Spinal accessory mononeuropathy following posterior fossa decompression surgery

Transitory spinal accessory nerve injury following post-fossa surgery for Chiari malformation

We report the case of a young patient with a transient transitory spinal accessory injury after foramen magnum decompression for Chiari malformation. The pathophysiology and the possible mechanisms of injury are highlighted and discussed. Some tips to avoid this potentially severe iatrogenic complication are provided.

Specific scapular kinematic patterns to differentiate two forms of dynamic scapular winging

BACKGROUND

Dynamic scapular winging (DSW) is a rare and misdiagnosed disorder causing considerable disability due to reduced scapular stability and abnormal motion. Two common causes are long thoracic nerve lesions resulting in serratus anterior muscle palsy and spinal accessory nerve lesions resulting in trapezius muscle palsy. The aim of this study was to analyse 3D scapular kinematic patterns in patients with DSW due to long thoracic (LTNL) or spinal accessory nerve lesions (SANL).

METHODS

3D scapular kinematics were assessed using a non invasive method involving an electromagnetic device during arm elevation in the frontal and sagittal planes in 9 patients (4 with SANL and 5 with LTNL) with unilateral DSW confirmed by electrical evidence. Within subject affected-unaffected differences were measured and compared between pathological groups (Mann-Whitney).

FINDINGS

Differences between affected and unaffected shoulders were significantly greater for scapular posterior tilt (at rest and 30° for sagittal arm elevation, at rest, 30° and 60° for frontal arm elevation) in the LTNL compared to the SANL group. Differences between affected and unaffected shoulders were significantly greater for scapular protraction (at rest and 60° of sagittal arm elevation, at rest, 30° and 60° of frontal arm elevation) and scapular lateral rotation at 60° for frontal arm elevation in the SANL compared to the LTNL group.

INTERPRETATIONS

These kinematic findings show two different scapular patterns that are specific to the neurological lesion. Moreover our kinematic data relate to specific clinical signs and the functional roles of the muscles involved.

Suprascapular nerve release for treatment of shoulder and periscapular pain following intracranial spinal accessory nerve injury

Iatrogenic injury to the spinal accessory nerve is one of the most common causes of trapezius muscle palsy. Dysfunction of this muscle can be a painful and disabling condition because scapular winging may impose traction on the soft tissues of the shoulder region, including the suprascapular nerve. There are few reports regarding therapeutic options for an intracranial injury of the accessory nerve. However, the surgical release of the suprascapular nerve at the level of the scapular notch is a promising alternative approach for treatment of shoulder pain in these cases. The author reports on 3 patients presenting with signs and symptoms of unilateral accessory nerve injury following resection of posterior fossa tumors. A posterior approach was used to release the suprascapular nerve at the level of the scapular notch, transecting the superior transverse scapular ligament. All patients experienced relief of their shoulder and scapular pain following the decompressive surgery. In 1 patient the primary dorsal branch of the C-2 nerve root was transferred to the extracranial segment of the accessory nerve, and in the other 2 patients a tendon transfer (the Eden–Lange procedure) was used. Results from this report show that surgical release of the suprascapular nerve is an effective treatment for shoulder and periscapular pain in patients who have sustained an unrepairable injury to the accessory nerve.

Isolated spinal accessory mononeuropathy associated with neurogenic muscle hypertrophy: restricted neuralgic amyotrophy or stretch-palsy? A case report

A 55-year-old man developed transient bi-brachial paresthesias followed by severe pain over his left shoulder ridge and periscapular region within 8 hours of rigorous hand-over-hand hoisting of a 33.8-kg (75-lb) object. He experienced weakness in shoulder abduction followed several weeks later by focal hypertrophy of the left trapezius. Electrophysiologic studies showed significant spontaneous motor activity in the form of denervation potentials, fasciculations, and complex repetitive discharges. The 2 major diagnostic considerations were restricted neuralgic amyotrophy versus stretch palsy of the spinal accessory nerve. The clinical similarities and differences between restricted forms of neuralgic amyotrophy and stretch palsies are discussed.

Spontaneous unilateral accessory nerve palsy: a case report and review of the literature

Isolated spinal accessory nerve (SAN) palsy is a well-recognized complication of surgical prodecures in the posterior triangle of the neck. Various rare etiological factors were also described. Whatever the etiology, the typical clinical features of SAN palsy can be listed as atrophy/weakness of the trapezius muscle and moderate winging of the scapula. It is imperative to promptly diagnose this condition in the early stage to avoid long-term impairment and to have a better functional outcome. Herein, we present a patient with a diagnosis of spontaneous spinal accessory nerve palsy, which was rarely reported in the relevant literature.