Russell Payne

Pure neuritic leprosy presenting as ulnar nerve neuropathy: a case report of electrodiagnostic, radiographic, and histopathological findings

Hansens disease, or leprosy, is a chronic infectious disease with many manifestations. Though still a major health concern and leading cause of peripheral neuropathy in the developing world, it is rare in the United States, with only about 150 cases reported each year. Nevertheless, it is imperative that neurosurgeons consider it in the differential diagnosis of neuropathy. The causative organism is Mycobacterium leprae, which infects and damages Schwann cells in the peripheral nervous system, leading first to sensory and then to motor deficits. A rare presentation of Hansens disease is pure neuritic leprosy. It is characterized by nerve involvement without the characteristic cutaneous stigmata. The authors of this report describe a case of pure neuritic leprosy presenting as ulnar nerve neuropathy with corresponding radiographic, electrodiagnostic, and histopathological data. This 11-year-old, otherwise healthy male presented with progressive right-hand weakness and numbness with no cutaneous abnormalities. Physical examination and electrodiagnostic testing revealed findings consistent with a severe ulnar neuropathy at the elbow. Magnetic resonance imaging revealed diffuse thickening and enhancement of the ulnar nerve and narrowing at the cubital tunnel. The patient underwent ulnar nerve decompression with biopsy. Pathology revealed acid-fast organisms within the nerve, which was pathognomonic for Hansens disease. He was started on antibiotic therapy, and on follow-up he had improved strength and sensation in the ulnar nerve distribution. Pure neuritic leprosy, though rare in the United States, should be considered in the differential diagnosis of those presenting with peripheral neuropathy and a history of travel to leprosy-endemic areas. The long incubation period of M. leprae, the ability of leprosy to mimic other conditions, and the low sensitivity of serological tests make clinical, electrodiagnostic, and radiographic evaluation necessary for diagnosis. Prompt diagnosis and treatment is imperative to prevent permanent neurological injury.

Case Report: A Rosette-forming Glioneuronal Tumor in the Tectal Plate in a Patient with Neurofibromatosis Type I

We report the case of a 41–year-old female with neurofibromatosis Type 1 (NF1) who developed a rosette-forming glioneuronal tumor (RGNT) in the tectal plate. This tumor was diagnosed in 2002 when the patient presented with obstructive hydrocephalus, which was subsequently treated with a ventriculoperitoneal shunt and then an endoscopic third ventriculostomy. Initially thought to be a pilocytic astrocytoma, it was followed with serial magnetic resonance imaging (MRI) until tumor progression and development of a large fourth ventricular cystic component prompted resection via suboccipital craniotomy. Histological examination demonstrated an RGNT, a WHO Grade 1 tumor, with neurocytic rosettes, perivascular pseudorosettes, and elements resembling a pilocytic astrocytoma. Initially, the patient did well after her craniotomy, but postoperative complications set in that eventually led to her death. In this case report, we describe a relatively rare tumor that, despite its benign nature, leads to frequent complications and deficits due to its surgically challenging location. Along with previously reported examples, this cases raises the possibility of a causal relationship between NF1 and RGNT.

The angular course of the median nerve in the distal forearm and its anatomical importance in preventing nerve injury in a modern era of carpal tunnel release

OBJECTIVE A thorough understanding of anatomy is critical for successful carpal tunnel release. Several texts depict the median nerve (MN) as taking a course parallel to the long axis of the forearm (LAF). The authors report on their attempt to formally assess the course of the MN as it travels to the carpal tunnel in the distal wrist and discuss its potential clinical significance. METHODS The width of the wrist, the distance from the radial wrist to the MN, and the distance from the distal volar wrist crease to the point where the MN emerges between the flexor carpi radialis (FCR) tendon and the flexor digitorum superficialis (FDS) tendons were recorded during cadaveric dissection of 76 wrist specimens. The presence or absence of palmaris longus was documented. Finally, the angles between the MN and FCR tendon and between the MN and the LAF were measured using ImageJ. RESULTS The relative position of the MN at the distal wrist crease, as determined by the ratio of the distance from the MN to the radial wrist divided by wrist width, revealed a mean value of 0.48, indicating that the nerve was usually located just radial to midline. The mean distance between the distal wrist crease and the MNs emergence was 34.6 mm. The mean angle between the MN and the FCR tendon was 14.1°. The angle between the MN and the LAF had a mean value of 8.8° (range 0.0°-32.2°). The nerve was parallel to the LAF in only 10.7% of the studied wrists. Palmaris longus was absent in 14 (18.4%) of the 76 wrists. CONCLUSIONS The MN takes an angular approach to the carpal tunnel in the distal wrist in the vast majority of cases. This newly described finding will be useful to both clinicians and anatomists.

Fracture related ulnar and sciatic nerve transections: a report of two cases and literature review

IntroductionCase reports, case series, and case control studies have looked at the incidence of complete nerve transection in the setting of fracture and the need for surgical exploration dating back to the 1920s. We present two cases of nerve laceration accompanying traumatic fracture with a thorough review of the literature.MethodsWe used the following search terms: “ulnar nerve” OR “sciatic nerve” AND “laceration” OR “transection” AND “fracture.” Results were reviewed and included for discussion if they specifically reported ulnar or sciatic nerve laceration accompanying traumatic fracture.ResultsOur search yielded 15 papers reporting a total of 10 ulnar nerve lacerations and nine sciatic nerve lacerations. We present two additional cases. The first is a patient with a humerus fracture and complete ulnar nerve transection. The second case is a patient who suffered a femur fracture and complete transection of the sciatic nerve.ConclusionNerve laceration accompanying traumatic fracture is rare. We review the reported cases of nerve laceration and present two cases treated at our institution. Though uncommon, nerve laceration should be considered in the setting of traumatic fracture with neurological injury, particularly open fractures.

Adipose-Derived Stem Cells in Peripheral Nerve Regeneration

Purpose of the ReviewPeripheral nerve injuries are common, debilitating, and costly. The human body’s innate regenerative capacity is slow, and nerves are often misguided. The purpose of this article is to review a specific cellular, regenerative engineering technique that holds promise for the treatment of peripheral nerve injuries.Recent FindingsOver the past several decades, research has focused on the utilization of stem cells for peripheral nerve repair. More recently, stem cells collected from adipose tissue (adipose-derived stem cells or ADSCs) have gained traction due to their relative ease of collection and differentiation potential. Both undifferentiated and Schwann cell-like differentiated ADSCs have been used to seed conduits with variable results.SummaryTechnical and ethical issues surrounding stem cells’ self-expansion potential and genetic makeup exist. Ultimately, randomized control trials and FDA approval will be required before widespread clinical translation in the US is realized.

Evaluating the evidence: is neurolysis or neurectomy a better treatment for meralgia paresthetica?

BackgroundMeralgia paresthetica is a mononeuropathy of the lateral femoral cutaneous nerve (LCFN). Surgical treatment involves transection or decompression of the LCFN. There is no clear consensus on the superiority of one technique over the other. We performed a systematic review of the literature to answer this question.MethodsEligible studies included those that compared neurolysis versus neurectomy for the treatment of meralgia paresthetica after failure of conservative therapy. Our outcome of interest was resolution of symptoms. We performed a computerized search of MEDLINE (PubMed; all years) and of the Cochrane Central Register of Controlled Trials. Eligible studies had to include the words “meralgia paresthetica” and “surgery.” All patients regardless of age were included, and there was no language restriction. We then reviewed the articles’ titles and abstracts. All studies that compared neurolysis to neurectomy were included in the analysis.ResultsOf the studies identified, none were randomized controlled trials. There were two German language articles that were translated by a third researcher.Each study was evaluated by two independent researchers who assigned a level of evidence according to American Association of Neurologist algorithm and also performed data extraction (neurolysis vs. neurectomy and resolution of pain symptoms). Each study was found to be level four evidence.ConclusionAfter reviewing the data, there was insufficient evidence to recommended one method of treatment over the other. This highlights the importance of keeping a national registry in order to compare outcomes between the two methods of treatment.

Intraventricular Undifferentiated Pleomorphic Sarcoma: A Case Report

Undifferentiated pleomorphic sarcoma is a histologic diagnosis based on cell morphology. These tumors are found throughout the body. They are rarely found in the central nervous system and almost never occur as a primary intraventricular tumor. We present the unusual case of a 68-year-old woman with an intraventricular undifferentiated pleomorphic sarcoma. We go on to discuss the clinical presentation, radiographic characteristics, and management paradigm for these rare lesions. Our patient presented with acute confusion, inability to balance a checkbook, and gait imbalance. CT and MRI demonstrated a 4 x 3.6 x 3.6 cm enhancing lesion in the left lateral ventricle abutting the foramen of Monro. Pathology revealed an undifferentiated pleomorphic sarcoma.

Management of nerve compression in multiple hereditary exostoses: a report of two cases and review of the literature.

PurposeMultiple hereditary exostoses (MHE) is a rare autosomal dominant condition that results in the growth of cartilage-capped prominences that often cause nerve compression and injury. Many patients suffer from continued and debilitating chronic pain which leads some to advocate avoiding surgical intervention in patients with multiple hereditary exostoses. We present a review of the literature as well as a case series at our institution in order to evaluate the role of surgery in multiple hereditary exostoses.MethodsWe searched the literature for reports of patients with multiple hereditary exostoses undergoing surgery for nerve compression. We then reviewed the recent experience at our institution which revealed two patients with multiple hereditary exostoses.ResultsOur literature search revealed that there have been several case series and retrospective analyses in the literature that assess the benefit of surgery in the case of nerve compression caused by exostoses. The majority of these reports are of solitary exostoses. Few reports expand on the role of surgery in patients with multiple hereditary exostoses suffering from nerve compressions secondary to bony overgrowth. A recent review of the experience at our institution revealed two patients with multiple hereditary exostoses who together underwent a total of four surgeries for treatment of peripheral nerve compression resulting in pain or weakness. Postoperative evaluation revealed improvement in pain and/or motor strength following each operation.ConclusionBased on our experience and literature review, we advocate that nerve compression in selected individuals with multiple hereditary exostoses that results in neurological injury should be considered for nerve decompression and resection of the offending exostosis.

Tumor targeted delivery of doxorubicin in malignant peripheral nerve sheath tumors

Peripheral nerve sheath tumors are benign tumors that have the potential to transform into malignant peripheral nerve sheath tumors (MPNSTs). Interleukin-13 receptor alpha 2 (IL13Rα2) is a cancer associated receptor expressed in glioblastoma and other invasive cancers. We analyzed IL13Rα2 expression in several MPNST cell lines including the STS26T cell line, as well as in several peripheral nerve sheath tumors to utilize the IL13Rα2 receptor as a target for therapy. In our studies, we demonstrated the selective expression of IL13Rα2 in several peripheral nerve sheath tumors by immunohistochemistry (IHC) and immunoblots. We established a sciatic nerve MPNST mouse model in NIH III nude mice using a luciferase transfected STS26T MPNST cell line. Similarly, analysis of the mouse sciatic nerves after tumor induction revealed significant expression of IL13Rα2 by IHC when compared to a normal sciatic nerve. IL13 conjugated liposomal doxorubicin was formulated and shown to bind and internalized in the MPNST cell culture model demonstrating cytotoxic effect. Our subsequent in vivo investigation in the STS26T MPNST sciatic nerve tumor model indicated that IL13 conjugated liposomal doxorubicin (IL13LIPDXR) was more effective in inhibiting tumor progression compared to unconjugated liposomal doxorubicin (LIPDXR). This further supports that IL13 receptor targeted nanoliposomes is a potential approach for treating MPNSTs.

MLN8237 treatment in an orthoxenograft murine model for malignant peripheral nerve sheath tumors

OBJECTIVEMalignant peripheral nerve sheath tumors (MPNSTs) are soft-tissue sarcomas arising from peripheral nerves. MPNSTs have increased expression of the oncogene aurora kinase A, leading to enhanced cellular proliferation. This makes them extremely aggressive with high potential for metastasis and a devastating prognosis; 5-year survival estimates range from a dismal 15% to 60%. MPNSTs are currently treated with resection (sometimes requiring limb amputation) in combination with chemoradiation, both of which demonstrate limited effectiveness. The authors present the results of immunohistochemical, in vitro, and in vivo analyses of MLN8237 for the treatment of MPNSTs in an orthoxenograft murine model.METHODSImmunohistochemistry was performed on tumor sections to confirm the increased expression of aurora kinase A. Cytotoxicity analysis was then performed on an MPNST cell line (STS26T) to assess the efficacy of MLN8237 in vitro. A murine orthoxenograft MPNST model transfected to express luciferase was then developed to assess the efficacy of aurora kinase A inhibition in the treatment of MPNSTs in vivo. Mice with confirmed tumor on in vivo imaging were divided into 3 groups: 1) controls, 2) mice treated with MLN8237, and 3) mice treated with doxorubicin/ifosfamide. Treatment was carried out for 32 days, with imaging performed at weekly intervals until postinjection day 42. Average bioluminescence among groups was compared at weekly intervals using 1-way ANOVA. A survival analysis was performed using Kaplan-Meier curves.RESULTSImmunohistochemical analysis showed robust expression of aurora kinase A in tumor cells. Cytotoxicity analysis revealed STS26T susceptibility to MLN8237 in vitro. The group receiving treatment with MLN8237 showed a statistically significant difference in tumor size compared with the control group starting at postinjection day 21 and persisting until the end of the study. The MLN8237 group also showed decreased tumor size compared with the doxorubicin/ifosfamide group at the conclusion of the study (p = 0.036). Survival analysis revealed a significantly increased median survival in the MLN8237 group (83 days) compared with both the control (64 days) and doxorubicin/ifosfamide (67 days) groups. A hazard ratio comparing the 2 treatment groups showed a decreased hazard rate in the MLN8237 group compared with the doxorubicin/ifosfamide group (HR 2.945; p = 0.0134).CONCLUSIONSThe results of this study demonstrate that MLN8237 is superior to combination treatment with doxorubicin/ifosfamide in a preclinical orthoxenograft murine model. These data have major implications for the future of MPNST research by providing a robust murine model as well as providing evidence that MLN8237 may be an effective treatment for MPNSTs.