The centerpiece of Lévy’s reputation is a 1926 paper published in the Revue Neurologique, co-authored with Roussy, under a title that translates as Seven cases of a particular familial disease: gait disturbances, clubfeet and generalized tendon areflexia, with, incidentally, slight clumsiness of the hands. The seven patients, drawn from a single family, displayed a striking and reproducible combination of features. They walked with difficulty, a problem the authors captured in the term dystasia, and they had congenital or early-onset deformities of the feet. Most tellingly, their tendon reflexes were absent throughout, even though the clinical picture was far milder than that of the better-known hereditary ataxia of Friedreich, with which it was immediately compared.

The disorder they described became known as Roussy-Lévy syndrome, and its definition was a triumph of careful phenotyping. At a time when the tools of neurology were the hammer, the tuning fork, the ophthalmoscope and the clinical eye, Lévy and Roussy recognized that a syndrome could be defined by a constellation of signs rather than by any single finding. The combination of areflexia, pes cavus and other foot deformities, distal weakness and an essentially static or slowly progressive course distinguished their patients from those with Friedreich’s ataxia, who typically show pyramidal signs, scoliosis and cardiomyopathy, and from other hereditary neuropathies described in the same era. The 1926 paper stands as an early exercise in what would now be called genotype-phenotype correlation, conducted entirely at the bedside.

Lévy did not stop at description. In 1934, the year of her death, she and Roussy published a follow-up paper on hereditary areflexic dystasia framed as a contribution to the study of the genesis of familial diseases and their kinship with one another. That subtitle matters. The authors were explicitly wrestling with the question of how related clinical entities fit together, whether the syndrome they had described was a disease in its own right, a fruste or abortive form of Friedreich’s ataxia, or part of a broader family of hereditary degenerations. This was a conceptual debate that ran through French neurology of the period, and the 1933 paper by Darré, Mollaret and Landowski, which asked directly whether Roussy-Lévy disease was merely a mild form of Friedreich’s disease using labyrinthine and chronaxie examinations, shows how contested the boundaries remained.

The question was not settled for decades, and the eventual answer vindicated the distinctness of the syndrome in a way neither Lévy nor her contemporaries could have imagined. In 1956, Joseph Lapresle traced and re-examined four of the seven original patients, thirty years after the first publication, confirming the persistence of the phenotype and the remarkable stability of the clinical picture across the decades. Then, in 1973, Lapresle and Salisachs reported a finding that moved the debate from the clinic to the laboratory: a nerve biopsy specimen from one of the original cases of Roussy-Lévy disease showed onion bulb formations, the whorled proliferations of Schwann cell processes that are the pathological signature of a demyelinating and remyelinating hereditary neuropathy. The syndrome was, at its core, a disease of the peripheral nerves.

The molecular coda arrived at the end of the twentieth century. In 1998, Auer-Grumbach and colleagues demonstrated that the Roussy-Lévy syndrome is a phenotypic variant of Charcot-Marie-Tooth disease type 1A, associated with the characteristic duplication on chromosome 17p11.2 that underlies the commonest form of hereditary motor and sensory neuropathy. A year later, Planté-Bordeneuve and colleagues, in a paper pointedly titled The Roussy-Lévy family: from the original description to the gene, closed the loop by studying the descendants of the original kindred and confirming the genetic diagnosis. A clinical picture sketched in 1926 from seven patients and a family tree had been anchored, seventy-three years later, to a specific segment of the human genome.

That trajectory, from bedside description to chromosomal duplication, is precisely why historians of neuroscience find Lévy worth recovering. Her work illustrates how the great nosological debates of interwar neurology, over whether syndromes were separate diseases or variants of one another, were resolved not by better rhetoric but by accumulated follow-up data and, eventually, by molecular genetics. The Roussy-Lévy syndrome is now understood as part of the demyelinating Charcot-Marie-Tooth spectrum, yet its recognition as a distinct phenotype in 1926 helped clinicians for decades to counsel families, predict prognosis and distinguish patients whose disease would remain relatively static from those facing the progressive disability of Friedreich’s ataxia.

Lévy’s scientific range extended beyond hereditary neuropathy. In 1925 she published a monograph on the late manifestations of epidemic encephalitis, the prolonged and delayed forms of the disease that swept Europe in the wake of the First World War and left many patients with parkinsonian and other sequelae years after the acute infection. The work places her among the clinicians who grappled with encephalitis lethargica, one of the great unsolved puzzles of the era, and shows a career that engaged with both the degenerative and the infectious frontiers of neurology. Contemporaries remembered her within the vibrant Parisian school that included figures such as Jean Lhermitte, and the historical literature, notably Peter Koehler’s 2018 study of Lévy and the Roussy-Lévy syndrome in the Journal of the History of the Neurosciences, has begun to piece together the details of her short but productive career.

Her early death in 1934, at the age of forty-eight, cut short a career that had already produced two landmark papers on hereditary areflexic dystasia and a substantial monograph on post-encephalitic disease. It also helps explain why her name faded. Eponyms tend to attach to those who survive to promote, extend and defend their syndromes, and Lévy had no such opportunity. The new biographical account, written by Carlos Alvarado-De la Hoz, Andres Felipe Cardenas-Cruz and Alba Lucia Marentes-Cubillos, neurologists at the Hospital Universitario San Ignacio and the Pontificia Universidad Javeriana in Bogotá, forms part of a deliberate effort by the Journal of Neurology to document the pioneers whose contributions underpin modern practice, and it appeared in volume 273 of the journal as article number 601.

For a modern readership, the story carries a broader lesson about how medicine accumulates knowledge. The seven patients described in 1926 were examined with none of the instruments that would eventually explain their condition, yet the precision of the original observation was good enough that a biopsy in 1973 and a gene study in 1999 could be anchored to those very cases. Clinical description, often dismissed as the antiquarian wing of neuroscience, proved to be durable data. Gabrielle Lévy’s legacy is a reminder that the careful documentation of a single family, done well, can outlast the career and even the life of the observer, and that some of the most consequential figures in the history of the neurosciences are those whose names survive only in the hyphen of a syndrome they never lived to see explained.

Subject of Research: Historical biography of neurologist Gabrielle Lévy and the Roussy-Lévy syndrome

Article Title: Gabrielle Lévy (1886–1934)

Article References: Alvarado-De la Hoz, C., Cardenas-Cruz, A. F., & Marentes-Cubillos, A. L. (2026). Gabrielle Lévy (1886–1934). Journal of Neurology, 273(10), Article 601. https://doi.org/10.1007/s00415-026-14135-y

Image Credits: AI Generated

DOI: 10.1007/s00415-026-14135-y

Keywords: Gabrielle Lévy, Roussy-Lévy syndrome, hereditary areflexic dystasia, Charcot-Marie-Tooth disease, Friedreich's ataxia, neurology history, hereditary neuropathy, peripheral nerve, genetics, Pioneers in Neurology, Journal of Neurology, medical eponyms

The lateral femoral cutaneous nerve is unusual among the nerves of the leg because it carries only sensory fibers, not motor ones. It typically originates from the second and third lumbar spinal levels, travels down through the pelvis, and passes under or through the inguinal ligament near the front of the hip, just medial to a bony landmark called the anterior superior iliac spine. Once past the ligament, it splits into anterior and posterior branches that supply sensation to the front-outer and outer thigh, respectively. Because the nerve carries no motor fibers, meralgia paresthetica produces pain, burning, tingling, and numbness without any weakness or reflex changes, a hallmark that helps clinicians distinguish it from other causes of leg pain.

Why the nerve gets squeezed varies from person to person. Physical causes include tight clothing, pregnancy, obesity, and, rarely, tumors. Metabolic and chemical factors can also play a role, with diabetes mellitus, alcohol use disorder, hypothyroidism, and lead poisoning all implicated in nerve dysfunction. In some cases the damage is iatrogenic, meaning it occurs as an unintended consequence of surgery, including spine operations, hernia repairs, hip replacements, pelvic osteotomies, and acetabular fracture repair. Researchers expect the condition to become increasingly common as rates of obesity and diabetes continue to climb worldwide, which makes the search for effective treatments more urgent.

Most patients are managed in outpatient settings, and the first line of attack is deliberately low-tech: lose weight, wear looser clothing, and try physical therapy. Over-the-counter options such as nonsteroidal anti-inflammatory drugs, topical capsaicin, and lidocaine patches come next, followed by prescription anticonvulsants, tricyclic antidepressants, and corticosteroid injections. Alternative approaches, including botulinum toxin injections, acupuncture, and kinesio taping, have shown benefit in small studies. When everything else fails, surgery remains the final option, either cutting the nerve outright in a procedure called neurectomy or freeing it from surrounding tissue in a decompression known as neurolysis. Neither operation is clearly superior to the other, and both carry the risks inherent to any surgery.

Radiofrequency ablation sits in the gap between pills and scalpels. The technique relies on a closed electrical circuit in which high-frequency alternating current flows through an insulated probe tipped with an active electrode. The current causes water molecules near the electrode tip to vibrate rapidly, and in thermal, or conventional, ablation that vibration generates heat, creating a precisely controlled thermal lesion at temperatures of 75 to 90 degrees Celsius sustained for 90 to 180 seconds. The heat produces axonal degeneration and destroys the nerve sheath, interrupting the pain signals traveling to the brain. Two variants exist: cooled ablation, which circulates water to keep the probe itself at around 60 degrees while heating target tissue to 80 degrees and thereby creating a larger lesion, and pulsed ablation, which uses alternating current pulses that allow heat to dissipate between cycles, keeping the electrode tip below 42 degrees and avoiding permanent tissue destruction altogether.

In the new study, a team led by Alaa Abd-Elsayed of the University of Wisconsin School of Medicine and Public Health reviewed the electronic medical records of every patient who underwent thermal radiofrequency ablation of the lateral femoral cutaneous nerve at their center between January 2014 and May 2025. To qualify, patients had to be at least 18 years old, carry a diagnosis of meralgia paresthetica, and have failed conservative management such as transcutaneous electrical nerve stimulation, physical therapy, and massage therapy. Critically, each patient also needed two successful diagnostic nerve blocks with 0.25 percent bupivacaine, each producing at least a 50 percent reduction in pain, before being considered a candidate for ablation. Cooled and pulsed procedures were excluded so the analysis focused purely on the thermal technique.

The procedure itself is performed under ultrasound guidance with the patient lying supine. After the groin is prepped and draped, the nerve is identified at the lateral edge of the sartorius muscle, the overlying skin is anesthetized with lidocaine, and an ablation needle, either 18 or 21 gauge with a 4 or 10 millimeter active tip depending on the provider’s preference, is advanced toward the target. Sensory stimulation is tested to confirm that the needle sits near the nerve, producing tingling in the anterolateral thigh without any motor response, and then two milliliters of 2 percent lidocaine are injected before the lesion is created at 80 degrees Celsius. Patients go home the same day, and none required narcotic pain medication afterward.

The results, though drawn from a small group, are striking. Thirteen procedures across eight patients were analyzed, with two patients undergoing the procedure three times and one twice. The patients averaged just under 50 years of age with a mean body mass index of 35, and six of the eight were women. On the 10-centimeter visual analog scale, average pain scores fell from 5.77 at baseline to 3.23 after the procedure, a statistically significant drop with a p value of 0.007. Nine of the thirteen cases reported a reduction in pain, and among those responders the mean improvement was just over 62 percent. Where duration data were available, relief lasted an average of 6.43 months, with individual responses ranging from 2 to 15 months, and two patients were still pain-free at their most recent clinic visit. Not a single adverse event was recorded.

The findings align with a small but growing literature. Only one prior study has examined thermal ablation of this nerve, reporting roughly 75 percent average pain improvement in six patients, with most still experiencing relief at six months and two of three patients maintaining benefit at one year. A separate study of cooled ablation in seven patients found relief in nine of eleven procedures with nearly 65 percent average improvement lasting just under seven months. Pulsed ablation has been studied more extensively, in six reports covering 21 patients, with pain relief ranging from 75 to 100 percent and symptom recurrence in only one case. Which variant is best remains genuinely unresolved. Pulsed ablation is theoretically safer because it does not create lesions, and some insurers decline to cover it on the grounds that it is still investigational, an irony that highlights how reimbursement policy can lag behind clinical practice. In other pain conditions, however, continuous ablation has generally outperformed pulsed: meta-analyses of lumbar facet joint pain and trigeminal neuralgia, along with randomized trials in knee osteoarthritis and studies of post-herpetic neuralgia, have mostly favored thermal techniques for the magnitude and durability of relief, although results vary by condition.

The authors are candid about the limitations of their work. Because the study was retrospective, follow-up intervals varied and many patients returned only once, restricting the analysis to outcomes within two months of the procedure. The chart review format also prevented the team from capturing variables such as nerve size on ultrasound, and no data on function or quality of life were available, even though these outcomes matter enormously to chronic pain patients. The sample was small, there was no control group, and stratified analyses of factors like needle size, lesion duration, and diabetes were not possible. Still, the complete absence of complications, combined with statistically significant pain reduction and relief lasting on average more than six months, positions thermal radiofrequency ablation as a credible option for patients stranded between failed conservative care and the operating room. The researchers themselves call for prospective studies with larger samples, fixed long-term follow-ups, and additional parameters to identify which patients respond best, a question that will determine whether this technique becomes a standard stopgap or simply another tool in a crowded pain medicine arsenal.

Subject of Research: Thermal radiofrequency ablation of the lateral femoral cutaneous nerve as a treatment for refractory meralgia paresthetica

Article Title: Lateral Femoral Cutaneous Nerve Radiofrequency Ablation for the Treatment of Meralgia Paresthetica: A Retrospective Case Series

Article References: Abd-Elsayed, A., Jin, M. Y., Shiferaw, B. T., Murphy, A. P., & Henjum, L. J. (2026). Lateral Femoral Cutaneous Nerve Radiofrequency Ablation for the Treatment of Meralgia Paresthetica: A Retrospective Case Series. Advances in Therapy. https://doi.org/10.1007/s12325-026-03819-6

Image Credits: AI Generated

DOI: 10.1007/s12325-026-03819-6

Keywords: meralgia paresthetica, lateral femoral cutaneous nerve, radiofrequency ablation, chronic pain, neuropathic pain, ultrasound guidance, minimally invasive, pain management, peripheral nerve, retrospective case series, obesity, diabetes