Peripheral Nerve Involvement in a Neurofibromatosis Type 2 Patient With Plexiform Neurofibroma of the Cauda Equina: A Sonographic Vignette

Plexiform neurofibroma of the cauda equina with follow-up of 10 years: A case report

BACKGROUND

Plexiform neurofibromas are extremely rarely found in the region of cauda equina and can pose a significant challenge in the diagnostic and management sense. To our knowledge, only 7 cases of cauda equina neurofibromatosis (CENF) have been reported up-to-date.

CASE SUMMARY

We describe a case of a 55-year-old man with a 10 years history of progressive lower extremities weakness and bladder dysfunction. Before presenting, patient was misdiagnosed with idiopathic polyneuropathy. Lumbar spine MRI revealed a tortuous tumorous masses in the cauda equina region, extending through the Th12-L4 vertebrae. The patient underwent Th12-L3 Laminectomy with duraplasty. During the operation, the most enlarged electroneurographically silent nerve root was resected, anticipating inadequate decompression if nerve root was spared. The patient’s neurological condition improved post-operatively, but urinary retention became the major complaint. We provide a follow-up period of 10 years. During this time, the patient’s condition progressively worsened despite extensive decompression. The consequent MRI scans showed progressive enlargement of cauda equina roots and increasing lumbar stenosis, predominantly affecting L3-L4 segment. During the follow-up 8 years after the operation, the patient complained of worsening lower extremities sensorimotor function and neurogenic claudication. Subsequent MRI revealed lumbar spine stenosis at the level of L3-L4, requiring further decompression. The patient underwent a second surgery involving L4-L5 Laminectomy with duraplasty and L2-L5 transpedicular fixation. The post-operative period was uneventful. Latest follow-up 18 mo after the second surgery revealed substantial improvement in patient’s well-being.

CONCLUSION

CENF should be kept in mind during the differential diagnostic work-up for polyneuropathies. Management with an extensive decompression, duraplasty and primary spinal fixation represents a rational approach to achieve a sustained symptomatic improvement and superior overall outcome.

Mobility Functional Outcomes of Neurofibromatosis Patients: A Preliminary Report

OBJECTIVE

The aim of the study was to describe the mobility outcomes of neurofibromatosis (NF) patients who received acute inpatient rehabilitation.

DESIGN

This is a retrospective study of 62 consecutive neurofibromatosis patients of any age who received physical medicine and rehabilitation consultations at a comprehensive cancer center. Postoperative, inpatient rehabilitation admission and discharge functional independence measures (FIM scores) of transfers and gait and length of hospital stay were obtained from 37 patients who were transferred to inpatient rehabilitation (acute rehabilitation) and 25 who had an alternative disposition (consultation only).

RESULTS

Mean age was 34 yrs. Both groups had similar postoperative FIM transfer and gait scores; however, at approximately postoperative day 10, the consultation only group was discharged with median FIM of 5 (supervision level) as compared with the acute rehabilitation group FIM of 4 (P = 0.000). The acute rehabilitation group had improved mobility FIM scores from postoperative to rehabilitation admission and again from rehabilitation admission to discharge (P < 0.0001). At discharge, the acute rehabilitation group ambulated a significantly longer distance (500 f. vs. 300 ft) (P = 0.04). The median length of hospital stay for the acute rehabilitation and consultation only groups was 20 and 10 days, respectively (P = 0.004).

CONCLUSIONS

Acute inpatient rehabilitation leads to improvement in mobility-associated FIM scores for neurofibromatosis patients minimizing caregiver needs at home.

Muscle action potential scans and ultrasound imaging in neurofibromatosis type 2

INTRODUCTION

The neuropathy in patients with neurofibromatosis type 2 (NF2) is difficult to quantify and follow up. In this study we compared 3 methods that may help assess motor axon pathology in NF2 patients.

METHODS

Nerve conduction studies in median nerves were supplemented by deriving motor unit number estimates (MUNEs) from compound muscle action potential (CMAP) scans and by high-resolution ultrasound (US) peripheral nerve imaging.

RESULTS

CMAP amplitudes and nerve conduction velocity were normal in the vast majority of affected individuals, but CMAP scan MUNE revealed denervation and reinnervation in many peripheral nerves. In addition, nerve US imaging enabled monitoring of the size and number of schwannoma-like fascicular enlargements in median nerve trunks.

CONCLUSION

In contrast to conventional nerve conduction studies, CMAP scan MUNE in combination with US nerve imaging can quantify the NF2-associated neuropathy and may help to monitor disease progression and drug treatments. Muscle Nerve 55: 350-358, 2017.

A case of diffuse bilateral scrotal neurofibroma in a rabbit

This report details a rare case of diffuse bilateral scrotal neurofibroma complicated by hindlimb paralysis in a rabbit. The animal was evaluated for unusual bilateral scrotal enlargement. After physical examination, ultrasound scan, radiography, computed tomography and laparoscopy, surgical exploration of the scrotum was undertaken. A homogeneous rubbery firm mass was revealed in contact with the subcutaneous tissue expanding to the entire scrotum without involving the testicles. The mass was excised and diagnosed as diffuse scrotal neurofibroma based on histological and immunohistochemical findings (S-100 antibody positive). Over the following month, progressive neurological signs (faecal incontinence, flaccid bladder and hindlimb paralysis) were observed. After excluding central nervous system infection with Encephalitozoon cuniculi, expansion of the neurofibroma to the vertebral canal causing compression of the spinal cord was suspected, although not histopathologically verified.