Ganglion of the peroneal nerve. CULLY A. COBB, III, M.D., AND RICHARD H. MoIr4 M.D.

Transcription

1 Ganglion of the peroneal nerve Report of two cases CULLY A. COBB, III, M.D., AND RICHARD H. MoIr4 M.D. Division of Neurological Surgery, Baylor College of Medicine, Houston, Texas ~" Peroneal nerve ganglion masquerades as other lesions and may not be diagnosed except at operation; it can be treated by surgery. Two cases are reported and the literature summarized. KEY WORDS 9 foot-drop 9 peroneal nerve ganglion 9 intraneural ganglion cyst F OOT-DROP Occurs frequently as a result of either lumbar disc disease or sciatic nerve injury. In addition to these familiar syndromes, a poorly recognized disease exists which may require operative exploration for diagnosis and treatment. We report two recent cases to demonstrate this. Case l Case Reports A 14-year-old baseball pitcher was first seen in July, He had noted the onset of dull aching pain in the lateral aspect of his left knee during the baseball season. He developed a gradual but progressive weakness of toe dorsiflexion, and the anterior aspect of his ankle was numb. He was placed in a dorsiflexion foot brace in the expectation that his nerve function would improve. However, on reevaluation, the peroneal palsy continued, and an electromyogram (EMG) showed complete degeneration of the deep peroneal nerve with no response to stimulation. He had no history of trauma and no family history of nerve lesions. Examination. On admission, left anterior tibial atrophy was present and the patient was unable to dorsiflex his left foot or toes. Hypalgesia was present over the dorsal web between the first and second toes on the left foot. Although the nerve was not enlarged to palpation, percussion over the peroneal nerve at the knee produced paresthesias in the foot. A repeat EMG showed no signs of reinnervation. Operation. In November, 1971, the nerve was explored. It was found to have a fusiform swelling, beginning at the level of the knee joint superiorly and extending distally past the limits of the incision. The anterior aspect of the nerve did not respond to stimulation while the posterior portion did respond. A small gauge needle was inserted into the nerve and no fluid could be aspirated; however, on withdrawing the needle, a drop of clear gelatinous viscid material appeared at the site of the needle puncture. Under magnification, this area of the nerve was incised and opened and 5.0 cc of cyst contents removed (Fig. 1). A Silastic catheter was placed in the cyst and threaded proximally 2.0 cm and distally 7.0 cm. The cyst was irrigated with saline and left open. Microscopic examination of a fragment of the cyst wall revealed no neoplasia. The boy has done well and examination 18 months later showed complete recovery with reinnervation on EMG. J. Neurosurg. / Volume 41 / August,

2 C. A. Cobb and R. H. Moiel TABLE 1 Summary of 28 cases of peroneal nerve ganglion Case No. Author, Year Age, Sex Injury Duration Leg or Tinel's of Symptoms Knee Pain Sign 1 Sultan (1921) 2 Zarr (1926) 3 Wadstein 4 (1932) 5 E/lis 6 (1936) 7 Ferguson (1937) 8 Warren (1946) 9 Brooks (1952) 10 Tupman (1957) Clark (1961) Parkes (1961) Barrett & Cramer (1963) Gurdjian, etal, (1965) Stack, et al, (1965) Katz & Lenobel (1970) Cobb & Moiel (1974) 56 M no -- yes 22 M no 2 mo M yes 8 mo yes M no 1 mo yes yes 13 M -- 2 mo yes M yes 1 mo no 15 M no 2 wk yes 29 M no 6 wk no no 44 M no 6 yr yes yes 18 F no 6 mo no 42 M -- 1 yr yes yes 52 M yes 2 mo yes M yes 7 mo yes 15 M no 3 mo yes -- yes 47 M no 6 mo M yes 2 yr yes yes 74 M -- 3 mo yes M -- 2 yr yes M yes 5-6 mo yes no 24 M no 4 mo yes M yes 2 yr yes M yes 10 rno no no 20 M -- 4 mo no F -- 3 mo yes M -- 4 mo yes M no 2 rno yes yes 14 M no 6 mo yes yes 25 M yes 3 yr yes yes Case 2 This 25-year-old man developed intermittent aching of the left calf in March, 1969, while in Army basic training. He fell over a trash can and injured his left ankle in December, 1971, after which the pain in the calf and left knee increased. The pain lasted for a few weeks, then subsided. Shortly thereafter, the patient developed a left foot- 256 J. Neurosurg. / Volume 41 / August, 1974

3 - - yes Ganglion of the peroneal nerve TABLE 1 (continued) Loss of Function Sensory Motor Mass Single Cyst deep sup. deep sup. Procedure Period Follow-Up Results -- yes yes -- yes mult. excision -- no change excision yes no yes no yes mult. yes yes yes no yes sing. yes -- yes mult yes -- yes mult. incision 15 mo recurrence excision 1 yr improved incision 1 yr recovered incision 3 mo recovered excision 12 days recovered resection yes yes no yes yes sing. excision 1 yr worse excision 5 mo improved no no yes no yes mult yes -- yes scar yes yes.... yes mult. yes yes yes no yes sing yes -- yes mult. yes -- yes mult. resection 5 yr recurrence lysis resection 6 yr improved resection 5 yr worse incision 13 mo recurrence resection -- worse excision 2 yr recovered excision 2 yr worse incision 4 yr recovered incision 17 mo recurrence incision 21 mo improved no no yes mult. yes yes yes no -- sing. yes yes yes yes no sing. excision 2 yr improved excision -- improved excision -- improved incision 5 mo improved yes mult. yes sing. yes sing. resection 6 yr improved excision 12 mo improved excision 16 yr improved yes no yes yes yes sing. excision 6 mo improved yes no yes no no sing. yes yes yes yes no mult. incision 18 mo recovered incision 16 mo improved drop. Two weeks prior to admission, numbness along the left lateral calf, lateral aspect of the left foot and dorsal web between the first and second toes on the left side appeared. An EMG showed extensive dener- vation of the tibialis anterior and extensor hallucis brevis. There was no family history of nerve lesions. Examination. In February, 1972, the patient was admitted to the hospital; on ex- J. Neurosurg. / Volume 41 / August,

4 C. A. Cobb and R. H. Moiel FIG. 1. Case 1. Operative photograph following cystotomy. A retraction suture displays the cystic cavity. amination he had a left foot-drop and paralysis of left foot eversion. Paresthesias in the left foot occurred on percussion of the peroneal nerve over the fibular head. The nerve was normal to palpation preoperatively. Operation. When explored at surgery, the nerve was found to be thicker and paler than normal, with a nodular appearance. On incision of the nerve, clear viscid material was identified. A trabeculated cyst 2.5 cm in diameter was found in the nerve; three fenestrations were necessary for drainage. Postoperatively, the patient has done well and 16 months after the procedure shows moderate return of function. Discussion Intraneural ganglion cysts of the peroneal nerve are rare. The true incidence is probably underestimated since these cysts may present as a foot-drop with knee pain and not as a mass lesion. As a result of this, the lesion can closely mimic the pressure neuropathy seen in people with thin legs and a habit of crossing them. We have found 26 previously reported cases of intraneural peroneal ganglia (Table 1). 1,2,48,1~ Parkes 1~ mentions three other cases but gives no details. Other lesions reported to be peroneal nerve ganglia ~2,1~ are, we believe, joint ganglia which have exerted an extrinsic pressure on the nerve. Some authors have questioned the validity of the first two cases but we believe them to be true intraneural ganglia and not cystic neurofibromas. The anatomic extent of these lesions has been variable. They always seem to involve the peroneal nerve at the level of the head of the fibula. The lesion may reach as high as the gluteal fold or as low as the midleg. Of the 28 reported cases only 7% were found in women. The ages ranged from 13 to 74 years. Many cases arose following injury, TABLE 2 Results obtained in different operative procedures* Procedure Recovered Improved No Change Worse Recurrence incision partial or complete excision nerve resection *One patient whose symptoms recurred after cyst incision did well following a second procedure. 258 J. Neurosurg. / Volume 41 / August, 1974

5 Ganglion of the peroneal nerve and other patients with no known injury may have been exposed to trauma at work. The duration of symptoms before operation ranged from 2 weeks to 6 years. Knee pain was usually present. Tinel's sign could be evaluated in only nine cases but was present in most of these. All patients had a deficit related to the deep peroneal nerve but in only two-thirds was the superficial peroneal nerve involved. In most cases the mass was palpable; half of the cysts were multilocular. The histological examination invariably demonstrated fibrous connective tissue with no organized cyst lining. Although 30% of the patients who underwent cyst incision developed later recurrence of their symptoms, these patients were sometimes not made worse in the long run. This contrasts with the results following cyst excision in which 29% of the patients were permanently worse or were unimproved (Table 2). Carp and Stout s believed that all ganglia are "cysts resulting from mucinous degeneration of connective tissue. They occur generally in or are attached to capsules of joints or tendon sheaths but do not communicate primarily with joints or sheath spaces." King 9 postulated that the process is not a degeneration but a normal response to a stimulus to the specialized connective tissue forming joints and tendon sheaths. Perhaps the perineural connective tissue is also subject to such degeneration or metaplasia. Gurdjian, et al., 7 have postulated that intraneural ganglia may follow intraneural hemorrhage with reabsorption of the hematoma; however, hemosiderin in the cyst wall has not been reported. Although intraneural ganglia may dissect down the articular branch of the peroneal nerve, we believe that ganglia arising from the joint capsule are a different entity and, although they may cause dysfunction by extrinsic pressure on the nerve, are not intraneural. We would consider surgical exploration in all instances of foot-drop that have lasted more than 3 months and have a Tinel's sign, swelling of the nerve, or pain at the head of the fibula. If a cyst can be easily excised without nerve damage, this might be done under magnification. If the cyst is embedded in the nerve, the cyst wall should be incised over each loculation and a Silastic catheter passed to allow evacuation of the cyst contents by irrigation. A surgical approach to foot-drop might uncover many more of these cysts and would forestall the development of irreversible nerve and muscle atrophy. References 1. Barrett R, Cramer F: Tumors of the peripheral nerves and so-called "ganglia" of the peroneal nerve. Clin Orthop 27: , Brooks DM: Nerve compression by simple ganglia. A review of thirteen collected cases. J Bone Joint Surg (Brit) 34: , Carp L, Stout AP: A study of ganglion, with especial reference to treatment. Surg Gynec Obstet 47: , Clark K: Ganglion of the lateral popliteal nerve. J Bone Joint Surg (Brit) 43: , Ellis VH: Two cases of ganglia in the sheath of the peroneal nerve. Brit J Surg 24: , Ferguson LK: Ganglion of the peroneal nerve. Ann Surg 106: , Gurdjian ES, Larsen RD, Lindner DW: Intraneural cyst of the peroneal and ulnar nerves. Report of two cases. J Neurosurg 23:76-78, Katz MR, Lenobel MI: Intraneural ganglionic cyst of the peroneal nerve. J Neurosurg 32: , King ESJ: Pathology of ganglion. Aust New Zealand J Surg 1: , Parkes A: lntraneural ganglion of the lateral popliteal nerve. J Bone Joint Surg (Brit) 43: , Stack RE, Bianco A J, MacCarty CS: Compression of the common peroneal nerve by ganglion cysts. Report of nine cases. J Bone Joint Surg (Amer) 47: , Sultan C: Ganglion der Nervenscheide des Nervus peroneus. Zbl Chir 48: , Tupman GS: Axonotmesis of anterior tibial branch of lateral popliteal nerve due to ganglion of the nerve-sheath. Brit J Surg 45:23-24, Wadstein T: Two cases of ganglia in the sheath of the peroneal nerve. Acta Orthop Scand 2: , Warren R: Ganglion of the common peroneal nerve. Ann Surg 124: , Zarr: l~ber Ganglien in der Nervenscheide. Zbl Chit 53:2551, 1926 Address reprint requests to: Cully A. Cobb, III, M.D., Division of Neurological Surgery, Baylor College of Medicine, Houston, Texas J. Neurosurg. / Volume 41 / August, ,59