Intraneural ganglion cyst of the peroneal nerve occurring after coronavirus disease-19 vaccination: A case report.

Ganglion cysts are relatively common, but intraneural ganglion cysts (INGCs) within peripheral nerves are rare and poorly understood. We present the case of a 58-year-old woman who presented with acute right-foot drop. She experienced acute knee pain radiating from the lateral leg to the dorsal foot two days after the first coronavirus disease-19 (COVID-19) vaccination (BNT162b2, Pfizer-BioNTech). She had no history of trauma or medication use. Two weeks after the onset of symptoms, she developed a dorsiflexor weakness of the right foot (Medical Research Council grade, poor). The weakness worsened to a "trace" grade despite providing conservative management for one month. Ultrasonography revealed a fusiform echolucent structure within the course of the right common peroneal nerve around the fibular head. Magnetic resonance imaging revealed multiple intraneural cysts within the right common peroneal nerve. Nerve conduction and electromyographic studies revealed multiphasic motor unit action potentials accompanied by abnormal spontaneous activities in the innervated muscles, along with axonal degeneration of the deep peroneal nerves. Surgical removal of the cyst was performed, and the patient's symptoms gradually improved. Pathological examination revealed a cystic structure containing mucinous or gelatinous fluid and lined with flattened or cuboidal cells. The clinical course and sequential electromyographic findings relevant to this symptomatic cyst were temporally related to the vaccination date. The present case suggests that INGC-induced peroneal palsy is a possible complication after COVID-19 vaccination.

Foot drop in patients treated with bortezomib - a case series and review of the literature.

Bortezomib-induced peripheral neuropathy (BIPN) has a profound impact on quality of life, which is an important issue considering the growing number of survivors of multiple myeloma and amyloidosis. BIPN is typically symmetric, distal, "stocking and glove" distribution and predominantly consists of sensory rather than motor symptoms. In this case series, we report an acute neurotoxicity syndrome induced by bortezomib, which is clinically distinct from BIPN by not being peripheral and distal. We describe six patients that developed unilateral or bilateral foot drop attributed to bortezomib. With bortezomib discontinuation symptoms improved gradually over months to years.

A Rare Case of Vincristine-Induced Neuropathy Presenting as Foot Drop in the Postoperative Period.

Patients with cancer receiving chemotherapy are at risk of neuropathy development. Many of them may have subclinical neuropathies, which may be missed before planning anesthesia, especially in emergency scenarios. This case report highlights the importance of a thorough neurologic examination in patients with subclinical neuropathy to avoid any complications and medicolegal issues. A patient with a diagnosis of diffuse large B-cell lymphoma being treated with vincristine-based chemotherapy was scheduled for an emergency laparotomy. There was no history of any neurologic deficit before surgery. The surgery was done using general anesthesia, and intrathecal morphine was given for postoperative analgesia. This patient experienced bilateral foot drop postoperatively. A bilateral lower limb and upper limb sensory-motor neuropathy was detected on a nerve conduction study, probably due to vincristine-induced peripheral neuropathy. The literature is deficient regarding manifestations of neurologic complications in previously asymptomatic patients in the immediate postoperative period. These patients pose a diagnostic dilemma perioperatively that may lead to medicolegal challenges to the anesthesia provider. Anesthesia providers should be wary of the possibility of exacerbation of any subclinical neuropathy in patients with cancer receiving neurotoxic chemotherapy and should probably avoid any neuraxial intervention in such patients if possible.

Unilateral common peroneal nerve palsy following renal transplantation: a case report of tacrolimus neurotoxicity.

Neurologic complications are not uncommon in renal transplant recipients. Acute femoral neuropathy, lumbosacral plexopathy, and sciatic neuropathy have been reported after kidney transplantation probably due to perioperative nerve compression and ischemia. To the best of our knowledge, common peroneal nerve (CPN) palsy has not been described in the early postoperative period following renal transplantation. Also, mononeuropathy due to tacrolimus (TAC) therapy has not been described so far. We report a case of isolated CPN palsy presenting as unilateral foot drop following renal transplantation and that improved only after replacing TAC with cyclosporine.

δ-Aminolevulinic acid dehydratase genotype predicts toxic effects of lead on workers' peripheral nervous system.

There is a wide variation in sensitivity to lead (Pb) exposure, which may be due to genetic susceptibility towards Pb. We investigated whether a polymorphism (rs1800435) in the δ-aminolevulinic acid dehydratase (ALAD) gene affected the toxicokinetics and toxicodynamics of Pb. Among 461 Chinese Pb-exposed storage battery and 175 unexposed workers, allele frequencies for the ALAD1 and ALAD2 alleles were 0.968 and 0.032, respectively. The Pb-exposed workers had a higher fraction of the ALAD1-2/2-2 genotype than unexposed workers (7.8% vs. 2.3%, p=0.01). The Pb levels in blood (B-Pb) and urine (U-Pb) were higher in Pb-exposed workers carrying the ALAD2 allele compared to homozygotes for ALAD1 (median B-Pb: 606 vs. 499 µg/L; U-Pb: 233 vs. 164 µg/g creatinine), while there was no statistically significant difference in the unexposed controls (median: 24 vs. 37 µg/L, and 3.9 vs. 6.4µg/g creatinine, respectively). High B-Pb and U-Pb were associated with statistically significantly lower sensory and motor conduction velocities in the median, ulnar and peroneal nerves. At the same B-Pb and U-Pb, ALAD1 homozygotes had lower conduction velocities than the ALAD2 carriers. There were similar trends for toxic effects on haem synthesis (zinc protoporphyrin and haemoglobin in blood) and renal function (albumin and N-acetyl-d-ß-acetylglucosaminidase in urine), but without statistical significance. There was no difference in Pb toxicokinetics and toxicodynamics associated with VDR BsmI polymorphism. Our results show that the ALAD genotype modifies the relationship between Pb and its toxic effects on the peripheral nervous system. This must be considered in the assessment of risks at Pb exposure.

Peroneal mononeuropathy in pediatric Hodgkin's disease.

A 12-year-old boy with Hodgkin's disease developed left peroneal nerve palsy during combination therapy with chemotherapy and low-dose irradiation. The palsy occurred twice; around 1-2 weeks after the second administration of vincristine in the second and third COPP (cyclophosphamide, vincristine, prednisolone, and procarbazine) regimens. Without any treatment, the peroneal neuropathy completely resolved clinically three months and electromyographically six months after the onset. He used to play television games for more than 6 hours a day with the legs crossed while sitting on the bedside. Compared to adult patients, little is known about the relationship between peroneal neuropathy and systemic malignant diseases in pediatric patients. This case shows for the first time that habitual leg crossing during potentially neurotoxic chemotherapy could induce peroneal mononeuropathy in a pediatric cancer patient.