cure" of the old diseases. Over decades of refining his surgical technique, documenting the outcomes, and enduring the skepticism he often faced, Jannetta's theory and his microvascular decompression procedure withstood critical analysis and have become recognized as one the great discoveries and advances in neurosurgery and medicine.

The Evolution of Selective Dorsal Rhizotomy for the Management of Spasticity.

Selective dorsal rhizotomy is a key technique in the surgical management of spasticity in patients with cerebral palsy. The technique evolved from the late 1800s when pioneers like Dana and Abbe performed dorsal rhizotomy in their treatment of refractory pain. These surgeons noted a reduction in muscle tone associated with the operation. When Sherrington then published his Nobel prize-winning work on the corticospinal tract and its role in the neuromuscular system in the 1890s, the course was set for modifying spasticity by aiming surgery at the dorsal roots. This procedure underwent multiple modifications through the next century and today it is, arguably, the most commonly performed operation to treat cerebral palsy children with spasticity. Selective dorsal rhizotomy is a technique that still teaches us a great deal about neurophysiology on a daily basis and it is thanks to the pioneers, described in this article, that we have this tool in our armamentarium.

"Fulfilling the chief of his duties as a physician": Harvey Cushing, selective dorsal rhizotomy and elective spine surgery for quality of life.

At the beginning of the 20th century, the development of safer anesthesia, antiseptic techniques, and meticulous surgical dissection led to a substantial decrease in operative risk. In turn, the scope of surgery expanded to include elective procedures performed with the intention of improving the quality of life of patients. Between 1908 and 1912, Harvey Cushing performed 3 dorsal rhizotomies to improve the quality of life of 3 patients with debilitating neuralgia: a 54-year-old man with "lightning" radicular pain from tabes dorsalis, a 12-year-old boy cutaneous hyperesthesia and spasticity in his hemiplegic arm, and a 61-year-old man with postamputation neuropathic pain. Symptomatic improvement was seen postoperatively in the first 2 cases, although the third patient continued to have severe pain. Cushing also removed a prominent spinous process from each of 2 patients with debilitating headaches; both patients, however, experienced only minimal postoperative improvement. These cases, which have not been previously published, highlight Cushing's views on the role of surgery and illustrate the broader movement that occurred in surgery at the time, whereby elective procedures for quality of life became performed and accepted.

The first meta-analysis of randomized controlled surgical trials in cerebral palsy (2002).

This study is a comparative analysis and meta-analysis of three randomized clinical trials. Children with spastic diplegia received either 'selective' dorsal rhizotomy (SDR) plus physiotherapy (SDR+PT) or PT without SDR (PT-only). Common outcome measures were used for spasticity (Ashworth scale) and function (Gross Motor Function Measure [GMFM]). Baseline and 9- to 12-month outcome data were pooled (n=90). At baseline, 82 children were under 8 years old and 65 had Gross Motor Function Classification System level II or III disability. Pooled Ashworth data analysis confirmed a reduction of spasticity with SDR+PT (mean change score difference -1.2; Wilcoxon p<0.001). Pooled GMFM data revealed greater functional improvement with SDR+PT (difference in change score +4.0, p=0.008). Multivariate analysis in the SDR+PT group revealed a direct relationship between percentage of dorsal root tissue transected and functional improvement. SDR+PT is efficacious in reducing spasticity in children with spastic diplegia and has a small positive effect on gross motor function.

Selective dorsal rhizotomy: long-term experience from Cape Town.

INTRODUCTION: Given the large number of cerebral palsy patients who have undergone selective dorsal rhizotomy in the past two decades, it is clearly imperative that the clinical community be provided with objective and compelling evidence of the long-term sequelae of the procedure. MATERIALS AND METHODS: In the early 1980s, Peacock in Cape Town shifted the site of the rhizotomy from the conus medullaris to the cauda equina, and in the past 25 years, more than 200 children have been operated on. We have studied the incidence of spinal deformities after multiple-level laminectomy and recorded a 20% incidence of isthmic spondylolysis or grade-I spondylolisthesis. We have also conducted a long-term prospective gait analysis study on a cohort of 14 ambulatory patients who were operated on in 1985. RESULTS: Ten years after surgery, our patients had increased ranges of motion that were within normal limits. Step length was significantly improved, although cadence was unchanged postoperatively and was significantly less than normal age-matched control subjects. DISCUSSION: We have recently tracked down all 14 patients from the original cohort and are currently completing a 20-year prospective follow-up analysis of their neuromuscular function and gait. Our preliminary data suggest that selective dorsal rhizotomy is not only an effective method for alleviating spasticity but it also leads to long-term functional benefits.

Functional posterior rhizotomy: the Tokyo experience.

PURPOSE: The author describes the history of functional posterior rhizotomy (FPR), the surgical procedure currently used, and the results together with its future perspective in Japan. The modern form of FPR was introduced to Japan in 1995, and the first surgery was carried out in 1996. Despite initial resistance from orthopedic surgeons, the procedure has eventually gained wide recognition in the country. MATERIALS AND METHODS: The author has operated on 98 patients (60 boys and 38 girls, aged from 2 to 19 years old) by the end of 2006. Most patients were mild to severely disabled children with spastic hypertonia because of cerebral palsy and other diseases. The surgical procedure used is based on the Peacock's procedure with some modification for the mildly disabled children whose spasticity was predominantly the muscles of the ankle joint. Intraoperative neurophysiology was an indispensable tool for preserving urogenital function and for judging which root/rootlet to be cut. RESULTS: Seventeen to 83% of the root/rootlets were found to be abnormal and were cut, clearly correlating with the degree of disability. However, there was a wide difference in the cutting rate, even in children with the same degree of disability. The result of surgery in this group of patients was the same as in previously published data. Twenty out of 51 patients (39%) followed for more than a year at the current institute showed improved locomotion after FPR. Thirty patients (59%) demonstrated suprasegmental effects after FPR. CONCLUSION: The role of FPR will grow in importance as a treatment for spasticity in Japan in the future.

Otfrid Foerster (1873-1941): one of the distinguished neuroscientists of his time.

Otfrid Foerster was a German neurologist and neurosurgeon who made innovative contributions to neurology and neurosurgery. Foerster performed the first electrocorticographic studies, the hyperventilation test on patient with epilepsy and described the atonic-astatic from of infantile cerebral palsy. He will be remembered best for the operation which bears his name (Foerster's operation) and on creating a cytoarchitectonic map of the human cerebral cortex. His most famous patient was Vladimir Ilyich Lenin (1870-1924).

[Dorsal rhizotomies in children]. / Radicotomies dorsales (=postérieures) chez l'enfant.

Described for the first time by Foerster in 1908, dorsal rhizotomies are widely performed in spastic children, mainly in diplegics. The different techniques are presented: selective then sectorial rhizotomies developed by Gros in Montpellier, functional rhizotomies developed by Fasano. Literature analysis show a decrease in spasticity for 75% of the cases with a functional improvement in the less affected patients, i.e. those with still effective motor function. The most recent studies are devoted to the improvement of the spinal approach by laminotomies and show an increased interest for preoperative monitoring to limit the extent of the sections. In our experience, this surgery should be limited to children with uncontrolled spasticity which interferes with locomotor performances.

Application of spinal ablative techniques for the treatment of benign chronic painful conditions: history, methods, and outcomes.

STUDY DESIGN: The literature on current neuroablative techniques for treating benign chronic painful conditions is comprehensively reviewed. OBJECTIVE: To provide the reader with an understanding of the indications, techniques, and outcomes for the various ablative procedures used to treat chronic pain syndromes. SUMMARY OF BACKGROUND DATA: Neuromodulatory techniques are rapidly supplanting the traditional neuroablative procedures used to treat many types of pain. METHODS: A MEDLINE search was conducted for each of the following procedures: radiofrequency facet denervation, cordotomy, myelotomy, sympathectomy, DREZotomy, rhizotomy, and ganglionectomy. In the review of each article, special attention given to the outcome, length of follow-up, complications, and number of patients. Summaries of this data were compiled to provided historical perspective, current techniques, indications, and outcomes for each of the aforementioned procedures. The outcomes cited for each procedure generally represent the data from the three or four largest series with adequate follow-up length. RESULTS: The aforementioned procedures have 30% to 90% success rates, with success defined as at least a 50% reduction in perceived pain. These results tend to diminish with time. However, most are associated with a significant degree of morbidity and relatively high complication rates. In addition, many of the techniques lead to deafferentation pain syndromes. CONCLUSIONS: Ablative spinal techniques offer pain relief for many patients, but the use of these methods should be considered carefully in the light of available nondestructive procedures that may achieve similar goals with potentially lower morbidities.

Lesions as therapy: rigidity and Parkinson's disease.

Since James Parkinson (1817) first characterized the shaking palsy as a unique condition, significant confusion has remained concerning the causes and treatments of Parkinson's disease (PD). Through the 19th century, a wide variety of approaches were attempted in an effort to reduce its cardinal signs--rigidity, tremor, and bradykinesia--but to little effect. Today, approaching 200 years after Parkinson's seminal work, this disorder is commonly treated by surgical means, inducing a lesion in one specific portion of a small nucleus in the central nervous system (Desaloms et al., 1998, Lang et al., 1999). The notion of providing a lesion to the nervous system as a therapy for PD, however, began in earnest at the beginning of the 20th century. The first attempt to alleviate the symptoms of PD through surgical means involved a section of the dorsal roots of the spinal cord supplying the affected limb (also known as dorsal rhizotomy). Although ultimately resulting in disastrous effects, these early surgical attempts proceeded from a firm body of clinical and experimental research on both the central and peripheral nervous systems. After briefly reviewing the use and failure of dorsal rhizotomy as a treatment for parkinsonian rigidity, this paper will examine the manner in which clinicians and scientists justified the procedure.