Mixed carcinomatous neuropathy in patients with lung cancer and lymphoma

External neurolysis as a treatment for foot drop secondary to weight loss: a retrospective analysis of 200 cases

BACKGROUND

Peroneal nerve entrapment is the most common peripheral mononeuropathy of the lower limbs. Foot drop, a common presentation, leads to an impaired eversion and dorsiflexion of the foot. An intriguing observation is the occurrence of foot drop secondary to weight loss.

METHODS

A retrospective study of patients surgically treated for peroneal nerve entrapment was performed between January 1, 1995 and December 31, 2016, at the Department of Neurosurgery, Genk, Belgium. Out of a total of 421 patients, 200 patients with foot drop secondary to weight loss were included. For each subject, motor and sensory outcomes after external neurolysis were investigated. As a primary objective, we examined the postoperative outcomes of external neurolysis as a treatment for foot drop in patients with peroneal nerve entrapment at the fibular head secondary to weight loss. As a secondary objective, we analyzed the correlation between patient characteristics and the success rate of external neurolysis.

RESULTS

When defining success as a postoperative MRC score of 4 or 5, external neurolysis has a success rate of 85% in patients with foot drop secondary to weight loss. A significant difference (P = < 0.0001) between postoperative and preoperative MRC scores indicates that external neurolysis leads to significant improvement of motor function in patients with foot drop secondary to weight loss. A multiple logistic regression model showed that "preoperative MRC scores" and "duration of symptoms" were the only variables with an impact on postoperative MRC scores. Other variables such as "age," "gender," and "side of entrapment" had no significant impact on postoperative results.

CONCLUSIONS

Statistical analysis emphasizes the important role of external neurolysis in the treatment of peripheral peroneal nerve entrapment. Therefore, external neurolysis at the fibular head should be regarded as a very effective and safe procedure in patients with foot drop secondary to weight loss.

Lymphoma-associated dysimmune polyneuropathies

Lymphoma consists of a variety of malignancies of lymphocyte origin. A spectrum of clinical peripheral neuropathy syndromes with different disease mechanisms occurs in about 5% of lymphoma patients. There exists a complex inter-relationship between lymphoproliferative malignancies and autoimmunity. An imbalance in the regulation of the immune system presumably underlies various immune-mediated neuropathies in patients with lymphoma. This article reviews lymphoma and more-or-less well-defined dysimmune neuropathy subgroups that are caused by humoral and/or cell-mediated immune disease mechanisms directed against known or undetermined peripheral nerve antigens.

Peripheral nervous system involvement in patients with cancer

Involvement of the peripheral nervous system (PNS) is common in patients with cancer and any part, including motor neurons, sensory ganglia, nerve roots, plexuses, cranial and peripheral nerves, and neuromuscular junctions, can be affected. Different mechanisms can initiate damage associated with cancer-related PNS disorders. These include tumour infiltration, toxicity of treatments, metabolic and nutritional perturbations, cachexia, virus infections, and paraneoplastic neurological syndromes. The type of cancer, lymphoma, or solid tumour is a further determinant of a PNS disorder. In this Review we discuss the different causes and mechanisms of disorders of the PNS in patients with cancer and we will focus on their assessment and diagnosis.

Les neuropathies périphériques paranéoplasiques

Paraneoplastic peripheral neuropathies constitute a heterogeneous group of conditions. A link between the tumor and the neuropathy has been demonstrated in a subgroup only. Definite paraneoplastic neuropathies correspond to neuropathies associated with antibodies reacting with antigens common to the peripheral nervous system and the cancer. Neuropathies associated with anti-Hu antibodies are the most frequent and consist mainly in subacute sensory neuronopathy. Sensory or sensory-motor neuropathies with anti-CV2 antibodies are less frequent. The link between the cancer and the neuropathy is less clear in the other forms. The frequency of cancer in this group varies from 1 to 18 p.cent.These neuropathies include inflammatory demyelinating neuropathies, neuropathy and vasculitis, lower motor neurone diseases, and autonomic neuropathies. Occasionally, the neuropathy improves with treatment of the tumor. Recent data suggest that gangliosides may be the target of the immune process in neuropathies associated with melanoma.

Multifocal polyradiculoneuropathy and carcinoma of the thymus

We studied a patient with polyradiculoneuropathy with anaplastic carcinoma of the thymus. Motor manifestations dominated. Postmortem examinations indicated that the primary changes were in the spinal nerve roots, peripheral nerves and, possibly, the spinal anterior horn cells. The posterior funiculi and posterior root ganglia were also affected, implying multifocal and multiphasic degeneration. This unusual polyradiculoneuropathy is a form of carcinomatous neuropathy.

Antineuronal antibody-associated paraneoplastic neuropathy in Hodgkin's disease

Paraneoplastic neurological syndromes in patients with Hodgkin's disease are rare findings. Subacute, paraneoplastic cerebellar degeneration or autonomic dysfunctions were described before. In some of these cases, autoantibodies against central or peripheral nervous system structures were found in serum and CSF. We present a 30-year-old white male who developed a progredient, clinical and electrophysiological distal sensomotoric neuropathy. Six months after the beginning of the neurological disturbances, Hodgkin's disease (Stadium III BE) was diagnosed. Other reasons for neuropathy, such as direct impairment of the peripheral nervous system by tumor masses or drug-induced neuropathy, were excluded. Cerebrospinal fluid (CSF) analysis showed a mild pleocytosis, elevated total protein (9.8 g/l) and identical oligoclonal bands in serum and CSF. Blood-CSF barrier damage was detected by Reiber formula. Indirect immunofluorescence and western blot analysis demonstrated an autoantibody against peripheral and central nervous system structures in serum and CSF. Although the autoantibody responded to a 38-40 kDa-protein in western blot and showed nuclear staining of myenteric plexus and Purkinje cell nuclei in the immunofluorescence test, this antibody was shown to be not identical to anti-Hu. An intrathecal synthesis of the antineuronal antibody was detected by antibody specificity index. Tumor therapy, plasmapheresis and treatment with intravenous immunoglobulins did not improve the neuropathy. According to our knowledge this is the first case of antineuronal antibody-associated sensomotoric neuropathy in Hodgkin's disease.

Clinical utilization and complications of sural nerve biopsy

Surgeons frequently perform sural nerve biopsy as part of the work-up of patients with peripheral neuropathy. The indications for the procedure, therapeutic value, and complications associated with the procedure have received little attention in the surgical literature. A retrospective chart review of 60 patients with the suspected diagnosis of peripheral neuropathy undergoing sural nerve biopsy was performed. Vasculitis was suspected in 29 (48%) patients undergoing biopsy. This diagnosis was confirmed in 6 of the 29 patients and resulted in the alteration of therapy in 31% of patients with this suspected diagnosis. In 27 (45%) patients, the etiology of their peripheral neuropathy was unknown. Twelve (44%) patients in this group had sural nerve pathology; however, no change in therapy was required. Ten patients in our series had associated malignant tumors; some of these patients were diagnosed after referral for sural nerve biopsy. Twenty-five (42%) patients remained undiagnosed after biopsy. Nerve conduction studies were performed in 14 (22%) patients. Thirteen patients with abnormal lower extremity nerve conduction studies had 6 normal and 7 abnormal biopsy results. The one patient with a normal study had a normal nerve biopsy result. There were six (10%) patients with wound infections, seven (12%) patients with delayed wound healing, and three (5%) patients with new onset of chronic pain in the distribution of the sural nerve, for an overall complication rate of 27%. There was no correlation between the preoperative use of antibiotics, type of local anesthetic used, or length of nerve excised and complication rate. We conclude that the complication rate after sural nerve biopsy is significant. Strict criteria should be employed in selecting patients for sural nerve biopsy including a careful neurologic history and physical examination, nerve conduction studies, appropriate work-up for vasculitis if suspected, and implementation of a search for malignancy if this is not apparent. If the diagnosis is still in question, then sural nerve biopsy would seem appropriate, especially in patients with suspected vasculitis.

Peripheral neuropathies and lymphoma without monoclonal gammopathy: a new classification

Recent progress in immunopathological studies of peripheral nerve and lymph node fragments together with 16 personal cases and numerous clinicopathological reports have suggested a new classification of peripheral neuropathies (PN) and lymphomas. These are: (1) PN due to local infiltrations by a T-cell lymphoma: (2) acute polyradiculoneuritis due to active demyelination and associated with infiltrates of a T-cell lymphoma in the epineurium, resembling Marek's disease (which is a T-cell lymphoma); (3) B-cell lymphoma proliferation which may be restricted to or predominate in the peripheral nervous system, with a large clinicopathological heterogeneity ranging from localized forms to ascending polyradiculoneuropathies; (4) angiotropic lymphoma, which is a B-cell lymphoma and may present as an acute mononeuropathy; (5) patients with acquired immunodeficiency syndrome due to lymphomatous infiltrates in the endoneurium, of which 2 cases of PN have been reported; (6) PN associated with organomegaly, endocrinopathy, M-component and skin lesions, certain cases being associated with a plasmocytoma and sometimes Castleman's disease but without any monoclonal gammopathy: (7) classic Guillain-Barré syndrome, prone to develop in patients with extraneural lymphoma but without any lymphomatous infiltrates in the peripheral nervous system; (8) certain cases (4 out of 16 in our series) where there is no clear relationship between PN and lymphoma, and there are mainly features of axonal degeneration. Inflammatory perivascular infiltrates were sometimes present in the epineurium.

Peripheral neuropathy associated with angioimmunoblastic lymphadenopathy

A 49-year-old man developed mononeuritis multiplex associated with angioimmunoblastic lymphadenopathy. The biopsy of the sural nerve revealed focal reduction of myelinated fibres and axonal degeneration, as well as perivascular inflammatory infiltrates composed of lymphocytes and plasma cells, exhibiting policlonal immunoglobulin expression, proliferation of blood vessels, thickening of the vessel wall and endothelial hyperplasia. These latter changes are similar to those commonly encountered in the lymph nodes, as well as in other organs, in patients suffering from angioimmunoblastic lymphadenopathy.

Leptomeningeal metastases: peripheral nerve and root involvement--clinical and electrophysiological study

Twenty-five patients with recently diagnosed leptomeningeal metastases underwent a prospective clinical and electro-physiological study to assess the mode and extent of peripheral nerve and spinal root involvement. Motor conduction velocities and F wave latencies in the legs were found frequently to be disturbed compared with normal subjects and a control group of cancer patients. F wave changes were the most sensitive indicator of root involvement. Electrophysiological abnormalities were detected in 20 patients, compared with 15 who had abnormal clinical signs suggesting peripheral nerve dysfunction. Electrophysiological studies can be useful in the evaluation of patients with suspected leptomeningeal metastases, and repeated recording of F wave latencies may serve to indicate root recovery in a clinically stable patient.