Browse

You are looking at 21 - 28 of 28 items for :

  • Neurosurgical Focus x
  • Refine by Access: all x
  • By Author: Spinner, Robert J. x
Clear All
Full access

Dynamic phases of peroneal and tibial intraneural ganglia formation: a new dimension added to the unifying articular theory

Robert J. Spinner, Kimberly K. Amrami, Alexandra P. Wolanskyj, Nicholas M. Desy, Huan Wang, Eduardo E. Benarroch, John A. Skinner, Michael G. Rock, and Bernd W. Scheithauer

Object

The pathogenesis of intraneural ganglia has been a controversial issue for longer than a century. Recently the authors identified a stereotypical pattern of occurrence of peroneal and tibial intraneural ganglia, and based on an understanding of their pathogenesis provided a unifying articular explanation. Atypical features, which occasionally are observed, have offered an opportunity to verify further and expand on the authors' proposed theory.

Methods

Three unusual cases are presented to exemplify the dynamic features of peroneal and tibial intraneural ganglia formation.

Results

Two patients with a predominant deep peroneal nerve deficit shared essential anatomical findings common to peroneal intraneural ganglia: namely, 1) joint connections to the anterior portion of the superior tibiofibular joint, and 2) dissection of the cyst along the articular branch of the peroneal nerve and proximally. Magnetic resonance (MR) images obtained in these patients demonstrated some unusual findings, including the presence of a cyst within the tibial and sural nerves in the popliteal fossa region, and spontaneous regression of the cysts, which was observed on serial images obtained weeks apart. The authors identified a clinical outlier, a case that could not be understood within the context of their previously reported theory of intraneural ganglion cyst formation. Described 32 years ago, this patient had a tibial neuropathy and was found at surgery to have tibial, peroneal, and sciatic intraneural cysts without a joint connection. The authors' hypothesis about this case, based on their unified theory, was twofold: 1) the lesion was a primary tibial intraneural ganglion with proximal extension followed by sciatic cross-over and distal descent; and 2) a joint connection to the posterior aspect of the superior tibiofibular joint with a remnant cyst within the articular branch would be present, a finding that would help explain the formation of different cysts by a single mechanism. The authors proved their hypothesis by careful inspection of a recently obtained postoperative MR image.

Conclusions

These three cases together with data obtained from a retrospective review of the authors' clinical material and findings reported in the literature provide firm evidence for mechanisms underlying intraneural ganglia formation. Thus, expansion of the authors' unified articular theory permits understanding and elucidation of unusual presentations of intraneural cysts. Whereas an articular connection and fluid following the path of least resistance was pivotal, the authors now incorporate dynamic aspects of cyst formation due to pressure fluxes. These basic principles explain patterns of ascent, cross-over, and descent down terminal nerve branches based on articular connections, paths of diminished resistance to fluid flow within recognized anatomical compartments, and the effects of fluctuating pressure gradients.

Full access

Peroneal and tibial intraneural ganglia: correlation between intraepineurial compartments observed on magnetic resonance images and the potential importance of these compartments

Robert J. Spinner, Kimberly K. Amrami, Diana Angius, Huan Wang, and Stephen W. Carmichael

Object

Previously the authors demonstrated that peroneal and tibial intraneural ganglia arising from the superior tibiofibular joint may occasionally extend proximally within the epineurium to reach the sciatic nerve. The dynamic nature of these cysts, dependent on intraarticular pressures, may give rise to differing clinical and imaging presentations that have remained unexplained until now. To identify the pathogenesis of these unusual cysts and to correlate their atypical magnetic resonance (MR) imaging appearance, the authors retrospectively reviewed their own experience as well as the published literature on these types of intraneural ganglia.

Methods

A careful review of MR images obtained in 22 patients with intraneural ganglia located about the knee region (18 peroneal and four tibial intraneural ganglia) allowed the authors to substantiate three different patterns: outer (epifascicular) epineurial (20 cases); inner (interfascicular) epineurial (one case); and combined outer and inner epineurial (one case). In these cases serial MR images allowed the investigators to track the movement of the cyst within the same layer of the epineurium. All lesions had connections to the superior tibiofibular joint. Nine patients were identified as having lesions with sciatic nerve extension. Seven patients harboring an outer epineurial cyst (six in whom the cyst involved the peroneal nerve and one in whom it involved the tibial nerve) had signs of sciatic nerve cross-over, with the cyst seen in the sciatic nerve and/or other terminal branches. In only two of these cases had the cyst previously been recognized to have sciatic nerve involvement. In contrast, in one case an inner epineurial cyst involving the tibial nerve ascended within the tibial division of the sciatic nerve and did not cross over. A single patient had a combination of both outer and inner epineurial cysts; these were easily distinguished by their distinctive imaging patterns.

Conclusions

This anatomical compartmentalization of intraneural cysts can be used to explain varied clinical and imaging patterns of cleavage planes for cyst formation and propagation. Compartmentalization elucidates the mechanism for cases of outer epineurial cysts in which there are primary ascent, sciatic cross-over, and descent of the lesion down terminal branches; correlates these cysts' atypical MR imaging features; and contrasts a different pattern of inner epineurial cysts in which ascent and descent occur without cross-over. The authors present data demonstrating that the dynamic phases of these intraneural ganglia frequently involve the sciatic nerve. Their imaging features are subtle and serve to explain the underrecognition and underreporting of the longitudinal extension of these cysts. Importantly, cysts extending to the sciatic nerve are still derived from the superior tibiofibular joint. Combined with the authors' previous experimental data, the current observations help the reader understand intraneural ganglia with a different, deeper degree of anatomical detail.

Full access

Peroneal intraneural ganglia

Part I. Techniques for successful diagnosis and treatment

Robert J. Spinner, Nicholas M. Desy, Michael G. Rock, and Kimberly K. Amrami

✓The common peroneal nerve is the peripheral nerve most often affected by intraneural ganglion cysts. Although the pathogenesis of these cysts has been the subject of controversy in the literature, it is becoming increasingly evident that they are of articular origin. Recent recognition of this fact has proven to be significant in reducing recurrences and improving treatment outcomes for patients. The authors present a stepwise method of assessing and treating peroneal intraneural ganglion cysts.

Full access

Peroneal intraneural ganglia

Part II. Lessons learned and pitfalls to avoid for successful diagnosis and treatment

Robert J. Spinner, Nicholas M. Desy, Michael G. Rock, and Kimberly K. Amrami

✓The authors describe common modes of failure in the diagnosis and treatment of patients with peroneal intraneural ganglia. Illustrated examples correlate the modes of failure and the diagnostic or surgical errors. Understanding these pitfalls reinforces the rationale behind current treatment recommendations as outlined in the companion article. Avoiding these pitfalls will ultimately improve outcomes.

Full access

Tumoral calcinosis producing peripheral nerve compression

A report of two cases

Ziv Williams, Kimberly K. Amrami, and Robert J. Spinner

✓Tumoral calcinosis is a rare disorder that leads to diffuse calcium phosphate deposition into soft tissue and may be seen in the setting of uremia, hyperparathyroidism, or vitamin D intoxication. This lesion can produce significant local pain and can limit mobility in large joints where it tends to occur. Less commonly, it may produce neurological symptoms by compressing or encompassing adjacent neurovascular structures. Tumoral calcinosis involving nerve structures is challenging to treat, primarily because of its extensive size and propensity to infiltrate. Although surgical intervention can often provide symptomatic improvement, this lesion tends to recur in the presence of elevated calcium phosphate levels, and its management therefore requires a combined multidisciplinary surgical and medical approach. The authors describe two cases in which patients developed tumoral calcinosis producing peripheral nerve compression and discuss their respective surgical and medical management.

Full access

Brachial plexus surgery, the “orphan drug,” whose time has come

Robert J. Spinner, Alexander Y. Shin, and Allen T. Bishop

Full access

Delayed central nervous system superficial siderosis following brachial plexus avulsion injury

Report of three cases

Aaron A. Cohen-Gadol, William E. Krauss, and Robert J. Spinner

Chronic subarachnoid hemorrhage may cause deposition of hemosiderin on the leptomeninges and subpial layers of the neuraxis, leading to superficial siderosis (SS). The symptoms and signs of SS are progressive and fatal. Exploration of potential sites responsible for intrathecal bleeding and subsequent hemosiderin deposition may prevent disease progression. A source of hemorrhage including dural pathological entities, tumors, and vascular lesions has been previously identified in as many as 50% of patients with SS. In this report, the authors present three patients in whom central nervous system SS developed decades after brachial plexus avulsion injury. They believe that the traumatic dural diverticula in these cases may be a potential source of bleeding. A better understanding of the pathophysiology of SS is important to develop more suitable therapies.

Full access

Gracilis free muscle transfer for restoration of function after complete brachial plexus avulsion

Kimberly A. Barrie, Scott P. Steinmann, Alexander Y. Shin, Robert J. Spinner, and Allen T. Bishop

Object

The authors report the functional outcomes after functioning free muscle transfer (FFMT) for restoration of the upper-extremity movement after brachial plexus injury (BPI).

Methods

The authors conducted a retrospective review of 36 gracilis FFMT procedures performed in 27 patients with BPI between 1990 and 2000. Eighteen patients underwent a single gracilis FFMT procedure for restoration of either elbow flexion (17 cases) or finger flexion (one case). Nine patients underwent a double free muscle transfer for simultaneous restoration of elbow flexion and wrist extension (first muscle) and finger flexion (second muscle), combined with direct triceps neurotization. The results obtained in 29 cases of FFMT in which the follow-up period was 1 year are reported.

Neurotization of the donor muscle was performed using the musculocutaneous nerve (one case), spinal accessory nerve (12 cases), or multiple intercostal motor nerves (16 cases). Two second-stage muscle flaps failed secondary to vascular insufficiency. Mean electromyography-measured reinnervation time was 5 months. At a minimum follow-up period of 1 year, five muscles achieved less than or equal to Grade M2, eight Grade M3, four Grade M4, and 12 Grade M5. Transfer for combined elbow flexion and wrist extension compared with elbow flexion alone lowered the overall results for elbow flexion strength. Seventy-nine percent of the FFMTs for elbow flexion alone (single transfer) and 63% of similarly innervated muscles transferred for combined motion achieved at least Grade M4 elbow flexion strength.

Conclusions

Functioning free muscle transfer is a viable reconstructive option for restoration of upper-extremity function in the setting of severe BPI. It is possible to achieve good to excellent outcomes in terms of muscle grades with the simultaneous reconstruction of two functions by one FFMT, making restoration of basic hand function possible. More reliable results are obtained when a single FFMT is performed for a single function.