Utility of Carpal Tunnel Release and Ulnar Decompression in CMT1A and HNPP.

INTRODUCTION/AIMS: Carpal and cubital tunnel syndrome (CTS, CuTS) are common among patients with hereditary neuropathy with liability to pressure-palsies (HNPP) and Charcot-Marie-Tooth type 1A (CMT1A) and may impact quality of life. We aimed to evaluate the utility of nerve decompression surgeries in these patients. METHODS: Medical records were reviewed for patients with PMP22 mutations confirmed in Mayo Clinic laboratories from January 1999 to December 2020, who had CTS and CuTS and underwent surgical decompression. RESULTS: CTS occurred in 53.3% of HNPP and 11.5% of CMT1A, while CuTS was present in 43.3% of HNPP and 5.8% of CMT1A patients. CTS decompression occurred in 10-HNPP and 5-CMT1A patients, and CuTS decompression with/without transposition was performed in 5-HNPP and 1-CMT1A patients. In HNPP, electrodiagnostic studies identified median neuropathy at the wrist in 9/10 patients and ultrasound showed focal enlargements at the carpal and cubital tunnels. In CMT1A, median and ulnar sensory responses were all absent, and the nerves were diffusely enlarged. After CTS surgery, pain, sensory loss, and strength improved in 4/5 CMT1A, and 6/10 HNPP patients. Of clinical, electrophysiologic and ultrasound findings, only activity-provoked features significantly correlated with CTS surgical benefit in HNPP patients (odds ratio = 117.0:95% confidence interval, 1.94 > 999.99, p = 0.01). One CMT1A and one HNPP patient improved with CuTS surgery while 2 HNPP patients worsened. DISCUSSION: CTS symptom improvement post-surgery can be seen in CMT1A and (less frequent) in HNPP patients. CuTS surgery commonly worsened course in HNPP. Activity-provoked symptoms in HNPP best informed benefits from CTS surgery.

Nerve wrapping for recurrent compression neuropathy: A systematic review.

BACKGROUND: The recurrence of symptoms following primary nerve compression surgery can occur in up to 25% of cases. Nerve wrapping can be utilised for revision surgery. An ideal barrier should minimise the chance of fibrosis, scarring and allow for adequate nerve gliding. This review evaluates the use of autologous or commercially available allograft and xenograft options as barriers against nerve scarring following revision surgery. METHODS: PubMed, Ovid Embase and Cochrane databases were searched using the All Fields Index. Nine hundred titles underwent title screening with 11 studies being included in the final analysis. The risk of bias was assessed using the Methodological Index for Non-Randomised Studies (MINORS) tool. PRISMA guidelines were followed at all stages and the review was registered with PROSPERO (CRD 42020182818). RESULTS: The 11 studies comprised of all case series. In total, 114 patients were included, with ages ranging from 28 to 90. Previously, the number of revision surgeries ranged from 0 to 5. Autologous veins were used in 6 studies, collagen in 3 studies and human amniotic membrane in 2 studies. Improvements in subjective and objective outcomes were seen with all wrap types. Pain was the most common residual symptom (46% of patients). The most common complication was pain at the donor site following vein harvest (19% of patients). CONCLUSION: This is the first systematic review to summarise the outcomes of nerve wraps for revision compression neuropathy. While improvements in outcomes were reported, further comparative studies are needed to determine the best nerve wrap.

Compression neuropathy of common peroneal nerve caused by a popliteal cyst: A case report.

RATIONALE: Popliteal cyst developing in the sheath of a peripheral nerve or joint capsule may cause compression neuropathy. Although popliteal cyst is very common lesion, it seldom causes serious complications. Common peroneal nerve compression is rarely caused by an extraneural popliteal cyst. PATIENT CONCERNS: We presented the case of a 52-year-old female with common peroneal nerve compression caused by an extraneural popliteal cyst. DIAGNOSES: Electromyography showed the damage of common peroneal nerve. MRI magnetic resonance imaging showed the lump to be a popliteal cyst. She was diagnosed as peroneal nerve injury and popliteal cyst. INTERVENTIONS: The patient was performed peroneal nerve decompression and popliteal cyst excision surgery. We excised the cyst completely and soluted the common peroneal nerve thoroughly. The cyst was filled with thick mucinous material. OUTCOMES: The pathological report showed that the excised mass was a popliteal cyst. There were no postoperative complications. Pain and hypoesthesia resolved 6 months after surgery. LESSONS: In this case, compression of the common peroneal nerve was due to an extraneural popliteal cyst, a situation rarely encountered. MRI can show in better detail their size and internal contents as well as their relation with surrounding anatomic structures. Patients with nerve entrapment caused by enlarged or ruptured cysts must be microsurgically excised if symptomatic.

[Corrective procedures and indications for cavovarus foot deformities in children and adolescents]. / Korrekturen und Indikationen einer Pes-cavovarus-Deformität bei Kindern und Jugendlichen.

Cavovarus deformities in children and adolescents require sound considerations concerning the timing for corrective surgery. Progression can be recognized best by repeated pedographic examination with evaluation of the typical features of cavovarus deformity. Surgical correction consists of a combination of soft tissue release, bony realignment, and restoration of muscle balance. In most cases plantar or medioplantar soft tissue release should be considered, whereas calf muscle lengthening is rarely indicated. Typical joint-sparing bone procedures are elevating osteotomies at the medial tarsometatarsal ray and realigning calcaneal osteotomies. Advanced cases require navicular-cuneiforme arthrodesis for correction of severe cavus component, hindfoot fusion at the Chopart line, or Lambrinudi triple fusion. Supramalleolar rotational osteotomy should be considered in severe cases. Peroneal dysfunction is addressed by peroneus longus to brevis transfer, posterior tibial tendon transfer compensates for severe extensor weakness to a certain degree, claw toes can be rebalanced by flexor or extensor tendon transfer, often in combination with proximal interphalangeal joint fusion. Surgical treatment should take into account the components of deformity, muscular function, progression and the underlying disease of the individual case. Further deterioration can be prevented by adequate surgery in the young patient. However, repeated surgical interventions may be necessary later in this patient group.

Isolated paralysis of the serratus anterior muscle: surgical release of the distal segment of the long thoracic nerve in 52 patients.

INTRODUCTION: Isolated serratus anterior (SA) paralysis is a rare condition that is secondary to direct trauma or overuse. Patients complain of neuropathic pain and/or muscle pain secondary to overexertion of the other shoulder stabilizing muscles. As the long thoracic nerve (LTN) passes along the thorax, it can be compressed by blood vessels and/or fibrotic tissue. The goal of the current study was to evaluate the outcomes of surgical release of the distal segment of the LTN in cases of isolated SA paralysis. PATIENTS AND METHODS: This was a retrospective study of 52 consecutive cases operated on between 1997 and 2012. The average patient age was 32 years (range 13-70). Patients had been suffering from paralysis for an average of 2 years (range 4-259 months); the paralysis was complete in 52% of cases. Every patient underwent a preoperative electroneuromyography (ENMG) assessment to confirm that only the SA was affected and there were no signs of re-innervation. RESULTS: Every patient had abnormal intraoperative findings. There were no complications. All patients showed at least partial improvement following the procedure. The improvement was excellent or good in 45 cases (86.7%), moderate in 4 cases (7.7%) and slight in 3 cases (5.6%). In 32 cases (61.5%), the winged scapula was completely corrected; it was less prominent in 19 cases and was unchanged in one case. The best outcomes following surgical release occurred in patients who presented without preoperative or neuropathic pain and were treated within 18 months of paralysis. DISCUSSION: Isolated SA paralysis due to mechanical injury resembles entrapment neuropathy. We discovered signs of LTN compression or restriction during surgery. Surgical release of the distal segment of the LTN is a simple, effective treatment for pain that provides complete motor recovery when performed within the first 12 months of the paralysis. LEVEL OF EVIDENCE: IV.

[Detection of oculomotor nerve compression by 3D-FIESTA MRI in a patient with pituitary apoplexy and diabetes mellitus].

We report the usefulness of 3D-FIESTA magnetic resonance imaging(MRI)for the detection of oculomotor nerve palsy in a case of pituitary apoplexy. A 69-year-old man with diabetes mellitus presented with complete left-side blepharoptosis. Computed tomography of the brain showed an intrasellar mass with hemorrhage. MRI demonstrated a pituitary adenoma with a cyst toward the left cavernous sinus, which was diagnosed as pituitary apoplexy. 3D-FIESTA revealed that the left oculomotor nerve was compressed by the cyst. He underwent trans-sphenoid tumor resection at 5 days after his hospitalization. Post-operative 3D-FIESTA MRI revealed decrease in compression of the left oculomotor nerve by the cyst. His left oculomotor palsy recovered completely within a few months. Oculomotor nerve palsy can occur due to various diseases, and 3D-FIESTA MRI is useful for detection of oculomotor nerve compression, especially in the field of parasellar lesions.

Compression neuropathy caused by cancer metastasis to the optic nerve canal.

BACKGROUND: Cancerous cells are known to metastasize to different ocular structures. This happens especially to the choroid in males with lung cancer and females with breast cancer. However, we observed two cases of cancerous metastasis to the optic canal region. Both cases showed only a progressive decrease in vision without any other remarkable ophthalmological symptoms or abnormalities in the affected eye. CASE PRESENTATION: Two females, a 60-year-old and a 73-year-old, came to our hospital because of progressive loss of vision. These patients showed no remarkable symptoms or signs in their eyes except visual acuity loss. Several ophthalmoscopic examinations, such as slit lamp microscopy and fundoscopy, showed no abnormal changes in their affected eye but magnetic resonance imaging indicated a massive legion around the optic nerve. CONCLUSION: It is possible for cancer to metastasize to the optic canal region and the existence of primary tumors should be considered.

Is carpal tunnel decompression warranted for HNPP?

The role of carpal tunnel decompression surgery for patients that have hereditary neuropathy with liability to pressure palsy (HNPP) is currently unknown. Since recovery from carpal tunnel compression is often associated with remyelination or nodal reconstruction rather than axonal regeneration, it is uncertain whether the PMP22 deletion associated with HNPP interrupts myelin or nodal reconstitution. We describe two patients with genetically confirmed HNPP and symptomatic carpal tunnel syndrome that had clinical and electrophysiological improvement after surgical decompression. The findings indicate a capacity for conduction repair in HNPP. They also suggest a need for further investigation and discussion around whether to offer carpal tunnel decompression to symptomatic HNPP patients.

[Hereditary neuropathy with liability to pressure palsy (HNPP): a diagnostic trap]. / Neuropathie héréditaire avec hypersensibilité à la pression: un piège diagnostique: à propos de deux cas.

The authors report two clinical cases of a rarely observed pathology in orthopedic surgery daily practice: hereditary neuropathy with liability to pressure palsy (HNPP), which leads to dysesthesiae, hypoesthesiae and regressive palsies. Onset, clinical signs and electromyographic abnormalities are described. Forensic consequences can occur in early postoperative period. Knowledge of this familial pathology allows precautionary measures at surgery and avoids unnecessary surgical revisions.

Clinical implications of peripheral myelin protein 22 for nerve compression and neural regeneration: a review.

Peripheral myelin protein 22 (PMP22) is a major component of the peripheral myelin sheath. The PMP22 gene is located on chromosome 17p11.2, and defects in PMP22 gene have been implicated in several common inherited peripheral neuropathies. Hereditary neuropathy with liability to pressure palsies (HNPP), Charcot-Marie Tooth disease type 1A (CMT1A), Dejerine-Sottas syndrome, and congenital hypomyelinating neuropathy are all associated with defects in PMP22 gene. The disease phenotypes mirror the range of expression of PMP22 due to the corresponding genetic defect. HNPP, characterized by a milder recurrent episodic focal demyelinating neuropathy, is attributed to a deletion leading to PMP22 underexpression. On the other end of the spectrum, CMT1A leads to a more uniform demyelination and axonal loss, resulting in severe progressive distal weakness and paresthesias; it is due to a duplication at 17p11.2 leading to PMP22 overexpression. Additional point mutations result in varying phenotypes due to dysfunction of the resultant PMP22 protein. All inherited neuropathies are diagnosed with a combination of physical findings on examination, electromyography, sural nerve biopsies, and genetic testing. Treatment and management of these disorders differ depending on the underlying genetic defect, nerves involved, and resulting functional impairments. A review of current literature elucidates clinical, microsurgical implications, and management of patients with PMP22-related neuropathy.

Conus medulla-cauda compression from nerve root hypertrophy in a child with Dejerine-Sottas syndrome: improvement with laminectomy and duraplasty. Case report.

This 7-year-old boy with Dejerine-Sottas syndrome caused by a mutation in the myelin protein zero gene began to suffer rapid deterioration with increasing leg weakness, loss of the ability to ambulate, and bowel and bladder incontinence. Magnetic resonance imaging of the spine revealed nerve root hypertrophy resulting in compression of the conus medullaris and cauda equina. Decompressive surgery was successful in reversing some of his deficits.

[The Charcot joint]. / Das Charcot-Gelenk.

Charcot foot in its original sense is equivalent to stage 4 of hereditary motor and sensory neuropathy (HMSN) which is known as Charcot-Marie-Tooth disease since 1886. This entity, which can be subdivided into 3 groups including subgroups, predominantly begins during childhood and progresses slowly. The first symptom, often unnoticed by the patient for a long period, is weakness of the intrinsic foot muscles with consecutive hammer-toe formation and mobile pes cavus. Progredient atrophy of the peroneal, extensor, tibialis posterior and finally triceps surae muscles leads to fixed pes cavus varus excavatus with severe varus deformity of the hindfoot, secondary varus position of the talus at the ankle level and subsequent arthrosis of the medial compartment. Permanent varus deformity of the ankle almost invariably leads to stress fractures of the malleoli because of repetitive microtrauma (stage 5 of HMSN). Early detection of the disease with nerve conduction studies at clinical suspicion allows tibialis posterior transfer, correctional osteotomy of the hindfoot or arthrodesis of Chopart's or Lisfranc's joint and can postpone or prevent the otherwise inevitable triple arthrodesis which has a less favorable long-term prognosis. At stage 4 (manifest Charcot foot) and stage 5 (neuropathic fracture of the ankle) a reorientating ankle arthrodesis is advocated, with additional subtalar pathology correctional double arthrodesis becomes necessary. In diabetic arthropathy of the ankle (Type IV according to Sanders and Frykberg), which is often referred to as "Charcot Ankle", tibiocalcanear arthrodesis is indicated. In case of supervening infection or extensive necrosis a modified Pirogoff amputation is carried out as a salvage procedure. Doubled periods of non weight-bearing, immobilization and brace protection of the ankle help to reduce the frequently observed implant failure in both forms of osteoarthropathy. In addition to stable implants retrograde calcaneotalotibial transfixation with a Steinmann pin may help to protect the achieved result despite prolonged bone consolidation.

[The foot in hereditary motor and sensory neuropathies in children]. / Le pied dans les neuropathies périphériques héréditaíres sensitivo-motrices chez l'enfant.

PURPOSE: Although Charcot-Marie-Tooth disease (CMT) is known to be the most common neuromuscular cause of pes cavovarus, other paralytic deformities of the foot may be present with hereditary motor and sensory neuropathies (HMSN). The purpose of our review is to analyze these foot deformities and to assess the results of the different therapeutic methods used. MATERIAL AND METHODS: We evaluated 66 patients who had HMSN and had a total of 127 foot deformities. Fifty three patients had CMT, 6 patients Déjerine Sottas disease (DS), and 7 patients had an unclassified HMSN. The average age at diagnosis was of 9 years and 11 months. There were 35 males and 31 females. The deformity was unilateral in 5 cases. In 50 bilateral cases, the severity of the deformity was not similar in both feet. In three bilateral cases, the deformity was completely asymmetrical. The chief complaint was mainly deformity in all cases, followed by subtalar or ankle instability in 57 cases. There were 105 cases of cavus or cavovarus, and 22 cases or valgus or planovalgus deformity (8 of which changed spontaneously to cavovarus). A non surgical treatment was undertaken in 57 cases for minor deformity. Soft tissue release with or without osteotomies was done in 39 cases, and triple arthrodesis in the remaining 31 cases. A clawtoe deformity was treated operatively in 14 cases. RESULTS: The mean follow-up period was 6 years and 9 months for non operated feet and 7 years and 10 months for operated feet (all of the surgically treated feet were reviewed after the end of growth). Three patients of the non operated group and 8 patients of the surgically treated feet underwent triple arthrodesis for a recurrence of the deformity. Thirty nine per cent of the feet which underwent triple arthrodesis (a total of 42 feet) were considered to have fair or bad result at 6 years and 3 months follow-up period. DISCUSSION AND CONCLUSION: The foot deformity in HMSN is of a wide variety. A valgus flat foot is not uncommon, especially in DS and unclassified neuropathies. The young age of the patient is not a contrindication to surgical management. Even if minor previous surgeries do not always succeed in avoiding recurrence of the deformity, they nevertheless prepare the foot fort a possible triple arthrodesis, that will be done in better anatomical conditions.